WorldWideScience

Sample records for raytracing dynamic scenes

  1. Categorization of natural dynamic audiovisual scenes.

    Directory of Open Access Journals (Sweden)

    Olli Rummukainen

    Full Text Available This work analyzed the perceptual attributes of natural dynamic audiovisual scenes. We presented thirty participants with 19 natural scenes in a similarity categorization task, followed by a semi-structured interview. The scenes were reproduced with an immersive audiovisual display. Natural scene perception has been studied mainly with unimodal settings, which have identified motion as one of the most salient attributes related to visual scenes, and sound intensity along with pitch trajectories related to auditory scenes. However, controlled laboratory experiments with natural multimodal stimuli are still scarce. Our results show that humans pay attention to similar perceptual attributes in natural scenes, and a two-dimensional perceptual map of the stimulus scenes and perceptual attributes was obtained in this work. The exploratory results show the amount of movement, perceived noisiness, and eventfulness of the scene to be the most important perceptual attributes in naturalistically reproduced real-world urban environments. We found the scene gist properties openness and expansion to remain as important factors in scenes with no salient auditory or visual events. We propose that the study of scene perception should move forward to understand better the processes behind multimodal scene processing in real-world environments. We publish our stimulus scenes as spherical video recordings and sound field recordings in a publicly available database.

  2. Dynamic Frames Based Generation of 3D Scenes and Applications

    Directory of Open Access Journals (Sweden)

    Danijel Radošević

    2015-05-01

    Full Text Available Modern graphic/programming tools like Unity enables the possibility of creating 3D scenes as well as making 3D scene based program applications, including full physical model, motion, sounds, lightning effects etc. This paper deals with the usage of dynamic frames based generator in the automatic generation of 3D scene and related source code. The suggested model enables the possibility to specify features of the 3D scene in a form of textual specification, as well as exporting such features from a 3D tool. This approach enables higher level of code generation flexibility and the reusability of the main code and scene artifacts in a form of textual templates. An example of the generated application is presented and discussed.

  3. STREAM PROCESSING ALGORITHMS FOR DYNAMIC 3D SCENE ANALYSIS

    Science.gov (United States)

    2018-02-15

    PROCESSING ALGORITHMS FOR DYNAMIC 3D SCENE ANALYSIS 5a. CONTRACT NUMBER FA8750-14-2-0072 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER 62788F 6...of Figures 1 The 3D processing pipeline flowchart showing key modules. . . . . . . . . . . . . . . . . 12 2 Overall view (data flow) of the proposed...pipeline flowchart showing key modules. from motion and bundle adjustment algorithm. By fusion of depth masks of the scene obtained from 3D

  4. Research on hyperspectral dynamic scene and image sequence simulation

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    Sun, Dandan; Liu, Fang; Gao, Jiaobo; Sun, Kefeng; Hu, Yu; Li, Yu; Xie, Junhu; Zhang, Lei

    2016-10-01

    This paper presents a simulation method of hyperspectral dynamic scene and image sequence for hyperspectral equipment evaluation and target detection algorithm. Because of high spectral resolution, strong band continuity, anti-interference and other advantages, in recent years, hyperspectral imaging technology has been rapidly developed and is widely used in many areas such as optoelectronic target detection, military defense and remote sensing systems. Digital imaging simulation, as a crucial part of hardware in loop simulation, can be applied to testing and evaluation hyperspectral imaging equipment with lower development cost and shorter development period. Meanwhile, visual simulation can produce a lot of original image data under various conditions for hyperspectral image feature extraction and classification algorithm. Based on radiation physic model and material characteristic parameters this paper proposes a generation method of digital scene. By building multiple sensor models under different bands and different bandwidths, hyperspectral scenes in visible, MWIR, LWIR band, with spectral resolution 0.01μm, 0.05μm and 0.1μm have been simulated in this paper. The final dynamic scenes have high real-time and realistic, with frequency up to 100 HZ. By means of saving all the scene gray data in the same viewpoint image sequence is obtained. The analysis results show whether in the infrared band or the visible band, the grayscale variations of simulated hyperspectral images are consistent with the theoretical analysis results.

  5. Spin dynamics modeling in the AGS based on a stepwise ray-tracing method

    Energy Technology Data Exchange (ETDEWEB)

    Dutheil, Yann [Univ. of Grenoble (France)

    2006-08-07

    The AGS provides a polarized proton beam to RHIC. The beam is accelerated in the AGS from Gγ= 4.5 to Gγ = 45.5 and the polarization transmission is critical to the RHIC spin program. In the recent years, various systems were implemented to improve the AGS polarization transmission. These upgrades include the double partial snakes configuration and the tune jumps system. However, 100% polarization transmission through the AGS acceleration cycle is not yet reached. The current efficiency of the polarization transmission is estimated to be around 85% in typical running conditions. Understanding the sources of depolarization in the AGS is critical to improve the AGS polarized proton performances. The complexity of beam and spin dynamics, which is in part due to the specialized Siberian snake magnets, drove a strong interest for original methods of simulations. For that, the Zgoubi code, capable of direct particle and spin tracking through field maps, was here used to model the AGS. A model of the AGS using the Zgoubi code was developed and interfaced with the current system through a simple command: the AgsFromSnapRampCmd. Interfacing with the machine control system allows for fast modelization using actual machine parameters. Those developments allowed the model to realistically reproduce the optics of the AGS along the acceleration ramp. Additional developments on the Zgoubi code, as well as on post-processing and pre-processing tools, granted long term multiturn beam tracking capabilities: the tracking of realistic beams along the complete AGS acceleration cycle. Beam multiturn tracking simulations in the AGS, using realistic beam and machine parameters, provided a unique insight into the mechanisms behind the evolution of the beam emittance and polarization during the acceleration cycle. Post-processing softwares were developed to allow the representation of the relevant quantities from the Zgoubi simulations data. The Zgoubi simulations proved particularly

  6. High performance dosimetry calculations using adapted ray-tracing

    International Nuclear Information System (INIS)

    Perrotte, Lancelot; Saupin, Guillaume

    2010-01-01

    When preparing interventions on nuclear sites, it is interesting to study different scenarios, to identify the most appropriate one for the operator(s). Using virtual reality tools is a good way to simulate the potential scenarios. Thus, taking advantage of very efficient computation times can help the user studying different complex scenarios, by immediately evaluating the impact of any changes. In the field of radiation protection, people often use computation codes based on the straight line attenuation method with build-up factors. As for other approaches, geometrical computations (finding all the interactions between radiation rays and the scene objects) remain the bottleneck of the simulation. We present in this paper several optimizations used to speed up these geometrical computations, using innovative GPU ray-tracing algorithms. For instance, we manage to compute every intersection between 600 000 rays and a huge 3D industrial scene in a fraction of second. Moreover, our algorithm works the same way for both static and dynamic scenes, allowing easier study of complex intervention scenarios (where everything moves: the operator(s), the shielding objects, the radiation sources).

  7. POTENTIALS OF IMAGE BASED ACTIVE RANGING TO CAPTURE DYNAMIC SCENES

    Directory of Open Access Journals (Sweden)

    B. Jutzi

    2012-09-01

    Full Text Available Obtaining a 3D description of man-made and natural environments is a basic task in Computer Vision and Remote Sensing. To this end, laser scanning is currently one of the dominating techniques to gather reliable 3D information. The scanning principle inherently needs a certain time interval to acquire the 3D point cloud. On the other hand, new active sensors provide the possibility of capturing range information by images with a single measurement. With this new technique image-based active ranging is possible which allows capturing dynamic scenes, e.g. like walking pedestrians in a yard or moving vehicles. Unfortunately most of these range imaging sensors have strong technical limitations and are not yet sufficient for airborne data acquisition. It can be seen from the recent development of highly specialized (far-range imaging sensors – so called flash-light lasers – that most of the limitations could be alleviated soon, so that future systems will be equipped with improved image size and potentially expanded operating range. The presented work is a first step towards the development of methods capable for application of range images in outdoor environments. To this end, an experimental setup was set up for investigating these proposed possibilities. With the experimental setup a measurement campaign was carried out and first results will be presented within this paper.

  8. HDR video synthesis for vision systems in dynamic scenes

    Science.gov (United States)

    Shopovska, Ivana; Jovanov, Ljubomir; Goossens, Bart; Philips, Wilfried

    2016-09-01

    High dynamic range (HDR) image generation from a number of differently exposed low dynamic range (LDR) images has been extensively explored in the past few decades, and as a result of these efforts a large number of HDR synthesis methods have been proposed. Since HDR images are synthesized by combining well-exposed regions of the input images, one of the main challenges is dealing with camera or object motion. In this paper we propose a method for the synthesis of HDR video from a single camera using multiple, differently exposed video frames, with circularly alternating exposure times. One of the potential applications of the system is in driver assistance systems and autonomous vehicles, involving significant camera and object movement, non- uniform and temporally varying illumination, and the requirement of real-time performance. To achieve these goals simultaneously, we propose a HDR synthesis approach based on weighted averaging of aligned radiance maps. The computational complexity of high-quality optical flow methods for motion compensation is still pro- hibitively high for real-time applications. Instead, we rely on more efficient global projective transformations to solve camera movement, while moving objects are detected by thresholding the differences between the trans- formed and brightness adapted images in the set. To attain temporal consistency of the camera motion in the consecutive HDR frames, the parameters of the perspective transformation are stabilized over time by means of computationally efficient temporal filtering. We evaluated our results on several reference HDR videos, on synthetic scenes, and using 14-bit raw images taken with a standard camera.

  9. Developmental Changes in Attention to Faces and Bodies in Static and Dynamic Scenes

    Directory of Open Access Journals (Sweden)

    Brenda M Stoesz

    2014-03-01

    Full Text Available Typically developing individuals show a strong visual preference for faces and face-like stimuli; however, this may come at the expense of attending to bodies or to other aspects of a scene. The primary goal of the present study was to provide additional insight into the development of attentional mechanisms that underlie perception of real people in naturalistic scenes. We examined the looking behaviours of typical children, adolescents, and young adults as they viewed static and dynamic scenes depicting one or more people. Overall, participants showed a bias to attend to faces more than on other parts of the scenes. Adding motion cues led to a reduction in the number, but an increase in the average duration of face fixations in single-character scenes. When multiple characters appeared in a scene, motion-related effects were attenuated and participants shifted their gaze from faces to bodies, or made off-screen glances. Children showed the largest effects related to the introduction of motion cues or additional characters, suggesting that they find dynamic faces difficult to process, and are especially prone to look away from faces when viewing complex social scenes – a strategy that could reduce the cognitive and the affective load imposed by having to divide one’s attention between multiple faces. Our findings provide new insights into the typical development of social attention during natural scene viewing, and lay the foundation for future work examining gaze behaviours in typical and atypical development.

  10. Non-uniform crosstalk reduction for dynamic scenes

    NARCIS (Netherlands)

    Smit, F.A.; Liere, van R.; Fröhlich, B.

    2007-01-01

    Stereo displays suffer from crosstalk, an effect that reduces or even inhibits the viewer's ability to correctly perceive depth. Previous work on software crosstalk reduction focussed on the preprocessing of static scenes which are viewed from a fixed viewpoint. However, in virtual environments

  11. Dynamic thermal signature prediction for real-time scene generation

    Science.gov (United States)

    Christie, Chad L.; Gouthas, Efthimios (Themie); Williams, Owen M.; Swierkowski, Leszek

    2013-05-01

    At DSTO, a real-time scene generation framework, VIRSuite, has been developed in recent years, within which trials data are predominantly used for modelling the radiometric properties of the simulated objects. Since in many cases the data are insufficient, a physics-based simulator capable of predicting the infrared signatures of objects and their backgrounds has been developed as a new VIRSuite module. It includes transient heat conduction within the materials, and boundary conditions that take into account the heat fluxes due to solar radiation, wind convection and radiative transfer. In this paper, an overview is presented, covering both the steady-state and transient performance.

  12. Temporal dynamics of motor cortex excitability during perception of natural emotional scenes

    NARCIS (Netherlands)

    Borgomaneri, Sara; Gazzola, Valeria; Avenanti, Alessio

    2014-01-01

    Although it is widely assumed that emotions prime the body for action, the effects of visual perception of natural emotional scenes on the temporal dynamics of the human motor system have scarcely been investigated. Here, we used single-pulse transcranial magnetic stimulation (TMS) to assess motor

  13. Position-Invariant Robust Features for Long-Term Recognition of Dynamic Outdoor Scenes

    Science.gov (United States)

    Kawewong, Aram; Tangruamsub, Sirinart; Hasegawa, Osamu

    A novel Position-Invariant Robust Feature, designated as PIRF, is presented to address the problem of highly dynamic scene recognition. The PIRF is obtained by identifying existing local features (i.e. SIFT) that have a wide baseline visibility within a place (one place contains more than one sequential images). These wide-baseline visible features are then represented as a single PIRF, which is computed as an average of all descriptors associated with the PIRF. Particularly, PIRFs are robust against highly dynamical changes in scene: a single PIRF can be matched correctly against many features from many dynamical images. This paper also describes an approach to using these features for scene recognition. Recognition proceeds by matching an individual PIRF to a set of features from test images, with subsequent majority voting to identify a place with the highest matched PIRF. The PIRF system is trained and tested on 2000+ outdoor omnidirectional images and on COLD datasets. Despite its simplicity, PIRF offers a markedly better rate of recognition for dynamic outdoor scenes (ca. 90%) than the use of other features. Additionally, a robot navigation system based on PIRF (PIRF-Nav) can outperform other incremental topological mapping methods in terms of time (70% less) and memory. The number of PIRFs can be reduced further to reduce the time while retaining high accuracy, which makes it suitable for long-term recognition and localization.

  14. Camera pose estimation for augmented reality in a small indoor dynamic scene

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    Frikha, Rawia; Ejbali, Ridha; Zaied, Mourad

    2017-09-01

    Camera pose estimation remains a challenging task for augmented reality (AR) applications. Simultaneous localization and mapping (SLAM)-based methods are able to estimate the six degrees of freedom camera motion while constructing a map of an unknown environment. However, these methods do not provide any reference for where to insert virtual objects since they do not have any information about scene structure and may fail in cases of occlusion of three-dimensional (3-D) map points or dynamic objects. This paper presents a real-time monocular piece wise planar SLAM method using the planar scene assumption. Using planar structures in the mapping process allows rendering virtual objects in a meaningful way on the one hand and improving the precision of the camera pose and the quality of 3-D reconstruction of the environment by adding constraints on 3-D points and poses in the optimization process on the other hand. We proposed to benefit from the 3-D planes rigidity motion in the tracking process to enhance the system robustness in the case of dynamic scenes. Experimental results show that using a constrained planar scene improves our system accuracy and robustness compared with the classical SLAM systems.

  15. Multi- and hyperspectral scene modeling

    Science.gov (United States)

    Borel, Christoph C.; Tuttle, Ronald F.

    2011-06-01

    This paper shows how to use a public domain raytracer POV-Ray (Persistence Of Vision Raytracer) to render multiand hyper-spectral scenes. The scripting environment allows automatic changing of the reflectance and transmittance parameters. The radiosity rendering mode allows accurate simulation of multiple-reflections between surfaces and also allows semi-transparent surfaces such as plant leaves. We show that POV-Ray computes occlusion accurately using a test scene with two blocks under a uniform sky. A complex scene representing a plant canopy is generated using a few lines of script. With appropriate rendering settings, shadows cast by leaves are rendered in many bands. Comparing single and multiple reflection renderings, the effect of multiple reflections is clearly visible and accounts for 25% of the overall apparent canopy reflectance in the near infrared.

  16. Laser-Based Slam with Efficient Occupancy Likelihood Map Learning for Dynamic Indoor Scenes

    Science.gov (United States)

    Li, Li; Yao, Jian; Xie, Renping; Tu, Jinge; Feng, Chen

    2016-06-01

    Location-Based Services (LBS) have attracted growing attention in recent years, especially in indoor environments. The fundamental technique of LBS is the map building for unknown environments, this technique also named as simultaneous localization and mapping (SLAM) in robotic society. In this paper, we propose a novel approach for SLAMin dynamic indoor scenes based on a 2D laser scanner mounted on a mobile Unmanned Ground Vehicle (UGV) with the help of the grid-based occupancy likelihood map. Instead of applying scan matching in two adjacent scans, we propose to match current scan with the occupancy likelihood map learned from all previous scans in multiple scales to avoid the accumulation of matching errors. Due to that the acquisition of the points in a scan is sequential but not simultaneous, there unavoidably exists the scan distortion at different extents. To compensate the scan distortion caused by the motion of the UGV, we propose to integrate a velocity of a laser range finder (LRF) into the scan matching optimization framework. Besides, to reduce the effect of dynamic objects such as walking pedestrians often existed in indoor scenes as much as possible, we propose a new occupancy likelihood map learning strategy by increasing or decreasing the probability of each occupancy grid after each scan matching. Experimental results in several challenged indoor scenes demonstrate that our proposed approach is capable of providing high-precision SLAM results.

  17. A STEP TOWARDS DYNAMIC SCENE ANALYSIS WITH ACTIVE MULTI-VIEW RANGE IMAGING SYSTEMS

    Directory of Open Access Journals (Sweden)

    M. Weinmann

    2012-07-01

    Full Text Available Obtaining an appropriate 3D description of the local environment remains a challenging task in photogrammetric research. As terrestrial laser scanners (TLSs perform a highly accurate, but time-dependent spatial scanning of the local environment, they are only suited for capturing static scenes. In contrast, new types of active sensors provide the possibility of simultaneously capturing range and intensity information by images with a single measurement, and the high frame rate also allows for capturing dynamic scenes. However, due to the limited field of view, one observation is not sufficient to obtain a full scene coverage and therefore, typically, multiple observations are collected from different locations. This can be achieved by either placing several fixed sensors at different known locations or by using a moving sensor. In the latter case, the relation between different observations has to be estimated by using information extracted from the captured data and then, a limited field of view may lead to problems if there are too many moving objects within it. Hence, a moving sensor platform with multiple and coupled sensor devices offers the advantages of an extended field of view which results in a stabilized pose estimation, an improved registration of the recorded point clouds and an improved reconstruction of the scene. In this paper, a new experimental setup for investigating the potentials of such multi-view range imaging systems is presented which consists of a moving cable car equipped with two synchronized range imaging devices. The presented setup allows for monitoring in low altitudes and it is suitable for getting dynamic observations which might arise from moving cars or from moving pedestrians. Relying on both 3D geometry and 2D imagery, a reliable and fully automatic approach for co-registration of captured point cloud data is presented which is essential for a high quality of all subsequent tasks. The approach involves using

  18. Memory-guided attention during active viewing of edited dynamic scenes.

    Science.gov (United States)

    Valuch, Christian; König, Peter; Ansorge, Ulrich

    2017-01-01

    Films, TV shows, and other edited dynamic scenes contain many cuts, which are abrupt transitions from one video shot to the next. Cuts occur within or between scenes, and often join together visually and semantically related shots. Here, we tested to which degree memory for the visual features of the precut shot facilitates shifting attention to the postcut shot. We manipulated visual similarity across cuts, and measured how this affected covert attention (Experiment 1) and overt attention (Experiments 2 and 3). In Experiments 1 and 2, participants actively viewed a target movie that randomly switched locations with a second, distractor movie at the time of the cuts. In Experiments 1 and 2, participants were able to deploy attention more rapidly and accurately to the target movie's continuation when visual similarity was high than when it was low. Experiment 3 tested whether this could be explained by stimulus-driven (bottom-up) priming by feature similarity, using one clip at screen center that was followed by two alternative continuations to the left and right. Here, even the highest similarity across cuts did not capture attention. We conclude that following cuts of high visual similarity, memory-guided attention facilitates the deployment of attention, but this effect is (top-down) dependent on the viewer's active matching of scene content across cuts.

  19. Cortical networks dynamically emerge with the interplay of slow and fast oscillations for memory of a natural scene.

    Science.gov (United States)

    Mizuhara, Hiroaki; Sato, Naoyuki; Yamaguchi, Yoko

    2015-05-01

    Neural oscillations are crucial for revealing dynamic cortical networks and for serving as a possible mechanism of inter-cortical communication, especially in association with mnemonic function. The interplay of the slow and fast oscillations might dynamically coordinate the mnemonic cortical circuits to rehearse stored items during working memory retention. We recorded simultaneous EEG-fMRI during a working memory task involving a natural scene to verify whether the cortical networks emerge with the neural oscillations for memory of the natural scene. The slow EEG power was enhanced in association with the better accuracy of working memory retention, and accompanied cortical activities in the mnemonic circuits for the natural scene. Fast oscillation showed a phase-amplitude coupling to the slow oscillation, and its power was tightly coupled with the cortical activities for representing the visual images of natural scenes. The mnemonic cortical circuit with the slow neural oscillations would rehearse the distributed natural scene representations with the fast oscillation for working memory retention. The coincidence of the natural scene representations could be obtained by the slow oscillation phase to create a coherent whole of the natural scene in the working memory. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Complex scenes and situations visualization in hierarchical learning algorithm with dynamic 3D NeoAxis engine

    Science.gov (United States)

    Graham, James; Ternovskiy, Igor V.

    2013-06-01

    We applied a two stage unsupervised hierarchical learning system to model complex dynamic surveillance and cyber space monitoring systems using a non-commercial version of the NeoAxis visualization software. The hierarchical scene learning and recognition approach is based on hierarchical expectation maximization, and was linked to a 3D graphics engine for validation of learning and classification results and understanding the human - autonomous system relationship. Scene recognition is performed by taking synthetically generated data and feeding it to a dynamic logic algorithm. The algorithm performs hierarchical recognition of the scene by first examining the features of the objects to determine which objects are present, and then determines the scene based on the objects present. This paper presents a framework within which low level data linked to higher-level visualization can provide support to a human operator and be evaluated in a detailed and systematic way.

  1. Suspiciousness perception in dynamic scenes: a comparison of CCTV operators and novices.

    Directory of Open Access Journals (Sweden)

    Christina Jayne Howard

    2013-08-01

    Full Text Available Perception of scenes has typically been investigated by using static or simplified visual displays. How attention is used to perceive and evaluate dynamic, realistic scenes is more poorly understood, in part due to the problem of comparing eye fixations to moving stimuli across observers. When the task and stimulus is common across observers, consistent fixation location can indicate that that region has high goal-based relevance. Here we investigated these issues when an observer has a specific, and naturalistic, task: closed-circuit television (CCTV monitoring. We concurrently recorded eye movements and ratings of perceived suspiciousness as different observers watched the same set of clips from real CCTV footage. Trained CCTV operators showed a greater consistency in fixation location and greater consistency in suspiciousness judgements than untrained observers. Training appears to increase between-operators consistency by learning 'knowing what to look for' in these scenes. We used a novel ‘Dynamic Area of Focus (DAF’ analysis to show that in CCTV monitoring there is a temporal relationship between eye movements and subsequent manual responses, as we have previously found for a sports video watching task. For trained CCTV operators and for untrained observers, manual responses were most highly related to between-observer eye position spread when a temporal lag was introduced between the fixation and response data. Shortly after between-observer eye positions became most similar, observers tended to push the joystick to indicate perceived suspiciousness. Conversely, shortly after between-observer eye positions became dissimilar, observers tended to rate suspiciousness as low. These data provide further support for this DAF method as an important tool for examining goal-directed fixation behaviour when the stimulus is a real moving image.

  2. Design and implementation of a scene-dependent dynamically selfadaptable wavefront coding imaging system

    Science.gov (United States)

    Carles, Guillem; Ferran, Carme; Carnicer, Artur; Bosch, Salvador

    2012-01-01

    A computational imaging system based on wavefront coding is presented. Wavefront coding provides an extension of the depth-of-field at the expense of a slight reduction of image quality. This trade-off results from the amount of coding used. By using spatial light modulators, a flexible coding is achieved which permits it to be increased or decreased as needed. In this paper a computational method is proposed for evaluating the output of a wavefront coding imaging system equipped with a spatial light modulator, with the aim of thus making it possible to implement the most suitable coding strength for a given scene. This is achieved in an unsupervised manner, thus the whole system acts as a dynamically selfadaptable imaging system. The program presented here controls the spatial light modulator and the camera, and also processes the images in a synchronised way in order to implement the dynamic system in real time. A prototype of the system was implemented in the laboratory and illustrative examples of the performance are reported in this paper. Program summaryProgram title: DynWFC (Dynamic WaveFront Coding) Catalogue identifier: AEKC_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKC_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 10 483 No. of bytes in distributed program, including test data, etc.: 2 437 713 Distribution format: tar.gz Programming language: Labview 8.5 and NI Vision and MinGW C Compiler Computer: Tested on PC Intel ® Pentium ® Operating system: Tested on Windows XP Classification: 18 Nature of problem: The program implements an enhanced wavefront coding imaging system able to adapt the degree of coding to the requirements of a specific scene. The program controls the acquisition by a camera, the display of a spatial light modulator

  3. Micromachined single-level nonplanar polycrystalline SiGe thermal microemitters for infrared dynamic scene projection

    Science.gov (United States)

    Malyutenko, V. K.; Malyutenko, O. Yu.; Leonov, V.; Van Hoof, C.

    2009-05-01

    The technology for self-supported membraneless polycrystalline SiGe thermal microemitters, their design, and performance are presented. The 128-element arrays with a fill factor of 88% and a 2.5-μm-thick resonant cavity have been grown by low-pressure chemical vapor deposition and fabricated using surface micromachining technology. The 200-nm-thick 60×60 μm2 emitting pixels enforced with a U-shape profile pattern demonstrate a thermal time constant of 2-7 ms and an apparent temperature of 700 K in the 3-5 and 8-12 μm atmospheric transparency windows. The application of the devices to the infrared dynamic scene simulation and their benefit over conventional planar membrane-supported emitters are discussed.

  4. Image-Based Reconstruction and Analysis of Dynamic Scenes in a Landslide Simulation Facility

    Science.gov (United States)

    Scaioni, M.; Crippa, J.; Longoni, L.; Papini, M.; Zanzi, L.

    2017-12-01

    The application of image processing and photogrammetric techniques to dynamic reconstruction of landslide simulations in a scaled-down facility is described. Simulations are also used here for active-learning purpose: students are helped understand how physical processes happen and which kinds of observations may be obtained from a sensor network. In particular, the use of digital images to obtain multi-temporal information is presented. On one side, using a multi-view sensor set up based on four synchronized GoPro 4 Black® cameras, a 4D (3D spatial position and time) reconstruction of the dynamic scene is obtained through the composition of several 3D models obtained from dense image matching. The final textured 4D model allows one to revisit in dynamic and interactive mode a completed experiment at any time. On the other side, a digital image correlation (DIC) technique has been used to track surface point displacements from the image sequence obtained from the camera in front of the simulation facility. While the 4D model may provide a qualitative description and documentation of the experiment running, DIC analysis output quantitative information such as local point displacements and velocities, to be related to physical processes and to other observations. All the hardware and software equipment adopted for the photogrammetric reconstruction has been based on low-cost and open-source solutions.

  5. IMAGE-BASED RECONSTRUCTION AND ANALYSIS OF DYNAMIC SCENES IN A LANDSLIDE SIMULATION FACILITY

    Directory of Open Access Journals (Sweden)

    M. Scaioni

    2017-12-01

    Full Text Available The application of image processing and photogrammetric techniques to dynamic reconstruction of landslide simulations in a scaled-down facility is described. Simulations are also used here for active-learning purpose: students are helped understand how physical processes happen and which kinds of observations may be obtained from a sensor network. In particular, the use of digital images to obtain multi-temporal information is presented. On one side, using a multi-view sensor set up based on four synchronized GoPro 4 Black® cameras, a 4D (3D spatial position and time reconstruction of the dynamic scene is obtained through the composition of several 3D models obtained from dense image matching. The final textured 4D model allows one to revisit in dynamic and interactive mode a completed experiment at any time. On the other side, a digital image correlation (DIC technique has been used to track surface point displacements from the image sequence obtained from the camera in front of the simulation facility. While the 4D model may provide a qualitative description and documentation of the experiment running, DIC analysis output quantitative information such as local point displacements and velocities, to be related to physical processes and to other observations. All the hardware and software equipment adopted for the photogrammetric reconstruction has been based on low-cost and open-source solutions.

  6. Dynamics of scene representations in the human brain revealed by magnetoencephalography and deep neural networks

    Science.gov (United States)

    Cichy, Radoslaw Martin; Khosla, Aditya; Pantazis, Dimitrios; Oliva, Aude

    2017-01-01

    Human scene recognition is a rapid multistep process evolving over time from single scene image to spatial layout processing. We used multivariate pattern analyses on magnetoencephalography (MEG) data to unravel the time course of this cortical process. Following an early signal for lower-level visual analysis of single scenes at ~100 ms, we found a marker of real-world scene size, i.e. spatial layout processing, at ~250 ms indexing neural representations robust to changes in unrelated scene properties and viewing conditions. For a quantitative model of how scene size representations may arise in the brain, we compared MEG data to a deep neural network model trained on scene classification. Representations of scene size emerged intrinsically in the model, and resolved emerging neural scene size representation. Together our data provide a first description of an electrophysiological signal for layout processing in humans, and suggest that deep neural networks are a promising framework to investigate how spatial layout representations emerge in the human brain. PMID:27039703

  7. Breaking the excitation-inhibition balance makes the cortical network’s space-time dynamics distinguish simple visual scenes

    DEFF Research Database (Denmark)

    Roland, Per E.; Bonde, Lars H.; Forsberg, Lars E.

    2017-01-01

    Brain dynamics are often taken to be temporal dynamics of spiking and membrane potentials in a balanced network. Almost all evidence for a balanced network comes from recordings of cell bodies of few single neurons, neglecting more than 99% of the cortical network. We examined the space......-time dynamics of excitation and inhibition simultaneously in dendrites and axons over four visual areas of ferrets exposed to visual scenes with stationary and moving objects. The visual stimuli broke the tight balance between excitation and inhibition such that the network exhibited longer episodes of net...... excitation subsequently balanced by net inhibition, in contrast to a balanced network. Locally in all four areas the amount of net inhibition matched the amount of net excitation with a delay of 125 ms. The space-time dynamics of excitation-inhibition evolved to reduce the complexity of neuron interactions...

  8. High-efficiency photorealistic computer-generated holograms based on the backward ray-tracing technique

    Science.gov (United States)

    Wang, Yuan; Chen, Zhidong; Sang, Xinzhu; Li, Hui; Zhao, Linmin

    2018-03-01

    Holographic displays can provide the complete optical wave field of a three-dimensional (3D) scene, including the depth perception. However, it often takes a long computation time to produce traditional computer-generated holograms (CGHs) without more complex and photorealistic rendering. The backward ray-tracing technique is able to render photorealistic high-quality images, which noticeably reduce the computation time achieved from the high-degree parallelism. Here, a high-efficiency photorealistic computer-generated hologram method is presented based on the ray-tracing technique. Rays are parallelly launched and traced under different illuminations and circumstances. Experimental results demonstrate the effectiveness of the proposed method. Compared with the traditional point cloud CGH, the computation time is decreased to 24 s to reconstruct a 3D object of 100 ×100 rays with continuous depth change.

  9. Dynamical scene analysis with a moving camera: mobile targets detection system

    International Nuclear Information System (INIS)

    Hennebert, Christine

    1996-01-01

    This thesis work deals with the detection of moving objects in monocular image sequences acquired with a mobile camera. We propose a method able to detect small moving objects in visible or infrared images of real outdoor scenes. In order to detect objects of very low apparent motion, we consider an analysis on a large temporal interval. We have chosen to compensate for the dominant motion due to the camera displacement for several consecutive images in order to form a sub-sequence of images for which the camera seems virtually static. We have also developed a new approach allowing to extract the different layers of a real scene in order to deal with cases where the 2D motion due to the camera displacement cannot be globally compensated for. To this end, we use a hierarchical model with two levels: the local merging step and the global merging one. Then, an appropriate temporal filtering is applied to registered image sub-sequence to enhance signals corresponding to moving objects. The detection issue is stated as a labeling problem within a statistical regularization based on Markov Random Fields. Our method has been validated on numerous real image sequences depicting complex outdoor scenes. Finally, the feasibility of an integrated circuit for mobile object detection has been proved. This circuit could lead to an ASIC creation. (author) [fr

  10. Raytracing and Direct-Drive Targets

    Science.gov (United States)

    Schmitt, Andrew J.; Bates, Jason; Fyfe, David; Eimerl, David

    2013-10-01

    Accurate simulation of the effects of laser imprinting and drive asymmetries in directly driven targets requires the ability to distinguish between raytrace noise and the intensity structure produced by the spatial and temporal incoherence of optical smoothing. We have developed and implemented a smoother raytrace algorithm for our mpi-parallel radiation hydrodynamics code, FAST3D. The underlying approach is to connect the rays into either sheets (in 2D) or volume-enclosing chunks (in 3D) so that the absorbed energy distribution continuously covers the propagation area illuminated by the laser. We will describe the status and show the different scalings encountered in 2D and 3D problems as the computational size, parallelization strategy, and number of rays is varied. Finally, we show results using the method in current NIKE experimental target simulations and in proposed symmetric and polar direct-drive target designs. Supported by US DoE/NNSA.

  11. China's new oil import status underpins world's most dynamic petroleum scene

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    China is poised to become a net importer of oil in 1994--95. That sets the stage for China importing more than 1 million b/d of crude oil and refined products on a net basis by the turn of the century. That development underpins a bigger story -- arguably the biggest story on the petroleum scene today. The turnabout that is seeing the world's fifth biggest oil producer go from significant oil exporter in recent years to major oil importer by the turn of the century points to several other truisms in the petroleum industry: That an oil demand surge in the Asia-Pacific region led by China will fuel overall world oil demand growth for years to come; that a refining and petrochemical boom in a country that accounts for about one fifth of the world's population has dramatic implications for those two industries; that privatization has gathered so much momentum in the global petroleum industry that even Communist China has embraced some form of it; that China's domestic crude supply shortfall is creating unprecedented opportunities for foreign upstream investors in one of the world's most prospective yet underexplored and underexploited regions; and that the same new openness that is distinguishing China's petroleum industry today is turning some of its state owned companies into major competitors to be reckoned with on the international scene, upstream and downstream. The paper discusses China's oil export/import balance, supply/demand outlook, policy changes, and new regulations governing export of crude oil and products

  12. Brief Report: Diminished Gaze Preference for Dynamic Social Interaction Scenes in Youth with Autism Spectrum Disorders.

    Science.gov (United States)

    Shaffer, Rebecca C; Pedapati, Ernest V; Shic, Frederick; Gaietto, Kristina; Bowers, Katherine; Wink, Logan K; Erickson, Craig A

    2017-02-01

    In this study, we present an eye-tracking paradigm, adapted from previous work with toddlers, for assessing social-interaction looking preferences in youth ages 5-17 with ASD and typically-developing controls (TDC). Videos of children playing together (Social Scenes, SS) were presented side-by-side with animated geometric shapes (GS). Participants with ASD demonstrated reduced SS preferences compared to TDC, results also represented continuously by associations between higher SS preferences and fewer social difficulties across the combined sample. Exploratory analyses identified associations between increased SS preferences and higher Vineland Daily Living Skills in ASD and suggested SS preferences in TDC females might drive ASD versus TDC between-group differences. These findings describe potentially sex-linked couplings between preferences for social information and social functioning in school-aged children.

  13. Motion field estimation for a dynamic scene using a 3D LiDAR.

    Science.gov (United States)

    Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington

    2014-09-09

    This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively.

  14. Motion Field Estimation for a Dynamic Scene Using a 3D LiDAR

    Directory of Open Access Journals (Sweden)

    Qingquan Li

    2014-09-01

    Full Text Available This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively.

  15. Dr TIM: Ray-tracer TIM, with additional specialist scientific capabilities

    Science.gov (United States)

    Oxburgh, Stephen; Tyc, Tomáš; Courtial, Johannes

    2014-03-01

    We describe several extensions to TIM, a raytracing program for ray-optics research. These include relativistic raytracing; simulation of the external appearance of Eaton lenses, Luneburg lenses and generalised focusing gradient-index lens (GGRIN) lenses, which are types of perfect imaging devices; raytracing through interfaces between spaces with different optical metrics; and refraction with generalised confocal lenslet arrays, which are particularly versatile METATOYs. Catalogue identifier: AEKY_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKY_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licencing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 106905 No. of bytes in distributed program, including test data, etc.: 6327715 Distribution format: tar.gz Programming language: Java. Computer: Any computer capable of running the Java Virtual Machine (JVM) 1.6. Operating system: Any, developed under Mac OS X Version 10.6 and 10.8.3. RAM: Typically 130 MB (interactive version running under Mac OS X Version 10.8.3) Classification: 14, 18. Catalogue identifier of previous version: AEKY_v1_0 Journal reference of previous version: Comput. Phys. Comm. 183(2012)711 External routines: JAMA [1] (source code included) Does the new version supersede the previous version?: Yes Nature of problem: Visualisation of scenes that include scene objects that create wave-optically forbidden light-ray fields. Solution method: Ray tracing. Reasons for new version: Significant extension of the capabilities (see Summary of revisions), as demanded by our research. Summary of revisions: Added capabilities include the simulation of different types of camera moving at relativistic speeds relative to the scene; visualisation of the external appearance of generalised focusing gradient-index (GGRIN) lenses, including Maxwell fisheye, Eaton and Luneburg lenses; calculation of

  16. TIM, a ray-tracing program for METATOY research and its dissemination

    Science.gov (United States)

    Lambert, Dean; Hamilton, Alasdair C.; Constable, George; Snehanshu, Harsh; Talati, Sharvil; Courtial, Johannes

    2012-03-01

    TIM (The Interactive METATOY) is a ray-tracing program specifically tailored towards our research in METATOYs, which are optical components that appear to be able to create wave-optically forbidden light-ray fields. For this reason, TIM possesses features not found in other ray-tracing programs. TIM can either be used interactively or by modifying the openly available source code; in both cases, it can easily be run as an applet embedded in a web page. Here we describe the basic structure of TIM's source code and how to extend it, and we give examples of how we have used TIM in our own research. Program summaryProgram title: TIM Catalogue identifier: AEKY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKY_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License No. of lines in distributed program, including test data, etc.: 124 478 No. of bytes in distributed program, including test data, etc.: 4 120 052 Distribution format: tar.gz Programming language: Java Computer: Any computer capable of running the Java Virtual Machine (JVM) 1.6 Operating system: Any; developed under Mac OS X Version 10.6 RAM: Typically 145 MB (interactive version running under Mac OS X Version 10.6) Classification: 14, 18 External routines: JAMA [1] (source code included) Nature of problem: Visualisation of scenes that include scene objects that create wave-optically forbidden light-ray fields. Solution method: Ray tracing. Unusual features: Specifically designed to visualise wave-optically forbidden light-ray fields; can visualise ray trajectories; can visualise geometric optic transformations; can create anaglyphs (for viewing with coloured "3D glasses") and random-dot autostereograms of the scene; integrable into web pages. Running time: Problem-dependent; typically seconds for a simple scene.

  17. Setting scene for TV white spaces and dynamic spectrum access in South Africa

    CSIR Research Space (South Africa)

    Masonta, MT

    2012-05-01

    Full Text Available -and-control static spectrum regulation regime. In order to keep up with a growing demand for wireless broadband access; new and dynamic spectrum regulation and management approaches are crucial. The ongoing global television (TV) broadcast digital switchover (DSO... ?white spaces? (TVWS). In the US, for example, TV DSO was completed in June 2009. However, this was not a smooth process. For instance, it was reported that digital TV viewers from many cities experienced several reception problems [2]. Due...

  18. High-speed three-dimensional shape measurement for dynamic scenes using bi-frequency tripolar pulse-width-modulation fringe projection

    Science.gov (United States)

    Zuo, Chao; Chen, Qian; Gu, Guohua; Feng, Shijie; Feng, Fangxiaoyu; Li, Rubin; Shen, Guochen

    2013-08-01

    This paper introduces a high-speed three-dimensional (3-D) shape measurement technique for dynamic scenes by using bi-frequency tripolar pulse-width-modulation (TPWM) fringe projection. Two wrapped phase maps with different wavelengths can be obtained simultaneously by our bi-frequency phase-shifting algorithm. Then the two phase maps are unwrapped using a simple look-up-table based number-theoretical approach. To guarantee the robustness of phase unwrapping as well as the high sinusoidality of projected patterns, TPWM technique is employed to generate ideal fringe patterns with slight defocus. We detailed our technique, including its principle, pattern design, and system setup. Several experiments on dynamic scenes were performed, verifying that our method can achieve a speed of 1250 frames per second for fast, dense, and accurate 3-D measurements.

  19. A signal normalization technique for illumination-based synchronization of 1,000-fps real-time vision sensors in dynamic scenes.

    Science.gov (United States)

    Hou, Lei; Kagami, Shingo; Hashimoto, Koichi

    2010-01-01

    To acquire images of dynamic scenes from multiple points of view simultaneously, the acquisition time of vision sensors should be synchronized. In this paper, an illumination-based synchronization derived from the phase-locked loop (PLL) mechanism based on the signal normalization method is proposed and evaluated. To eliminate the system dependency due to the amplitude fluctuation of the reference illumination, which may be caused by the moving objects or relative positional distance change between the light source and the observed objects, the fluctuant amplitude of the reference signal is normalized framely by the estimated maximum amplitude between the reference signal and its quadrature counterpart to generate a stable synchronization in highly dynamic scenes. Both simulated results and real world experimental results demonstrated successful synchronization result that 1,000-Hz frame rate vision sensors can be successfully synchronized to a LED illumination or its reflected light with satisfactory stability and only 28-μs jitters.

  20. A Signal Normalization Technique for Illumination-Based Synchronization of 1,000-fps Real-Time Vision Sensors in Dynamic Scenes

    Directory of Open Access Journals (Sweden)

    Koichi Hashimoto

    2010-09-01

    Full Text Available To acquire images of dynamic scenes from multiple points of view simultaneously, the acquisition time of vision sensors should be synchronized. In this paper, an illumination-based synchronization derived from the phase-locked loop (PLL mechanism based on the signal normalization method is proposed and evaluated. To eliminate the system dependency due to the amplitude fluctuation of the reference illumination, which may be caused by the moving objects or relative positional distance change between the light source and the observed objects, the fluctuant amplitude of the reference signal is normalized framely by the estimated maximum amplitude between the reference signal and its quadrature counterpart to generate a stable synchronization in highly dynamic scenes. Both simulated results and real world experimental results demonstrated successful synchronization result that 1,000-Hz frame rate vision sensors can be successfully synchronized to a LED illumination or its reflected light with satisfactory stability and only 28-μs jitters.

  1. Beam Stability: Raytracing Requirements and Implementations

    International Nuclear Information System (INIS)

    Green, Michael A.; Bissen, Mark J.; Pedley, Robert T.; Severson, Mary C.; Stott, John P.; Hallin, Emil L.

    2004-01-01

    Stability to-the-user fundamentally starts with present needs and future goals from the user community conveyed to facility staff in terms of user observables into the sample chamber. These are then projected onto the requirements for both the beamlines and the sources. In turn, specifications unfold for performance of subsystems, individual components, and facility services. Altogether, this process involves users, and facility staff from beamlines, operations, engineering, controls, and machine physics.This paper focuses on the transformation of user-to-source requirements, which is a small, but critical, part of the general subject. This translation has been expedited by semi-automated use, via scripting, of the SHADOW raytracing software. The dependence of each user observable on each source parameter is functionally determined, and inverted, for variable values of the user observables. In this way, source stability requirements can be readily determined for the needs of a given experiment on a given beamline in a particular mode. A description of the algorithms, with a working example on a new, slitless undulator beamline at SRC are presented

  2. Evaluation of simulation alternatives for the brute-force ray-tracing approach used in backlight design

    Science.gov (United States)

    Desnijder, Karel; Hanselaer, Peter; Meuret, Youri

    2016-04-01

    A key requirement to obtain a uniform luminance for a side-lit LED backlight is the optimised spatial pattern of structures on the light guide that extract the light. The generation of such a scatter pattern is usually performed by applying an iterative approach. In each iteration, the luminance distribution of the backlight with a particular scatter pattern is analysed. This is typically performed with a brute-force ray-tracing algorithm, although this approach results in a time-consuming optimisation process. In this study, the Adding-Doubling method is explored as an alternative way for evaluating the luminance of a backlight. Due to the similarities between light propagating in a backlight with extraction structures and light scattering in a cloud of light scatterers, the Adding-Doubling method which is used to model the latter could also be used to model the light distribution in a backlight. The backlight problem is translated to a form upon which the Adding-Doubling method is directly applicable. The calculated luminance for a simple uniform extraction pattern with the Adding-Doubling method matches the luminance generated by a commercial raytracer very well. Although successful, no clear computational advantage over ray tracers is realised. However, the dynamics of light propagation in a light guide as used the Adding-Doubling method, also allow to enhance the efficiency of brute-force ray-tracing algorithms. The performance of this enhanced ray-tracing approach for the simulation of backlights is also evaluated against a typical brute-force ray-tracing approach.

  3. Differential Raytracing for special illumination systems; Differentielles Raytracing fuer spezielle Beleuchtungssysteme

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, Oliver

    2010-02-19

    Differential ray tracing is implemented into the optics design software RAYTRACE and its performance is compared to Monte Carlo calculations. Simulations of illumination systems show that differential ray tracing yields smooth and noiseless results in (mostly) much smaller computational time as compared to the Monte Carlo simulations. Both shape and absolute values of the intensity distributions are in good agreement. When calculating with the differential method instead of using the Monte Carlo method one could, depending on the optical setup, save up to a tenfold of time. In optical systems containing lens arrays, the speed advantage of the differential ray tracing method slightly decreases. This is because the differential approach generates ray groups and calculates the total intensity distribution as the superposition of the separately interpolated distributions of each group. Another main focus of this work was the development of an improved optimization algorithm for optical illumination systems and in particular also for refractive beam-shaping elements which are based on free-form surfaces. The optimization aim is coded into a mathematical expression, the so called ''merit function''. Contrary to the merit function based on the Monte-Carlo ray tracing technique, a new merit function based on differential ray tracing is derived. As the differential approach works noiseless the resulting merit function excels through a smooth and continuous form. Comparative calculations between deterministic (e.g. gradient methods) and stochastical optimization techniques (e.g. Monte-Carlo method, simulated annealing, evolutionary algorithms, particle swarm optimization) are presented for both types of merit functions. It is shown that combinations of differential ray tracing with modern population-based optimization methods, like the evolutionary algorithms and the particle swarm optimization can achieve an actual reduction of computational time while

  4. Scene incongruity and attention.

    Science.gov (United States)

    Mack, Arien; Clarke, Jason; Erol, Muge; Bert, John

    2017-02-01

    Does scene incongruity, (a mismatch between scene gist and a semantically incongruent object), capture attention and lead to conscious perception? We explored this question using 4 different procedures: Inattention (Experiment 1), Scene description (Experiment 2), Change detection (Experiment 3), and Iconic Memory (Experiment 4). We found no differences between scene incongruity and scene congruity in Experiments 1, 2, and 4, although in Experiment 3 change detection was faster for scenes containing an incongruent object. We offer an explanation for why the change detection results differ from the results of the other three experiments. In all four experiments, participants invariably failed to report the incongruity and routinely mis-described it by normalizing the incongruent object. None of the results supports the claim that semantic incongruity within a scene invariably captures attention and provide strong evidence of the dominant role of scene gist in determining what is perceived. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Hebbian learning in a model with dynamic rate-coded neurons: an alternative to the generative model approach for learning receptive fields from natural scenes.

    Science.gov (United States)

    Hamker, Fred H; Wiltschut, Jan

    2007-09-01

    Most computational models of coding are based on a generative model according to which the feedback signal aims to reconstruct the visual scene as close as possible. We here explore an alternative model of feedback. It is derived from studies of attention and thus, probably more flexible with respect to attentive processing in higher brain areas. According to this model, feedback implements a gain increase of the feedforward signal. We use a dynamic model with presynaptic inhibition and Hebbian learning to simultaneously learn feedforward and feedback weights. The weights converge to localized, oriented, and bandpass filters similar as the ones found in V1. Due to presynaptic inhibition the model predicts the organization of receptive fields within the feedforward pathway, whereas feedback primarily serves to tune early visual processing according to the needs of the task.

  6. PC Scene Generation

    Science.gov (United States)

    Buford, James A., Jr.; Cosby, David; Bunfield, Dennis H.; Mayhall, Anthony J.; Trimble, Darian E.

    2007-04-01

    AMRDEC has successfully tested hardware and software for Real-Time Scene Generation for IR and SAL Sensors on COTS PC based hardware and video cards. AMRDEC personnel worked with nVidia and Concurrent Computer Corporation to develop a Scene Generation system capable of frame rates of at least 120Hz while frame locked to an external source (such as a missile seeker) with no dropped frames. Latency measurements and image validation were performed using COTS and in-house developed hardware and software. Software for the Scene Generation system was developed using OpenSceneGraph.

  7. The Sport Expert's Attention Superiority on Skill-related Scene Dynamic by the Activation of left Medial Frontal Gyrus: An ERP and LORETA Study.

    Science.gov (United States)

    He, Mengyang; Qi, Changzhu; Lu, Yang; Song, Amanda; Hayat, Saba Z; Xu, Xia

    2018-05-21

    Extensive studies have shown that a sports expert is superior to a sports novice in visually perceptual-cognitive processes of sports scene information, however the attentional and neural basis of it has not been thoroughly explored. The present study examined whether a sport expert has the attentional superiority on scene information relevant to his/her sport skill, and explored what factor drives this superiority. To address this problem, EEGs were recorded as participants passively viewed sport scenes (tennis vs. non-tennis) and negative emotional faces in the context of a visual attention task, where the pictures of sport scenes or of negative emotional faces randomly followed the pictures with overlapping sport scenes and negative emotional faces. ERP results showed that for experts, the evoked potential of attentional competition elicited by the overlap of tennis scene was significantly larger than that evoked by the overlap of non-tennis scene, while this effect was absent for novices. The LORETA showed that the experts' left medial frontal gyrus (MFG) cortex was significantly more active as compared to the right MFG when processing the overlap of tennis scene, but the lateralization effect was not significant in novices. Those results indicate that experts have attentional superiority on skill-related scene information, despite intruding the scene through negative emotional faces that are prone to cause negativity bias toward their visual field as a strong distractor. This superiority is actuated by the activation of left MFG cortex and probably due to self-reference. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Underwater Scene Composition

    Science.gov (United States)

    Kim, Nanyoung

    2009-01-01

    In this article, the author describes an underwater scene composition for elementary-education majors. This project deals with watercolor with crayon or oil-pastel resist (medium); the beauty of nature represented by fish in the underwater scene (theme); texture and pattern (design elements); drawing simple forms (drawing skill); and composition…

  9. Scene construction in schizophrenia.

    Science.gov (United States)

    Raffard, Stéphane; D'Argembeau, Arnaud; Bayard, Sophie; Boulenger, Jean-Philippe; Van der Linden, Martial

    2010-09-01

    Recent research has revealed that schizophrenia patients are impaired in remembering the past and imagining the future. In this study, we examined patients' ability to engage in scene construction (i.e., the process of mentally generating and maintaining a complex and coherent scene), which is a key part of retrieving past experiences and episodic future thinking. 24 participants with schizophrenia and 25 healthy controls were asked to imagine new fictitious experiences and described their mental representations of the scenes in as much detail as possible. Descriptions were scored according to various dimensions (e.g., sensory details, spatial reference), and participants also provided ratings of their subjective experience when imagining the scenes (e.g., their sense of presence, the perceived similarity of imagined events to past experiences). Imagined scenes contained less phenomenological details (d = 1.11) and were more fragmented (d = 2.81) in schizophrenia patients compared to controls. Furthermore, positive symptoms were positively correlated to the sense of presence (r = .43) and the perceived similarity of imagined events to past episodes (r = .47), whereas negative symptoms were negatively related to the overall richness of the imagined scenes (r = -.43). The results suggest that schizophrenic patients' impairments in remembering the past and imagining the future are, at least in part, due to deficits in the process of scene construction. The relationships between the characteristics of imagined scenes and positive and negative symptoms could be related to reality monitoring deficits and difficulties in strategic retrieval processes, respectively. Copyright 2010 APA, all rights reserved.

  10. Memory for temporally dynamic scenes.

    Science.gov (United States)

    Ferguson, Ryan; Homa, Donald; Ellis, Derek

    2017-07-01

    Recognition memory was investigated for individual frames extracted from temporally continuous, visually rich film segments of 5-15 min. Participants viewed a short clip from a film in either a coherent or a jumbled order, followed by a recognition test of studied frames. Foils came either from an earlier or a later part of the film (Experiment 1) or from deleted segments selected from random cuts of varying duration (0.5 to 30 s) within the film itself (Experiment 2). When the foils came from an earlier or later part of the film (Experiment 1), recognition was excellent, with the hit rate far exceeding the false-alarm rate (.78 vs. 18). In Experiment 2, recognition was far worse, with the hit rate (.76) exceeding the false-alarm rate only for foils drawn from the longest cuts (15 and 30 s) and matching the false-alarm rate for the 5 s segments. When the foils were drawn from the briefest cuts (0.5 and 1.0 s), the false-alarm rate exceeded the hit rate. Unexpectedly, jumbling had no effect on recognition in either experiment. These results are consistent with the view that memory for complex visually temporal events is excellent, with the integrity unperturbed by disruption of the global structure of the visual stream. Disruption of memory was observed only when foils were drawn from embedded segments of duration less than 5 s, an outcome consistent with the view that memory at these shortest durations are consolidated with expectations drawn from the previous stream.

  11. Application of ray-traced tropospheric slant delays to geodetic VLBI analysis

    Science.gov (United States)

    Hofmeister, Armin; Böhm, Johannes

    2017-08-01

    The correction of tropospheric influences via so-called path delays is critical for the analysis of observations from space geodetic techniques like the very long baseline interferometry (VLBI). In standard VLBI analysis, the a priori slant path delays are determined using the concept of zenith delays, mapping functions and gradients. The a priori use of ray-traced delays, i.e., tropospheric slant path delays determined with the technique of ray-tracing through the meteorological data of numerical weather models (NWM), serves as an alternative way of correcting the influences of the troposphere on the VLBI observations within the analysis. In the presented research, the application of ray-traced delays to the VLBI analysis of sessions in a time span of 16.5 years is investigated. Ray-traced delays have been determined with program RADIATE (see Hofmeister in Ph.D. thesis, Department of Geodesy and Geophysics, Faculty of Mathematics and Geoinformation, Technische Universität Wien. http://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-3444, 2016) utilizing meteorological data provided by NWM of the European Centre for Medium-Range Weather Forecasts (ECMWF). In comparison with a standard VLBI analysis, which includes the tropospheric gradient estimation, the application of the ray-traced delays to an analysis, which uses the same parameterization except for the a priori slant path delay handling and the used wet mapping factors for the zenith wet delay (ZWD) estimation, improves the baseline length repeatability (BLR) at 55.9% of the baselines at sub-mm level. If no tropospheric gradients are estimated within the compared analyses, 90.6% of all baselines benefit from the application of the ray-traced delays, which leads to an average improvement of the BLR of 1 mm. The effects of the ray-traced delays on the terrestrial reference frame are also investigated. A separate assessment of the RADIATE ray-traced delays is carried out by comparison to the ray-traced delays from the

  12. Moving through a multiplex holographic scene

    Science.gov (United States)

    Mrongovius, Martina

    2013-02-01

    This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

  13. SOLFAST, a Ray-Tracing Monte-Carlo software for solar concentrating facilities

    International Nuclear Information System (INIS)

    Roccia, J P; Piaud, B; Coustet, C; Caliot, C; Guillot, E; Flamant, G; Delatorre, J

    2012-01-01

    In this communication, the software SOLFAST is presented. It is a simulation tool based on the Monte-Carlo method and accelerated Ray-Tracing techniques to evaluate efficiently the energy flux in concentrated solar installations.

  14. Crime Scene Investigation.

    Science.gov (United States)

    Harris, Barbara; Kohlmeier, Kris; Kiel, Robert D.

    Casting students in grades 5 through 12 in the roles of reporters, lawyers, and detectives at the scene of a crime, this interdisciplinary activity involves participants in the intrigue and drama of crime investigation. Using a hands-on, step-by-step approach, students work in teams to investigate a crime and solve a mystery. Through role-playing…

  15. Scene independent real-time indirect illumination

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Christensen, Niels Jørgen; Falster, Peter

    2005-01-01

    A novel method for real-time simulation of indirect illumination is presented in this paper. The method, which we call Direct Radiance Mapping (DRM), is based on basal radiance calculations and does not impose any restrictions on scene geometry or dynamics. This makes the method tractable for rea...

  16. Review of infrared scene projector technology-1993

    Science.gov (United States)

    Driggers, Ronald G.; Barnard, Kenneth J.; Burroughs, E. E.; Deep, Raymond G.; Williams, Owen M.

    1994-07-01

    The importance of testing IR imagers and missile seekers with realistic IR scenes warrants a review of the current technologies used in dynamic infrared scene projection. These technologies include resistive arrays, deformable mirror arrays, mirror membrane devices, liquid crystal light valves, laser writers, laser diode arrays, and CRTs. Other methods include frustrated total internal reflection, thermoelectric devices, galvanic cells, Bly cells, and vanadium dioxide. A description of each technology is presented along with a discussion of their relative benefits and disadvantages. The current state of each methodology is also summarized. Finally, the methods are compared and contrasted in terms of their performance parameters.

  17. Robust ray-tracing algorithms for interactive dose rate evaluation

    International Nuclear Information System (INIS)

    Perrotte, L.

    2011-01-01

    More than ever, it is essential today to develop simulation tools to rapidly evaluate the dose rate received by operators working on nuclear sites. In order to easily study numerous different scenarios of intervention, computation times of available softwares have to be all lowered. This mainly implies to accelerate the geometrical computations needed for the dose rate evaluation. These computations consist in finding and sorting the whole list of intersections between a big 3D scene and multiple groups of 'radiative' rays meeting at the point where the dose has to be measured. In order to perform all these computations in less than a second, we first propose a GPU algorithm that enables the efficient management of one big group of coherent rays. Then we present a modification of this algorithm that guarantees the robustness of the ray-triangle intersection tests through the elimination of the precision issues due to floating-point arithmetic. This modification does not require the definition of scene-dependent coefficients ('epsilon' style) and only implies a small loss of performance (less than 10%). Finally we propose an efficient strategy to handle multiple ray groups (corresponding to multiple radiative objects) which use the previous results.Thanks to these improvements, we are able to perform an interactive and robust dose rate evaluation on big 3D scenes: all of the intersections (more than 13 million) between 700 000 triangles and 12 groups of 100 000 rays each are found, sorted along each ray and transferred to the CPU in 470 milliseconds. (author) [fr

  18. An Over 90 dB Intra-Scene Single-Exposure Dynamic Range CMOS Image Sensor Using a 3.0 μm Triple-Gain Pixel Fabricated in a Standard BSI Process

    Directory of Open Access Journals (Sweden)

    Isao Takayanagi

    2018-01-01

    Full Text Available To respond to the high demand for high dynamic range imaging suitable for moving objects with few artifacts, we have developed a single-exposure dynamic range image sensor by introducing a triple-gain pixel and a low noise dual-gain readout circuit. The developed 3 μm pixel is capable of having three conversion gains. Introducing a new split-pinned photodiode structure, linear full well reaches 40 ke−. Readout noise under the highest pixel gain condition is 1 e− with a low noise readout circuit. Merging two signals, one with high pixel gain and high analog gain, and the other with low pixel gain and low analog gain, a single exposure dynamic rage (SEHDR signal is obtained. Using this technology, a 1/2.7”, 2M-pixel CMOS image sensor has been developed and characterized. The image sensor also employs an on-chip linearization function, yielding a 16-bit linear signal at 60 fps, and an intra-scene dynamic range of higher than 90 dB was successfully demonstrated. This SEHDR approach inherently mitigates the artifacts from moving objects or time-varying light sources that can appear in the multiple exposure high dynamic range (MEHDR approach.

  19. An Over 90 dB Intra-Scene Single-Exposure Dynamic Range CMOS Image Sensor Using a 3.0 μm Triple-Gain Pixel Fabricated in a Standard BSI Process.

    Science.gov (United States)

    Takayanagi, Isao; Yoshimura, Norio; Mori, Kazuya; Matsuo, Shinichiro; Tanaka, Shunsuke; Abe, Hirofumi; Yasuda, Naoto; Ishikawa, Kenichiro; Okura, Shunsuke; Ohsawa, Shinji; Otaka, Toshinori

    2018-01-12

    To respond to the high demand for high dynamic range imaging suitable for moving objects with few artifacts, we have developed a single-exposure dynamic range image sensor by introducing a triple-gain pixel and a low noise dual-gain readout circuit. The developed 3 μm pixel is capable of having three conversion gains. Introducing a new split-pinned photodiode structure, linear full well reaches 40 ke - . Readout noise under the highest pixel gain condition is 1 e - with a low noise readout circuit. Merging two signals, one with high pixel gain and high analog gain, and the other with low pixel gain and low analog gain, a single exposure dynamic rage (SEHDR) signal is obtained. Using this technology, a 1/2.7", 2M-pixel CMOS image sensor has been developed and characterized. The image sensor also employs an on-chip linearization function, yielding a 16-bit linear signal at 60 fps, and an intra-scene dynamic range of higher than 90 dB was successfully demonstrated. This SEHDR approach inherently mitigates the artifacts from moving objects or time-varying light sources that can appear in the multiple exposure high dynamic range (MEHDR) approach.

  20. Hydrological AnthropoScenes

    Science.gov (United States)

    Cudennec, Christophe

    2016-04-01

    The Anthropocene concept encapsulates the planetary-scale changes resulting from accelerating socio-ecological transformations, beyond the stratigraphic definition actually in debate. The emergence of multi-scale and proteiform complexity requires inter-discipline and system approaches. Yet, to reduce the cognitive challenge of tackling this complexity, the global Anthropocene syndrome must now be studied from various topical points of view, and grounded at regional and local levels. A system approach should allow to identify AnthropoScenes, i.e. settings where a socio-ecological transformation subsystem is clearly coherent within boundaries and displays explicit relationships with neighbouring/remote scenes and within a nesting architecture. Hydrology is a key topical point of view to be explored, as it is important in many aspects of the Anthropocene, either with water itself being a resource, hazard or transport force; or through the network, connectivity, interface, teleconnection, emergence and scaling issues it determines. We will schematically exemplify these aspects with three contrasted hydrological AnthropoScenes in Tunisia, France and Iceland; and reframe therein concepts of the hydrological change debate. Bai X., van der Leeuw S., O'Brien K., Berkhout F., Biermann F., Brondizio E., Cudennec C., Dearing J., Duraiappah A., Glaser M., Revkin A., Steffen W., Syvitski J., 2016. Plausible and desirable futures in the Anthropocene: A new research agenda. Global Environmental Change, in press, http://dx.doi.org/10.1016/j.gloenvcha.2015.09.017 Brondizio E., O'Brien K., Bai X., Biermann F., Steffen W., Berkhout F., Cudennec C., Lemos M.C., Wolfe A., Palma-Oliveira J., Chen A. C-T. Re-conceptualizing the Anthropocene: A call for collaboration. Global Environmental Change, in review. Montanari A., Young G., Savenije H., Hughes D., Wagener T., Ren L., Koutsoyiannis D., Cudennec C., Grimaldi S., Blöschl G., Sivapalan M., Beven K., Gupta H., Arheimer B., Huang Y

  1. Automatic structural scene digitalization.

    Science.gov (United States)

    Tang, Rui; Wang, Yuhan; Cosker, Darren; Li, Wenbin

    2017-01-01

    In this paper, we present an automatic system for the analysis and labeling of structural scenes, floor plan drawings in Computer-aided Design (CAD) format. The proposed system applies a fusion strategy to detect and recognize various components of CAD floor plans, such as walls, doors, windows and other ambiguous assets. Technically, a general rule-based filter parsing method is fist adopted to extract effective information from the original floor plan. Then, an image-processing based recovery method is employed to correct information extracted in the first step. Our proposed method is fully automatic and real-time. Such analysis system provides high accuracy and is also evaluated on a public website that, on average, archives more than ten thousands effective uses per day and reaches a relatively high satisfaction rate.

  2. Pseudo forward ray-tracing: A new method for surface validation in cornea topography

    NARCIS (Netherlands)

    Sicam, V.; Snellenburg, J.J.; van der Heijde, R.G.; van Stokkum, I.H.M.

    2007-01-01

    PURPOSE. A pseudo forward ray-tracing (PFRT) algorithm is developed to evaluate surface reconstruction in corneal topography. The method can be applied to topographers where one-to-one correspondence between mire and image points can be established. METHODS. The PFRT algorithm was applied on a

  3. An Energy Conservative Ray-Tracing Method With a Time Interpolation of the Force Field

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-02-10

    A new algorithm that constructs a continuous force field interpolated in time is proposed for resolving existing difficulties in numerical methods for ray-tracing. This new method has improved accuracy, but with the same degree of algebraic complexity compared to Kaisers method.

  4. Interior metric and ray-tracing map in the firework black-to-white hole transition

    OpenAIRE

    Rovelli, Carlo; Martin-Dussaud, Pierre

    2018-01-01

    The possibility that a black hole could tunnel into to white hole has recently received attention. Here we present a metric that improves the "firework" metric: it describes the entire process and solves the Einstein's equations everywhere except on a small transition surface that corresponds to the quantum tunneling. We compute the corresponding ray-tracing map from past infinity to future infinity explicitly.

  5. Investigation of propagation algorithms for ray-tracing simulation of polarized neutrons

    DEFF Research Database (Denmark)

    Bergbäck Knudsen, Erik; Tranum-Rømer, A.; Willendrup, Peter Kjær

    2014-01-01

    Ray-tracing of polarized neutrons faces a challenge when the neutron propagates through an inhomogeneous magnetic field. This affects simulations of novel instruments using encoding of energy or angle into the neutron spin. We here present a new implementation of propagation of polarized neutrons...

  6. Fast voxel and polygon ray-tracing algorithms in intensity modulated radiation therapy treatment planning

    International Nuclear Information System (INIS)

    Fox, Christopher; Romeijn, H. Edwin; Dempsey, James F.

    2006-01-01

    We present work on combining three algorithms to improve ray-tracing efficiency in radiation therapy dose computation. The three algorithms include: An improved point-in-polygon algorithm, incremental voxel ray tracing algorithm, and stereographic projection of beamlets for voxel truncation. The point-in-polygon and incremental voxel ray-tracing algorithms have been used in computer graphics and nuclear medicine applications while the stereographic projection algorithm was developed by our group. These algorithms demonstrate significant improvements over the current standard algorithms in peer reviewed literature, i.e., the polygon and voxel ray-tracing algorithms of Siddon for voxel classification (point-in-polygon testing) and dose computation, respectively, and radius testing for voxel truncation. The presented polygon ray-tracing technique was tested on 10 intensity modulated radiation therapy (IMRT) treatment planning cases that required the classification of between 0.58 and 2.0 million voxels on a 2.5 mm isotropic dose grid into 1-4 targets and 5-14 structures represented as extruded polygons (a.k.a. Siddon prisms). Incremental voxel ray tracing and voxel truncation employing virtual stereographic projection was tested on the same IMRT treatment planning cases where voxel dose was required for 230-2400 beamlets using a finite-size pencil-beam algorithm. Between a 100 and 360 fold cpu time improvement over Siddon's method was observed for the polygon ray-tracing algorithm to perform classification of voxels for target and structure membership. Between a 2.6 and 3.1 fold reduction in cpu time over current algorithms was found for the implementation of incremental ray tracing. Additionally, voxel truncation via stereographic projection was observed to be 11-25 times faster than the radial-testing beamlet extent approach and was further improved 1.7-2.0 fold through point-classification using the method of translation over the cross product technique

  7. Semantic Reasoning for Scene Interpretation

    DEFF Research Database (Denmark)

    Jensen, Lars Baunegaard With; Baseski, Emre; Pugeault, Nicolas

    2008-01-01

    In this paper, we propose a hierarchical architecture for representing scenes, covering 2D and 3D aspects of visual scenes as well as the semantic relations between the different aspects. We argue that labeled graphs are a suitable representational framework for this representation and demonstrat...

  8. Setting the scene

    International Nuclear Information System (INIS)

    Curran, S.

    1977-01-01

    The reasons for the special meeting on the breeder reactor are outlined with some reference to the special Scottish interest in the topic. Approximately 30% of the electrical energy generated in Scotland is nuclear and the special developments at Dounreay make policy decisions on the future of the commercial breeder reactor urgent. The participants review the major questions arising in arriving at such decisions. In effect an attempt is made to respond to the wish of the Secretary of State for Energy to have informed debate. To set the scene the importance of energy availability as regards to the strength of the national economy is stressed and the reasons for an increasing energy demand put forward. Examination of alternative sources of energy shows that none is definitely capable of filling the foreseen energy gap. This implies an integrated thermal/breeder reactor programme as the way to close the anticipated gap. The problems of disposal of radioactive waste and the safeguards in the handling of plutonium are outlined. Longer-term benefits, including the consumption of plutonium and naturally occurring radioactive materials, are examined. (author)

  9. Albedo estimation for scene segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C H; Rosenfeld, A

    1983-03-01

    Standard methods of image segmentation do not take into account the three-dimensional nature of the underlying scene. For example, histogram-based segmentation tacitly assumes that the image intensity is piecewise constant, and this is not true when the scene contains curved surfaces. This paper introduces a method of taking 3d information into account in the segmentation process. The image intensities are adjusted to compensate for the effects of estimated surface orientation; the adjusted intensities can be regarded as reflectivity estimates. When histogram-based segmentation is applied to these new values, the image is segmented into parts corresponding to surfaces of constant reflectivity in the scene. 7 references.

  10. A comparison of ray-tracing software for the design of quadrupole microbeam systems

    International Nuclear Information System (INIS)

    Incerti, S.; Smith, R.W.; Merchant, M.; Grime, G.W.; Meot, F.; Serani, L.; Moretto, Ph.; Touzeau, C.; Barberet, Ph.; Habchi, C.; Nguyen, D.T.

    2005-01-01

    For many years the only ray-tracing software available with sufficient precision for the design of quadrupole microbeam focusing systems has been OXRAY and its successor TRAX, developed at Oxford in the 1980s. With the current interest in pushing the beam diameter into the nanometre region, this software has become dated and more importantly the precision at small displacements may not be sufficient and new simulation tools are required. Two candidates for this are Zgoubi, developed at CEA as a general beam line design tool and the CERN simulation program Geant in its latest version Geant4. In order to use Geant4 new quadrupole field modules have been developed and implemented. In this paper the capabilities of the three codes TRAX, Zgoubi and Geant4 are reviewed. Comparisons of ray-tracing calculations in a high demagnification quadrupole probe-forming system for the sub-micron region are presented

  11. Random ray-tracing and graphic analysing of charged particle trajectories

    International Nuclear Information System (INIS)

    Lin Xiaomei; Mao Naifeng; Chen Jingxian

    1990-01-01

    In order to describe the optical properties of a charged particle beam realistically, the random sampling of initial conditions of particles in ray-tracing is discussed. The emission surface of particles may be a plane, a cylindrical surface or a spherical surface. The distribution functions may be expressed analytically or numerically. In order to analyse the properties of the charged particle beam systematically by use of the results from ray-tracing efficiently, the graphic processing and analysing of particle trajectories are also discussed, including the spline function fitting of trajectories, the graphic drafting of trajectories and beam envelopes, the determining of image dimensions and the correspinding positions, and also the graphic drafting of particle distributions on arbitrary cross sections

  12. Computation and analysis of backward ray-tracing in aero-optics flow fields.

    Science.gov (United States)

    Xu, Liang; Xue, Deting; Lv, Xiaoyi

    2018-01-08

    A backward ray-tracing method is proposed for aero-optics simulation. Different from forward tracing, the backward tracing direction is from the internal sensor to the distant target. Along this direction, the tracing in turn goes through the internal gas region, the aero-optics flow field, and the freestream. The coordinate value, the density, and the refractive index are calculated at each tracing step. A stopping criterion is developed to ensure the tracing stops at the outer edge of the aero-optics flow field. As a demonstration, the analysis is carried out for a typical blunt nosed vehicle. The backward tracing method and stopping criterion greatly simplify the ray-tracing computations in the aero-optics flow field, and they can be extended to our active laser illumination aero-optics study because of the reciprocity principle.

  13. Three-dimensional ray-tracing model for the study of advanced refractive errors in keratoconus.

    Science.gov (United States)

    Schedin, Staffan; Hallberg, Per; Behndig, Anders

    2016-01-20

    We propose a numerical three-dimensional (3D) ray-tracing model for the analysis of advanced corneal refractive errors. The 3D modeling was based on measured corneal elevation data by means of Scheimpflug photography. A mathematical description of the measured corneal surfaces from a keratoconus (KC) patient was used for the 3D ray tracing, based on Snell's law of refraction. A model of a commercial intraocular lens (IOL) was included in the analysis. By modifying the posterior IOL surface, it was shown that the imaging quality could be significantly improved. The RMS values were reduced by approximately 50% close to the retina, both for on- and off-axis geometries. The 3D ray-tracing model can constitute a basis for simulation of customized IOLs that are able to correct the advanced, irregular refractive errors in KC.

  14. Solar Proton Transport Within an ICRU Sphere Surrounded by a Complex Shield: Ray-trace Geometry

    Science.gov (United States)

    Slaba, Tony C.; Wilson, John W.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-01-01

    A computationally efficient 3DHZETRN code with enhanced neutron and light ion (Z is less than or equal to 2) propagation was recently developed for complex, inhomogeneous shield geometry described by combinatorial objects. Comparisons were made between 3DHZETRN results and Monte Carlo (MC) simulations at locations within the combinatorial geometry, and it was shown that 3DHZETRN agrees with the MC codes to the extent they agree with each other. In the present report, the 3DHZETRN code is extended to enable analysis in ray-trace geometry. This latest extension enables the code to be used within current engineering design practices utilizing fully detailed vehicle and habitat geometries. Through convergence testing, it is shown that fidelity in an actual shield geometry can be maintained in the discrete ray-trace description by systematically increasing the number of discrete rays used. It is also shown that this fidelity is carried into transport procedures and resulting exposure quantities without sacrificing computational efficiency.

  15. Experimental and raytrace results for throat-to-throat compound parabolic concentrators

    Science.gov (United States)

    Leviton, D. B.; Leitch, J. W.

    1986-01-01

    Compound parabolic concentrators are nonimaging cone-shaped optics with useful angular transmission characteristics. Two cones used throat-to-throat accept radiant flux within one well-defined acceptance angle and redistribute it into another. If the entrance cone is fed with Lambertian flux, the exit cone produces a beam whose half-angle is the exit cone's acceptance angle and whose cross section shows uniform irradiance from near the exit mouth to infinity. (The pair is a beam angle transformer). The design of one pair of cones is discussed, also an experiment to map the irradiance of the emergent beam, and a raytracing program which models the cones fed by Lambertian flux. Experimental results compare favorably with raytrace results.

  16. Forensic 3D Scene Reconstruction

    International Nuclear Information System (INIS)

    LITTLE, CHARLES Q.; PETERS, RALPH R.; RIGDON, J. BRIAN; SMALL, DANIEL E.

    1999-01-01

    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene

  17. Multiscale optical simulation settings: challenging applications handled with an iterative ray-tracing FDTD interface method.

    Science.gov (United States)

    Leiner, Claude; Nemitz, Wolfgang; Schweitzer, Susanne; Kuna, Ladislav; Wenzl, Franz P; Hartmann, Paul; Satzinger, Valentin; Sommer, Christian

    2016-03-20

    We show that with an appropriate combination of two optical simulation techniques-classical ray-tracing and the finite difference time domain method-an optical device containing multiple diffractive and refractive optical elements can be accurately simulated in an iterative simulation approach. We compare the simulation results with experimental measurements of the device to discuss the applicability and accuracy of our iterative simulation procedure.

  18. 3D Laser Imprint Using a Smoother Ray-Traced Power Deposition Method

    Science.gov (United States)

    Schmitt, Andrew J.

    2017-10-01

    Imprinting of laser nonuniformities in directly-driven icf targets is a challenging problem to accurately simulate with large radiation-hydro codes. One of the most challenging aspects is the proper construction of the complex and rapidly changing laser interference structure driving the imprint using the reduced laser propagation models (usually ray-tracing) found in these codes. We have upgraded the modelling capability in our massively-parallel fastrad3d code by adding a more realistic EM-wave interference structure. This interference model adds an axial laser speckle to the previous transverse-only laser structure, and can be impressed on our improved smoothed 3D raytrace package. This latter package, which connects rays to form bundles and performs power deposition calculations on the bundles, is intended to decrease ray-trace noise (which can mask or add to imprint) while using fewer rays. We apply this improved model to 3D simulations of recent imprint experiments performed on the Omega-EP laser and the Nike laser that examined the reduction of imprinting due to very thin high-Z target coatings. We report on the conditions in which this new model makes a significant impact on the development of laser imprint. Supported by US DoE/NNSA.

  19. Tracker: A three-dimensional raytracing program for ionospheric radio propagation

    Energy Technology Data Exchange (ETDEWEB)

    Argo, P.E.; DeLapp, D.; Sutherland, C.D.; Farrer, R.G.

    1994-12-01

    TRACKER is an extension of a three-dimensional Hamiltonian raytrace code developed some thirty years ago by R. Michael Jones. Subsequent modifications to this code, which is commonly called the {open_quotes}Jones Code,{close_quotes} were documented by Jones and Stephensen (1975). TRACKER incorporates an interactive user`s interface, modern differential equation integrators, graphical outputs, homing algorithms, and the Ionospheric Conductivity and Electron Density (ICED) ionosphere. TRACKER predicts the three-dimensional paths of radio waves through model ionospheres by numerically integrating Hamilton`s equations, which are a differential expression of Fermat`s principle of least time. By using continuous models, the Hamiltonian method avoids false caustics and discontinuous raypath properties often encountered in other raytracing methods. In addition to computing the raypath, TRACKER also calculates the group path (or pulse travel time), the phase path, the geometrical (or {open_quotes}real{close_quotes}) pathlength, and the Doppler shift (if the time variation of the ionosphere is explicitly included). Computational speed can be traded for accuracy by specifying the maximum allowable integration error per step in the integration. Only geometrical optics are included in the main raytrace code; no partial reflections or diffraction effects are taken into account. In addition, TRACKER does not lend itself to statistical descriptions of propagation -- it requires a deterministic model of the ionosphere.

  20. Taming Crowded Visual Scenes

    Science.gov (United States)

    2014-08-12

    Nolan Warner, Mubarak Shah. Tracking in Dense Crowds Using Prominenceand Neighborhood Motion Concurrence, IEEE Transactions on Pattern Analysis...of  computer  vision,   computer   graphics  and  evacuation  dynamics  by  providing  a  common  platform,  and  provides...areas  that  includes  Computer  Vision,  Computer   Graphics ,  and  Pedestrian   Evacuation  Dynamics.  Despite  the

  1. Real-time maritime scene simulation for ladar sensors

    Science.gov (United States)

    Christie, Chad L.; Gouthas, Efthimios; Swierkowski, Leszek; Williams, Owen M.

    2011-06-01

    Continuing interest exists in the development of cost-effective synthetic environments for testing Laser Detection and Ranging (ladar) sensors. In this paper we describe a PC-based system for real-time ladar scene simulation of ships and small boats in a dynamic maritime environment. In particular, we describe the techniques employed to generate range imagery accompanied by passive radiance imagery. Our ladar scene generation system is an evolutionary extension of the VIRSuite infrared scene simulation program and includes all previous features such as ocean wave simulation, the physically-realistic representation of boat and ship dynamics, wake generation and simulation of whitecaps, spray, wake trails and foam. A terrain simulation extension is also under development. In this paper we outline the development, capabilities and limitations of the VIRSuite extensions.

  2. Crime Scenes as Augmented Reality

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    2010-01-01

    Using the concept of augmented reality, this article will investigate how places in various ways have become augmented by means of different mediatization strategies. Augmentation of reality implies an enhancement of the places' emotional character: a certain mood, atmosphere or narrative surplus......, physical damage: they are all readable and interpretable signs. As augmented reality the crime scene carries a narrative which at first is hidden and must be revealed. Due to the process of investigation and the detective's ability to reason and deduce, the crime scene as place is reconstructed as virtual...

  3. Raytracing, chopper, and guideline for double-headed Dragon monochromators (invited)

    International Nuclear Information System (INIS)

    Chen, C.T.

    1992-01-01

    The raytracing of the double-headed Dragon, a recently proposed monochromator for producing two simultaneous left and right circularly polarized soft x-ray beams, is presented. The energy resolution and wavelength of these two beams are confirmed to be identical, and the high performance of the original Dragon is found to be preserved in the double-headed configuration. A compact ultra-high vacuum compatible chopper for rapid alternation between left and right helicities is presented, and a guideline for collecting circularly polarized light from bending magnet sources is given

  4. Developments in the ray-tracing code Zgoubi for 6-D multiturn tracking in FFAG rings

    International Nuclear Information System (INIS)

    Lemuet, F.; Meot, F.

    2005-01-01

    A geometrical method for 3-D modeling of the magnetic field in scaling and non-scaling FFAG magnets has been installed in the ray-tracing code Zgoubi. The method in particular allows a good simulation of transverse non-linearities, of field fall-offs and possible merging fields in configurations of neighboring magnets, while using realistic models of magnetic fields. That yields an efficient tool for FFAG lattice design and optimizations, and for 6-D tracking studies. It is applied for illustration to the simulation of an acceleration cycle in a 150 MeV radial sector proton FFAG

  5. Scene reassembly after multimodal digitization and pipeline evaluation using photorealistic rendering

    DEFF Research Database (Denmark)

    Stets, Jonathan Dyssel; Dal Corso, Alessandro; Nielsen, Jannik Boll

    2017-01-01

    of the lighting environment. This enables pixelwise comparison of photographs of the real scene with renderings of the digital version of the scene. Such quantitative evaluation is useful for verifying acquired material appearance and reconstructed surface geometry, which is an important aspect of digital content......Transparent objects require acquisition modalities that are very different from the ones used for objects with more diffuse reflectance properties. Digitizing a scene where objects must be acquired with different modalities requires scene reassembly after reconstruction of the object surfaces....... This reassembly of a scene that was picked apart for scanning seems unexplored. We contribute with a multimodal digitization pipeline for scenes that require this step of reassembly. Our pipeline includes measurement of bidirectional reflectance distribution functions and high dynamic range imaging...

  6. Mission Driven Scene Understanding: Dynamic Environments

    Science.gov (United States)

    2016-06-01

    WindowsSdkDir%VisualStudioInteg ration \\Tools\\Bin;%PATH% set INCLUDE=%VCINSTALLDIR%Include;%WindowsSdkDir%VisualStudioInte gration\\Common\\Inc;%INCLUDE...Hung HSW. From visual saliency to video behaviour understanding [doctoral dissertation]. [London (UK)]: Queen Mary, University of London; 2007. 10

  7. Global intensity correction in dynamic scenes

    NARCIS (Netherlands)

    Withagen, P.J.; Schutte, K.; Groen, F.C.A.

    2007-01-01

    Changing image intensities causes problems for many computer vision applications operating in unconstrained environments. We propose generally applicable algorithms to correct for global differences in intensity between images recorded with a static or slowly moving camera, regardless of the cause

  8. Vision Based SLAM in Dynamic Scenes

    Science.gov (United States)

    2012-12-20

    the correct relative poses between cameras at frame F. For this purpose, we detect and match SURF features between cameras in dilierent groups, and...all cameras in s uch a challenging case. For a compa rison, we disabled the ’ inte r-camera pose estimation’ and applied the ’ intra-camera pose esti

  9. Beyond scene gist: Objects guide search more than scene background.

    Science.gov (United States)

    Koehler, Kathryn; Eckstein, Miguel P

    2017-06-01

    Although the facilitation of visual search by contextual information is well established, there is little understanding of the independent contributions of different types of contextual cues in scenes. Here we manipulated 3 types of contextual information: object co-occurrence, multiple object configurations, and background category. We isolated the benefits of each contextual cue to target detectability, its impact on decision bias, confidence, and the guidance of eye movements. We find that object-based information guides eye movements and facilitates perceptual judgments more than scene background. The degree of guidance and facilitation of each contextual cue can be related to its inherent informativeness about the target spatial location as measured by human explicit judgments about likely target locations. Our results improve the understanding of the contributions of distinct contextual scene components to search and suggest that the brain's utilization of cues to guide eye movements is linked to the cue's informativeness about the target's location. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  10. GPU-accelerated ray-tracing for real-time treatment planning

    International Nuclear Information System (INIS)

    Heinrich, H; Ziegenhein, P; Kamerling, C P; Oelfke, U; Froening, H

    2014-01-01

    Dose calculation methods in radiotherapy treatment planning require the radiological depth information of the voxels that represent the patient volume to correct for tissue inhomogeneities. This information is acquired by time consuming ray-tracing-based calculations. For treatment planning scenarios with changing geometries and real-time constraints this is a severe bottleneck. We implemented an algorithm for the graphics processing unit (GPU) which implements a ray-matrix approach to reduce the number of rays to trace. Furthermore, we investigated the impact of different strategies of accessing memory in kernel implementations as well as strategies for rapid data transfers between main memory and memory of the graphics device. Our study included the overlapping of computations and memory transfers to reduce the overall runtime using Hyper-Q. We tested our approach on a prostate case (9 beams, coplanar). The measured execution times for a complete ray-tracing range from 28 msec for the computations on the GPU to 99 msec when considering data transfers to and from the graphics device. Our GPU-based algorithm performed the ray-tracing in real-time. The strategies efficiently reduce the time consumption of memory accesses and data transfer overhead. The achieved runtimes demonstrate the viability of this approach and allow improved real-time performance for dose calculation methods in clinical routine.

  11. Development of Extended Ray-tracing method including diffraction, polarization and wave decay effects

    Science.gov (United States)

    Yanagihara, Kota; Kubo, Shin; Dodin, Ilya; Nakamura, Hiroaki; Tsujimura, Toru

    2017-10-01

    Geometrical Optics Ray-tracing is a reasonable numerical analytic approach for describing the Electron Cyclotron resonance Wave (ECW) in slowly varying spatially inhomogeneous plasma. It is well known that the result with this conventional method is adequate in most cases. However, in the case of Helical fusion plasma which has complicated magnetic structure, strong magnetic shear with a large scale length of density can cause a mode coupling of waves outside the last closed flux surface, and complicated absorption structure requires a strong focused wave for ECH. Since conventional Ray Equations to describe ECW do not have any terms to describe the diffraction, polarization and wave decay effects, we can not describe accurately a mode coupling of waves, strong focus waves, behavior of waves in inhomogeneous absorption region and so on. For fundamental solution of these problems, we consider the extension of the Ray-tracing method. Specific process is planned as follows. First, calculate the reference ray by conventional method, and define the local ray-base coordinate system along the reference ray. Then, calculate the evolution of the distributions of amplitude and phase on ray-base coordinate step by step. The progress of our extended method will be presented.

  12. A versatile ray-tracing code for studying rf wave propagation in toroidal magnetized plasmas

    International Nuclear Information System (INIS)

    Peysson, Y; Decker, J; Morini, L

    2012-01-01

    A new ray-tracing code named C3PO has been developed to study the propagation of arbitrary electromagnetic radio-frequency (rf) waves in magnetized toroidal plasmas. Its structure is designed for maximum flexibility regarding the choice of coordinate system and dielectric model. The versatility of this code makes it particularly suitable for integrated modeling systems. Using a coordinate system that reflects the nested structure of magnetic flux surfaces in tokamaks, fast and accurate calculations inside the plasma separatrix can be performed using analytical derivatives of a spline-Fourier interpolation of the axisymmetric toroidal MHD equilibrium. Applications to reverse field pinch magnetic configuration are also included. The effects of 3D perturbations of the axisymmetric toroidal MHD equilibrium, due to the discreteness of the magnetic coil system or plasma fluctuations in an original quasi-optical approach, are also studied. Using a Runge–Kutta–Fehlberg method for solving the set of ordinary differential equations, the ray-tracing code is extensively benchmarked against analytical models and other codes for lower hybrid and electron cyclotron waves. (paper)

  13. Neural Scene Segmentation by Oscillatory Correlation

    National Research Council Canada - National Science Library

    Wang, DeLiang

    2000-01-01

    The segmentation of a visual scene into a set of coherent patterns (objects) is a fundamental aspect of perception, which underlies a variety of important tasks such as figure/ground segregation, and scene analysis...

  14. Pooling Objects for Recognizing Scenes without Examples

    NARCIS (Netherlands)

    Kordumova, S.; Mensink, T.; Snoek, C.G.M.

    2016-01-01

    In this paper we aim to recognize scenes in images without using any scene images as training data. Different from attribute based approaches, we do not carefully select the training classes to match the unseen scene classes. Instead, we propose a pooling over ten thousand of off-the-shelf object

  15. Stages As Models of Scene Geometry

    NARCIS (Netherlands)

    Nedović, V.; Smeulders, A.W.M.; Redert, A.; Geusebroek, J.M.

    2010-01-01

    Reconstruction of 3D scene geometry is an important element for scene understanding, autonomous vehicle and robot navigation, image retrieval, and 3D television. We propose accounting for the inherent structure of the visual world when trying to solve the scene reconstruction problem. Consequently,

  16. Simulator scene display evaluation device

    Science.gov (United States)

    Haines, R. F. (Inventor)

    1986-01-01

    An apparatus for aligning and calibrating scene displays in an aircraft simulator has a base on which all of the instruments for the aligning and calibrating are mounted. Laser directs beam at double right prism which is attached to pivoting support on base. The pivot point of the prism is located at the design eye point (DEP) of simulator during the aligning and calibrating. The objective lens in the base is movable on a track to follow the laser beam at different angles within the field of vision at the DEP. An eyepiece and a precision diopter are movable into a position behind the prism during the scene evaluation. A photometer or illuminometer is pivotable about the pivot into and out of position behind the eyepiece.

  17. Improved content aware scene retargeting for retinitis pigmentosa patients

    Directory of Open Access Journals (Sweden)

    Al-Atabany Walid I

    2010-09-01

    Full Text Available Abstract Background In this paper we present a novel scene retargeting technique to reduce the visual scene while maintaining the size of the key features. The algorithm is scalable to implementation onto portable devices, and thus, has potential for augmented reality systems to provide visual support for those with tunnel vision. We therefore test the efficacy of our algorithm on shrinking the visual scene into the remaining field of view for those patients. Methods Simple spatial compression of visual scenes makes objects appear further away. We have therefore developed an algorithm which removes low importance information, maintaining the size of the significant features. Previous approaches in this field have included seam carving, which removes low importance seams from the scene, and shrinkability which dynamically shrinks the scene according to a generated importance map. The former method causes significant artifacts and the latter is inefficient. In this work we have developed a new algorithm, combining the best aspects of both these two previous methods. In particular, our approach is to generate a shrinkability importance map using as seam based approach. We then use it to dynamically shrink the scene in similar fashion to the shrinkability method. Importantly, we have implemented it so that it can be used in real time without prior knowledge of future frames. Results We have evaluated and compared our algorithm to the seam carving and image shrinkability approaches from a content preservation perspective and a compression quality perspective. Also our technique has been evaluated and tested on a trial included 20 participants with simulated tunnel vision. Results show the robustness of our method at reducing scenes up to 50% with minimal distortion. We also demonstrate efficacy in its use for those with simulated tunnel vision of 22 degrees of field of view or less. Conclusions Our approach allows us to perform content aware video

  18. Ray-tracing traveltime tomography versus wave-equation traveltime inversion for near-surface seismic land data

    KAUST Repository

    Fu, Lei; Hanafy, Sherif M.

    2017-01-01

    . This initial starting model can be obtained by inverting traveltimes with ray-tracing traveltime tomography (RT) or wave-equation traveltime (WT) inversion. We have found that WT can provide a more accurate tomogram than RT by inverting the first

  19. MC ray-tracing optimization of lobster-eye focusing devices with RESTRAX

    International Nuclear Information System (INIS)

    Saroun, Jan; Kulda, Jiri

    2006-01-01

    The enhanced functionalities of the latest version of the RESTRAX software, providing a high-speed Monte Carlo (MC) ray-tracing code to represent a virtual three-axis neutron spectrometer, include representation of parabolic and elliptic guide profiles and facilities for numerical optimization of parameter values, characterizing the instrument components. As examples, we present simulations of a doubly focusing monochromator in combination with cold neutron guides and lobster-eye supermirror devices, concentrating a monochromatic beam to small sample volumes. A Levenberg-Marquardt minimization algorithm is used to optimize simultaneously several parameters of the monochromator and lobster-eye guides. We compare the performance of optimized configurations in terms of monochromatic neutron flux and energy spread and demonstrate the effect of lobster-eye optics on beam transformations in real and momentum subspaces

  20. Introducing GAMER: A Fast and Accurate Method for Ray-tracing Galaxies Using Procedural Noise

    Science.gov (United States)

    Groeneboom, N. E.; Dahle, H.

    2014-03-01

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  1. Introducing GAMER: A fast and accurate method for ray-tracing galaxies using procedural noise

    International Nuclear Information System (INIS)

    Groeneboom, N. E.; Dahle, H.

    2014-01-01

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  2. Introducing GAMER: A fast and accurate method for ray-tracing galaxies using procedural noise

    Energy Technology Data Exchange (ETDEWEB)

    Groeneboom, N. E.; Dahle, H., E-mail: nicolaag@astro.uio.no [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo (Norway)

    2014-03-10

    We developed a novel approach for fast and accurate ray-tracing of galaxies using procedural noise fields. Our method allows for efficient and realistic rendering of synthetic galaxy morphologies, where individual components such as the bulge, disk, stars, and dust can be synthesized in different wavelengths. These components follow empirically motivated overall intensity profiles but contain an additional procedural noise component that gives rise to complex natural patterns that mimic interstellar dust and star-forming regions. These patterns produce more realistic-looking galaxy images than using analytical expressions alone. The method is fully parallelized and creates accurate high- and low- resolution images that can be used, for example, in codes simulating strong and weak gravitational lensing. In addition to having a user-friendly graphical user interface, the C++ software package GAMER is easy to implement into an existing code.

  3. Accounting for partiality in serial crystallography using ray-tracing principles

    International Nuclear Information System (INIS)

    Kroon-Batenburg, Loes M. J.; Schreurs, Antoine M. M.; Ravelli, Raimond B. G.; Gros, Piet

    2015-01-01

    Serial crystallography generates partial reflections from still diffraction images. Partialities are estimated with EVAL ray-tracing simulations, thereby improving merged reflection data to a similar quality as conventional rotation data. Serial crystallography generates ‘still’ diffraction data sets that are composed of single diffraction images obtained from a large number of crystals arbitrarily oriented in the X-ray beam. Estimation of the reflection partialities, which accounts for the expected observed fractions of diffraction intensities, has so far been problematic. In this paper, a method is derived for modelling the partialities by making use of the ray-tracing diffraction-integration method EVAL. The method estimates partialities based on crystal mosaicity, beam divergence, wavelength dispersion, crystal size and the interference function, accounting for crystallite size. It is shown that modelling of each reflection by a distribution of interference-function weighted rays yields a ‘still’ Lorentz factor. Still data are compared with a conventional rotation data set collected from a single lysozyme crystal. Overall, the presented still integration method improves the data quality markedly. The R factor of the still data compared with the rotation data decreases from 26% using a Monte Carlo approach to 12% after applying the Lorentz correction, to 5.3% when estimating partialities by EVAL and finally to 4.7% after post-refinement. The merging R int factor of the still data improves from 105 to 56% but remains high. This suggests that the accuracy of the model parameters could be further improved. However, with a multiplicity of around 40 and an R int of ∼50% the merged still data approximate the quality of the rotation data. The presented integration method suitably accounts for the partiality of the observed intensities in still diffraction data, which is a critical step to improve data quality in serial crystallography

  4. Accounting for partiality in serial crystallography using ray-tracing principles

    Energy Technology Data Exchange (ETDEWEB)

    Kroon-Batenburg, Loes M. J., E-mail: l.m.j.kroon-batenburg@uu.nl; Schreurs, Antoine M. M. [Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands); Ravelli, Raimond B. G. [Maastricht University, PO Box 616, 6200 MD Maastricht (Netherlands); Gros, Piet [Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands)

    2015-08-25

    Serial crystallography generates partial reflections from still diffraction images. Partialities are estimated with EVAL ray-tracing simulations, thereby improving merged reflection data to a similar quality as conventional rotation data. Serial crystallography generates ‘still’ diffraction data sets that are composed of single diffraction images obtained from a large number of crystals arbitrarily oriented in the X-ray beam. Estimation of the reflection partialities, which accounts for the expected observed fractions of diffraction intensities, has so far been problematic. In this paper, a method is derived for modelling the partialities by making use of the ray-tracing diffraction-integration method EVAL. The method estimates partialities based on crystal mosaicity, beam divergence, wavelength dispersion, crystal size and the interference function, accounting for crystallite size. It is shown that modelling of each reflection by a distribution of interference-function weighted rays yields a ‘still’ Lorentz factor. Still data are compared with a conventional rotation data set collected from a single lysozyme crystal. Overall, the presented still integration method improves the data quality markedly. The R factor of the still data compared with the rotation data decreases from 26% using a Monte Carlo approach to 12% after applying the Lorentz correction, to 5.3% when estimating partialities by EVAL and finally to 4.7% after post-refinement. The merging R{sub int} factor of the still data improves from 105 to 56% but remains high. This suggests that the accuracy of the model parameters could be further improved. However, with a multiplicity of around 40 and an R{sub int} of ∼50% the merged still data approximate the quality of the rotation data. The presented integration method suitably accounts for the partiality of the observed intensities in still diffraction data, which is a critical step to improve data quality in serial crystallography.

  5. Scene-Based Contextual Cueing in Pigeons

    Science.gov (United States)

    Wasserman, Edward A.; Teng, Yuejia; Brooks, Daniel I.

    2014-01-01

    Repeated pairings of a particular visual context with a specific location of a target stimulus facilitate target search in humans. We explored an animal model of such contextual cueing. Pigeons had to peck a target which could appear in one of four locations on color photographs of real-world scenes. On half of the trials, each of four scenes was consistently paired with one of four possible target locations; on the other half of the trials, each of four different scenes was randomly paired with the same four possible target locations. In Experiments 1 and 2, pigeons exhibited robust contextual cueing when the context preceded the target by 1 s to 8 s, with reaction times to the target being shorter on predictive-scene trials than on random-scene trials. Pigeons also responded more frequently during the delay on predictive-scene trials than on random-scene trials; indeed, during the delay on predictive-scene trials, pigeons predominately pecked toward the location of the upcoming target, suggesting that attentional guidance contributes to contextual cueing. In Experiment 3, involving left-right and top-bottom scene reversals, pigeons exhibited stronger control by global than by local scene cues. These results attest to the robustness and associative basis of contextual cueing in pigeons. PMID:25546098

  6. Associative Processing Is Inherent in Scene Perception

    Science.gov (United States)

    Aminoff, Elissa M.; Tarr, Michael J.

    2015-01-01

    How are complex visual entities such as scenes represented in the human brain? More concretely, along what visual and semantic dimensions are scenes encoded in memory? One hypothesis is that global spatial properties provide a basis for categorizing the neural response patterns arising from scenes. In contrast, non-spatial properties, such as single objects, also account for variance in neural responses. The list of critical scene dimensions has continued to grow—sometimes in a contradictory manner—coming to encompass properties such as geometric layout, big/small, crowded/sparse, and three-dimensionality. We demonstrate that these dimensions may be better understood within the more general framework of associative properties. That is, across both the perceptual and semantic domains, features of scene representations are related to one another through learned associations. Critically, the components of such associations are consistent with the dimensions that are typically invoked to account for scene understanding and its neural bases. Using fMRI, we show that non-scene stimuli displaying novel associations across identities or locations recruit putatively scene-selective regions of the human brain (the parahippocampal/lingual region, the retrosplenial complex, and the transverse occipital sulcus/occipital place area). Moreover, we find that the voxel-wise neural patterns arising from these associations are significantly correlated with the neural patterns arising from everyday scenes providing critical evidence whether the same encoding principals underlie both types of processing. These neuroimaging results provide evidence for the hypothesis that the neural representation of scenes is better understood within the broader theoretical framework of associative processing. In addition, the results demonstrate a division of labor that arises across scene-selective regions when processing associations and scenes providing better understanding of the functional

  7. Imaging infrared: Scene simulation, modeling, and real image tracking; Proceedings of the Meeting, Orlando, FL, Mar. 30, 31, 1989

    Science.gov (United States)

    Triplett, Milton J.; Wolverton, James R.; Hubert, August J.

    1989-09-01

    Various papers on scene simulation, modeling, and real image tracking using IR imaging are presented. Individual topics addressed include: tactical IR scene generator, dynamic FLIR simulation in flight training research, high-speed dynamic scene simulation in UV to IR spectra, development of an IR sensor calibration facility, IR celestial background scene description, transmission measurement of optical components at cryogenic temperatures, diffraction model for a point-source generator, silhouette-based tracking for tactical IR systems, use of knowledge in electrooptical trackers, detection and classification of target formations in IR image sequences, SMPRAD: simplified three-dimensional cloud radiance model, IR target generator, recent advances in testing of thermal imagers, generic IR system models with dynamic image generation, modeling realistic target acquisition using IR sensors in multiple-observer scenarios, and novel concept of scene generation and comprehensive dynamic sensor test.

  8. Modelling Technology for Building Fire Scene with Virtual Geographic Environment

    Science.gov (United States)

    Song, Y.; Zhao, L.; Wei, M.; Zhang, H.; Liu, W.

    2017-09-01

    Building fire is a risky activity that can lead to disaster and massive destruction. The management and disposal of building fire has always attracted much interest from researchers. Integrated Virtual Geographic Environment (VGE) is a good choice for building fire safety management and emergency decisions, in which a more real and rich fire process can be computed and obtained dynamically, and the results of fire simulations and analyses can be much more accurate as well. To modelling building fire scene with VGE, the application requirements and modelling objective of building fire scene were analysed in this paper. Then, the four core elements of modelling building fire scene (the building space environment, the fire event, the indoor Fire Extinguishing System (FES) and the indoor crowd) were implemented, and the relationship between the elements was discussed also. Finally, with the theory and framework of VGE, the technology of building fire scene system with VGE was designed within the data environment, the model environment, the expression environment, and the collaborative environment as well. The functions and key techniques in each environment are also analysed, which may provide a reference for further development and other research on VGE.

  9. Scene Integration Without Awareness: No Conclusive Evidence for Processing Scene Congruency During Continuous Flash Suppression.

    Science.gov (United States)

    Moors, Pieter; Boelens, David; van Overwalle, Jaana; Wagemans, Johan

    2016-07-01

    A recent study showed that scenes with an object-background relationship that is semantically incongruent break interocular suppression faster than scenes with a semantically congruent relationship. These results implied that semantic relations between the objects and the background of a scene could be extracted in the absence of visual awareness of the stimulus. In the current study, we assessed the replicability of this finding and tried to rule out an alternative explanation dependent on low-level differences between the stimuli. Furthermore, we used a Bayesian analysis to quantify the evidence in favor of the presence or absence of a scene-congruency effect. Across three experiments, we found no convincing evidence for a scene-congruency effect or a modulation of scene congruency by scene inversion. These findings question the generalizability of previous observations and cast doubt on whether genuine semantic processing of object-background relationships in scenes can manifest during interocular suppression. © The Author(s) 2016.

  10. Literacy in the contemporary scene

    Directory of Open Access Journals (Sweden)

    Angela B. Kleiman

    2014-11-01

    Full Text Available In this paper I examine the relationship between literacy and contemporaneity. I take as a point of departure for my discussion school literacy and its links with literacies in other institutions of the contemporary scene, in order to determine the relation between contemporary ends of reading and writing (in other words, the meaning of being literate in contemporary society and the practices and activities effectively realized at school in order to reach those objectives. Using various examples from teaching and learning situations, I discuss digital literacy practices and multimodal texts and multiliteracies from both printed and digital cultures. Throughout, I keep as a background for the discussion the functions and objectives of school literacy and the professional training of teachers who would like to be effective literacy agents in the contemporary world.

  11. When Does Repeated Search in Scenes Involve Memory? Looking at versus Looking for Objects in Scenes

    Science.gov (United States)

    Vo, Melissa L. -H.; Wolfe, Jeremy M.

    2012-01-01

    One might assume that familiarity with a scene or previous encounters with objects embedded in a scene would benefit subsequent search for those items. However, in a series of experiments we show that this is not the case: When participants were asked to subsequently search for multiple objects in the same scene, search performance remained…

  12. A ray-tracing study of electron cyclotron resonance heating in Tokamak plasmas with a superthermal electron tail

    International Nuclear Information System (INIS)

    Montes, A.; Dendy, R.O.

    1987-09-01

    We consider a Tokamak plasma in which the distribution of electron velocities in the direction parallel to the magnetic field has a monotonically decreasing superthermal tail. A fully three-dimensional ray-tracing code, which includes a realistic antenna pattern, toroidal effects, and refaction, is used to calculate the absorption of the extraordinary mode in the nonrelativistic limit away from perpendicular incidence. The ray-tracing approach extends results previously obtained in slab geometry (3-8) to a more realistic configuration; it is also essential in dealing with strong refraction in high-density plasmas. Our analytical model for the tail makes available a wide range of tail shapes and parameters. At low densities small tails (tail fraction [pt

  13. A generalized ray-tracing procedure for an atmospheric Cherenkov imaging telescope and optical characteristics of the TACTIC light collector

    International Nuclear Information System (INIS)

    Tickoo, A.K.; Suthar, R.L.; Koul, R.; Sapru, M.L.; Kumar, N.; Kaul, C.L.; Yadav, K.K.; Thoudam, S.; Kaul, S.K.; Venugopal, K.; Kothari, M.; Goyal, H.C.; Chandra, P.; Dhar, V.K.; Rannot, R.C.; Koul, M.K.; Kaul, S.R.

    2005-01-01

    A generalized ray-tracing procedure has been developed, which facilitates the design of a multimirror-based light collector used in atmospheric Cherenkov telescopes. This procedure has been employed to study the optical characteristics of the 3.5 m diameter light collector of the TACTIC Imaging telescope. Comparison of the measured point-spread function of the light collector with the simulated performance of ideal Davies-Cotton and paraboloid designs has been made to determine an optimum arrangement of the 34 spherical mirror facets used in the telescope to obtain the best possible point-spread function. A description of the ray-tracing subroutine used for processing CORSIKA-generated Cherenkov data, required for carrying out Monte-Carlo simulation studies, is also discussed in the paper

  14. Solar proton exposure of an ICRU sphere within a complex structure part II: Ray-trace geometry.

    Science.gov (United States)

    Slaba, Tony C; Wilson, John W; Badavi, Francis F; Reddell, Brandon D; Bahadori, Amir A

    2016-06-01

    A computationally efficient 3DHZETRN code with enhanced neutron and light ion (Z ≤ 2) propagation was recently developed for complex, inhomogeneous shield geometry described by combinatorial objects. Comparisons were made between 3DHZETRN results and Monte Carlo (MC) simulations at locations within the combinatorial geometry, and it was shown that 3DHZETRN agrees with the MC codes to the extent they agree with each other. In the present report, the 3DHZETRN code is extended to enable analysis in ray-trace geometry. This latest extension enables the code to be used within current engineering design practices utilizing fully detailed vehicle and habitat geometries. Through convergence testing, it is shown that fidelity in an actual shield geometry can be maintained in the discrete ray-trace description by systematically increasing the number of discrete rays used. It is also shown that this fidelity is carried into transport procedures and resulting exposure quantities without sacrificing computational efficiency. Published by Elsevier Ltd.

  15. Stages as models of scene geometry.

    Science.gov (United States)

    Nedović, Vladimir; Smeulders, Arnold W M; Redert, André; Geusebroek, Jan-Mark

    2010-09-01

    Reconstruction of 3D scene geometry is an important element for scene understanding, autonomous vehicle and robot navigation, image retrieval, and 3D television. We propose accounting for the inherent structure of the visual world when trying to solve the scene reconstruction problem. Consequently, we identify geometric scene categorization as the first step toward robust and efficient depth estimation from single images. We introduce 15 typical 3D scene geometries called stages, each with a unique depth profile, which roughly correspond to a large majority of broadcast video frames. Stage information serves as a first approximation of global depth, narrowing down the search space in depth estimation and object localization. We propose different sets of low-level features for depth estimation, and perform stage classification on two diverse data sets of television broadcasts. Classification results demonstrate that stages can often be efficiently learned from low-dimensional image representations.

  16. (U) Second-Order Sensitivity Analysis of Uncollided Particle Contributions to Radiation Detector Responses Using Ray-Tracing

    Energy Technology Data Exchange (ETDEWEB)

    Favorite, Jeffrey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-30

    The Second-Level Adjoint Sensitivity System (2nd-LASS) that yields the second-order sensitivities of a response of uncollided particles with respect to isotope densities, cross sections, and source emission rates is derived in Refs. 1 and 2. In Ref. 2, we solved problems for the uncollided leakage from a homogeneous sphere and a multiregion cylinder using the PARTISN multigroup discrete-ordinates code. In this memo, we derive solutions of the 2nd-LASS for the particular case when the response is a flux or partial current density computed at a single point on the boundary, and the inner products are computed using ray-tracing. Both the PARTISN approach and the ray-tracing approach are implemented in a computer code, SENSPG. The next section of this report presents the equations of the 1st- and 2nd-LASS for uncollided particles and the first- and second-order sensitivities that use the solutions of the 1st- and 2nd-LASS. Section III presents solutions of the 1st- and 2nd-LASS equations for the case of ray-tracing from a detector point. Section IV presents specific solutions of the 2nd-LASS and derives the ray-trace form of the inner products needed for second-order sensitivities. Numerical results for the total leakage from a homogeneous sphere are presented in Sec. V and for the leakage from one side of a two-region slab in Sec. VI. Section VII is a summary and conclusions.

  17. Ray-tracing analysis of electron-cyclotron-resonance heating in straight stellarators

    International Nuclear Information System (INIS)

    Kato, K.

    1983-05-01

    A ray-tracing computer code is developed and implemented to simulate electron cyclotron resonance heating (ECRH) in stellarators. A straight stellarator model is developed to simulate the confinement geometry. Following a review of ECRH, a cold plasma model is used to define the dispersion relation. To calculate the wave power deposition, a finite temperature damping approximation is used. 3-D ray equations in cylindrical coordinates are derived and put into suitable forms for computation. The three computer codes, MAC, HERA, and GROUT, developed for this research, are described next. ECRH simulation is then carried out for three models including Heliotron E and Wendelstein VII A. Investigated aspects include launching position and mode scan, frequency detuning, helical effects, start-up, and toroidal effects. Results indicate: (1) an elliptical waveguide radiation pattern, with its long axis oriented half-way between the toroidal axis and the saddle point line, is more efficient than a circular one; and (2) mid-plane, high field side launch is favored for both O- and X-waves

  18. A model of polarized-beam AGS in the ray-tracing code Zgoubi

    Energy Technology Data Exchange (ETDEWEB)

    Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ahrens, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brown, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dutheil, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States); Glenn, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Huang, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Shoefer, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-07-12

    A model of the Alternating Gradient Synchrotron, based on the AGS snapramps, has been developed in the stepwise ray-tracing code Zgoubi. It has been used over the past 5 years in a number of accelerator studies aimed at enhancing RHIC proton beam polarization. It is also used to study and optimize proton and Helion beam polarization in view of future RHIC and eRHIC programs. The AGS model in Zgoubi is operational on-line via three different applications, ’ZgoubiFromSnaprampCmd’, ’AgsZgoubiModel’ and ’AgsModelViewer’, with the latter two essentially interfaces to the former which is the actual model ’engine’. All three commands are available from the controls system application launcher in the AGS ’StartUp’ menu, or from eponymous commands on shell terminals. Main aspects of the model and of its operation are presented in this technical note, brief excerpts from various studies performed so far are given for illustration, means and methods entering in ZgoubiFromSnaprampCmd are developed further in appendix.

  19. Comparison between ray-tracing and physical optics for the computation of light absorption in capillaries--the influence of diffraction and interference.

    Science.gov (United States)

    Qin, Yuan; Michalowski, Andreas; Weber, Rudolf; Yang, Sen; Graf, Thomas; Ni, Xiaowu

    2012-11-19

    Ray-tracing is the commonly used technique to calculate the absorption of light in laser deep-penetration welding or drilling. Since new lasers with high brilliance enable small capillaries with high aspect ratios, diffraction might become important. To examine the applicability of the ray-tracing method, we studied the total absorptance and the absorbed intensity of polarized beams in several capillary geometries. The ray-tracing results are compared with more sophisticated simulations based on physical optics. The comparison shows that the simple ray-tracing is applicable to calculate the total absorptance in triangular grooves and in conical capillaries but not in rectangular grooves. To calculate the distribution of the absorbed intensity ray-tracing fails due to the neglected interference, diffraction, and the effects of beam propagation in the capillaries with sub-wavelength diameter. If diffraction is avoided e.g. with beams smaller than the entrance pupil of the capillary or with very shallow capillaries, the distribution of the absorbed intensity calculated by ray-tracing corresponds to the local average of the interference pattern found by physical optics.

  20. Scenes of the self, and trance

    Directory of Open Access Journals (Sweden)

    Jan M. Broekman

    2014-02-01

    Full Text Available Trance shows the Self as a process involved in all sorts and forms of life. A Western perspective on a self and its reifying tendencies is only one (or one series of those variations. The process character of the self does not allow any coherent theory but shows, in particular when confronted with trance, its variability in all regards. What is more: the Self is always first on the scene of itself―a situation in which it becomes a sign for itself. That particular semiotic feature is again not a unified one but leads, as the Self in view of itself does, to series of scenes with changing colors, circumstances and environments. Our first scene “Beyond Monotheism” shows semiotic importance in that a self as determining component of a trance-phenomenon must abolish its own referent and seems not able to answer the question, what makes trance a trance. The Pizzica is an example here. Other social features of trance appear in the second scene, US post traumatic psychological treatments included. Our third scene underlines structures of an unfolding self: beginning with ‘split-ego’ conclusions, a self’s engenderment appears dependent on linguistic events and on spoken words in the first place. A fourth scene explores that theme and explains modern forms of an ego ―in particular those inherent to ‘citizenship’ or a ‘corporation’. The legal consequences are concentrated in the fifth scene, which considers a legal subject by revealing its ‘standing’. Our sixth and final scene pertains to the relation between trance and commerce. All scenes tie together and show parallels between Pizzica, rights-based behavior, RAVE music versus disco, commerce and trance; they demonstrate the meaning of trance as a multifaceted social phenomenon.

  1. Scene analysis in the natural environment

    DEFF Research Database (Denmark)

    Lewicki, Michael S; Olshausen, Bruno A; Surlykke, Annemarie

    2014-01-01

    The problem of scene analysis has been studied in a number of different fields over the past decades. These studies have led to important insights into problems of scene analysis, but not all of these insights are widely appreciated, and there remain critical shortcomings in current approaches th...... ill-posed problems, (2) the ability to integrate and store information across time and modality, (3) efficient recovery and representation of 3D scene structure, and (4) the use of optimal motor actions for acquiring information to progress toward behavioral goals....

  2. Accounting for partiality in serial crystallography using ray-tracing principles.

    Science.gov (United States)

    Kroon-Batenburg, Loes M J; Schreurs, Antoine M M; Ravelli, Raimond B G; Gros, Piet

    2015-09-01

    Serial crystallography generates `still' diffraction data sets that are composed of single diffraction images obtained from a large number of crystals arbitrarily oriented in the X-ray beam. Estimation of the reflection partialities, which accounts for the expected observed fractions of diffraction intensities, has so far been problematic. In this paper, a method is derived for modelling the partialities by making use of the ray-tracing diffraction-integration method EVAL. The method estimates partialities based on crystal mosaicity, beam divergence, wavelength dispersion, crystal size and the interference function, accounting for crystallite size. It is shown that modelling of each reflection by a distribution of interference-function weighted rays yields a `still' Lorentz factor. Still data are compared with a conventional rotation data set collected from a single lysozyme crystal. Overall, the presented still integration method improves the data quality markedly. The R factor of the still data compared with the rotation data decreases from 26% using a Monte Carlo approach to 12% after applying the Lorentz correction, to 5.3% when estimating partialities by EVAL and finally to 4.7% after post-refinement. The merging R(int) factor of the still data improves from 105 to 56% but remains high. This suggests that the accuracy of the model parameters could be further improved. However, with a multiplicity of around 40 and an R(int) of ∼50% the merged still data approximate the quality of the rotation data. The presented integration method suitably accounts for the partiality of the observed intensities in still diffraction data, which is a critical step to improve data quality in serial crystallography.

  3. Global Transsaccadic Change Blindness During Scene Perception

    National Research Council Canada - National Science Library

    Henderson, John

    2003-01-01

    .... The results from two experiments demonstrated a global transsaccadic change-blindness effect, suggesting that point-by-point visual representations are not functional across saccades during complex scene perception. Ahstract.

  4. Robotic Discovery of the Auditory Scene

    National Research Council Canada - National Science Library

    Martinson, E; Schultz, A

    2007-01-01

    .... Motivated by the large negative effect of ambient noise sources on robot audition, the long-term goal is to provide awareness of the auditory scene to a robot, so that it may more effectively act...

  5. Scene Integration for Online VR Advertising Clouds

    Directory of Open Access Journals (Sweden)

    Michael Kalochristianakis

    2014-12-01

    Full Text Available This paper presents a scene composition approach that allows the combinational use of standard three dimensional objects, called models, in order to create X3D scenes. The module is an integral part of a broader design aiming to construct large scale online advertising infrastructures that rely on virtual reality technologies. The architecture addresses a number of problems regarding remote rendering for low end devices and last but not least, the provision of scene composition and integration. Since viewers do not keep information regarding individual input models or scenes, composition requires the consideration of mechanisms that add state to viewing technologies. In terms of this work we extended a well-known, open source X3D authoring tool.

  6. Statistics of high-level scene context.

    Science.gov (United States)

    Greene, Michelle R

    2013-01-01

    CONTEXT IS CRITICAL FOR RECOGNIZING ENVIRONMENTS AND FOR SEARCHING FOR OBJECTS WITHIN THEM: contextual associations have been shown to modulate reaction time and object recognition accuracy, as well as influence the distribution of eye movements and patterns of brain activations. However, we have not yet systematically quantified the relationships between objects and their scene environments. Here I seek to fill this gap by providing descriptive statistics of object-scene relationships. A total of 48, 167 objects were hand-labeled in 3499 scenes using the LabelMe tool (Russell et al., 2008). From these data, I computed a variety of descriptive statistics at three different levels of analysis: the ensemble statistics that describe the density and spatial distribution of unnamed "things" in the scene; the bag of words level where scenes are described by the list of objects contained within them; and the structural level where the spatial distribution and relationships between the objects are measured. The utility of each level of description for scene categorization was assessed through the use of linear classifiers, and the plausibility of each level for modeling human scene categorization is discussed. Of the three levels, ensemble statistics were found to be the most informative (per feature), and also best explained human patterns of categorization errors. Although a bag of words classifier had similar performance to human observers, it had a markedly different pattern of errors. However, certain objects are more useful than others, and ceiling classification performance could be achieved using only the 64 most informative objects. As object location tends not to vary as a function of category, structural information provided little additional information. Additionally, these data provide valuable information on natural scene redundancy that can be exploited for machine vision, and can help the visual cognition community to design experiments guided by statistics

  7. The Hip-Hop club scene: Gender, grinding and sex.

    Science.gov (United States)

    Muñoz-Laboy, Miguel; Weinstein, Hannah; Parker, Richard

    2007-01-01

    Hip-Hop culture is a key social medium through which many young men and women from communities of colour in the USA construct their gender. In this study, we focused on the Hip-Hop club scene in New York City with the intention of unpacking narratives of gender dynamics from the perspective of young men and women, and how these relate to their sexual experiences. We conducted a three-year ethnographic study that included ethnographic observations of Hip-Hop clubs and their social scene, and in-depth interviews with young men and young women aged 15-21. This paper describes how young people negotiate gender relations on the dance floor of Hip-Hop clubs. The Hip-Hop club scene represents a context or setting where young men's masculinities are contested by the social environment, where women challenge hypermasculine privilege and where young people can set the stage for what happens next in their sexual and emotional interactions. Hip-Hop culture therefore provides a window into the gender and sexual scripts of many urban minority youth. A fuller understanding of these patterns can offer key insights into the social construction of sexual risk, as well as the possibilities for sexual health promotion, among young people in urban minority populations.

  8. Temporal properties of natural scenes

    NARCIS (Netherlands)

    Hateren, J.H. van; Schaaf, A. van der; Rogowitz, BE; Allebach, JP

    1996-01-01

    A major problem a visual system faces is how to fit the large intensity variation of natural image streams into the limited dynamic range of its neurons. One of the means to accomplish this is through the use of fast light adaptation of the photoreceptors. In order to investigate this, we measured

  9. A new hybrid algorithm using thermodynamic and backward ray-tracing approaches for modeling luminescent solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Ch. K.; Lim, Y. S.; Tan, S. G.; Rahman, F. A. [Faculty of Engineering and Science, University Tunku Abdul Rahman, Jalan Genting Klang, 53300, Kuala Lumpur (Malaysia)

    2010-12-15

    A Luminescent Solar Concentrator (LSC) is a transparent plate containing luminescent material with photovoltaic (PV) cells attached to its edges. Sunlight entering the plate is absorbed by the luminescent material, which in turn emits light. The emitted light propagates through the plate and arrives at the PV cells through total internal reflection. The ratio of the area of the relatively cheap polymer plate to that of the expensive PV cells is increased, and the cost per unit of solar electricity can be reduced by 75%. To improve the emission performance of LSCs, simulation modeling of LSCs becomes essential. Ray-tracing modeling is a popular approach for simulating LSCs due to its great ability of modeling various LSC structures under direct and diffuse sunlight. However, this approach requires substantial amount of measurement input data. Also, the simulation time is enormous because it is a forward-ray tracing method that traces all the rays propagating from the light source to the concentrator. On the other hand, the thermodynamic approach requires substantially less input parameters and simulation time, but it can only be used to model simple LSC designs with direct sunlight. Therefore, a new hybrid model was developed to perform various simulation studies effectively without facing the issues arisen from the existing ray-tracing and thermodynamic models. The simulation results show that at least 60% of the total output irradiance of a LSC is contributed by the light trapped and channeled by the LSC. The novelty of this hybrid model is the concept of integrating the thermodynamic model with a well-developed Radiance ray-tracing model, hence making this model as a fast, powerful and cost-effective tool for the design of LSCs. (authors)

  10. Combination of ray-tracing and the method of moments for electromagnetic radiation analysis using reduced meshes

    Science.gov (United States)

    Delgado, Carlos; Cátedra, Manuel Felipe

    2018-05-01

    This work presents a technique that allows a very noticeable relaxation of the computational requirements for full-wave electromagnetic simulations based on the Method of Moments. A ray-tracing analysis of the geometry is performed in order to extract the critical points with significant contributions. These points are then used to generate a reduced mesh, considering the regions of the geometry that surround each critical point and taking into account the electrical path followed from the source. The electromagnetic analysis of the reduced mesh produces very accurate results, requiring a fraction of the resources that the conventional analysis would utilize.

  11. HDR IMAGING FOR FEATURE DETECTION ON DETAILED ARCHITECTURAL SCENES

    Directory of Open Access Journals (Sweden)

    G. Kontogianni

    2015-02-01

    Full Text Available 3D reconstruction relies on accurate detection, extraction, description and matching of image features. This is even truer for complex architectural scenes that pose needs for 3D models of high quality, without any loss of detail in geometry or color. Illumination conditions influence the radiometric quality of images, as standard sensors cannot depict properly a wide range of intensities in the same scene. Indeed, overexposed or underexposed pixels cause irreplaceable information loss and degrade digital representation. Images taken under extreme lighting environments may be thus prohibitive for feature detection/extraction and consequently for matching and 3D reconstruction. High Dynamic Range (HDR images could be helpful for these operators because they broaden the limits of illumination range that Standard or Low Dynamic Range (SDR/LDR images can capture and increase in this way the amount of details contained in the image. Experimental results of this study prove this assumption as they examine state of the art feature detectors applied both on standard dynamic range and HDR images.

  12. Video Inpainting of Complex Scenes

    OpenAIRE

    Newson, Alasdair; Almansa, Andrés; Fradet, Matthieu; Gousseau, Yann; Pérez, Patrick

    2015-01-01

    We propose an automatic video inpainting algorithm which relies on the optimisation of a global, patch-based functional. Our algorithm is able to deal with a variety of challenging situations which naturally arise in video inpainting, such as the correct reconstruction of dynamic textures, multiple moving objects and moving background. Furthermore, we achieve this in an order of magnitude less execution time with respect to the state-of-the-art. We are also able to achieve good quality result...

  13. Maxwellian Eye Fixation during Natural Scene Perception

    Directory of Open Access Journals (Sweden)

    Jean Duchesne

    2012-01-01

    Full Text Available When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell’s law for each participant and for each scene condition (normal or scrambled. The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes.

  14. Maxwellian Eye Fixation during Natural Scene Perception

    Science.gov (United States)

    Duchesne, Jean; Bouvier, Vincent; Guillemé, Julien; Coubard, Olivier A.

    2012-01-01

    When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF) of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell's law for each participant and for each scene condition (normal or scrambled). The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes. PMID:23226987

  15. Correlated Topic Vector for Scene Classification.

    Science.gov (United States)

    Wei, Pengxu; Qin, Fei; Wan, Fang; Zhu, Yi; Jiao, Jianbin; Ye, Qixiang

    2017-07-01

    Scene images usually involve semantic correlations, particularly when considering large-scale image data sets. This paper proposes a novel generative image representation, correlated topic vector, to model such semantic correlations. Oriented from the correlated topic model, correlated topic vector intends to naturally utilize the correlations among topics, which are seldom considered in the conventional feature encoding, e.g., Fisher vector, but do exist in scene images. It is expected that the involvement of correlations can increase the discriminative capability of the learned generative model and consequently improve the recognition accuracy. Incorporated with the Fisher kernel method, correlated topic vector inherits the advantages of Fisher vector. The contributions to the topics of visual words have been further employed by incorporating the Fisher kernel framework to indicate the differences among scenes. Combined with the deep convolutional neural network (CNN) features and Gibbs sampling solution, correlated topic vector shows great potential when processing large-scale and complex scene image data sets. Experiments on two scene image data sets demonstrate that correlated topic vector improves significantly the deep CNN features, and outperforms existing Fisher kernel-based features.

  16. Modeling global scene factors in attention

    Science.gov (United States)

    Torralba, Antonio

    2003-07-01

    Models of visual attention have focused predominantly on bottom-up approaches that ignored structured contextual and scene information. I propose a model of contextual cueing for attention guidance based on the global scene configuration. It is shown that the statistics of low-level features across the whole image can be used to prime the presence or absence of objects in the scene and to predict their location, scale, and appearance before exploring the image. In this scheme, visual context information can become available early in the visual processing chain, which allows modulation of the saliency of image regions and provides an efficient shortcut for object detection and recognition. 2003 Optical Society of America

  17. Rapid simulation of X-ray transmission imaging for baggage inspection via GPU-based ray-tracing

    Science.gov (United States)

    Gong, Qian; Stoian, Razvan-Ionut; Coccarelli, David S.; Greenberg, Joel A.; Vera, Esteban; Gehm, Michael E.

    2018-01-01

    We present a pipeline that rapidly simulates X-ray transmission imaging for arbitrary system architectures using GPU-based ray-tracing techniques. The purpose of the pipeline is to enable statistical analysis of threat detection in the context of airline baggage inspection. As a faster alternative to Monte Carlo methods, we adopt a deterministic approach for simulating photoelectric absorption-based imaging. The highly-optimized NVIDIA OptiX API is used to implement ray-tracing, greatly speeding code execution. In addition, we implement the first hierarchical representation structure to determine the interaction path length of rays traversing heterogeneous media described by layered polygons. The accuracy of the pipeline has been validated by comparing simulated data with experimental data collected using a heterogenous phantom and a laboratory X-ray imaging system. On a single computer, our approach allows us to generate over 400 2D transmission projections (125 × 125 pixels per frame) per hour for a bag packed with hundreds of everyday objects. By implementing our approach on cloud-based GPU computing platforms, we find that the same 2D projections of approximately 3.9 million bags can be obtained in a single day using 400 GPU instances, at a cost of only 0.001 per bag.

  18. Real-time scene and signature generation for ladar and imaging sensors

    Science.gov (United States)

    Swierkowski, Leszek; Christie, Chad L.; Antanovskii, Leonid; Gouthas, Efthimios

    2014-05-01

    This paper describes development of two key functionalities within the VIRSuite scene simulation program, broadening its scene generation capabilities and increasing accuracy of thermal signatures. Firstly, a new LADAR scene generation module has been designed. It is capable of simulating range imagery for Geiger mode LADAR, in addition to the already existing functionality for linear mode systems. Furthermore, a new 3D heat diffusion solver has been developed within the VIRSuite signature prediction module. It is capable of calculating the temperature distribution in complex three-dimensional objects for enhanced dynamic prediction of thermal signatures. With these enhancements, VIRSuite is now a robust tool for conducting dynamic simulation for missiles with multi-mode seekers.

  19. Hyperspectral target detection analysis of a cluttered scene from a virtual airborne sensor platform using MuSES

    Science.gov (United States)

    Packard, Corey D.; Viola, Timothy S.; Klein, Mark D.

    2017-10-01

    The ability to predict spectral electro-optical (EO) signatures for various targets against realistic, cluttered backgrounds is paramount for rigorous signature evaluation. Knowledge of background and target signatures, including plumes, is essential for a variety of scientific and defense-related applications including contrast analysis, camouflage development, automatic target recognition (ATR) algorithm development and scene material classification. The capability to simulate any desired mission scenario with forecast or historical weather is a tremendous asset for defense agencies, serving as a complement to (or substitute for) target and background signature measurement campaigns. In this paper, a systematic process for the physical temperature and visible-through-infrared radiance prediction of several diverse targets in a cluttered natural environment scene is presented. The ability of a virtual airborne sensor platform to detect and differentiate targets from a cluttered background, from a variety of sensor perspectives and across numerous wavelengths in differing atmospheric conditions, is considered. The process described utilizes the thermal and radiance simulation software MuSES and provides a repeatable, accurate approach for analyzing wavelength-dependent background and target (including plume) signatures in multiple band-integrated wavebands (multispectral) or hyperspectrally. The engineering workflow required to combine 3D geometric descriptions, thermal material properties, natural weather boundary conditions, all modes of heat transfer and spectral surface properties is summarized. This procedure includes geometric scene creation, material and optical property attribution, and transient physical temperature prediction. Radiance renderings, based on ray-tracing and the Sandford-Robertson BRDF model, are coupled with MODTRAN for the inclusion of atmospheric effects. This virtual hyperspectral/multispectral radiance prediction methodology has been

  20. Behind the scenes at the LHC inauguration

    CERN Document Server

    2008-01-01

    On 21 October the LHC inauguration ceremony will take place and people from all over CERN have been busy preparing. With delegations from 38 countries attending, including ministers and heads of state, the Bulletin has gone behind the scenes to see what it takes to put together an event of this scale.

  1. OpenSceneGraph 3 Cookbook

    CERN Document Server

    Wang, Rui

    2012-01-01

    This is a cookbook full of recipes with practical examples enriched with code and the required screenshots for easy and quick comprehension. You should be familiar with the basic concepts of the OpenSceneGraph API and should be able to write simple programs. Some OpenGL and math knowledge will help a lot, too.

  2. The primal scene and symbol formation.

    Science.gov (United States)

    Niedecken, Dietmut

    2016-06-01

    This article discusses the meaning of the primal scene for symbol formation by exploring its way of processing in a child's play. The author questions the notion that a sadomasochistic way of processing is the only possible one. A model of an alternative mode of processing is being presented. It is suggested that both ways of processing intertwine in the "fabric of life" (D. Laub). Two clinical vignettes, one from an analytic child psychotherapy and the other from the analysis of a 30 year-old female patient, illustrate how the primal scene is being played out in the form of a terzet. The author explores whether the sadomasochistic way of processing actually precedes the "primal scene as a terzet". She discusses if it could even be regarded as a precondition for the formation of the latter or, alternatively, if the "combined parent-figure" gives rise to ways of processing. The question is being left open. Finally, it is shown how both modes of experiencing the primal scene underlie the discoursive and presentative symbol formation, respectively. Copyright © 2015 Institute of Psychoanalysis.

  3. Wall grid structure for interior scene synthesis

    KAUST Repository

    Xu, Wenzhuo; Wang, Bin; Yan, Dongming

    2015-01-01

    We present a system for automatically synthesizing a diverse set of semantically valid, and well-arranged 3D interior scenes for a given empty room shape. Unlike existing work on layout synthesis, that typically knows potentially needed 3D models

  4. From Theatre Improvisation To Video Scenes

    DEFF Research Database (Denmark)

    Larsen, Henry; Hvidt, Niels Christian; Friis, Preben

    2018-01-01

    At Sygehus Lillebaelt, a Danish hospital, there has been a focus for several years on patient communi- cation. This paper reflects on a course focusing on engaging with the patient’s existential themes in particular the negotiations around the creation of video scenes. In the initial workshops, w...

  5. Technical Note : A direct ray-tracing method to compute integral depth dose in pencil beam proton radiography with a multilayer ionization chamber

    NARCIS (Netherlands)

    Farace, Paolo; Righetto, Roberto; Deffet, Sylvain; Meijers, Arturs; Vander Stappen, Francois

    2016-01-01

    Purpose: To introduce a fast ray-tracing algorithm in pencil proton radiography (PR) with a multilayer ionization chamber (MLIC) for in vivo range error mapping. Methods: Pencil beam PR was obtained by delivering spots uniformly positioned in a square (45x45 mm(2) field-of-view) of 9x9 spots capable

  6. A general ray-tracing algorithm for the solution of the neutron transport equation by the collision probability method

    International Nuclear Information System (INIS)

    Ball, G.

    1990-01-01

    The development and analysis of methods for generating first-flight collision probabilities in two-dimensional geometries consistent with Light Water Moderated (LWR) fuel assemblies are examined. A new ray-tracing algorithm is discussed. A number of numerical results are given demonstrating the feasibility of this algorithm and the effects of the moderator (and fuel) sectorizations on the resulting flux distributions. The collision probabilties have been introduced and their subsequent utilization in the flux calculation procedures illustrated. A brief description of the Coxy-1 and Coxy-2 programs (which were developed in the Reactor Theory Division of the Atomic Energy Agency of South Africa Ltd) has also been added. 41 figs., 9 tabs., 18 refs

  7. HARPA: A versatile three-dimensional Hamiltonian ray-tracing program for acoustic waves in the atmosphere above irregular terrain

    Science.gov (United States)

    Jones, R. M.; Riley, J. P.; Georges, T. M.

    1986-08-01

    The modular FORTRAN 77 computer program traces the three-dimensional paths of acoustic rays through continuous model atmospheres by numerically integrating Hamilton's equations (a differential expression of Fermat's principle). The user specifies an atmospheric model by writing closed-form formulas for its three-dimensional wind and temperature (or sound speed) distribution, and by defining the height of the reflecting terrain vs. geographic latitude and longitude. Some general-purpose models are provided, or users can readily design their own. In addition to computing the geometry of each raypath, HARPA can calculate pulse travel time, phase time, Doppler shift (if the medium varies in time), absorption, and geometrical path length. The program prints a step-by-step account of a ray's progress. The 410-page documentation describes the ray-tracing equations and the structure of the program, and provides complete instructions, illustrated by a sample case.

  8. Towards modeling of random lasing in dye doped bio-organic based systems: ray-tracing and cellular automaton analysis

    Science.gov (United States)

    Mitus, A. C.; Stopa, P.; Zaklukiewicz, W.; Pawlik, G.; Mysliwiec, J.; Kajzar, F.; Rau, I.

    2015-08-01

    One of many photonic applications of biopolymers as functional materials is random lasing resulting from an incorporation of highly luminescent dyes into biopolymeric matrix, which leads to a random but coherent light scattering in amplifying medium. In spite of numerous theoretical and experimental studies the origin of the coherence is still not clear and various scenarios are discussed. In particular, inhomogeneity of biopolymeric layers can hypothetically promote the feedback in the scattering of the emitted light resulting in coherent and incoherent random lasing. In this paper we analyze the light scattering in a model system of scattering centers of circular shapes and various dimensions using ray-tracing techniques. In the second part, which has mostly a tutorial character, we present the approach to the study of random lasing using a cellular automaton model of Wiersma et al.

  9. Emotional and neutral scenes in competition: orienting, efficiency, and identification.

    Science.gov (United States)

    Calvo, Manuel G; Nummenmaa, Lauri; Hyönä, Jukka

    2007-12-01

    To investigate preferential processing of emotional scenes competing for limited attentional resources with neutral scenes, prime pictures were presented briefly (450 ms), peripherally (5.2 degrees away from fixation), and simultaneously (one emotional and one neutral scene) versus singly. Primes were followed by a mask and a probe for recognition. Hit rate was higher for emotional than for neutral scenes in the dual- but not in the single-prime condition, and A' sensitivity decreased for neutral but not for emotional scenes in the dual-prime condition. This preferential processing involved both selective orienting and efficient encoding, as revealed, respectively, by a higher probability of first fixation on--and shorter saccade latencies to--emotional scenes and by shorter fixation time needed to accurately identify emotional scenes, in comparison with neutral scenes.

  10. The time course of natural scene perception with reduced attention

    NARCIS (Netherlands)

    Groen, I.I.A.; Ghebreab, S.; Lamme, V.A.F.; Scholte, H.S.

    Attention is thought to impose an informational bottleneck on vision by selecting particular information from visual scenes for enhanced processing. Behavioral evidence suggests, however, that some scene information is extracted even when attention is directed elsewhere. Here, we investigated the

  11. Technical Note: A direct ray-tracing method to compute integral depth dose in pencil beam proton radiography with a multilayer ionization chamber.

    Science.gov (United States)

    Farace, Paolo; Righetto, Roberto; Deffet, Sylvain; Meijers, Arturs; Vander Stappen, Francois

    2016-12-01

    To introduce a fast ray-tracing algorithm in pencil proton radiography (PR) with a multilayer ionization chamber (MLIC) for in vivo range error mapping. Pencil beam PR was obtained by delivering spots uniformly positioned in a square (45 × 45 mm 2 field-of-view) of 9 × 9 spots capable of crossing the phantoms (210 MeV). The exit beam was collected by a MLIC to sample the integral depth dose (IDD MLIC ). PRs of an electron-density and of a head phantom were acquired by moving the couch to obtain multiple 45 × 45 mm 2 frames. To map the corresponding range errors, the two-dimensional set of IDD MLIC was compared with (i) the integral depth dose computed by the treatment planning system (TPS) by both analytic (IDD TPS ) and Monte Carlo (IDD MC ) algorithms in a volume of water simulating the MLIC at the CT, and (ii) the integral depth dose directly computed by a simple ray-tracing algorithm (IDD direct ) through the same CT data. The exact spatial position of the spot pattern was numerically adjusted testing different in-plane positions and selecting the one that minimized the range differences between IDD direct and IDD MLIC . Range error mapping was feasible by both the TPS and the ray-tracing methods, but very sensitive to even small misalignments. In homogeneous regions, the range errors computed by the direct ray-tracing algorithm matched the results obtained by both the analytic and the Monte Carlo algorithms. In both phantoms, lateral heterogeneities were better modeled by the ray-tracing and the Monte Carlo algorithms than by the analytic TPS computation. Accordingly, when the pencil beam crossed lateral heterogeneities, the range errors mapped by the direct algorithm matched better the Monte Carlo maps than those obtained by the analytic algorithm. Finally, the simplicity of the ray-tracing algorithm allowed to implement a prototype procedure for automated spatial alignment. The ray-tracing algorithm can reliably replace the TPS method in MLIC PR for in

  12. Development and testing of a new ray-tracing approach to GNSS carrier-phase multipath modelling

    Science.gov (United States)

    Lau, Lawrence; Cross, Paul

    2007-11-01

    Multipath is one of the most important error sources in Global Navigation Satellite System (GNSS) carrier-phase-based precise relative positioning. Its theoretical maximum is a quarter of the carrier wavelength (about 4.8 cm for the Global Positioning System (GPS) L1 carrier) and, although it rarely reaches this size, it must clearly be mitigated if millimetre-accuracy positioning is to be achieved. In most static applications, this may be accomplished by averaging over a sufficiently long period of observation, but in kinematic applications, a modelling approach must be used. This paper is concerned with one such approach: the use of ray-tracing to reconstruct the error and therefore remove it. In order to apply such an approach, it is necessary to have a detailed understanding of the signal transmitted from the satellite, the reflection process, the antenna characteristics and the way that the reflected and direct signal are processed within the receiver. This paper reviews all of these and introduces a formal ray-tracing method for multipath estimation based on precise knowledge of the satellite reflector antenna geometry and of the reflector material and antenna characteristics. It is validated experimentally using GPS signals reflected from metal, water and a brick building, and is shown to be able to model most of the main multipath characteristics. The method will have important practical applications for correcting for multipath in well-constrained environments (such as at base stations for local area GPS networks, at International GNSS Service (IGS) reference stations, and on spacecraft), and it can be used to simulate realistic multipath errors for various performance analyses in high-precision positioning.

  13. Collaborating Filtering Community Image Recommendation System Based on Scene

    Directory of Open Access Journals (Sweden)

    He Tao

    2017-01-01

    Full Text Available With the advancement of smart city, the development of intelligent mobile terminal and wireless network, the traditional text information service no longer meet the needs of the community residents, community image service appeared as a new media service. “There are pictures of the truth” has become a community residents to understand and master the new dynamic community, image information service has become a new information service. However, there are two major problems in image information service. Firstly, the underlying eigenvalues extracted by current image feature extraction techniques are difficult for users to understand, and there is a semantic gap between the image content itself and the user’s understanding; secondly, in community life of the image data increasing quickly, it is difficult to find their own interested image data. Aiming at the two problems, this paper proposes a unified image semantic scene model to express the image content. On this basis, a collaborative filtering recommendation model of fusion scene semantics is proposed. In the recommendation model, a comprehensiveness and accuracy user interest model is proposed to improve the recommendation quality. The results of the present study have achieved good results in the pilot cities of Wenzhou and Yan'an, and it is applied normally.

  14. The role of forensic botany in crime scene investigation: case report and review of literature.

    Science.gov (United States)

    Aquila, Isabella; Ausania, Francesco; Di Nunzio, Ciro; Serra, Arianna; Boca, Silvia; Capelli, Arnaldo; Magni, Paola; Ricci, Pietrantonio

    2014-05-01

    Management of a crime is the process of ensuring accurate and effective collection and preservation of physical evidence. Forensic botany can provide significant supporting evidences during criminal investigations. The aim of this study is to demonstrate the importance of forensic botany in the crime scene. We reported a case of a woman affected by dementia who had disappeared from nursing care and was found dead near the banks of a river that flowed under a railroad. Two possible ways of access to crime scene were identified and denominated "Path A" and "Path B." Both types of soil and plants were identified. Botanical survey was performed. Some samples of Xanthium Orientalis subsp. Italicum were identified. The fall of woman resulted in external injuries and vertebral fracture at autopsy. The botanical evidence is important when crime scene and autopsy findings are not sufficient to define the dynamics and the modality of death. © 2014 American Academy of Forensic Sciences.

  15. Integration of an open interface PC scene generator using COTS DVI converter hardware

    Science.gov (United States)

    Nordland, Todd; Lyles, Patrick; Schultz, Bret

    2006-05-01

    Commercial-Off-The-Shelf (COTS) personal computer (PC) hardware is increasingly capable of computing high dynamic range (HDR) scenes for military sensor testing at high frame rates. New electro-optical and infrared (EO/IR) scene projectors feature electrical interfaces that can accept the DVI output of these PC systems. However, military Hardware-in-the-loop (HWIL) facilities such as those at the US Army Aviation and Missile Research Development and Engineering Center (AMRDEC) utilize a sizeable inventory of existing projection systems that were designed to use the Silicon Graphics Incorporated (SGI) digital video port (DVP, also known as DVP2 or DD02) interface. To mate the new DVI-based scene generation systems to these legacy projection systems, CG2 Inc., a Quantum3D Company (CG2), has developed a DVI-to-DVP converter called Delta DVP. This device takes progressive scan DVI input, converts it to digital parallel data, and combines and routes color components to derive a 16-bit wide luminance channel replicated on a DVP output interface. The HWIL Functional Area of AMRDEC has developed a suite of modular software to perform deterministic real-time, wave band-specific rendering of sensor scenes, leveraging the features of commodity graphics hardware and open source software. Together, these technologies enable sensor simulation and test facilities to integrate scene generation and projection components with diverse pedigrees.

  16. Video Scene Parsing with Predictive Feature Learning

    OpenAIRE

    Jin, Xiaojie; Li, Xin; Xiao, Huaxin; Shen, Xiaohui; Lin, Zhe; Yang, Jimei; Chen, Yunpeng; Dong, Jian; Liu, Luoqi; Jie, Zequn; Feng, Jiashi; Yan, Shuicheng

    2016-01-01

    In this work, we address the challenging video scene parsing problem by developing effective representation learning methods given limited parsing annotations. In particular, we contribute two novel methods that constitute a unified parsing framework. (1) \\textbf{Predictive feature learning}} from nearly unlimited unlabeled video data. Different from existing methods learning features from single frame parsing, we learn spatiotemporal discriminative features by enforcing a parsing network to ...

  17. Interactive Procedural Modelling of Coherent Waterfall Scenes

    OpenAIRE

    Emilien , Arnaud; Poulin , Pierre; Cani , Marie-Paule; Vimont , Ulysse

    2015-01-01

    International audience; Combining procedural generation and user control is a fundamental challenge for the interactive design of natural scenery. This is particularly true for modelling complex waterfall scenes where, in addition to taking charge of geometric details, an ideal tool should also provide a user with the freedom to shape the running streams and falls, while automatically maintaining physical plausibility in terms of flow network, embedding into the terrain, and visual aspects of...

  18. Where and when Do Objects Become Scenes?

    Directory of Open Access Journals (Sweden)

    Jiye G. Kim

    2011-05-01

    Full Text Available Scenes can be understood with extraordinary speed and facility, not merely as an inventory of individual objects but in the coding of the relations among them. These relations, which can be readily described by prepositions or gerunds (e.g., a hand holding a pen, allows the explicit representation of complex structures. Where in the brain are inter-object relations specified? In a series of fMRI experiments, we show that pairs of objects shown as interacting elicit greater activity in LOC than when the objects are depicted side-by-side (e.g., a hand beside a pen. Other visual areas, PPA, IPS, and DLPFC, did not show this sensitivity to scene relations, rendering it unlikely that the relations were computed in these regions. Using EEG and TMS, we further show that LOC's sensitivity to object interactions arises around 170ms post stimulus onset and that disruption of normal LOC activity—but not IPS activity—is detrimental to the behavioral sensitivity of inter-object relations. Insofar as LOC is the earliest cortical region where shape is distinguished from texture, our results provide strong evidence that scene-like relations are achieved simultaneously with the perception of object shape and not inferred at some stage following object identification.

  19. A Virtual Environments Editor for Driving Scenes

    Directory of Open Access Journals (Sweden)

    Ronald R. Mourant

    2003-12-01

    Full Text Available The goal of this project was to enable the rapid creation of three-dimensional virtual driving environments. We designed and implemented a high-level scene editor that allows a user to construct a driving environment by pasting icons that represent 1 road segments, 2 road signs, 3 trees and 4 buildings. These icons represent two- and three-dimensional objects that have been predesigned. Icons can be placed in the scene at specific locations (x, y, and z coordinates. The editor includes the capability of a user to "drive" a vehicle using a computer mouse for steering, accelerating and braking. At any time during the process of building a virtual environment, a user may switch to "Run Mode" and inspect the three-dimensional scene by "driving" through it using the mouse. Adjustments and additions can be made to the virtual environment by going back to "Build Mode". Once a user is satisfied with the threedimensional virtual environment, it can be saved in a file. The file can used with Java3D software that enables the traversing of three-dimensional environments. The process of building virtual environments from predesigned icons can be applied to many other application areas. It will enable novice computer users to rapidly construct and use three-dimensional virtual environments.

  20. Gay and Lesbian Scene in Metelkova

    Directory of Open Access Journals (Sweden)

    Nataša Velikonja

    2013-09-01

    Full Text Available The article deals with the development of the gay and lesbian scene in ACC Metelkova, while specifying the preliminary aspects of establishing and building gay and lesbian activism associated with spatial issues. The struggle for space or occupying public space is vital for the gay and lesbian scene, as it provides not only the necessary socializing opportunities for gays and lesbians, but also does away with the historical hiding of homosexuality in the closet, in seclusion and silence. Because of their autonomy and long-term, continuous existence, homo-clubs at Metelkova contributed to the consolidation of the gay and lesbian scene in Slovenia and significantly improved the opportunities for cultural, social and political expression of gays and lesbians. Such a synthesis of the cultural, social and political, further intensified in Metelkova, and characterizes the gay and lesbian community in Slovenia from the very outset of gay and lesbian activism in 1984. It is this long-term synthesis that keeps this community in Slovenia so vital and politically resilient.

  1. The time course of natural scene perception with reduced attention.

    Science.gov (United States)

    Groen, Iris I A; Ghebreab, Sennay; Lamme, Victor A F; Scholte, H Steven

    2016-02-01

    Attention is thought to impose an informational bottleneck on vision by selecting particular information from visual scenes for enhanced processing. Behavioral evidence suggests, however, that some scene information is extracted even when attention is directed elsewhere. Here, we investigated the neural correlates of this ability by examining how attention affects electrophysiological markers of scene perception. In two electro-encephalography (EEG) experiments, human subjects categorized real-world scenes as manmade or natural (full attention condition) or performed tasks on unrelated stimuli in the center or periphery of the scenes (reduced attention conditions). Scene processing was examined in two ways: traditional trial averaging was used to assess the presence of a categorical manmade/natural distinction in event-related potentials, whereas single-trial analyses assessed whether EEG activity was modulated by scene statistics that are diagnostic of naturalness of individual scenes. The results indicated that evoked activity up to 250 ms was unaffected by reduced attention, showing intact categorical differences between manmade and natural scenes and strong modulations of single-trial activity by scene statistics in all conditions. Thus initial processing of both categorical and individual scene information remained intact with reduced attention. Importantly, however, attention did have profound effects on later evoked activity; full attention on the scene resulted in prolonged manmade/natural differences, increased neural sensitivity to scene statistics, and enhanced scene memory. These results show that initial processing of real-world scene information is intact with diminished attention but that the depth of processing of this information does depend on attention. Copyright © 2016 the American Physiological Society.

  2. Characterization, propagation, and simulation of infrared scenes; Proceedings of the Meeting, Orlando, FL, Apr. 16-20, 1990

    Science.gov (United States)

    Watkins, Wendell R.; Zegel, Ferdinand H.; Triplett, Milton J.

    1990-09-01

    Various papers on the characterization, propagation, and simulation of IR scenes are presented. Individual topics addressed include: total radiant exitance measurements, absolute measurement of diffuse and specular reflectance using an FTIR spectrometer with an integrating sphere, fundamental limits in temperature estimation, incorporating the BRDF into an IR scene-generation system, characterizing IR dynamic response for foliage backgrounds, modeling sea surface effects in FLIR performance codes, automated imaging IR seeker performance evaluation system, generation of signature data bases with fast codes, background measurements using the NPS-IRST system. Also discussed are: naval ocean IR background analysis, camouflage simulation and effectiveness assessment for the individual soldier, discussion of IR scene generators, multiwavelength Scophony IR scene projector, LBIR target generator and calibrator for preflight seeker tests, dual-mode hardware-in-the-loop simulation facility, development of the IR blackbody source of gravity-type heat pipe and study of its characteristic.

  3. Forensic botany as a useful tool in the crime scene: Report of a case.

    Science.gov (United States)

    Margiotta, Gabriele; Bacaro, Giovanni; Carnevali, Eugenia; Severini, Simona; Bacci, Mauro; Gabbrielli, Mario

    2015-08-01

    The ubiquitous presence of plant species makes forensic botany useful for many criminal cases. Particularly, bryophytes are useful for forensic investigations because many of them are clonal and largely distributed. Bryophyte shoots can easily become attached to shoes and clothes and it is possible to be found on footwear, providing links between crime scene and individuals. We report a case of suicide of a young girl happened in Siena, Tuscany, Italia. The cause of traumatic injuries could be ascribed to suicide, to homicide, or to accident. In absence of eyewitnesses who could testify the dynamics of the event, the crime scene investigation was fundamental to clarify the accident. During the scene analysis, some fragments of Tortula muralis Hedw. and Bryum capillare Hedw were found. The fragments were analyzed by a bryologists in order to compare them with the moss present on the stairs that the victim used immediately before the death. The analysis of these bryophytes found at the crime scene allowed to reconstruct the accident. Even if this evidence, of course, is circumstantial, it can be useful in forensic cases, together with the other evidences, to reconstruct the dynamics of events. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  4. Primal scene derivatives in the work of Yukio Mishima: the primal scene fantasy.

    Science.gov (United States)

    Turco, Ronald N

    2002-01-01

    This article discusses the preoccupation with fire, revenge, crucifixion, and other fantasies as they relate to the primal scene. The manifestations of these fantasies are demonstrated in a work of fiction by Yukio Mishima. The Temple of the Golden Pavillion. As is the case in other writings of Mishima there is a fusion of aggressive and libidinal drives and a preoccupation with death. The primal scene is directly connected with pyromania and destructive "acting out" of fantasies. This article is timely with regard to understanding contemporary events of cultural and national destruction.

  5. Popular music scenes and aging bodies.

    Science.gov (United States)

    Bennett, Andy

    2018-06-01

    During the last two decades there has been increasing interest in the phenomenon of the aging popular music audience (Bennett & Hodkinson, 2012). Although the specter of the aging fan is by no means new, the notion of, for example, the aging rocker or the aging punk has attracted significant sociological attention, not least of all because of what this says about the shifting socio-cultural significance of rock and punk and similar genres - which at the time of their emergence were inextricably tied to youth and vociferously marketed as "youth musics". As such, initial interpretations of aging music fans tended to paint a somewhat negative picture, suggesting a sense in which such fans were cultural misfits (Ross, 1994). In more recent times, however, work informed by cultural aging perspectives has begun to consider how so-called "youth cultural" identities may in fact provide the basis of more stable and evolving identities over the life course (Bennett, 2013). Starting from this position, the purpose of this article is to critically examine how aging members of popular music scenes might be recast as a salient example of the more pluralistic fashion in which aging is anticipated, managed and articulated in contemporary social settings. The article then branches out to consider two ways that aging members of music scenes continue their scene involvement. The first focuses on evolving a series of discourses that legitimately position them as aging bodies in cultural spaces that also continue to be inhabited by significant numbers of people in their teens, twenties and thirties. The second sees aging fans taking advantage of new opportunities for consuming live music including winery concerts and dinner and show events. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Terrain Simplification Research in Augmented Scene Modeling

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    environment. As one of the most important tasks in augmented scene modeling, terrain simplification research has gained more and more attention. In this paper, we mainly focus on point selection problem in terrain simplification using triangulated irregular network. Based on the analysis and comparison of traditional importance measures for each input point, we put forward a new importance measure based on local entropy. The results demonstrate that the local entropy criterion has a better performance than any traditional methods. In addition, it can effectively conquer the "short-sight" problem associated with the traditional methods.

  7. The anatomy of the crime scene

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    2010-01-01

    in the way that the certain actions and events which have taken place have left a variety of marks and traces which may be read and interpreted. Traces of blood, nails, hair constitutes (DNA)codes which can be decrypted and deciphered, in the same way as traces of gun powder, bullet holes, physical damage...... and interpretation. During her investigation the detective's ability to make logical reasoning and deductive thinking as well as to make use of her imagination is crucial to how the crime scene is first deconstructed and then reconstructed as a setting for the story (that is the actions of crime). By decoding...

  8. Image policy, subjectivation and argument scenes

    Directory of Open Access Journals (Sweden)

    Ângela Cristina Salgueiro Marques

    2014-12-01

    Full Text Available This paper is aimed at discussing, with focus on Jacques Rancière, how an image policy can be noticed in the creative production of scenes of dissent from which the political agent emerge, appears and constitute himself in a process of subjectivation. The political and critical power of the image is linked to survival acts: operations and attempts that enable to resist to captures, silences and excesses comitted by the media discourses, by the social institutions and by the State.

  9. IR characteristic simulation of city scenes based on radiosity model

    Science.gov (United States)

    Xiong, Xixian; Zhou, Fugen; Bai, Xiangzhi; Yu, Xiyu

    2013-09-01

    Reliable modeling for thermal infrared (IR) signatures of real-world city scenes is required for signature management of civil and military platforms. Traditional modeling methods generally assume that scene objects are individual entities during the physical processes occurring in infrared range. However, in reality, the physical scene involves convective and conductive interactions between objects as well as the radiations interactions between objects. A method based on radiosity model describes these complex effects. It has been developed to enable an accurate simulation for the radiance distribution of the city scenes. Firstly, the physical processes affecting the IR characteristic of city scenes were described. Secondly, heat balance equations were formed on the basis of combining the atmospheric conditions, shadow maps and the geometry of scene. Finally, finite difference method was used to calculate the kinetic temperature of object surface. A radiosity model was introduced to describe the scattering effect of radiation between surface elements in the scene. By the synthesis of objects radiance distribution in infrared range, we could obtain the IR characteristic of scene. Real infrared images and model predictions were shown and compared. The results demonstrate that this method can realistically simulate the IR characteristic of city scenes. It effectively displays the infrared shadow effects and the radiation interactions between objects in city scenes.

  10. Semantic guidance of eye movements in real-world scenes.

    Science.gov (United States)

    Hwang, Alex D; Wang, Hsueh-Cheng; Pomplun, Marc

    2011-05-25

    The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movements by semantic similarity among objects during real-world scene inspection and search. By selecting scenes from the LabelMe object-annotated image database and applying latent semantic analysis (LSA) to the object labels, we generated semantic saliency maps of real-world scenes based on the semantic similarity of scene objects to the currently fixated object or the search target. An ROC analysis of these maps as predictors of subjects' gaze transitions between objects during scene inspection revealed a preference for transitions to objects that were semantically similar to the currently inspected one. Furthermore, during the course of a scene search, subjects' eye movements were progressively guided toward objects that were semantically similar to the search target. These findings demonstrate substantial semantic guidance of eye movements in real-world scenes and show its importance for understanding real-world attentional control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Lateralized discrimination of emotional scenes in peripheral vision.

    Science.gov (United States)

    Calvo, Manuel G; Rodríguez-Chinea, Sandra; Fernández-Martín, Andrés

    2015-03-01

    This study investigates whether there is lateralized processing of emotional scenes in the visual periphery, in the absence of eye fixations; and whether this varies with emotional valence (pleasant vs. unpleasant), specific emotional scene content (babies, erotica, human attack, mutilation, etc.), and sex of the viewer. Pairs of emotional (positive or negative) and neutral photographs were presented for 150 ms peripherally (≥6.5° away from fixation). Observers judged on which side the emotional picture was located. Low-level image properties, scene visual saliency, and eye movements were controlled. Results showed that (a) correct identification of the emotional scene exceeded the chance level; (b) performance was more accurate and faster when the emotional scene appeared in the left than in the right visual field; (c) lateralization was equivalent for females and males for pleasant scenes, but was greater for females and unpleasant scenes; and (d) lateralization occurred similarly for different emotional scene categories. These findings reveal discrimination between emotional and neutral scenes, and right brain hemisphere dominance for emotional processing, which is modulated by sex of the viewer and scene valence, and suggest that coarse affective significance can be extracted in peripheral vision.

  12. Discrete curved ray-tracing method for radiative transfer in an absorbing-emitting semitransparent slab with variable spatial refractive index

    International Nuclear Information System (INIS)

    Liu, L.H.

    2004-01-01

    A discrete curved ray-tracing method is developed to analyze the radiative transfer in one-dimensional absorbing-emitting semitransparent slab with variable spatial refractive index. The curved ray trajectory is locally treated as straight line and the complicated and time-consuming computation of ray trajectory is cut down. A problem of radiative equilibrium with linear variable spatial refractive index is taken as an example to examine the accuracy of the proposed method. The temperature distributions are determined by the proposed method and compared with the data in references, which are obtained by other different methods. The results show that the discrete curved ray-tracing method has a good accuracy in solving the radiative transfer in one-dimensional semitransparent slab with variable spatial refractive index

  13. Ray-tracing techniques to assess the electromagnetic field radiated by radio base stations: Application and experimental validation in an urban environment

    International Nuclear Information System (INIS)

    Adda, S.; Anglesio, L.; D'Amore, G.; Mantovan, M.; Menegolli, M.

    2004-01-01

    This paper aims to validate a ray-tracing model for electromagnetic field calculation, which is used in urban environments to predict irradiation from radio base stations for population exposure evaluation. Validation was carried out through a measurement campaign by choosing measurement points in order to test different propagation environments and analysing broadcast control channels through narrow band measurements. Comparison of the calculated and measured fields indicates that the ray-tracing model used calculates electric field with good accuracy, in spite of the fact that the propagation environment is not described in detail, because of difficulties in modelling the geometrical and electrical characteristics of urban areas. Differences between the calculated and measured results remain below 1.5 dB, with a mean value of 1 dB. (authors)

  14. Integration and segregation in auditory scene analysis

    Science.gov (United States)

    Sussman, Elyse S.

    2005-03-01

    Assessment of the neural correlates of auditory scene analysis, using an index of sound change detection that does not require the listener to attend to the sounds [a component of event-related brain potentials called the mismatch negativity (MMN)], has previously demonstrated that segregation processes can occur without attention focused on the sounds and that within-stream contextual factors influence how sound elements are integrated and represented in auditory memory. The current study investigated the relationship between the segregation and integration processes when they were called upon to function together. The pattern of MMN results showed that the integration of sound elements within a sound stream occurred after the segregation of sounds into independent streams and, further, that the individual streams were subject to contextual effects. These results are consistent with a view of auditory processing that suggests that the auditory scene is rapidly organized into distinct streams and the integration of sequential elements to perceptual units takes place on the already formed streams. This would allow for the flexibility required to identify changing within-stream sound patterns, needed to appreciate music or comprehend speech..

  15. Efficient 3D scene modeling and mosaicing

    CERN Document Server

    Nicosevici, Tudor

    2013-01-01

    This book proposes a complete pipeline for monocular (single camera) based 3D mapping of terrestrial and underwater environments. The aim is to provide a solution to large-scale scene modeling that is both accurate and efficient. To this end, we have developed a novel Structure from Motion algorithm that increases mapping accuracy by registering camera views directly with the maps. The camera registration uses a dual approach that adapts to the type of environment being mapped.   In order to further increase the accuracy of the resulting maps, a new method is presented, allowing detection of images corresponding to the same scene region (crossovers). Crossovers then used in conjunction with global alignment methods in order to highly reduce estimation errors, especially when mapping large areas. Our method is based on Visual Bag of Words paradigm (BoW), offering a more efficient and simpler solution by eliminating the training stage, generally required by state of the art BoW algorithms.   Also, towards dev...

  16. Tachistoscopic illumination and masking of real scenes.

    Science.gov (United States)

    Chichka, David; Philbeck, John W; Gajewski, Daniel A

    2015-03-01

    Tachistoscopic presentation of scenes has been valuable for studying the emerging properties of visual scene representations. The spatial aspects of this work have generally been focused on the conceptual locations (e.g., next to the refrigerator) and directional locations of objects in 2-D arrays and/or images. Less is known about how the perceived egocentric distance of objects develops. Here we describe a novel system for presenting brief glimpses of a real-world environment, followed by a mask. The system includes projectors with mechanical shutters for projecting the fixation and masking images, a set of LED floodlights for illuminating the environment, and computer-controlled electronics to set the timing and initiate the process. Because a real environment is used, most visual distance and depth cues can be manipulated using traditional methods. The system is inexpensive, robust, and its components are readily available in the marketplace. This article describes the system and the timing characteristics of each component. We verified the system's ability to control exposure to time scales as low as a few milliseconds.

  17. Spectrophotometric study of Saturn's main rings by means of Monte Carlo ray-tracing and Hapke's theory

    Science.gov (United States)

    Ciarniello, Mauro; Filacchione, Gianrico; D'Aversa, Emiliano; Cuzzi, Jeffrey N.; Capaccioni, Fabrizio; Hedman, Matthew M.; Dalle Ore, Cristina M.; Nicholson, Philip D.; Clark, Roger Nelson; Brown, Robert H.; Cerroni, Priscilla; Spilker, Linda

    2017-10-01

    This work is devoted to the investigation of the spectrophotometric properties of Saturn's rings from Cassini-VIMS (Visible and Infrared Mapping Spectrometer) observations. The dataset used for this analysis is represented by ten radial spectrograms of the rings which have been derived in Filacchione et al. (2014) by radial mosaics produced by VIMS. Spectrograms report the measured radiance factor of the main Saturn's rings as a function of both radial distance (from 73.500 to 141.375 km) and wavelength (0.35-5.1 µm) for different observation geometries (phase angle ranging in the 1.9°-132.2° interval). We take advantage of a Monte Carlo ray-tracing routine to characterize the photometric behavior of the rings at each wavelength and derive the spectral Bond albedo of rings particles. This quantity is used to infer the composition of the regolith covering rings particles by applying Hapke's theory. Four different regions, characterized by different optical depths, and respectively located in the C ring, inner B ring, mid B ring and A ring, have been investigated. Results from spectral modeling indicate that rings spectrum can be described by water ice with minimal inclusion of organic materials (tholin, exogenous material, which is more effective in the less dense regions of the rings because of their lower content of pure water ice.

  18. Ray-tracing traveltime tomography versus wave-equation traveltime inversion for near-surface seismic land data

    KAUST Repository

    Fu, Lei

    2017-05-11

    Full-waveform inversion of land seismic data tends to get stuck in a local minimum associated with the waveform misfit function. This problem can be partly mitigated by using an initial velocity model that is close to the true velocity model. This initial starting model can be obtained by inverting traveltimes with ray-tracing traveltime tomography (RT) or wave-equation traveltime (WT) inversion. We have found that WT can provide a more accurate tomogram than RT by inverting the first-arrival traveltimes, and empirical tests suggest that RT is more sensitive to the additive noise in the input data than WT. We present two examples of applying WT and RT to land seismic data acquired in western Saudi Arabia. One of the seismic experiments investigated the water-table depth, and the other one attempted to detect the location of a buried fault. The seismic land data were inverted by WT and RT to generate the P-velocity tomograms, from which we can clearly identify the water table depth along the seismic survey line in the first example and the fault location in the second example.

  19. Modeling UV Radiation Feedback from Massive Stars. I. Implementation of Adaptive Ray-tracing Method and Tests

    Science.gov (United States)

    Kim, Jeong-Gyu; Kim, Woong-Tae; Ostriker, Eve C.; Skinner, M. Aaron

    2017-12-01

    We present an implementation of an adaptive ray-tracing (ART) module in the Athena hydrodynamics code that accurately and efficiently handles the radiative transfer involving multiple point sources on a three-dimensional Cartesian grid. We adopt a recently proposed parallel algorithm that uses nonblocking, asynchronous MPI communications to accelerate transport of rays across the computational domain. We validate our implementation through several standard test problems, including the propagation of radiation in vacuum and the expansions of various types of H II regions. Additionally, scaling tests show that the cost of a full ray trace per source remains comparable to that of the hydrodynamics update on up to ∼ {10}3 processors. To demonstrate application of our ART implementation, we perform a simulation of star cluster formation in a marginally bound, turbulent cloud, finding that its star formation efficiency is 12% when both radiation pressure forces and photoionization by UV radiation are treated. We directly compare the radiation forces computed from the ART scheme with those from the M 1 closure relation. Although the ART and M 1 schemes yield similar results on large scales, the latter is unable to resolve the radiation field accurately near individual point sources.

  20. Implementation of diffraction in a ray-tracing model for the prediction of noise in open-plan offices.

    Science.gov (United States)

    Chevret, P; Chatillon, J

    2012-11-01

    Sound prediction in open-plan offices is a real challenge because of the complexity of the layout of such offices, and therefore because of the multitude of acoustic phenomena involved. One such phenomenon, of primary importance, and not the least challenging of them, is the diffraction by screens and low dividers that usually partition the workspace. This paper describes implementing the equations of the Uniform Theory of Diffraction [McNamara et al. (1990). Introduction to the Uniform Theory of Diffraction (Artech House, Boston)] in an existing ray-tracing model initially dedicated to sound prediction in industrial premises. For the purposes of validation, a series of measurements was conducted in a semi-anechoic chamber in the same manner as Wang and Bradley [(2002). Appl. Acoust. 63, 849-866] but including real desktops instead of single screens. A first phase was dedicated to controlling the quality of the installation by making comparisons with McNamara's solution for a single screen on a rigid floor. Then, the validation itself was conducted with measurements on real desktops, first without a ceiling, and then with a rigid ceiling suspended above the double desk. The results of the comparisons between calculations and measurements in this configuration have demonstrated that the model is an effective tool for predicting sound levels in an open-plan office.

  1. Ray-tracing 3D dust radiative transfer with DART-Ray: code upgrade and public release

    Science.gov (United States)

    Natale, Giovanni; Popescu, Cristina C.; Tuffs, Richard J.; Clarke, Adam J.; Debattista, Victor P.; Fischera, Jörg; Pasetto, Stefano; Rushton, Mark; Thirlwall, Jordan J.

    2017-11-01

    We present an extensively updated version of the purely ray-tracing 3D dust radiation transfer code DART-Ray. The new version includes five major upgrades: 1) a series of optimizations for the ray-angular density and the scattered radiation source function; 2) the implementation of several data and task parallelizations using hybrid MPI+OpenMP schemes; 3) the inclusion of dust self-heating; 4) the ability to produce surface brightness maps for observers within the models in HEALPix format; 5) the possibility to set the expected numerical accuracy already at the start of the calculation. We tested the updated code with benchmark models where the dust self-heating is not negligible. Furthermore, we performed a study of the extent of the source influence volumes, using galaxy models, which are critical in determining the efficiency of the DART-Ray algorithm. The new code is publicly available, documented for both users and developers, and accompanied by several programmes to create input grids for different model geometries and to import the results of N-body and SPH simulations. These programmes can be easily adapted to different input geometries, and for different dust models or stellar emission libraries.

  2. Interpretation of shallow seismic refraction data using raytracing inversion: A simple example from a groundwater resource study in Pocatello, Idaho

    International Nuclear Information System (INIS)

    Pelton, J.R.; Dougherty, M.E.; Welhan, J.A.

    1994-01-01

    Raytracing inversion of seismic refraction data acquired on the northeast side of the Portneuf River valley at the base of Red HIll in Pocatello shows that the thickness of Quaternary and Tertiary sediments above much older quartzite bedrock is 46-53 m. This estimate, which was derived independently of any borehole data, is consistent with the lithologic log of a recently drilled monitoring well (PMW-3) drilled about 1 km northwest of the seismic line. The water table is horizontal at a depth of 22-29 m beneath a gently rising topography (20m/km to the southeast) in the vicinity of the seismic line. The top surface of the quartzite bedrock is either horizontal or dips slightly (1.2 degrees) to the southeast. Unsaturated sediments are characterized by a strong vertical velocity gradient (13-16 s -1 ) probably caused by compaction of the near-surface materials. Seismic P-velocities are estimated as follows: unsaturated sediments (320-780 m/s), saturated sediments (1,670 m/s), and quartzite bedrock (2,950-3,050 m/s). 52 refs

  3. The scene and the unseen: manipulating photographs for experiments on change blindness and scene memory: image manipulation for change blindness.

    Science.gov (United States)

    Ball, Felix; Elzemann, Anne; Busch, Niko A

    2014-09-01

    The change blindness paradigm, in which participants often fail to notice substantial changes in a scene, is a popular tool for studying scene perception, visual memory, and the link between awareness and attention. Some of the most striking and popular examples of change blindness have been demonstrated with digital photographs of natural scenes; in most studies, however, much simpler displays, such as abstract stimuli or "free-floating" objects, are typically used. Although simple displays have undeniable advantages, natural scenes remain a very useful and attractive stimulus for change blindness research. To assist researchers interested in using natural-scene stimuli in change blindness experiments, we provide here a step-by-step tutorial on how to produce changes in natural-scene images with a freely available image-processing tool (GIMP). We explain how changes in a scene can be made by deleting objects or relocating them within the scene or by changing the color of an object, in just a few simple steps. We also explain how the physical properties of such changes can be analyzed using GIMP and MATLAB (a high-level scientific programming tool). Finally, we present an experiment confirming that scenes manipulated according to our guidelines are effective in inducing change blindness and demonstrating the relationship between change blindness and the physical properties of the change and inter-individual differences in performance measures. We expect that this tutorial will be useful for researchers interested in studying the mechanisms of change blindness, attention, or visual memory using natural scenes.

  4. A hierarchical inferential method for indoor scene classification

    Directory of Open Access Journals (Sweden)

    Jiang Jingzhe

    2017-12-01

    Full Text Available Indoor scene classification forms a basis for scene interaction for service robots. The task is challenging because the layout and decoration of a scene vary considerably. Previous studies on knowledge-based methods commonly ignore the importance of visual attributes when constructing the knowledge base. These shortcomings restrict the performance of classification. The structure of a semantic hierarchy was proposed to describe similarities of different parts of scenes in a fine-grained way. Besides the commonly used semantic features, visual attributes were also introduced to construct the knowledge base. Inspired by the processes of human cognition and the characteristics of indoor scenes, we proposed an inferential framework based on the Markov logic network. The framework is evaluated on a popular indoor scene dataset, and the experimental results demonstrate its effectiveness.

  5. Recognizing the Stranger: Recognition Scenes in the Gospel of John

    DEFF Research Database (Denmark)

    Larsen, Kasper Bro

    Recognizing the Stranger is the first monographic study of recognition scenes and motifs in the Gospel of John. The recognition type-scene (anagnōrisis) was a common feature in ancient drama and narrative, highly valued by Aristotle as a touching moment of truth, e.g., in Oedipus’ tragic self...... structures of the type-scene in order to show how Jesus’ true identity can be recognized behind the half-mask of his human appearance....

  6. Global scene layout modulates contextual learning in change detection.

    Science.gov (United States)

    Conci, Markus; Müller, Hermann J

    2014-01-01

    Change in the visual scene often goes unnoticed - a phenomenon referred to as "change blindness." This study examined whether the hierarchical structure, i.e., the global-local layout of a scene can influence performance in a one-shot change detection paradigm. To this end, natural scenes of a laid breakfast table were presented, and observers were asked to locate the onset of a new local object. Importantly, the global structure of the scene was manipulated by varying the relations among objects in the scene layouts. The very same items were either presented as global-congruent (typical) layouts or as global-incongruent (random) arrangements. Change blindness was less severe for congruent than for incongruent displays, and this congruency benefit increased with the duration of the experiment. These findings show that global layouts are learned, supporting detection of local changes with enhanced efficiency. However, performance was not affected by scene congruency in a subsequent control experiment that required observers to localize a static discontinuity (i.e., an object that was missing from the repeated layouts). Our results thus show that learning of the global layout is particularly linked to the local objects. Taken together, our results reveal an effect of "global precedence" in natural scenes. We suggest that relational properties within the hierarchy of a natural scene are governed, in particular, by global image analysis, reducing change blindness for local objects through scene learning.

  7. Global scene layout modulates contextual learning in change detection

    Directory of Open Access Journals (Sweden)

    Markus eConci

    2014-02-01

    Full Text Available Change in the visual scene often goes unnoticed – a phenomenon referred to as ‘change blindness’. This study examined whether the hierarchical structure, i.e., the global-local layout of a scene can influence performance in a one-shot change detection paradigm. To this end, natural scenes of a laid breakfast table were presented, and observers were asked to locate the onset of a new local object. Importantly, the global structure of the scene was manipulated by varying the relations among objects in the scene layouts. The very same items were either presented as global-congruent (typical layouts or as global-incongruent (random arrangements. Change blindness was less severe for congruent than for incongruent displays, and this congruency benefit increased with the duration of the experiment. These findings show that global layouts are learned, supporting detection of local changes with enhanced efficiency. However, performance was not affected by scene congruency in a subsequent control experiment that required observers to localize a static discontinuity (i.e., an object that was missing from the repeated layouts. Our results thus show that learning of the global layout is particularly linked to the local objects. Taken together, our results reveal an effect of global precedence in natural scenes. We suggest that relational properties within the hierarchy of a natural scene are governed, in particular, by global image analysis, reducing change blindness for local objects through scene learning.

  8. The occipital place area represents the local elements of scenes.

    Science.gov (United States)

    Kamps, Frederik S; Julian, Joshua B; Kubilius, Jonas; Kanwisher, Nancy; Dilks, Daniel D

    2016-05-15

    Neuroimaging studies have identified three scene-selective regions in human cortex: parahippocampal place area (PPA), retrosplenial complex (RSC), and occipital place area (OPA). However, precisely what scene information each region represents is not clear, especially for the least studied, more posterior OPA. Here we hypothesized that OPA represents local elements of scenes within two independent, yet complementary scene descriptors: spatial boundary (i.e., the layout of external surfaces) and scene content (e.g., internal objects). If OPA processes the local elements of spatial boundary information, then it should respond to these local elements (e.g., walls) themselves, regardless of their spatial arrangement. Indeed, we found that OPA, but not PPA or RSC, responded similarly to images of intact rooms and these same rooms in which the surfaces were fractured and rearranged, disrupting the spatial boundary. Next, if OPA represents the local elements of scene content information, then it should respond more when more such local elements (e.g., furniture) are present. Indeed, we found that OPA, but not PPA or RSC, responded more to multiple than single pieces of furniture. Taken together, these findings reveal that OPA analyzes local scene elements - both in spatial boundary and scene content representation - while PPA and RSC represent global scene properties. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. A statistical model for radar images of agricultural scenes

    Science.gov (United States)

    Frost, V. S.; Shanmugan, K. S.; Holtzman, J. C.; Stiles, J. A.

    1982-01-01

    The presently derived and validated statistical model for radar images containing many different homogeneous fields predicts the probability density functions of radar images of entire agricultural scenes, thereby allowing histograms of large scenes composed of a variety of crops to be described. Seasat-A SAR images of agricultural scenes are accurately predicted by the model on the basis of three assumptions: each field has the same SNR, all target classes cover approximately the same area, and the true reflectivity characterizing each individual target class is a uniformly distributed random variable. The model is expected to be useful in the design of data processing algorithms and for scene analysis using radar images.

  10. Research on 3D virtual campus scene modeling based on 3ds Max and VRML

    Science.gov (United States)

    Kang, Chuanli; Zhou, Yanliu; Liang, Xianyue

    2015-12-01

    With the rapid development of modem technology, the digital information management and the virtual reality simulation technology has become a research hotspot. Virtual campus 3D model can not only express the real world objects of natural, real and vivid, and can expand the campus of the reality of time and space dimension, the combination of school environment and information. This paper mainly uses 3ds Max technology to create three-dimensional model of building and on campus buildings, special land etc. And then, the dynamic interactive function is realized by programming the object model in 3ds Max by VRML .This research focus on virtual campus scene modeling technology and VRML Scene Design, and the scene design process in a variety of real-time processing technology optimization strategy. This paper guarantees texture map image quality and improve the running speed of image texture mapping. According to the features and architecture of Guilin University of Technology, 3ds Max, AutoCAD and VRML were used to model the different objects of the virtual campus. Finally, the result of virtual campus scene is summarized.

  11. The scene is set for ALICE

    CERN Multimedia

    2008-01-01

    Now that the electromagnetic calorimeter support and the mini space frame have been installed, practically all ALICE’s infrastructure is in place. The calorimeter support, an austenitic stainless steel shell weighing 30 tonnes, was slid gently inside the detector, in between the face of the magnet and the space frame. With the completion of two major installation projects, the scene is finally set for the ALICE experiment…or at least it nearly is, as a few design studies, minor installation jobs and measurements still need to be carried out before the curtain can finally be raised. The experiment’s chief engineer Diego Perini confirms: "All the heavy infrastructure for ALICE has been in place and ready for the grand opening since December 2007." The next step will be the installation of additional modules on the TOF and TRD detectors between January and March 2008, and physicists have already started testing the equipment with co...

  12. Wall grid structure for interior scene synthesis

    KAUST Repository

    Xu, Wenzhuo

    2015-02-01

    We present a system for automatically synthesizing a diverse set of semantically valid, and well-arranged 3D interior scenes for a given empty room shape. Unlike existing work on layout synthesis, that typically knows potentially needed 3D models and optimizes their location through cost functions, our technique performs the retrieval and placement of 3D models by discovering the relationships between the room space and the models\\' categories. This is enabled by a new analytical structure, called Wall Grid Structure, which jointly considers the categories and locations of 3D models. Our technique greatly reduces the amount of user intervention and provides users with suggestions and inspirations. We demonstrate the applicability of our approach on three types of scenarios: conference rooms, living rooms and bedrooms.

  13. Collision probability in two-dimensional lattice by ray-trace method and its applications to cell calculations

    International Nuclear Information System (INIS)

    Tsuchihashi, Keichiro

    1985-03-01

    A series of formulations to evaluate collision probability for multi-region cells expressed by either of three one-dimensional coordinate systems (plane, sphere and cylinder) or by the general two-dimensional cylindrical coordinate system is presented. They are expressed in a suitable form to have a common numerical process named ''Ray-Trace'' method. Applications of the collision probability method to two optional treatments for the resonance absorption are presented. One is a modified table-look-up method based on the intermediate resonance approximation, and the other is a rigorous method to calculate the resonance absorption in a multi-region cell in which nearly continuous energy spectra of the resonance neutron range can be solved and interaction effect between different resonance nuclides can be evaluated. Two works on resonance absorption in a doubly heterogeneous system with grain structure are presented. First, the effect of a random distribution of particles embedded in graphite diluent on the resonance integral is studied. Next, the ''Accretion'' method proposed by Leslie and Jonsson to define the collision probability in a doubly heterogeneous system is applied to evaluate the resonance absorption in coated particles dispersed in fuel pellet of the HTGR. Several optional models are proposed to define the collision rates in the medium with the microscopic heterogeneity. By making use of the collision probability method developed by the present study, the JAERI thermal reactor standard nuclear design code system SRAC has been developed. Results of several benchmark tests for the SRAC are presented. The analyses of critical experiments of the SHE, DCA, and FNR show good agreement of critical masses with their experimental values. (J.P.N.)

  14. Mental Layout Extrapolations Prime Spatial Processing of Scenes

    Science.gov (United States)

    Gottesman, Carmela V.

    2011-01-01

    Four experiments examined whether scene processing is facilitated by layout representation, including layout that was not perceived but could be predicted based on a previous partial view (boundary extension). In a priming paradigm (after Sanocki, 2003), participants judged objects' distances in photographs. In Experiment 1, full scenes (target),…

  15. Being There: (Re)Making the Assessment Scene

    Science.gov (United States)

    Gallagher, Chris W.

    2011-01-01

    I use Burkean analysis to show how neoliberalism undermines faculty assessment expertise and underwrites testing industry expertise in the current assessment scene. Contending that we cannot extricate ourselves from our limited agency in this scene until we abandon the familiar "stakeholder" theory of power, I propose a rewriting of the…

  16. The Influence of Color on the Perception of Scene Gist

    Science.gov (United States)

    Castelhano, Monica S.; Henderson, John M.

    2008-01-01

    In 3 experiments the authors used a new contextual bias paradigm to explore how quickly information is extracted from a scene to activate gist, whether color contributes to this activation, and how color contributes, if it does. Participants were shown a brief presentation of a scene followed by the name of a target object. The target object could…

  17. Visual search for arbitrary objects in real scenes

    Science.gov (United States)

    Alvarez, George A.; Rosenholtz, Ruth; Kuzmova, Yoana I.; Sherman, Ashley M.

    2011-01-01

    How efficient is visual search in real scenes? In searches for targets among arrays of randomly placed distractors, efficiency is often indexed by the slope of the reaction time (RT) × Set Size function. However, it may be impossible to define set size for real scenes. As an approximation, we hand-labeled 100 indoor scenes and used the number of labeled regions as a surrogate for set size. In Experiment 1, observers searched for named objects (a chair, bowl, etc.). With set size defined as the number of labeled regions, search was very efficient (~5 ms/item). When we controlled for a possible guessing strategy in Experiment 2, slopes increased somewhat (~15 ms/item), but they were much shallower than search for a random object among other distinctive objects outside of a scene setting (Exp. 3: ~40 ms/item). In Experiments 4–6, observers searched repeatedly through the same scene for different objects. Increased familiarity with scenes had modest effects on RTs, while repetition of target items had large effects (>500 ms). We propose that visual search in scenes is efficient because scene-specific forms of attentional guidance can eliminate most regions from the “functional set size” of items that could possibly be the target. PMID:21671156

  18. SAMPEG: a scene-adaptive parallel MPEG-2 software encoder

    NARCIS (Netherlands)

    Farin, D.S.; Mache, N.; With, de P.H.N.; Girod, B.; Bouman, C.A.; Steinbach, E.G.

    2001-01-01

    This paper presents a fully software-based MPEG-2 encoder architecture, which uses scene-change detection to optimize the Group-of-Picture (GOP) structure for the actual video sequence. This feature enables easy, lossless edit cuts at scene-change positions and it also improves overall picture

  19. Children's Development of Analogical Reasoning: Insights from Scene Analogy Problems

    Science.gov (United States)

    Richland, Lindsey E.; Morrison, Robert G.; Holyoak, Keith J.

    2006-01-01

    We explored how relational complexity and featural distraction, as varied in scene analogy problems, affect children's analogical reasoning performance. Results with 3- and 4-year-olds, 6- and 7-year-olds, 9- to 11-year-olds, and 13- and 14-year-olds indicate that when children can identify the critical structural relations in a scene analogy…

  20. Automatic video surveillance of outdoor scenes using track before detect

    DEFF Research Database (Denmark)

    Hansen, Morten; Sørensen, Helge Bjarup Dissing; Birkemark, Christian M.

    2005-01-01

    This paper concerns automatic video surveillance of outdoor scenes using a single camera. The first step in automatic interpretation of the video stream is activity detection based on background subtraction. Usually, this process will generate a large number of false alarms in outdoor scenes due...

  1. Selective scene perception deficits in a case of topographical disorientation.

    Science.gov (United States)

    Robin, Jessica; Lowe, Matthew X; Pishdadian, Sara; Rivest, Josée; Cant, Jonathan S; Moscovitch, Morris

    2017-07-01

    Topographical disorientation (TD) is a neuropsychological condition characterized by an inability to find one's way, even in familiar environments. One common contributing cause of TD is landmark agnosia, a visual recognition impairment specific to scenes and landmarks. Although many cases of TD with landmark agnosia have been documented, little is known about the perceptual mechanisms which lead to selective deficits in recognizing scenes. In the present study, we test LH, a man who exhibits TD and landmark agnosia, on measures of scene perception that require selectively attending to either the configural or surface properties of a scene. Compared to healthy controls, LH demonstrates perceptual impairments when attending to the configuration of a scene, but not when attending to its surface properties, such as the pattern of the walls or whether the ground is sand or grass. In contrast, when focusing on objects instead of scenes, LH demonstrates intact perception of both geometric and surface properties. This study demonstrates that in a case of TD and landmark agnosia, the perceptual impairments are selective to the layout of scenes, providing insight into the mechanism of landmark agnosia and scene-selective perceptual processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The neural bases of spatial frequency processing during scene perception

    Science.gov (United States)

    Kauffmann, Louise; Ramanoël, Stephen; Peyrin, Carole

    2014-01-01

    Theories on visual perception agree that scenes are processed in terms of spatial frequencies. Low spatial frequencies (LSF) carry coarse information whereas high spatial frequencies (HSF) carry fine details of the scene. However, how and where spatial frequencies are processed within the brain remain unresolved questions. The present review addresses these issues and aims to identify the cerebral regions differentially involved in low and high spatial frequency processing, and to clarify their attributes during scene perception. Results from a number of behavioral and neuroimaging studies suggest that spatial frequency processing is lateralized in both hemispheres, with the right and left hemispheres predominantly involved in the categorization of LSF and HSF scenes, respectively. There is also evidence that spatial frequency processing is retinotopically mapped in the visual cortex. HSF scenes (as opposed to LSF) activate occipital areas in relation to foveal representations, while categorization of LSF scenes (as opposed to HSF) activates occipital areas in relation to more peripheral representations. Concomitantly, a number of studies have demonstrated that LSF information may reach high-order areas rapidly, allowing an initial coarse parsing of the visual scene, which could then be sent back through feedback into the occipito-temporal cortex to guide finer HSF-based analysis. Finally, the review addresses spatial frequency processing within scene-selective regions areas of the occipito-temporal cortex. PMID:24847226

  3. 47 CFR 80.1127 - On-scene communications.

    Science.gov (United States)

    2010-10-01

    ....1127 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) Operating Procedures for Distress and Safety Communications § 80.1127 On-scene communications. (a) On-scene communications...

  4. Emotional Scene Content Drives the Saccade Generation System Reflexively

    Science.gov (United States)

    Nummenmaa, Lauri; Hyona, Jukka; Calvo, Manuel G.

    2009-01-01

    The authors assessed whether parafoveal perception of emotional content influences saccade programming. In Experiment 1, paired emotional and neutral scenes were presented to parafoveal vision. Participants performed voluntary saccades toward either of the scenes according to an imperative signal (color cue). Saccadic reaction times were faster…

  5. Visual search for arbitrary objects in real scenes.

    Science.gov (United States)

    Wolfe, Jeremy M; Alvarez, George A; Rosenholtz, Ruth; Kuzmova, Yoana I; Sherman, Ashley M

    2011-08-01

    How efficient is visual search in real scenes? In searches for targets among arrays of randomly placed distractors, efficiency is often indexed by the slope of the reaction time (RT) × Set Size function. However, it may be impossible to define set size for real scenes. As an approximation, we hand-labeled 100 indoor scenes and used the number of labeled regions as a surrogate for set size. In Experiment 1, observers searched for named objects (a chair, bowl, etc.). With set size defined as the number of labeled regions, search was very efficient (~5 ms/item). When we controlled for a possible guessing strategy in Experiment 2, slopes increased somewhat (~15 ms/item), but they were much shallower than search for a random object among other distinctive objects outside of a scene setting (Exp. 3: ~40 ms/item). In Experiments 4-6, observers searched repeatedly through the same scene for different objects. Increased familiarity with scenes had modest effects on RTs, while repetition of target items had large effects (>500 ms). We propose that visual search in scenes is efficient because scene-specific forms of attentional guidance can eliminate most regions from the "functional set size" of items that could possibly be the target.

  6. Cognitive organization of roadway scenes : an empirical study.

    NARCIS (Netherlands)

    Gundy, C.M.

    1995-01-01

    This report describes six studies investigating the cognitive organization of roadway scenes. These scenes were represented by still photographs taken on a number of roads outside of built-up areas. Seventy-eight drivers, stratified by age and sex to simulate the Dutch driving population,

  7. Superpixel-Based Feature for Aerial Image Scene Recognition

    Directory of Open Access Journals (Sweden)

    Hongguang Li

    2018-01-01

    Full Text Available Image scene recognition is a core technology for many aerial remote sensing applications. Different landforms are inputted as different scenes in aerial imaging, and all landform information is regarded as valuable for aerial image scene recognition. However, the conventional features of the Bag-of-Words model are designed using local points or other related information and thus are unable to fully describe landform areas. This limitation cannot be ignored when the aim is to ensure accurate aerial scene recognition. A novel superpixel-based feature is proposed in this study to characterize aerial image scenes. Then, based on the proposed feature, a scene recognition method of the Bag-of-Words model for aerial imaging is designed. The proposed superpixel-based feature that utilizes landform information establishes top-task superpixel extraction of landforms to bottom-task expression of feature vectors. This characterization technique comprises the following steps: simple linear iterative clustering based superpixel segmentation, adaptive filter bank construction, Lie group-based feature quantification, and visual saliency model-based feature weighting. Experiments of image scene recognition are carried out using real image data captured by an unmanned aerial vehicle (UAV. The recognition accuracy of the proposed superpixel-based feature is 95.1%, which is higher than those of scene recognition algorithms based on other local features.

  8. Iconic memory for the gist of natural scenes.

    Science.gov (United States)

    Clarke, Jason; Mack, Arien

    2014-11-01

    Does iconic memory contain the gist of multiple scenes? Three experiments were conducted. In the first, four scenes from different basic-level categories were briefly presented in one of two conditions: a cue or a no-cue condition. The cue condition was designed to provide an index of the contents of iconic memory of the display. Subjects were more sensitive to scene gist in the cue condition than in the no-cue condition. In the second, the scenes came from the same basic-level category. We found no difference in sensitivity between the two conditions. In the third, six scenes from different basic level categories were presented in the visual periphery. Subjects were more sensitive to scene gist in the cue condition. These results suggest that scene gist is contained in iconic memory even in the visual periphery; however, iconic representations are not sufficiently detailed to distinguish between scenes coming from the same category. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. System and method for extracting dominant orientations from a scene

    Science.gov (United States)

    Straub, Julian; Rosman, Guy; Freifeld, Oren; Leonard, John J.; Fisher, III; , John W.

    2017-05-30

    In one embodiment, a method of identifying the dominant orientations of a scene comprises representing a scene as a plurality of directional vectors. The scene may comprise a three-dimensional representation of a scene, and the plurality of directional vectors may comprise a plurality of surface normals. The method further comprises determining, based on the plurality of directional vectors, a plurality of orientations describing the scene. The determined plurality of orientations explains the directionality of the plurality of directional vectors. In certain embodiments, the plurality of orientations may have independent axes of rotation. The plurality of orientations may be determined by representing the plurality of directional vectors as lying on a mathematical representation of a sphere, and inferring the parameters of a statistical model to adapt the plurality of orientations to explain the positioning of the plurality of directional vectors lying on the mathematical representation of the sphere.

  10. Review of On-Scene Management of Mass-Casualty Attacks

    Directory of Open Access Journals (Sweden)

    Annelie Holgersson

    2016-02-01

    Full Text Available Background: The scene of a mass-casualty attack (MCA entails a crime scene, a hazardous space, and a great number of people needing medical assistance. Public transportation has been the target of such attacks and involves a high probability of generating mass casualties. The review aimed to investigate challenges for on-scene responses to MCAs and suggestions made to counter these challenges, with special attention given to attacks on public transportation and associated terminals. Methods: Articles were found through PubMed and Scopus, “relevant articles” as defined by the databases, and a manual search of references. Inclusion criteria were that the article referred to attack(s and/or a public transportation-related incident and issues concerning formal on-scene response. An appraisal of the articles’ scientific quality was conducted based on an evidence hierarchy model developed for the study. Results: One hundred and five articles were reviewed. Challenges for command and coordination on scene included establishing leadership, inter-agency collaboration, multiple incident sites, and logistics. Safety issues entailed knowledge and use of personal protective equipment, risk awareness and expectations, cordons, dynamic risk assessment, defensive versus offensive approaches, and joining forces. Communication concerns were equipment shortfalls, dialoguing, and providing information. Assessment problems were scene layout and interpreting environmental indicators as well as understanding setting-driven needs for specialist skills and resources. Triage and treatment difficulties included differing triage systems, directing casualties, uncommon injuries, field hospitals, level of care, providing psychological and pediatric care. Transportation hardships included scene access, distance to hospitals, and distribution of casualties. Conclusion: Commonly encountered challenges during unintentional incidents were added to during MCAs

  11. Fixations on objects in natural scenes: dissociating importance from salience

    Directory of Open Access Journals (Sweden)

    Bernard Marius e’t Hart

    2013-07-01

    Full Text Available The relation of selective attention to understanding of natural scenes has been subject to intense behavioral research and computational modeling, and gaze is often used as a proxy for such attention. The probability of an image region to be fixated typically correlates with its contrast. However, this relation does not imply a causal role of contrast. Rather, contrast may relate to an object’s importance for a scene, which in turn drives attention. Here we operationalize importance by the probability that an observer names the object as characteristic for a scene. We modify luminance contrast of either a frequently named (common/important or a rarely named (rare/unimportant object, track the observers’ eye movements during scene viewing and ask them to provide keywords describing the scene immediately after.When no object is modified relative to the background, important objects draw more fixations than unimportant ones. Increases of contrast make an object more likely to be fixated, irrespective of whether it was important for the original scene, while decreases in contrast have little effect on fixations. Any contrast modification makes originally unimportant objects more important for the scene. Finally, important objects are fixated more centrally than unimportant objects, irrespective of contrast.Our data suggest a dissociation between object importance (relevance for the scene and salience (relevance for attention. If an object obeys natural scene statistics, important objects are also salient. However, when natural scene statistics are violated, importance and salience are differentially affected. Object salience is modulated by the expectation about object properties (e.g., formed by context or gist, and importance by the violation of such expectations. In addition, the dependence of fixated locations within an object on the object’s importance suggests an analogy to the effects of word frequency on landing positions in reading.

  12. 'Working behind the scenes'. An ethical view of mental health nursing and first-episode psychosis.

    Science.gov (United States)

    Moe, Cathrine; Kvig, Erling I; Brinchmann, Beate; Brinchmann, Berit S

    2013-08-01

    The aim of this study was to explore and reflect upon mental health nursing and first-episode psychosis. Seven multidisciplinary focus group interviews were conducted, and data analysis was influenced by a grounded theory approach. The core category was found to be a process named 'working behind the scenes'. It is presented along with three subcategories: 'keeping the patient in mind', 'invisible care' and 'invisible network contact'. Findings are illuminated with the ethical principles of respect for autonomy and paternalism. Nursing care is dynamic, and clinical work moves along continuums between autonomy and paternalism and between ethical reflective and non-reflective practice. 'Working behind the scenes' is considered to be in a paternalistic area, containing an ethical reflection. Treating and caring for individuals experiencing first-episode psychosis demands an ethical awareness and great vigilance by nurses. The study is a contribution to reflection upon everyday nursing practice, and the conclusion concerns the importance of making invisible work visible.

  13. Detecting anomalies in crowded scenes via locality-constrained affine subspace coding

    Science.gov (United States)

    Fan, Yaxiang; Wen, Gongjian; Qiu, Shaohua; Li, Deren

    2017-07-01

    Video anomaly event detection is the process of finding an abnormal event deviation compared with the majority of normal or usual events. The main challenges are the high structure redundancy and the dynamic changes in the scenes that are in surveillance videos. To address these problems, we present a framework for anomaly detection and localization in videos that is based on locality-constrained affine subspace coding (LASC) and a model updating procedure. In our algorithm, LASC attempts to reconstruct the test sample by its top-k nearest subspaces, which are obtained by segmenting the normal samples space using a clustering method. A sample with a large reconstruction cost is detected as abnormal by setting a threshold. To adapt to the scene changes over time, a model updating strategy is proposed. We experiment on two public datasets: the UCSD dataset and the Avenue dataset. The results demonstrate that our method achieves competitive performance at a 700 fps on a single desktop PC.

  14. Art Toys in the contemporary art scene

    Directory of Open Access Journals (Sweden)

    Laura Sernissi

    2014-03-01

    Full Text Available The Art Toys phenomenon, better known as Art Toy Movement, was born in China in the mid-nineties and quickly spread out to the rest of the world. The toys are an artistic production of serial sculpture, made by handcrafts or on an industrial scale. There are several types of toys, such as custom toys and canvas toys, synonyms of designer toys, although they are often defined according to the constituent material, such as vinyl toys (plastic and plush toys (fabric. Art toys are the heirs of an already pop-surrealist and neo-pop circuit, which since the eighties of the twentieth century has pervaded the Japanese-American art scene, winking to the playful spirit of the avant-garde of the early century. Some psychoanalytic, pedagogical and anthropological studies about “play theories”, may also help us to understand and identify these heterogeneous products as real works of art and not simply as collectible toys.

  15. Detection of chromatic and luminance distortions in natural scenes.

    Science.gov (United States)

    Jennings, Ben J; Wang, Karen; Menzies, Samantha; Kingdom, Frederick A A

    2015-09-01

    A number of studies have measured visual thresholds for detecting spatial distortions applied to images of natural scenes. In one study, Bex [J. Vis.10(2), 1 (2010)10.1167/10.2.231534-7362] measured sensitivity to sinusoidal spatial modulations of image scale. Here, we measure sensitivity to sinusoidal scale distortions applied to the chromatic, luminance, or both layers of natural scene images. We first established that sensitivity does not depend on whether the undistorted comparison image was of the same or of a different scene. Next, we found that, when the luminance but not chromatic layer was distorted, performance was the same regardless of whether the chromatic layer was present, absent, or phase-scrambled; in other words, the chromatic layer, in whatever form, did not affect sensitivity to the luminance layer distortion. However, when the chromatic layer was distorted, sensitivity was higher when the luminance layer was intact compared to when absent or phase-scrambled. These detection threshold results complement the appearance of periodic distortions of the image scale: when the luminance layer is distorted visibly, the scene appears distorted, but when the chromatic layer is distorted visibly, there is little apparent scene distortion. We conclude that (a) observers have a built-in sense of how a normal image of a natural scene should appear, and (b) the detection of distortion in, as well as the apparent distortion of, natural scene images is mediated predominantly by the luminance layer and not chromatic layer.

  16. Advanced radiometric and interferometric milimeter-wave scene simulations

    Science.gov (United States)

    Hauss, B. I.; Moffa, P. J.; Steele, W. G.; Agravante, H.; Davidheiser, R.; Samec, T.; Young, S. K.

    1993-01-01

    Smart munitions and weapons utilize various imaging sensors (including passive IR, active and passive millimeter-wave, and visible wavebands) to detect/identify targets at short standoff ranges and in varied terrain backgrounds. In order to design and evaluate these sensors under a variety of conditions, a high-fidelity scene simulation capability is necessary. Such a capability for passive millimeter-wave scene simulation exists at TRW. TRW's Advanced Radiometric Millimeter-Wave Scene Simulation (ARMSS) code is a rigorous, benchmarked, end-to-end passive millimeter-wave scene simulation code for interpreting millimeter-wave data, establishing scene signatures and evaluating sensor performance. In passive millimeter-wave imaging, resolution is limited due to wavelength and aperture size. Where high resolution is required, the utility of passive millimeter-wave imaging is confined to short ranges. Recent developments in interferometry have made possible high resolution applications on military platforms. Interferometry or synthetic aperture radiometry allows the creation of a high resolution image with a sparsely filled aperture. Borrowing from research work in radio astronomy, we have developed and tested at TRW scene reconstruction algorithms that allow the recovery of the scene from a relatively small number of spatial frequency components. In this paper, the TRW modeling capability is described and numerical results are presented.

  17. Three-dimensional measurement system for crime scene documentation

    Science.gov (United States)

    Adamczyk, Marcin; Hołowko, Elwira; Lech, Krzysztof; Michoński, Jakub; MÄ czkowski, Grzegorz; Bolewicki, Paweł; Januszkiewicz, Kamil; Sitnik, Robert

    2017-10-01

    Three dimensional measurements (such as photogrammetry, Time of Flight, Structure from Motion or Structured Light techniques) are becoming a standard in the crime scene documentation process. The usage of 3D measurement techniques provide an opportunity to prepare more insightful investigation and helps to show every trace in the context of the entire crime scene. In this paper we would like to present a hierarchical, three-dimensional measurement system that is designed for crime scenes documentation process. Our system reflects the actual standards in crime scene documentation process - it is designed to perform measurement in two stages. First stage of documentation, the most general, is prepared with a scanner with relatively low spatial resolution but also big measuring volume - it is used for the whole scene documentation. Second stage is much more detailed: high resolution but smaller size of measuring volume for areas that required more detailed approach. The documentation process is supervised by a specialised application CrimeView3D, that is a software platform for measurements management (connecting with scanners and carrying out measurements, automatic or semi-automatic data registration in the real time) and data visualisation (3D visualisation of documented scenes). It also provides a series of useful tools for forensic technicians: virtual measuring tape, searching for sources of blood spatter, virtual walk on the crime scene and many others. In this paper we present our measuring system and the developed software. We also provide an outcome from research on metrological validation of scanners that was performed according to VDI/VDE standard. We present a CrimeView3D - a software-platform that was developed to manage the crime scene documentation process. We also present an outcome from measurement sessions that were conducted on real crime scenes with cooperation with Technicians from Central Forensic Laboratory of Police.

  18. On self-consistent ray-tracing and Fokker-Planck modeling of the hard X-ray emission during lower-hybrid current driven in Tokamaks

    International Nuclear Information System (INIS)

    Bizarro, J.P.; Peysson, Y.; Bonoli, P.T.; Carrasco, J.; Dudok de Wit, T.; Fuchs, V.; Hoang, G.T.; Litaudon, X.; Moreau, D.; Pocheau, C.; Shkarofsky, I.P.

    1993-04-01

    A detailed investigation is presented on the ability of combined ray-tracing and Fokker-Planck calculations to predict the hard x-ray (HXR) emission during lower-hybrid (LH) current drive in tokamaks when toroidally induced-ray-stochasticity is important. A large number of rays is used and the electron distribution function is obtained by self-consistently iterating the appropriate LH power deposition and Fokker-Planck calculations. Most of the experimentally observed features of the HXR emission are correctly predicted. It is found that corrections due to radial diffusion of suprathermal electrons and to radiation scattering by the inner wall can be significant

  19. Efficient Time-Domain Ray-Tracing Technique for the Analysis of Ultra-Wideband Indoor Environments including Lossy Materials and Multiple Effects

    Directory of Open Access Journals (Sweden)

    F. Saez de Adana

    2009-01-01

    Full Text Available This paper presents an efficient application of the Time-Domain Uniform Theory of Diffraction (TD-UTD for the analysis of Ultra-Wideband (UWB mobile communications for indoor environments. The classical TD-UTD formulation is modified to include the contribution of lossy materials and multiple-ray interactions with the environment. The electromagnetic analysis is combined with a ray-tracing acceleration technique to treat realistic and complex environments. The validity of this method is tested with measurements performed inside the Polytechnic building of the University of Alcala and shows good performance of the model for the analysis of UWB propagation.

  20. Individual differences in the spontaneous recruitment of brain regions supporting mental state understanding when viewing natural social scenes.

    Science.gov (United States)

    Wagner, Dylan D; Kelley, William M; Heatherton, Todd F

    2011-12-01

    People are able to rapidly infer complex personality traits and mental states even from the most minimal person information. Research has shown that when observers view a natural scene containing people, they spend a disproportionate amount of their time looking at the social features (e.g., faces, bodies). Does this preference for social features merely reflect the biological salience of these features or are observers spontaneously attempting to make sense of complex social dynamics? Using functional neuroimaging, we investigated neural responses to social and nonsocial visual scenes in a large sample of participants (n = 48) who varied on an individual difference measure assessing empathy and mentalizing (i.e., empathizing). Compared with other scene categories, viewing natural social scenes activated regions associated with social cognition (e.g., dorsomedial prefrontal cortex and temporal poles). Moreover, activity in these regions during social scene viewing was strongly correlated with individual differences in empathizing. These findings offer neural evidence that observers spontaneously engage in social cognition when viewing complex social material but that the degree to which people do so is mediated by individual differences in trait empathizing.

  1. Utilising E-on Vue and Unity 3D scenes to generate synthetic images and videos for visible signature analysis

    Science.gov (United States)

    Madden, Christopher S.; Richards, Noel J.; Culpepper, Joanne B.

    2016-10-01

    This paper investigates the ability to develop synthetic scenes in an image generation tool, E-on Vue, and a gaming engine, Unity 3D, which can be used to generate synthetic imagery of target objects across a variety of conditions in land environments. Developments within these tools and gaming engines have allowed the computer gaming industry to dramatically enhance the realism of the games they develop; however they utilise short cuts to ensure that the games run smoothly in real-time to create an immersive effect. Whilst these short cuts may have an impact upon the realism of the synthetic imagery, they do promise a much more time efficient method of developing imagery of different environmental conditions and to investigate the dynamic aspect of military operations that is currently not evaluated in signature analysis. The results presented investigate how some of the common image metrics used in target acquisition modelling, namely the Δμ1, Δμ2, Δμ3, RSS, and Doyle metrics, perform on the synthetic scenes generated by E-on Vue and Unity 3D compared to real imagery of similar scenes. An exploration of the time required to develop the various aspects of the scene to enhance its realism are included, along with an overview of the difficulties associated with trying to recreate specific locations as a virtual scene. This work is an important start towards utilising virtual worlds for visible signature evaluation, and evaluating how equivalent synthetic imagery is to real photographs.

  2. Graphics processing unit (GPU) real-time infrared scene generation

    Science.gov (United States)

    Christie, Chad L.; Gouthas, Efthimios (Themie); Williams, Owen M.

    2007-04-01

    VIRSuite, the GPU-based suite of software tools developed at DSTO for real-time infrared scene generation, is described. The tools include the painting of scene objects with radiometrically-associated colours, translucent object generation, polar plot validation and versatile scene generation. Special features include radiometric scaling within the GPU and the presence of zoom anti-aliasing at the core of VIRSuite. Extension of the zoom anti-aliasing construct to cover target embedding and the treatment of translucent objects is described.

  3. Semantic guidance of eye movements in real-world scenes

    OpenAIRE

    Hwang, Alex D.; Wang, Hsueh-Cheng; Pomplun, Marc

    2011-01-01

    The perception of objects in our visual world is influenced by not only their low-level visual features such as shape and color, but also their high-level features such as meaning and semantic relations among them. While it has been shown that low-level features in real-world scenes guide eye movements during scene inspection and search, the influence of semantic similarity among scene objects on eye movements in such situations has not been investigated. Here we study guidance of eye movemen...

  4. Picture models for 2-scene comics creating system

    Directory of Open Access Journals (Sweden)

    Miki UENO

    2015-03-01

    Full Text Available Recently, computer understanding pictures and stories becomes one of the most important research topics in computer science. However, there are few researches about human like understanding by computers because pictures have not certain format and contain more lyric aspect than that of natural laguage. For picture understanding, a comic is the suitable target because it is consisted by clear and simple plot of stories and separated scenes.In this paper, we propose 2 different types of picture models for 2-scene comics creating system. We also show the method of the application of 2-scene comics creating system by means of proposed picture model.

  5. AR goggles make crime scene investigation a desk job

    OpenAIRE

    Aron, Jacob; NORTHFIELD, Dean

    2012-01-01

    CRIME scene investigators could one day help solve murders without leaving the office. A pair of augmented reality glasses could allow local police to virtually tag objects in a crime scene, and build a clean record of the scene in 3D video before evidence is removed for processing.\\ud The system, being developed by Oytun Akman and colleagues at the Delft University of Technology in the Netherlands, consists of a head-mounted display receiving 3D video from a pair of attached cameras controll...

  6. Embryo disposition and the new death scene

    Directory of Open Access Journals (Sweden)

    Ellison, David

    2011-01-01

    Full Text Available In the IVF clinic - a place designed principally for the production and implantation of embryos - scientists and IVF recipients are faced with decisions regarding the disposition of frozen embryos. At this time there are hundred of thousands of cryopreserved embryos awaiting such determinations. They may be thawed for transfer to the woman herself, they may be donated for research or for use by other infertile couples, they may remain in frozen storage, or they may variously be discarded by being allowed to 'succumb', or 'perish'. Where the choice is discard, some IVF clients have chosen to formalise the process through ceremony. A new language is emerging in response to the desires of the would-be-parents who might wish to characterise the discard experience as a ‘good death’. This article examines the procedure known as ‘compassionate transfer’ where the embryo to be discarded is placed in the woman’s vagina where it is clear that it will not develop further. An alternate method has the embryo transferred in the usual manner but without the benefit of fertility-enhancing hormones at a point in the cycle unreceptive to implantation. The embryo destined for disposal is thus removed from the realm of technological possibility and ‘returned’ to the female body for a homely death. While debates continue about whether or not embryos constitute life, new practices are developing in response to the emotional experience of embryo discard. We argue that compassionate transfer is a death scene taking shape. In this article, we take the measure of this new death scene’s fabrication, and consider the form, significance, and legal complexity of its ceremonies.

  7. The influence of color on emotional perception of natural scenes.

    Science.gov (United States)

    Codispoti, Maurizio; De Cesarei, Andrea; Ferrari, Vera

    2012-01-01

    Is color a critical factor when processing the emotional content of natural scenes? Under challenging perceptual conditions, such as when pictures are briefly presented, color might facilitate scene segmentation and/or function as a semantic cue via association with scene-relevant concepts (e.g., red and blood/injury). To clarify the influence of color on affective picture perception, we compared the late positive potentials (LPP) to color versus grayscale pictures, presented for very brief (24 ms) and longer (6 s) exposure durations. Results indicated that removing color information had no effect on the affective modulation of the LPP, regardless of exposure duration. These findings imply that the recognition of the emotional content of scenes, even when presented very briefly, does not critically rely on color information. Copyright © 2011 Society for Psychophysiological Research.

  8. Scene Categorization in Alzheimer's Disease: A Saccadic Choice Task

    Directory of Open Access Journals (Sweden)

    Quentin Lenoble

    2015-01-01

    Full Text Available Aims: We investigated the performance in scene categorization of patients with Alzheimer's disease (AD using a saccadic choice task. Method: 24 patients with mild AD, 28 age-matched controls and 26 young people participated in the study. The participants were presented pairs of coloured photographs and were asked to make a saccadic eye movement to the picture corresponding to the target scene (natural vs. urban, indoor vs. outdoor. Results: The patients' performance did not differ from chance for natural scenes. Differences between young and older controls and patients with AD were found in accuracy but not saccadic latency. Conclusions: The results are interpreted in terms of cerebral reorganization in the prefrontal and temporo-occipital cortex of patients with AD, but also in terms of impaired processing of visual global properties of scenes.

  9. Scene Classification Using High Spatial Resolution Multispectral Data

    National Research Council Canada - National Science Library

    Garner, Jamada

    2002-01-01

    ...), High-spatial resolution (8-meter), 4-color MSI data from IKONOS provide a new tool for scene classification, The utility of these data are studied for the purpose of classifying the Elkhorn Slough and surrounding wetlands in central...

  10. Radiative transfer model for heterogeneous 3-D scenes

    Science.gov (United States)

    Kimes, D. S.; Kirchner, J. A.

    1982-01-01

    A general mathematical framework for simulating processes in heterogeneous 3-D scenes is presented. Specifically, a model was designed and coded for application to radiative transfers in vegetative scenes. The model is unique in that it predicts (1) the directional spectral reflectance factors as a function of the sensor's azimuth and zenith angles and the sensor's position above the canopy, (2) the spectral absorption as a function of location within the scene, and (3) the directional spectral radiance as a function of the sensor's location within the scene. The model was shown to follow known physical principles of radiative transfer. Initial verification of the model as applied to a soybean row crop showed that the simulated directional reflectance data corresponded relatively well in gross trends to the measured data. However, the model can be greatly improved by incorporating more sophisticated and realistic anisotropic scattering algorithms

  11. Synchronous contextual irregularities affect early scene processing: replication and extension.

    Science.gov (United States)

    Mudrik, Liad; Shalgi, Shani; Lamy, Dominique; Deouell, Leon Y

    2014-04-01

    Whether contextual regularities facilitate perceptual stages of scene processing is widely debated, and empirical evidence is still inconclusive. Specifically, it was recently suggested that contextual violations affect early processing of a scene only when the incongruent object and the scene are presented a-synchronously, creating expectations. We compared event-related potentials (ERPs) evoked by scenes that depicted a person performing an action using either a congruent or an incongruent object (e.g., a man shaving with a razor or with a fork) when scene and object were presented simultaneously. We also explored the role of attention in contextual processing by using a pre-cue to direct subjects׳ attention towards or away from the congruent/incongruent object. Subjects׳ task was to determine how many hands the person in the picture used in order to perform the action. We replicated our previous findings of frontocentral negativity for incongruent scenes that started ~ 210 ms post stimulus presentation, even earlier than previously found. Surprisingly, this incongruency ERP effect was negatively correlated with the reaction times cost on incongruent scenes. The results did not allow us to draw conclusions about the role of attention in detecting the regularity, due to a weak attention manipulation. By replicating the 200-300 ms incongruity effect with a new group of subjects at even earlier latencies than previously reported, the results strengthen the evidence for contextual processing during this time window even when simultaneous presentation of the scene and object prevent the formation of prior expectations. We discuss possible methodological limitations that may account for previous failures to find this an effect, and conclude that contextual information affects object model selection processes prior to full object identification, with semantic knowledge activation stages unfolding only later on. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Developing Scene Understanding Neural Software for Realistic Autonomous Outdoor Missions

    Science.gov (United States)

    2017-09-01

    computer using a single graphics processing unit (GPU). To the best of our knowledge, an implementation of the open-source Python -based AlexNet CNN on...1. Introduction Neurons in the brain enable us to understand scenes by assessing the spatial, temporal, and feature relations of objects in the...effort to use computer neural networks to augment human neural intelligence to improve our scene understanding (Krizhevsky et al. 2012; Zhou et al

  13. 3D Traffic Scene Understanding From Movable Platforms.

    Science.gov (United States)

    Geiger, Andreas; Lauer, Martin; Wojek, Christian; Stiller, Christoph; Urtasun, Raquel

    2014-05-01

    In this paper, we present a novel probabilistic generative model for multi-object traffic scene understanding from movable platforms which reasons jointly about the 3D scene layout as well as the location and orientation of objects in the scene. In particular, the scene topology, geometry, and traffic activities are inferred from short video sequences. Inspired by the impressive driving capabilities of humans, our model does not rely on GPS, lidar, or map knowledge. Instead, it takes advantage of a diverse set of visual cues in the form of vehicle tracklets, vanishing points, semantic scene labels, scene flow, and occupancy grids. For each of these cues, we propose likelihood functions that are integrated into a probabilistic generative model. We learn all model parameters from training data using contrastive divergence. Experiments conducted on videos of 113 representative intersections show that our approach successfully infers the correct layout in a variety of very challenging scenarios. To evaluate the importance of each feature cue, experiments using different feature combinations are conducted. Furthermore, we show how by employing context derived from the proposed method we are able to improve over the state-of-the-art in terms of object detection and object orientation estimation in challenging and cluttered urban environments.

  14. Presentation of 3D Scenes Through Video Example.

    Science.gov (United States)

    Baldacci, Andrea; Ganovelli, Fabio; Corsini, Massimiliano; Scopigno, Roberto

    2017-09-01

    Using synthetic videos to present a 3D scene is a common requirement for architects, designers, engineers or Cultural Heritage professionals however it is usually time consuming and, in order to obtain high quality results, the support of a film maker/computer animation expert is necessary. We introduce an alternative approach that takes the 3D scene of interest and an example video as input, and automatically produces a video of the input scene that resembles the given video example. In other words, our algorithm allows the user to "replicate" an existing video, on a different 3D scene. We build on the intuition that a video sequence of a static environment is strongly characterized by its optical flow, or, in other words, that two videos are similar if their optical flows are similar. We therefore recast the problem as producing a video of the input scene whose optical flow is similar to the optical flow of the input video. Our intuition is supported by a user-study specifically designed to verify this statement. We have successfully tested our approach on several scenes and input videos, some of which are reported in the accompanying material of this paper.

  15. Political conservatism predicts asymmetries in emotional scene memory.

    Science.gov (United States)

    Mills, Mark; Gonzalez, Frank J; Giuseffi, Karl; Sievert, Benjamin; Smith, Kevin B; Hibbing, John R; Dodd, Michael D

    2016-06-01

    Variation in political ideology has been linked to differences in attention to and processing of emotional stimuli, with stronger responses to negative versus positive stimuli (negativity bias) the more politically conservative one is. As memory is enhanced by attention, such findings predict that memory for negative versus positive stimuli should similarly be enhanced the more conservative one is. The present study tests this prediction by having participants study 120 positive, negative, and neutral scenes in preparation for a subsequent memory test. On the memory test, the same 120 scenes were presented along with 120 new scenes and participants were to respond whether a scene was old or new. Results on the memory test showed that negative scenes were more likely to be remembered than positive scenes, though, this was true only for political conservatives. That is, a larger negativity bias was found the more conservative one was. The effect was sizeable, explaining 45% of the variance across subjects in the effect of emotion. These findings demonstrate that the relationship between political ideology and asymmetries in emotion processing extend to memory and, furthermore, suggest that exploring the extent to which subject variation in interactions among emotion, attention, and memory is predicted by conservatism may provide new insights into theories of political ideology. Published by Elsevier B.V.

  16. Two Distinct Scene-Processing Networks Connecting Vision and Memory.

    Science.gov (United States)

    Baldassano, Christopher; Esteva, Andre; Fei-Fei, Li; Beck, Diane M

    2016-01-01

    A number of regions in the human brain are known to be involved in processing natural scenes, but the field has lacked a unifying framework for understanding how these different regions are organized and interact. We provide evidence from functional connectivity and meta-analyses for a new organizational principle, in which scene processing relies upon two distinct networks that split the classically defined parahippocampal place area (PPA). The first network of strongly connected regions consists of the occipital place area/transverse occipital sulcus and posterior PPA, which contain retinotopic maps and are not strongly coupled to the hippocampus at rest. The second network consists of the caudal inferior parietal lobule, retrosplenial complex, and anterior PPA, which connect to the hippocampus (especially anterior hippocampus), and are implicated in both visual and nonvisual tasks, including episodic memory and navigation. We propose that these two distinct networks capture the primary functional division among scene-processing regions, between those that process visual features from the current view of a scene and those that connect information from a current scene view with a much broader temporal and spatial context. This new framework for understanding the neural substrates of scene-processing bridges results from many lines of research, and makes specific functional predictions.

  17. Visualization of spatial-temporal data based on 3D virtual scene

    Science.gov (United States)

    Wang, Xianghong; Liu, Jiping; Wang, Yong; Bi, Junfang

    2009-10-01

    The main purpose of this paper is to realize the expression of the three-dimensional dynamic visualization of spatialtemporal data based on three-dimensional virtual scene, using three-dimensional visualization technology, and combining with GIS so that the people's abilities of cognizing time and space are enhanced and improved by designing dynamic symbol and interactive expression. Using particle systems, three-dimensional simulation, virtual reality and other visual means, we can simulate the situations produced by changing the spatial location and property information of geographical entities over time, then explore and analyze its movement and transformation rules by changing the interactive manner, and also replay history and forecast of future. In this paper, the main research object is the vehicle track and the typhoon path and spatial-temporal data, through three-dimensional dynamic simulation of its track, and realize its timely monitoring its trends and historical track replaying; according to visualization techniques of spatialtemporal data in Three-dimensional virtual scene, providing us with excellent spatial-temporal information cognitive instrument not only can add clarity to show spatial-temporal information of the changes and developments in the situation, but also be used for future development and changes in the prediction and deduction.

  18. A view not to be missed: Salient scene content interferes with cognitive restoration

    Science.gov (United States)

    Van der Jagt, Alexander P. N.; Craig, Tony; Brewer, Mark J.; Pearson, David G.

    2017-01-01

    Attention Restoration Theory (ART) states that built scenes place greater load on attentional resources than natural scenes. This is explained in terms of "hard" and "soft" fascination of built and natural scenes. Given a lack of direct empirical evidence for this assumption we propose that perceptual saliency of scene content can function as an empirically derived indicator of fascination. Saliency levels were established by measuring speed of scene category detection using a Go/No-Go detection paradigm. Experiment 1 shows that built scenes are more salient than natural scenes. Experiment 2 replicates these findings using greyscale images, ruling out a colour-based response strategy, and additionally shows that built objects in natural scenes affect saliency to a greater extent than the reverse. Experiment 3 demonstrates that the saliency of scene content is directly linked to cognitive restoration using an established restoration paradigm. Overall, these findings demonstrate an important link between the saliency of scene content and related cognitive restoration. PMID:28723975

  19. Radio Wave Propagation Scene Partitioning for High-Speed Rails

    Directory of Open Access Journals (Sweden)

    Bo Ai

    2012-01-01

    Full Text Available Radio wave propagation scene partitioning is necessary for wireless channel modeling. As far as we know, there are no standards of scene partitioning for high-speed rail (HSR scenarios, and therefore we propose the radio wave propagation scene partitioning scheme for HSR scenarios in this paper. Based on our measurements along the Wuhan-Guangzhou HSR, Zhengzhou-Xian passenger-dedicated line, Shijiazhuang-Taiyuan passenger-dedicated line, and Beijing-Tianjin intercity line in China, whose operation speeds are above 300 km/h, and based on the investigations on Beijing South Railway Station, Zhengzhou Railway Station, Wuhan Railway Station, Changsha Railway Station, Xian North Railway Station, Shijiazhuang North Railway Station, Taiyuan Railway Station, and Tianjin Railway Station, we obtain an overview of HSR propagation channels and record many valuable measurement data for HSR scenarios. On the basis of these measurements and investigations, we partitioned the HSR scene into twelve scenarios. Further work on theoretical analysis based on radio wave propagation mechanisms, such as reflection and diffraction, may lead us to develop the standard of radio wave propagation scene partitioning for HSR. Our work can also be used as a basis for the wireless channel modeling and the selection of some key techniques for HSR systems.

  20. Changing scenes: memory for naturalistic events following change blindness.

    Science.gov (United States)

    Mäntylä, Timo; Sundström, Anna

    2004-11-01

    Research on scene perception indicates that viewers often fail to detect large changes to scene regions when these changes occur during a visual disruption such as a saccade or a movie cut. In two experiments, we examined whether this relative inability to detect changes would produce systematic biases in event memory. In Experiment 1, participants decided whether two successively presented images were the same or different, followed by a memory task, in which they recalled the content of the viewed scene. In Experiment 2, participants viewed a short video, in which an actor carried out a series of daily activities, and central scenes' attributes were changed during a movie cut. A high degree of change blindness was observed in both experiments, and these effects were related to scene complexity (Experiment 1) and level of retrieval support (Experiment 2). Most important, participants reported the changed, rather than the initial, event attributes following a failure in change detection. These findings suggest that attentional limitations during encoding contribute to biases in episodic memory.

  1. Integration of heterogeneous features for remote sensing scene classification

    Science.gov (United States)

    Wang, Xin; Xiong, Xingnan; Ning, Chen; Shi, Aiye; Lv, Guofang

    2018-01-01

    Scene classification is one of the most important issues in remote sensing (RS) image processing. We find that features from different channels (shape, spectral, texture, etc.), levels (low-level and middle-level), or perspectives (local and global) could provide various properties for RS images, and then propose a heterogeneous feature framework to extract and integrate heterogeneous features with different types for RS scene classification. The proposed method is composed of three modules (1) heterogeneous features extraction, where three heterogeneous feature types, called DS-SURF-LLC, mean-Std-LLC, and MS-CLBP, are calculated, (2) heterogeneous features fusion, where the multiple kernel learning (MKL) is utilized to integrate the heterogeneous features, and (3) an MKL support vector machine classifier for RS scene classification. The proposed method is extensively evaluated on three challenging benchmark datasets (a 6-class dataset, a 12-class dataset, and a 21-class dataset), and the experimental results show that the proposed method leads to good classification performance. It produces good informative features to describe the RS image scenes. Moreover, the integration of heterogeneous features outperforms some state-of-the-art features on RS scene classification tasks.

  2. Unconscious analyses of visual scenes based on feature conjunctions.

    Science.gov (United States)

    Tachibana, Ryosuke; Noguchi, Yasuki

    2015-06-01

    To efficiently process a cluttered scene, the visual system analyzes statistical properties or regularities of visual elements embedded in the scene. It is controversial, however, whether those scene analyses could also work for stimuli unconsciously perceived. Here we show that our brain performs the unconscious scene analyses not only using a single featural cue (e.g., orientation) but also based on conjunctions of multiple visual features (e.g., combinations of color and orientation information). Subjects foveally viewed a stimulus array (duration: 50 ms) where 4 types of bars (red-horizontal, red-vertical, green-horizontal, and green-vertical) were intermixed. Although a conscious perception of those bars was inhibited by a subsequent mask stimulus, the brain correctly analyzed the information about color, orientation, and color-orientation conjunctions of those invisible bars. The information of those features was then used for the unconscious configuration analysis (statistical processing) of the central bars, which induced a perceptual bias and illusory feature binding in visible stimuli at peripheral locations. While statistical analyses and feature binding are normally 2 key functions of the visual system to construct coherent percepts of visual scenes, our results show that a high-level analysis combining those 2 functions is correctly performed by unconscious computations in the brain. (c) 2015 APA, all rights reserved).

  3. Turbomachinery: latest developments in a changing scene

    International Nuclear Information System (INIS)

    1991-01-01

    The contributions to the 1991 European Conference on the latest developments in turbomachinery are presented. The topics covered include: computational fluid dynamics methods applied to the aerodynamics of turbine blades; developments associated with steam turbines and gas turbines; flow patterns for turbine blades; compressor design and development; turbine test facilities; film cooling; heat transfer; theoretical treatment of transonic and unsteady flow; condensation phenomena and wet steam flow; water extraction from steam turbine blades; wetness losses in steam turbines in nuclear power plants and pressure loss reduction; aerodynamic instabilities arising from governing valves in Pressurized Water Reactor steam turbines. (UK)

  4. Narrative Collage of Image Collections by Scene Graph Recombination.

    Science.gov (United States)

    Fang, Fei; Yi, Miao; Feng, Hui; Hu, Shenghong; Xiao, Chunxia

    2017-10-04

    Narrative collage is an interesting image editing art to summarize the main theme or storyline behind an image collection. We present a novel method to generate narrative images with plausible semantic scene structures. To achieve this goal, we introduce a layer graph and a scene graph to represent relative depth order and semantic relationship between image objects, respectively. We firstly cluster the input image collection to select representative images, and then extract a group of semantic salient objects from each representative image. Both Layer graphs and scene graphs are constructed and combined according to our specific rules for reorganizing the extracted objects in every image. We design an energy model to appropriately locate every object on the final canvas. Experiment results show that our method can produce competitive narrative collage result and works well on a wide range of image collections.

  5. Gordon Craig's Scene Project: a history open to revision

    Directory of Open Access Journals (Sweden)

    Luiz Fernando

    2014-09-01

    Full Text Available The article proposes a review of Gordon Craig’s Scene project, an invention patented in 1910 and developed until 1922. Craig himself kept an ambiguous position whether it was an unfulfilled project or not. His son and biographer Edward Craig sustained that Craig’s original aims were never achieved because of technical limitation, and most of the scholars who examined the matter followed this position. Departing from the actual screen models saved in the Bibliothèque Nationale de France, Craig’s original notebooks, and a short film from 1963, I defend that the patented project and the essay published in 1923 mean, indeed, the materialisation of the dreamed device of the thousand scenes in one scene

  6. Scene recognition based on integrating active learning with dictionary learning

    Science.gov (United States)

    Wang, Chengxi; Yin, Xueyan; Yang, Lin; Gong, Chengrong; Zheng, Caixia; Yi, Yugen

    2018-04-01

    Scene recognition is a significant topic in the field of computer vision. Most of the existing scene recognition models require a large amount of labeled training samples to achieve a good performance. However, labeling image manually is a time consuming task and often unrealistic in practice. In order to gain satisfying recognition results when labeled samples are insufficient, this paper proposed a scene recognition algorithm named Integrating Active Learning and Dictionary Leaning (IALDL). IALDL adopts projective dictionary pair learning (DPL) as classifier and introduces active learning mechanism into DPL for improving its performance. When constructing sampling criterion in active learning, IALDL considers both the uncertainty and representativeness as the sampling criteria to effectively select the useful unlabeled samples from a given sample set for expanding the training dataset. Experiment results on three standard databases demonstrate the feasibility and validity of the proposed IALDL.

  7. SAR Raw Data Generation for Complex Airport Scenes

    Directory of Open Access Journals (Sweden)

    Jia Li

    2014-10-01

    Full Text Available The method of generating the SAR raw data of complex airport scenes is studied in this paper. A formulation of the SAR raw signal model of airport scenes is given. Via generating the echoes from the background, aircrafts and buildings, respectively, the SAR raw data of the unified SAR imaging geometry is obtained from their vector additions. The multipath scattering and the shadowing between the background and different ground covers of standing airplanes and buildings are analyzed. Based on the scattering characteristics, coupling scattering models and SAR raw data models of different targets are given, respectively. A procedure is given to generate the SAR raw data of airport scenes. The SAR images from the simulated raw data demonstrate the validity of the proposed method.

  8. Use of AFIS for linking scenes of crime.

    Science.gov (United States)

    Hefetz, Ido; Liptz, Yakir; Vaturi, Shaul; Attias, David

    2016-05-01

    Forensic intelligence can provide critical information in criminal investigations - the linkage of crime scenes. The Automatic Fingerprint Identification System (AFIS) is an example of a technological improvement that has advanced the entire forensic identification field to strive for new goals and achievements. In one example using AFIS, a series of burglaries into private apartments enabled a fingerprint examiner to search latent prints from different burglary scenes against an unsolved latent print database. Latent finger and palm prints coming from the same source were associated with over than 20 cases. Then, by forensic intelligence and profile analysis the offender's behavior could be anticipated. He was caught, identified, and arrested. It is recommended to perform an AFIS search of LT/UL prints against current crimes automatically as part of laboratory protocol and not by an examiner's discretion. This approach may link different crime scenes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Virtual environments for scene of crime reconstruction and analysis

    Science.gov (United States)

    Howard, Toby L. J.; Murta, Alan D.; Gibson, Simon

    2000-02-01

    This paper describes research conducted in collaboration with Greater Manchester Police (UK), to evalute the utility of Virtual Environments for scene of crime analysis, forensic investigation, and law enforcement briefing and training. We present an illustrated case study of the construction of a high-fidelity virtual environment, intended to match a particular real-life crime scene as closely as possible. We describe and evaluate the combination of several approaches including: the use of the Manchester Scene Description Language for constructing complex geometrical models; the application of a radiosity rendering algorithm with several novel features based on human perceptual consideration; texture extraction from forensic photography; and experiments with interactive walkthroughs and large-screen stereoscopic display of the virtual environment implemented using the MAVERIK system. We also discuss the potential applications of Virtual Environment techniques in the Law Enforcement and Forensic communities.

  10. A global solution of the ICRH problem based on the combined use of a planar coupling model and hot-plasma ray-tracing in tokamak geometry

    International Nuclear Information System (INIS)

    Koch, R.; Bhatnagar, V.P.; Messiaen, A.M.; Eester, D. van

    1986-01-01

    The global solution of the theoretical problem of Ion Cyclotron Resonance Heating in tokamak plasmas is obtained by a subdivision of the problem into two simpler ones by virtue of the ''single pass absorption'' hypothesis. The coupling problem is solved in planar geometry, allowing computation of both the antenna electrical properties and the Radio-Frequency (RF) field distribution in the plasma facing the antenna. Starting from this field distribution, the initial conditions for ray-tracing are derived and the propagation and absorption of waves in the plasma bulk is solved in the geometric optics limit taking into account the full tokamak geometry and the kinetic wave description. In the minority heating, redistribution of the minority absorbed power to the other species is carred out using standard quasilinear theory. (orig.)

  11. Multiple vehicle routing and dispatching to an emergency scene

    OpenAIRE

    M S Daskin; A Haghani

    1984-01-01

    A model of the distribution of arrival time at the scene of an emergency for the first of many vehicles is developed for the case in which travel times on the links of the network are normally distributed and the path travel times of different vehicles are correlated. The model suggests that the probability that the first vehicle arrives at the scene within a given time may be increased by reducing the path time correlations, even if doing so necessitates increasing the mean path travel time ...

  12. Cortical Representations of Speech in a Multitalker Auditory Scene.

    Science.gov (United States)

    Puvvada, Krishna C; Simon, Jonathan Z

    2017-09-20

    The ability to parse a complex auditory scene into perceptual objects is facilitated by a hierarchical auditory system. Successive stages in the hierarchy transform an auditory scene of multiple overlapping sources, from peripheral tonotopically based representations in the auditory nerve, into perceptually distinct auditory-object-based representations in the auditory cortex. Here, using magnetoencephalography recordings from men and women, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in distinct hierarchical stages of the auditory cortex. Using systems-theoretic methods of stimulus reconstruction, we show that the primary-like areas in the auditory cortex contain dominantly spectrotemporal-based representations of the entire auditory scene. Here, both attended and ignored speech streams are represented with almost equal fidelity, and a global representation of the full auditory scene with all its streams is a better candidate neural representation than that of individual streams being represented separately. We also show that higher-order auditory cortical areas, by contrast, represent the attended stream separately and with significantly higher fidelity than unattended streams. Furthermore, the unattended background streams are more faithfully represented as a single unsegregated background object rather than as separated objects. Together, these findings demonstrate the progression of the representations and processing of a complex acoustic scene up through the hierarchy of the human auditory cortex. SIGNIFICANCE STATEMENT Using magnetoencephalography recordings from human listeners in a simulated cocktail party environment, we investigate how a complex acoustic scene consisting of multiple speech sources is represented in separate hierarchical stages of the auditory cortex. We show that the primary-like areas in the auditory cortex use a dominantly spectrotemporal-based representation of the entire auditory

  13. Image Chunking: Defining Spatial Building Blocks for Scene Analysis.

    Science.gov (United States)

    1987-04-01

    mumgs0.USmusa 7.AUWOJO 4. CIUTAC Rm6ANT Wuugme*j James V/. Mlahoney DACA? 6-85-C-00 10 NOQ 1 4-85-K-O 124 Artificial Inteligence Laboratory US USS 545...0197 672 IMAGE CHUWING: DEINING SPATIAL UILDING PLOCKS FOR 142 SCENE ANRLYSIS(U) MASSACHUSETTS INST OF TECH CAIIAIDGE ARTIFICIAL INTELLIGENCE LAO J...Technical Report 980 F-Image Chunking: Defining Spatial Building Blocks for Scene DTm -Analysis S ELECTED James V. Mahoney’ MIT Artificial Intelligence

  14. Recognition and attention guidance during contextual cueing in real-world scenes: evidence from eye movements.

    Science.gov (United States)

    Brockmole, James R; Henderson, John M

    2006-07-01

    When confronted with a previously encountered scene, what information is used to guide search to a known target? We contrasted the role of a scene's basic-level category membership with its specific arrangement of visual properties. Observers were repeatedly shown photographs of scenes that contained consistently but arbitrarily located targets, allowing target positions to be associated with scene content. Learned scenes were then unexpectedly mirror reversed, spatially translating visual features as well as the target across the display while preserving the scene's identity and concept. Mirror reversals produced a cost as the eyes initially moved toward the position in the display in which the target had previously appeared. The cost was not complete, however; when initial search failed, the eyes were quickly directed to the target's new position. These results suggest that in real-world scenes, shifts of attention are initially based on scene identity, and subsequent shifts are guided by more detailed information regarding scene and object layout.

  15. Fuzzy Emotional Semantic Analysis and Automated Annotation of Scene Images

    Directory of Open Access Journals (Sweden)

    Jianfang Cao

    2015-01-01

    Full Text Available With the advances in electronic and imaging techniques, the production of digital images has rapidly increased, and the extraction and automated annotation of emotional semantics implied by images have become issues that must be urgently addressed. To better simulate human subjectivity and ambiguity for understanding scene images, the current study proposes an emotional semantic annotation method for scene images based on fuzzy set theory. A fuzzy membership degree was calculated to describe the emotional degree of a scene image and was implemented using the Adaboost algorithm and a back-propagation (BP neural network. The automated annotation method was trained and tested using scene images from the SUN Database. The annotation results were then compared with those based on artificial annotation. Our method showed an annotation accuracy rate of 91.2% for basic emotional values and 82.4% after extended emotional values were added, which correspond to increases of 5.5% and 8.9%, respectively, compared with the results from using a single BP neural network algorithm. Furthermore, the retrieval accuracy rate based on our method reached approximately 89%. This study attempts to lay a solid foundation for the automated emotional semantic annotation of more types of images and therefore is of practical significance.

  16. Evaluating Color Descriptors for Object and Scene Recognition

    NARCIS (Netherlands)

    van de Sande, K.E.A.; Gevers, T.; Snoek, C.G.M.

    2010-01-01

    Image category recognition is important to access visual information on the level of objects and scene types. So far, intensity-based descriptors have been widely used for feature extraction at salient points. To increase illumination invariance and discriminative power, color descriptors have been

  17. Number of perceptually distinct surface colors in natural scenes.

    Science.gov (United States)

    Marín-Franch, Iván; Foster, David H

    2010-09-30

    The ability to perceptually identify distinct surfaces in natural scenes by virtue of their color depends not only on the relative frequency of surface colors but also on the probabilistic nature of observer judgments. Previous methods of estimating the number of discriminable surface colors, whether based on theoretical color gamuts or recorded from real scenes, have taken a deterministic approach. Thus, a three-dimensional representation of the gamut of colors is divided into elementary cells or points which are spaced at one discrimination-threshold unit intervals and which are then counted. In this study, information-theoretic methods were used to take into account both differing surface-color frequencies and observer response uncertainty. Spectral radiances were calculated from 50 hyperspectral images of natural scenes and were represented in a perceptually almost uniform color space. The average number of perceptually distinct surface colors was estimated as 7.3 × 10(3), much smaller than that based on counting methods. This number is also much smaller than the number of distinct points in a scene that are, in principle, available for reliable identification under illuminant changes, suggesting that color constancy, or the lack of it, does not generally determine the limit on the use of color for surface identification.

  18. Range and intensity vision for rock-scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, SG

    2007-11-01

    Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

  19. Words Matter: Scene Text for Image Classification and Retrieval

    NARCIS (Netherlands)

    Karaoglu, S.; Tao, R.; Gevers, T.; Smeulders, A.W.M.

    Text in natural images typically adds meaning to an object or scene. In particular, text specifies which business places serve drinks (e.g., cafe, teahouse) or food (e.g., restaurant, pizzeria), and what kind of service is provided (e.g., massage, repair). The mere presence of text, its words, and

  20. Significance of perceptually relevant image decolorization for scene classification

    Science.gov (United States)

    Viswanathan, Sowmya; Divakaran, Govind; Soman, Kutti Padanyl

    2017-11-01

    Color images contain luminance and chrominance components representing the intensity and color information, respectively. The objective of this paper is to show the significance of incorporating chrominance information to the task of scene classification. An improved color-to-grayscale image conversion algorithm that effectively incorporates chrominance information is proposed using the color-to-gray structure similarity index and singular value decomposition to improve the perceptual quality of the converted grayscale images. The experimental results based on an image quality assessment for image decolorization and its success rate (using the Cadik and COLOR250 datasets) show that the proposed image decolorization technique performs better than eight existing benchmark algorithms for image decolorization. In the second part of the paper, the effectiveness of incorporating the chrominance component for scene classification tasks is demonstrated using a deep belief network-based image classification system developed using dense scale-invariant feature transforms. The amount of chrominance information incorporated into the proposed image decolorization technique is confirmed with the improvement to the overall scene classification accuracy. Moreover, the overall scene classification performance improved by combining the models obtained using the proposed method and conventional decolorization methods.

  1. Estimating cotton canopy ground cover from remotely sensed scene reflectance

    International Nuclear Information System (INIS)

    Maas, S.J.

    1998-01-01

    Many agricultural applications require spatially distributed information on growth-related crop characteristics that could be supplied through aircraft or satellite remote sensing. A study was conducted to develop and test a methodology for estimating plant canopy ground cover for cotton (Gossypium hirsutum L.) from scene reflectance. Previous studies indicated that a relatively simple relationship between ground cover and scene reflectance could be developed based on linear mixture modeling. Theoretical analysis indicated that the effects of shadows in the scene could be compensated for by averaging the results obtained using scene reflectance in the red and near-infrared wavelengths. The methodology was tested using field data collected over several years from cotton test plots in Texas and California. Results of the study appear to verify the utility of this approach. Since the methodology relies on information that can be obtained solely through remote sensing, it would be particularly useful in applications where other field information, such as plant size, row spacing, and row orientation, is unavailable

  2. Ontology of a scene based on Java 3D architecture.

    Directory of Open Access Journals (Sweden)

    Rubén González Crespo

    2009-12-01

    Full Text Available The present article seeks to make an approach to the class hierarchy of a scene built with the architecture Java 3D, to develop an ontology of a scene as from the semantic essential components for the semantic structuring of the Web3D. Java was selected because the language recommended by the W3C Consortium for the Development of the Web3D oriented applications as from X3D standard is Xj3D which compositionof their Schemas is based the architecture of Java3D In first instance identifies the domain and scope of the ontology, defining classes and subclasses that comprise from Java3D architecture and the essential elements of a scene, as its point of origin, the field of rotation, translation The limitation of the scene and the definition of shaders, then define the slots that are declared in RDF as a framework for describing the properties of the classes established from identifying thedomain and range of each class, then develops composition of the OWL ontology on SWOOP Finally, be perform instantiations of the ontology building for a Iconosphere object as from class expressions defined.

  3. Audio scene segmentation for video with generic content

    Science.gov (United States)

    Niu, Feng; Goela, Naveen; Divakaran, Ajay; Abdel-Mottaleb, Mohamed

    2008-01-01

    In this paper, we present a content-adaptive audio texture based method to segment video into audio scenes. The audio scene is modeled as a semantically consistent chunk of audio data. Our algorithm is based on "semantic audio texture analysis." At first, we train GMM models for basic audio classes such as speech, music, etc. Then we define the semantic audio texture based on those classes. We study and present two types of scene changes, those corresponding to an overall audio texture change and those corresponding to a special "transition marker" used by the content creator, such as a short stretch of music in a sitcom or silence in dramatic content. Unlike prior work using genre specific heuristics, such as some methods presented for detecting commercials, we adaptively find out if such special transition markers are being used and if so, which of the base classes are being used as markers without any prior knowledge about the content. Our experimental results show that our proposed audio scene segmentation works well across a wide variety of broadcast content genres.

  4. Range sections as rock models for intensity rock scene segmentation

    CSIR Research Space (South Africa)

    Mkwelo, S

    2007-11-01

    Full Text Available This paper presents another approach to segmenting a scene of rocks on a conveyor belt for the purposes of measuring rock size. Rock size estimation instruments are used to monitor, optimize and control milling and crushing in the mining industry...

  5. Coping with Perceived Ethnic Prejudice on the Gay Scene

    Science.gov (United States)

    Jaspal, Rusi

    2017-01-01

    There has been only cursory research into the sociological and psychological aspects of ethnic/racial discrimination among ethnic minority gay and bisexual men, and none that focuses specifically upon British ethnic minority gay men. This article focuses on perceptions of intergroup relations on the gay scene among young British South Asian gay…

  6. Semantic Categorization Precedes Affective Evaluation of Visual Scenes

    Science.gov (United States)

    Nummenmaa, Lauri; Hyona, Jukka; Calvo, Manuel G.

    2010-01-01

    We compared the primacy of affective versus semantic categorization by using forced-choice saccadic and manual response tasks. Participants viewed paired emotional and neutral scenes involving humans or animals flashed rapidly in extrafoveal vision. Participants were instructed to categorize the targets by saccading toward the location occupied by…

  7. Cultural heritage and history in the European metal scene

    NARCIS (Netherlands)

    Klepper, de S.; Molpheta, S.; Pille, S.; Saouma, R.; During, R.; Muilwijk, M.

    2007-01-01

    This paper represents an inquiry on the use of history and cultural heritage in the metal scene. It is an attempt to show how history and cultural heritage can possibly be spread among people using an unconventional way. The followed research method was built on an explorative study that included an

  8. The role of memory for visual search in scenes.

    Science.gov (United States)

    Le-Hoa Võ, Melissa; Wolfe, Jeremy M

    2015-03-01

    Many daily activities involve looking for something. The ease with which these searches are performed often allows one to forget that searching represents complex interactions between visual attention and memory. Although a clear understanding exists of how search efficiency will be influenced by visual features of targets and their surrounding distractors or by the number of items in the display, the role of memory in search is less well understood. Contextual cueing studies have shown that implicit memory for repeated item configurations can facilitate search in artificial displays. When searching more naturalistic environments, other forms of memory come into play. For instance, semantic memory provides useful information about which objects are typically found where within a scene, and episodic scene memory provides information about where a particular object was seen the last time a particular scene was viewed. In this paper, we will review work on these topics, with special emphasis on the role of memory in guiding search in organized, real-world scenes. © 2015 New York Academy of Sciences.

  9. Learning object-to-class kernels for scene classification.

    Science.gov (United States)

    Zhang, Lei; Zhen, Xiantong; Shao, Ling

    2014-08-01

    High-level image representations have drawn increasing attention in visual recognition, e.g., scene classification, since the invention of the object bank. The object bank represents an image as a response map of a large number of pretrained object detectors and has achieved superior performance for visual recognition. In this paper, based on the object bank representation, we propose the object-to-class (O2C) distances to model scene images. In particular, four variants of O2C distances are presented, and with the O2C distances, we can represent the images using the object bank by lower-dimensional but more discriminative spaces, called distance spaces, which are spanned by the O2C distances. Due to the explicit computation of O2C distances based on the object bank, the obtained representations can possess more semantic meanings. To combine the discriminant ability of the O2C distances to all scene classes, we further propose to kernalize the distance representation for the final classification. We have conducted extensive experiments on four benchmark data sets, UIUC-Sports, Scene-15, MIT Indoor, and Caltech-101, which demonstrate that the proposed approaches can significantly improve the original object bank approach and achieve the state-of-the-art performance.

  10. Semi-Supervised Multitask Learning for Scene Recognition.

    Science.gov (United States)

    Lu, Xiaoqiang; Li, Xuelong; Mou, Lichao

    2015-09-01

    Scene recognition has been widely studied to understand visual information from the level of objects and their relationships. Toward scene recognition, many methods have been proposed. They, however, encounter difficulty to improve the accuracy, mainly due to two limitations: 1) lack of analysis of intrinsic relationships across different scales, say, the initial input and its down-sampled versions and 2) existence of redundant features. This paper develops a semi-supervised learning mechanism to reduce the above two limitations. To address the first limitation, we propose a multitask model to integrate scene images of different resolutions. For the second limitation, we build a model of sparse feature selection-based manifold regularization (SFSMR) to select the optimal information and preserve the underlying manifold structure of data. SFSMR coordinates the advantages of sparse feature selection and manifold regulation. Finally, we link the multitask model and SFSMR, and propose the semi-supervised learning method to reduce the two limitations. Experimental results report the improvements of the accuracy in scene recognition.

  11. Characteristics of nontrauma scene flights for air medical transport.

    Science.gov (United States)

    Krebs, Margaret G; Fletcher, Erica N; Werman, Howard; McKenzie, Lara B

    2014-01-01

    Little is known about the use of air medical transport for patients with medical, rather than traumatic, emergencies. This study describes the practices of air transport programs, with respect to nontrauma scene responses, in several areas throughout the United States and Canada. A descriptive, retrospective study was conducted of all nontrauma scene flights from 2008 and 2009. Flight information and patient demographic data were collected from 5 air transport programs. Descriptive statistics were used to examine indications for transport, Glasgow Coma Scale Scores, and loaded miles traveled. A total of 1,785 nontrauma scene flights were evaluated. The percentage of scene flights contributed by nontraumatic emergencies varied between programs, ranging from 0% to 44.3%. The most common indication for transport was cardiac, nonST-segment elevation myocardial infarction (22.9%). Cardiac arrest was the indication for transport in 2.5% of flights. One air transport program reported a high percentage (49.4) of neurologic, stroke, flights. The use of air transport for nontraumatic emergencies varied considerably between various air transport programs and regions. More research is needed to evaluate which nontraumatic emergencies benefit from air transport. National guidelines regarding the use of air transport for nontraumatic emergencies are needed. Copyright © 2014 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

  12. Anticipatory scene representation in preschool children's recall and recognition memory.

    Science.gov (United States)

    Kreindel, Erica; Intraub, Helene

    2017-09-01

    Behavioral and neuroscience research on boundary extension (false memory beyond the edges of a view of a scene) has provided new insights into the constructive nature of scene representation, and motivates questions about development. Early research with children (as young as 6-7 years) was consistent with boundary extension, but relied on an analysis of spatial errors in drawings which are open to alternative explanations (e.g. drawing ability). Experiment 1 replicated and extended prior drawing results with 4-5-year-olds and adults. In Experiment 2, a new, forced-choice immediate recognition memory test was implemented with the same children. On each trial, a card (photograph of a simple scene) was immediately replaced by a test card (identical view and either a closer or more wide-angle view) and participants indicated which one matched the original view. Error patterns supported boundary extension; identical photographs were more frequently rejected when the closer view was the original view, than vice versa. This asymmetry was not attributable to a selection bias (guessing tasks; Experiments 3-5). In Experiment 4, working memory load was increased by presenting more expansive views of more complex scenes. Again, children exhibited boundary extension, but now adults did not, unless stimulus duration was reduced to 5 s (limiting time to implement strategies; Experiment 5). We propose that like adults, children interpret photographs as views of places in the world; they extrapolate the anticipated continuation of the scene beyond the view and misattribute it to having been seen. Developmental differences in source attribution decision processes provide an explanation for the age-related differences observed. © 2016 John Wiley & Sons Ltd.

  13. Exploring eye movements in patients with glaucoma when viewing a driving scene.

    Directory of Open Access Journals (Sweden)

    David P Crabb

    Full Text Available BACKGROUND: Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT. METHODOLOGY/PRINCIPAL FINDINGS: The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers. Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis. On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%. Whilst the average region of 'point-of-regard' of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. CONCLUSIONS/SIGNIFICANCE: Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could

  14. Exploring eye movements in patients with glaucoma when viewing a driving scene.

    Science.gov (United States)

    Crabb, David P; Smith, Nicholas D; Rauscher, Franziska G; Chisholm, Catharine M; Barbur, John L; Edgar, David F; Garway-Heath, David F

    2010-03-16

    Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of 'point-of-regard' of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful information about the definition of the visual field component required for

  15. Construction and Optimization of Three-Dimensional Disaster Scenes within Mobile Virtual Reality

    Directory of Open Access Journals (Sweden)

    Ya Hu

    2018-06-01

    Full Text Available Because mobile virtual reality (VR is both mobile and immersive, three-dimensional (3D visualizations of disaster scenes based in mobile VR enable users to perceive and recognize disaster environments faster and better than is possible with other methods. To achieve immersion and prevent users from feeling dizzy, such visualizations require a high scene-rendering frame rate. However, the existing related visualization work cannot provide a sufficient solution for this purpose. This study focuses on the construction and optimization of a 3D disaster scene in order to satisfy the high frame-rate requirements for the rendering of 3D disaster scenes in mobile VR. First, the design of a plugin-free browser/server (B/S architecture for 3D disaster scene construction and visualization based in mobile VR is presented. Second, certain key technologies for scene optimization are discussed, including diverse modes of scene data representation, representation optimization of mobile scenes, and adaptive scheduling of mobile scenes. By means of these technologies, smartphones with various performance levels can achieve higher scene-rendering frame rates and improved visual quality. Finally, using a flood disaster as an example, a plugin-free prototype system was developed, and experiments were conducted. The experimental results demonstrate that a 3D disaster scene constructed via the methods addressed in this study has a sufficiently high scene-rendering frame rate to satisfy the requirements for rendering a 3D disaster scene in mobile VR.

  16. Sensory substitution: the spatial updating of auditory scenes ‘mimics’ the spatial updating of visual scenes

    Directory of Open Access Journals (Sweden)

    Achille ePasqualotto

    2016-04-01

    Full Text Available Visual-to-auditory sensory substitution is used to convey visual information through audition, and it was initially created to compensate for blindness; it consists of software converting the visual images captured by a video-camera into the equivalent auditory images, or ‘soundscapes’. Here, it was used by blindfolded sighted participants to learn the spatial position of simple shapes depicted in images arranged on the floor. Very few studies have used sensory substitution to investigate spatial representation, while it has been widely used to investigate object recognition. Additionally, with sensory substitution we could study the performance of participants actively exploring the environment through audition, rather than passively localising sound sources. Blindfolded participants egocentrically learnt the position of six images by using sensory substitution and then a judgement of relative direction task (JRD was used to determine how this scene was represented. This task consists of imagining being in a given location, oriented in a given direction, and pointing towards the required image. Before performing the JRD task, participants explored a map that provided allocentric information about the scene. Although spatial exploration was egocentric, surprisingly we found that performance in the JRD task was better for allocentric perspectives. This suggests that the egocentric representation of the scene was updated. This result is in line with previous studies using visual and somatosensory scenes, thus supporting the notion that different sensory modalities produce equivalent spatial representation(s. Moreover, our results have practical implications to improve training methods with sensory substitution devices.

  17. Technicolor/INRIA team at the MediaEval 2013 Violent Scenes Detection Task

    OpenAIRE

    Penet , Cédric; Demarty , Claire-Hélène; Gravier , Guillaume; Gros , Patrick

    2013-01-01

    International audience; This paper presents the work done at Technicolor and INRIA regarding the MediaEval 2013 Violent Scenes Detection task, which aims at detecting violent scenes in movies. We participated in both the objective and the subjective subtasks.

  18. 3D Aware Correction and Completion of Depth Maps in Piecewise Planar Scenes

    KAUST Repository

    Thabet, Ali Kassem; Lahoud, Jean; Asmar, Daniel; Ghanem, Bernard

    2015-01-01

    RGB-D sensors are popular in the computer vision community, especially for problems of scene understanding, semantic scene labeling, and segmentation. However, most of these methods depend on reliable input depth measurements, while discarding

  19. Scene and character: interdisciplinary analysis of musical and sound symbols for higher education

    Directory of Open Access Journals (Sweden)

    Josep Gustems Carnicer

    2017-01-01

    Full Text Available The aim of this paper is to analyze interdisciplinary and educationally the descriptive aspects of the characters in literature in the world of music (opera, ballet, musical theater, program music, audiovisual, etc. through a wide range of resources and creative processes in various skills that include or encompass the sound. Because of that a literature review and multidisciplinary documentary is done from the most relevant texts and principal authors of the dynamic and stable personality models, from the analysis of vocal features in the scene and in the audiovisuals, from the leitmotiv as a symbol and sound representation of the character, from the the conflicts faced by the characters and how they can overcome them and how we could translated into music those transitions. The subject of myths brought to the world of music scene, character stereotypes and sound symbols that may characterize these scenic and literary content is also addressed. Notably, there is a broad consensus on the use of sound resources to characterize the different characters throughout the history of Western music in its various styles and genres. Furthermore, indications for their use are given and suggestions for activities to higher education suggest.

  20. Feature diagnosticity and task context shape activity in human scene-selective cortex.

    Science.gov (United States)

    Lowe, Matthew X; Gallivan, Jason P; Ferber, Susanne; Cant, Jonathan S

    2016-01-15

    Scenes are constructed from multiple visual features, yet previous research investigating scene processing has often focused on the contributions of single features in isolation. In the real world, features rarely exist independently of one another and likely converge to inform scene identity in unique ways. Here, we utilize fMRI and pattern classification techniques to examine the interactions between task context (i.e., attend to diagnostic global scene features; texture or layout) and high-level scene attributes (content and spatial boundary) to test the novel hypothesis that scene-selective cortex represents multiple visual features, the importance of which varies according to their diagnostic relevance across scene categories and task demands. Our results show for the first time that scene representations are driven by interactions between multiple visual features and high-level scene attributes. Specifically, univariate analysis of scene-selective cortex revealed that task context and feature diagnosticity shape activity differentially across scene categories. Examination using multivariate decoding methods revealed results consistent with univariate findings, but also evidence for an interaction between high-level scene attributes and diagnostic visual features within scene categories. Critically, these findings suggest visual feature representations are not distributed uniformly across scene categories but are shaped by task context and feature diagnosticity. Thus, we propose that scene-selective cortex constructs a flexible representation of the environment by integrating multiple diagnostically relevant visual features, the nature of which varies according to the particular scene being perceived and the goals of the observer. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Intra- and interobserver variability of MRI-based volume measurements of the hippocampus and amygdala using the manual ray-tracing method

    International Nuclear Information System (INIS)

    Achten, E.; Deblaere, K.; Damme, F. van; Kunnen, M.; Wagter, C. de; Boon, P.; Reuck, J. de

    1998-01-01

    We studied the intra- and interobserver variability of volume measurments of the hippocampus (HC) and the amygdala as applied to the detection of HC atrophy in patients with complex partial seizures (CPE), measuring the volumes of the HC and amygdala of 11 normal volunteers and 12 patients with presumed CPE, using the manual ray-tracing method. Two independent observers performed these measurements twice each using home-made software. The intra- and interobserver variability of the absolute volumes and of the normalised left-to-right volume differences (δV) between the HC (δV HC ), the amygdala (δV A ) and the sum of both (δV HCA) were assessed. In our mainly right-handed normals, the right HC and amygdala were on average 0.05 and 0.03 ml larger respectively than on the left. The interobserver variability for volume measurements in normal subjects was 1.80 ml for the HC and 0.82 ml for the amygdala, the intraobserver variability roughly one third of these values. The interobserver variability coefficient in normals was 3.6 % for δV HCA , 4.7 % for δV HC and 7.3 % for δV A . The intraobserver variability coefficient was 3.4 % for δV HCA , 4.2 % for δV HC amd 5.6 % for δV A . The variability in patients was the same for volume differences less than 5 % either side of the interval for normality, but was higher when large volume differences were encountered, is probably due to the lack of thresholding and/or normalisation. Cutoff values for lateralisation with the δV were defined. No intra- or interobserver lateralisation differences were encountered with δV HCA and δV HC . From these observations we conclude that the manual ray-tracing method is a robust method for lateralisation in patients with TLE. Due to its higher variability, this method is less suited to measure absolute volumes. (orig.) (orig.)

  2. Intra- and interobserver variability of MRI-based volume measurements of the hippocampus and amygdala using the manual ray-tracing method

    Energy Technology Data Exchange (ETDEWEB)

    Achten, E.; Deblaere, K.; Damme, F. van; Kunnen, M. [MR Department 1K12, University Hospital Gent (Belgium); Wagter, C. de [Department of Radiotherapy and Nuclear Medicine, University Hospital Gent (Belgium); Boon, P.; Reuck, J. de [Department of Neurology, University Hospital Gent (Belgium)

    1998-09-01

    We studied the intra- and interobserver variability of volume measurments of the hippocampus (HC) and the amygdala as applied to the detection of HC atrophy in patients with complex partial seizures (CPE), measuring the volumes of the HC and amygdala of 11 normal volunteers and 12 patients with presumed CPE, using the manual ray-tracing method. Two independent observers performed these measurements twice each using home-made software. The intra- and interobserver variability of the absolute volumes and of the normalised left-to-right volume differences ({delta}V) between the HC ({delta}V{sub HC}), the amygdala ({delta}V{sub A}) and the sum of both ({delta}V{sub HCA)} were assessed. In our mainly right-handed normals, the right HC and amygdala were on average 0.05 and 0.03 ml larger respectively than on the left. The interobserver variability for volume measurements in normal subjects was 1.80 ml for the HC and 0.82 ml for the amygdala, the intraobserver variability roughly one third of these values. The interobserver variability coefficient in normals was 3.6 % for {delta}V{sub HCA}, 4.7 % for {delta}V{sub HC} and 7.3 % for {delta}V{sub A}. The intraobserver variability coefficient was 3.4 % for {delta}V{sub HCA}, 4.2 % for {delta}V{sub HC} amd 5.6 % for {delta}V{sub A}. The variability in patients was the same for volume differences less than 5 % either side of the interval for normality, but was higher when large volume differences were encountered, is probably due to the lack of thresholding and/or normalisation. Cutoff values for lateralisation with the {delta}V were defined. No intra- or interobserver lateralisation differences were encountered with {delta}V{sub HCA} and {delta}V{sub HC}. From these observations we conclude that the manual ray-tracing method is a robust method for lateralisation in patients with TLE. Due to its higher variability, this method is less suited to measure absolute volumes. (orig.) (orig.) With 2 figs., 7 tabs., 23 refs.

  3. A view not to be missed: Salient scene content interferes with cognitive restoration

    NARCIS (Netherlands)

    van der Jagt, A.P.N.; Craig, Tony; Brewer, Mark J.; Pearson, David G.

    2017-01-01

    Attention Restoration Theory (ART) states that built scenes place greater load on attentional resources than natural scenes. This is explained in terms of "hard" and "soft" fascination of built and natural scenes. Given a lack of direct empirical evidence for this assumption we propose that

  4. Scene complexity: influence on perception, memory, and development in the medial temporal lobe

    Directory of Open Access Journals (Sweden)

    Xiaoqian J Chai

    2010-03-01

    Full Text Available Regions in the medial temporal lobe (MTL and prefrontal cortex (PFC are involved in memory formation for scenes in both children and adults. The development in children and adolescents of successful memory encoding for scenes has been associated with increased activation in PFC, but not MTL, regions. However, evidence suggests that a functional subregion of the MTL that supports scene perception, located in the parahippocampal gyrus (PHG, goes through a prolonged maturation process. Here we tested the hypothesis that maturation of scene perception supports the development of memory for complex scenes. Scenes were characterized by their levels of complexity defined by the number of unique object categories depicted in the scene. Recognition memory improved with age, in participants ages 8-24, for high, but not low, complexity scenes. High-complexity compared to low-complexity scenes activated a network of regions including the posterior PHG. The difference in activations for high- versus low- complexity scenes increased with age in the right posterior PHG. Finally, activations in right posterior PHG were associated with age-related increases in successful memory formation for high-, but not low-, complexity scenes. These results suggest that functional maturation of the right posterior PHG plays a critical role in the development of enduring long-term recollection for high-complexity scenes.

  5. Separate and simultaneous adjustment of light qualities in a real scene

    NARCIS (Netherlands)

    Xia, L.; Pont, S.C.; Heynderickx, I.E.J.R.

    2017-01-01

    Humans are able to estimate light field properties in a scene in that they have expectations of the objects' appearance inside it. Previously, we probed such expectations in a real scene by asking whether a "probe object" fitted a real scene with regard to its lighting. But how well are observers

  6. Guidance of Attention to Objects and Locations by Long-Term Memory of Natural Scenes

    Science.gov (United States)

    Becker, Mark W.; Rasmussen, Ian P.

    2008-01-01

    Four flicker change-detection experiments demonstrate that scene-specific long-term memory guides attention to both behaviorally relevant locations and objects within a familiar scene. Participants performed an initial block of change-detection trials, detecting the addition of an object to a natural scene. After a 30-min delay, participants…

  7. Mirth and Murder: Crime Scene Investigation as a Work Context for Examining Humor Applications

    Science.gov (United States)

    Roth, Gene L.; Vivona, Brian

    2010-01-01

    Within work settings, humor is used by workers for a wide variety of purposes. This study examines humor applications of a specific type of worker in a unique work context: crime scene investigation. Crime scene investigators examine death and its details. Members of crime scene units observe death much more frequently than other police officers…

  8. Visual search for changes in scenes creates long-term, incidental memory traces.

    Science.gov (United States)

    Utochkin, Igor S; Wolfe, Jeremy M

    2018-05-01

    Humans are very good at remembering large numbers of scenes over substantial periods of time. But how good are they at remembering changes to scenes? In this study, we tested scene memory and change detection two weeks after initial scene learning. In Experiments 1-3, scenes were learned incidentally during visual search for change. In Experiment 4, observers explicitly memorized scenes. At test, after two weeks observers were asked to discriminate old from new scenes, to recall a change that they had detected in the study phase, or to detect a newly introduced change in the memorization experiment. Next, they performed a change detection task, usually looking for the same change as in the study period. Scene recognition memory was found to be similar in all experiments, regardless of the study task. In Experiment 1, more difficult change detection produced better scene memory. Experiments 2 and 3 supported a "depth-of-processing" account for the effects of initial search and change detection on incidental memory for scenes. Of most interest, change detection was faster during the test phase than during the study phase, even when the observer had no explicit memory of having found that change previously. This result was replicated in two of our three change detection experiments. We conclude that scenes can be encoded incidentally as well as explicitly and that changes in those scenes can leave measurable traces even if they are not explicitly recalled.

  9. Defining spatial relations in a specific ontology for automated scene creation

    Directory of Open Access Journals (Sweden)

    D. Contraş

    2013-06-01

    Full Text Available This paper presents the approach of building an ontology for automatic scene generation. Every scene contains various elements (backgrounds, characters, objects which are spatially interrelated. The article focuses on these spatial and temporal relationships of the elements constituting a scene.

  10. Multimodal computational attention for scene understanding and robotics

    CERN Document Server

    Schauerte, Boris

    2016-01-01

    This book presents state-of-the-art computational attention models that have been successfully tested in diverse application areas and can build the foundation for artificial systems to efficiently explore, analyze, and understand natural scenes. It gives a comprehensive overview of the most recent computational attention models for processing visual and acoustic input. It covers the biological background of visual and auditory attention, as well as bottom-up and top-down attentional mechanisms and discusses various applications. In the first part new approaches for bottom-up visual and acoustic saliency models are presented and applied to the task of audio-visual scene exploration of a robot. In the second part the influence of top-down cues for attention modeling is investigated. .

  11. Enhancing Visual Basic GUI Applications using VRML Scenes

    OpenAIRE

    Bala Dhandayuthapani Veerasamy

    2010-01-01

    Rapid Application Development (RAD) enables ever expanding needs for speedy development of computer application programs that are sophisticated, reliable, and full-featured. Visual Basic was the first RAD tool for the Windows operating system, and too many people say still it is the best. To provide very good attraction in visual basic 6 applications, this paper directing to use VRML scenes over the visual basic environment.

  12. Context modulates attention to social scenes in toddlers with autism

    Science.gov (United States)

    Chawarska, Katarzyna; Macari, Suzanne; Shic, Frederick

    2013-01-01

    Background In typical development, the unfolding of social and communicative skills hinges upon the ability to allocate and sustain attention towards people, a skill present moments after birth. Deficits in social attention have been well documented in autism, though the underlying mechanisms are poorly understood. Methods In order to parse the factors that are responsible for limited social attention in toddlers with autism, we manipulated the context in which a person appeared in their visual field with regard to the presence of salient social (child-directed speech and eye contact) and nonsocial (distractor toys) cues for attention. Participants included 13- to 25-month-old toddlers with autism (AUT; n=54), developmental delay (DD; n=22), and typical development (TD; n=48). Their visual responses were recorded with an eye-tracker. Results In conditions devoid of eye contact and speech, the distribution of attention between key features of the social scene in toddlers with autism was comparable to that in DD and TD controls. However, when explicit dyadic cues were introduced, toddlers with autism showed decreased attention to the entire scene and, when they looked at the scene, they spent less time looking at the speaker’s face and monitoring her lip movements than the control groups. In toddlers with autism, decreased time spent exploring the entire scene was associated with increased symptom severity and lower nonverbal functioning; atypical language profiles were associated with decreased monitoring of the speaker’s face and her mouth. Conclusions While in certain contexts toddlers with autism attend to people and objects in a typical manner, they show decreased attentional response to dyadic cues for attention. Given that mechanisms supporting responsivity to dyadic cues are present shortly after birth and are highly consequential for development of social cognition and communication, these findings have important implications for the understanding of the

  13. Overt attention in natural scenes: objects dominate features.

    Science.gov (United States)

    Stoll, Josef; Thrun, Michael; Nuthmann, Antje; Einhäuser, Wolfgang

    2015-02-01

    Whether overt attention in natural scenes is guided by object content or by low-level stimulus features has become a matter of intense debate. Experimental evidence seemed to indicate that once object locations in a scene are known, salience models provide little extra explanatory power. This approach has recently been criticized for using inadequate models of early salience; and indeed, state-of-the-art salience models outperform trivial object-based models that assume a uniform distribution of fixations on objects. Here we propose to use object-based models that take a preferred viewing location (PVL) close to the centre of objects into account. In experiment 1, we demonstrate that, when including this comparably subtle modification, object-based models again are at par with state-of-the-art salience models in predicting fixations in natural scenes. One possible interpretation of these results is that objects rather than early salience dominate attentional guidance. In this view, early-salience models predict fixations through the correlation of their features with object locations. To test this hypothesis directly, in two additional experiments we reduced low-level salience in image areas of high object content. For these modified stimuli, the object-based model predicted fixations significantly better than early salience. This finding held in an object-naming task (experiment 2) and a free-viewing task (experiment 3). These results provide further evidence for object-based fixation selection--and by inference object-based attentional guidance--in natural scenes. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. Effect of Smoking Scenes in Films on Immediate Smoking

    Science.gov (United States)

    Shmueli, Dikla; Prochaska, Judith J.; Glantz, Stanton A.

    2010-01-01

    Background The National Cancer Institute has concluded that exposure to smoking in movies causes adolescent smoking and there are similar results for young adults. Purpose This study investigated whether exposure of young adult smokers to images of smoking in films stimulated smoking behavior. Methods 100 cigarette smokers aged 18–25 years were randomly assigned to watch a movie montage composed with or without smoking scenes and paraphernalia followed by a10-minute recess. The outcome was whether or not participants smoked during the recess. Data were collected and analyzed in 2008 and 2009. Results Smokers who watched the smoking scenes were more likely to smoke during the break (OR3.06, 95% CI=1.01, 9.29). In addition to this acute effect of exposure, smokers who had seen more smoking in movies before the day of the experiment were more likely to smoke during the break (OR 6.73; 1.00–45.25 comparing the top to bottom percentiles of exposure) were more likely to smoke during the break. Level of nicotine dependence (OR 1.71; 1.27–2.32 per point on the FTND scale), “contemplation” (OR 9.07; 1.71–47.99) and “precontemplation” (OR 7.30; 1.39–38.36) stages of change, and impulsivity (OR 1.21; 1.03–1.43), were also associated with smoking during the break. Participants who watched the montage with smoking scenes and those with a higher level of nicotine dependence were also more likely to have smoked within 30 minutes after the study. Conclusions There is a direct link between viewing smoking scenes and immediate subsequent smoking behavior. This finding suggests that individuals attempting to limit or quit smoking should be advised to refrain from or reduce their exposure to movies that contain smoking. PMID:20307802

  15. TESSITURA OF A CREATIVE PROCESS: AUTOBIOGRAPHY ON SCENE

    Directory of Open Access Journals (Sweden)

    Daniel Santos Costa

    2015-04-01

    Full Text Available This text presents weavings of a way to make the arts scene using the autobiographical support the creative process. Thus, we elucidate some of these weavings process while legitimizing the production of knowledge through artistic praxis, of sensitive experience. Introducing the concept of autobiography in analogy to the artistic and sequentially present the possibility of a laboratory setting amalgamated into reality/fiction. Keywords: creative process; autobiography; body.

  16. Neural Correlates of Divided Attention in Natural Scenes.

    Science.gov (United States)

    Fagioli, Sabrina; Macaluso, Emiliano

    2016-09-01

    Individuals are able to split attention between separate locations, but divided spatial attention incurs the additional requirement of monitoring multiple streams of information. Here, we investigated divided attention using photos of natural scenes, where the rapid categorization of familiar objects and prior knowledge about the likely positions of objects in the real world might affect the interplay between these spatial and nonspatial factors. Sixteen participants underwent fMRI during an object detection task. They were presented with scenes containing either a person or a car, located on the left or right side of the photo. Participants monitored either one or both object categories, in one or both visual hemifields. First, we investigated the interplay between spatial and nonspatial attention by comparing conditions of divided attention between categories and/or locations. We then assessed the contribution of top-down processes versus stimulus-driven signals by separately testing the effects of divided attention in target and nontarget trials. The results revealed activation of a bilateral frontoparietal network when dividing attention between the two object categories versus attending to a single category but no main effect of dividing attention between spatial locations. Within this network, the left dorsal premotor cortex and the left intraparietal sulcus were found to combine task- and stimulus-related signals. These regions showed maximal activation when participants monitored two categories at spatially separate locations and the scene included a nontarget object. We conclude that the dorsal frontoparietal cortex integrates top-down and bottom-up signals in the presence of distractors during divided attention in real-world scenes.

  17. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  18. The Anthropo-scene: A guide for the perplexed.

    Science.gov (United States)

    Lorimer, Jamie

    2017-02-01

    The scientific proposal that the Earth has entered a new epoch as a result of human activities - the Anthropocene - has catalysed a flurry of intellectual activity. I introduce and review the rich, inchoate and multi-disciplinary diversity of this Anthropo-scene. I identify five ways in which the concept of the Anthropocene has been mobilized: scientific question, intellectual zeitgeist, ideological provocation, new ontologies and science fiction. This typology offers an analytical framework for parsing this diversity, for understanding the interactions between different ways of thinking in the Anthropo-scene, and thus for comprehending elements of its particular and peculiar sociabilities. Here I deploy this framework to situate Earth Systems Science within the Anthropo-scene, exploring both the status afforded science in discussions of this new epoch, and the various ways in which the other means of engaging with the concept come to shape the conduct, content and politics of this scientific enquiry. In conclusion the paper reflects on the potential of the Anthropocene for new modes of academic praxis.

  19. Oxytocin increases amygdala reactivity to threatening scenes in females.

    Science.gov (United States)

    Lischke, Alexander; Gamer, Matthias; Berger, Christoph; Grossmann, Annette; Hauenstein, Karlheinz; Heinrichs, Markus; Herpertz, Sabine C; Domes, Gregor

    2012-09-01

    The neuropeptide oxytocin (OT) is well known for its profound effects on social behavior, which appear to be mediated by an OT-dependent modulation of amygdala activity in the context of social stimuli. In humans, OT decreases amygdala reactivity to threatening faces in males, but enhances amygdala reactivity to similar faces in females, suggesting sex-specific differences in OT-dependent threat-processing. To further explore whether OT generally enhances amygdala-dependent threat-processing in females, we used functional magnetic resonance imaging (fMRI) in a randomized within-subject crossover design to measure amygdala activity in response to threatening and non-threatening scenes in 14 females following intranasal administration of OT or placebo. Participants' eye movements were recorded to investigate whether an OT-dependent modulation of amygdala activity is accompanied by enhanced exploration of salient scene features. Although OT had no effect on participants' gazing behavior, it increased amygdala reactivity to scenes depicting social and non-social threat. In females, OT may, thus, enhance the detection of threatening stimuli in the environment, potentially by interacting with gonadal steroids, such as progesterone and estrogen. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. A Benchmark for Endoluminal Scene Segmentation of Colonoscopy Images

    Directory of Open Access Journals (Sweden)

    David Vázquez

    2017-01-01

    Full Text Available Colorectal cancer (CRC is the third cause of cancer death worldwide. Currently, the standard approach to reduce CRC-related mortality is to perform regular screening in search for polyps and colonoscopy is the screening tool of choice. The main limitations of this screening procedure are polyp miss rate and the inability to perform visual assessment of polyp malignancy. These drawbacks can be reduced by designing decision support systems (DSS aiming to help clinicians in the different stages of the procedure by providing endoluminal scene segmentation. Thus, in this paper, we introduce an extended benchmark of colonoscopy image segmentation, with the hope of establishing a new strong benchmark for colonoscopy image analysis research. The proposed dataset consists of 4 relevant classes to inspect the endoluminal scene, targeting different clinical needs. Together with the dataset and taking advantage of advances in semantic segmentation literature, we provide new baselines by training standard fully convolutional networks (FCNs. We perform a comparative study to show that FCNs significantly outperform, without any further postprocessing, prior results in endoluminal scene segmentation, especially with respect to polyp segmentation and localization.

  1. Higher-order scene statistics of breast images

    Science.gov (United States)

    Abbey, Craig K.; Sohl-Dickstein, Jascha N.; Olshausen, Bruno A.; Eckstein, Miguel P.; Boone, John M.

    2009-02-01

    Researchers studying human and computer vision have found description and construction of these systems greatly aided by analysis of the statistical properties of naturally occurring scenes. More specifically, it has been found that receptive fields with directional selectivity and bandwidth properties similar to mammalian visual systems are more closely matched to the statistics of natural scenes. It is argued that this allows for sparse representation of the independent components of natural images [Olshausen and Field, Nature, 1996]. These theories have important implications for medical image perception. For example, will a system that is designed to represent the independent components of natural scenes, where objects occlude one another and illumination is typically reflected, be appropriate for X-ray imaging, where features superimpose on one another and illumination is transmissive? In this research we begin to examine these issues by evaluating higher-order statistical properties of breast images from X-ray projection mammography (PM) and dedicated breast computed tomography (bCT). We evaluate kurtosis in responses of octave bandwidth Gabor filters applied to PM and to coronal slices of bCT scans. We find that kurtosis in PM rises and quickly saturates for filter center frequencies with an average value above 0.95. By contrast, kurtosis in bCT peaks near 0.20 cyc/mm with kurtosis of approximately 2. Our findings suggest that the human visual system may be tuned to represent breast tissue more effectively in bCT over a specific range of spatial frequencies.

  2. Seismic modeling of fluvial-estuarine deposits in the Athabasca oil sands using ray-tracing techniques, Steepbank River area, northeastern Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Langenberg, C. W.; Hein, F. J. [Alberta Energy and Utilities Board, Edmonton, AB (Canada); Lawton, D.; Cunningham, J. [Calgary Univ., Dept. of Geology and Geophysics, Calgary, AB (Canada)

    2002-03-01

    Seismic reflection characteristics of contrasting channel geometries in a five-section portion of the Steepbank River are modeled using ray-tracing techniques. Outcrop lithofacies associations are used to create a seismic model that can be used as a subsurface analog of other similar oil-sands successions. At least four channel complexes based on stratal bounding surfaces, arrangement of lithofacies, and consistent paleoflow patterns have been identified. The lower part of each channel complex contains trough crossbedded sandstone, exhibiting high porosity and permeability. These sandstones were deposited in channel axes and are the highest grade bitumen deposits in the area. The upper parts of the channels contain significantly lower bitumen saturation values due to common interbedded mudstone. Nearby wells contain cored and logged intervals that are similar to exposed outcrops in the riverbank. Overall modeling results indicate that channel complexes can be imaged seismically, given data of sufficient quality and frequency. Bitumen grade may be predicted in these seismic lines, which has important consequences for bitumen exploration and extraction in the Steepbank River region. 64 refs., 26 figs.

  3. Smoking scenes in popular Japanese serial television dramas: descriptive analysis during the same 3-month period in two consecutive years.

    Science.gov (United States)

    Kanda, Hideyuki; Okamura, Tomonori; Turin, Tanvir Chowdhury; Hayakawa, Takehito; Kadowaki, Takashi; Ueshima, Hirotsugu

    2006-06-01

    Japanese serial television dramas are becoming very popular overseas, particularly in other Asian countries. Exposure to smoking scenes in movies and television dramas has been known to trigger initiation of habitual smoking in young people. Smoking scenes in Japanese dramas may affect the smoking behavior of many young Asians. We examined smoking scenes and smoking-related items in serial television dramas targeting young audiences in Japan during the same season in two consecutive years. Fourteen television dramas targeting the young audience broadcast between July and September in 2001 and 2002 were analyzed. A total of 136 h 42 min of television programs were divided into unit scenes of 3 min (a total of 2734 unit scenes). All the unit scenes were reviewed for smoking scenes and smoking-related items. Of the 2734 3-min unit scenes, 205 (7.5%) were actual smoking scenes and 387 (14.2%) depicted smoking environments with the presence of smoking-related items, such as ash trays. In 185 unit scenes (90.2% of total smoking scenes), actors were shown smoking. Actresses were less frequently shown smoking (9.8% of total smoking scenes). Smoking characters in dramas were in the 20-49 age group in 193 unit scenes (94.1% of total smoking scenes). In 96 unit scenes (46.8% of total smoking scenes), at least one non-smoker was present in the smoking scenes. The smoking locations were mainly indoors, including offices, restaurants and homes (122 unit scenes, 59.6%). The most common smoking-related items shown were ash trays (in 45.5% of smoking-item-related scenes) and cigarettes (in 30.2% of smoking-item-related scenes). Only 3 unit scenes (0.1 % of all scenes) promoted smoking prohibition. This was a descriptive study to examine the nature of smoking scenes observed in Japanese television dramas from a public health perspective.

  4. Effects of scene content and layout on the perceived light direction in 3D spaces.

    Science.gov (United States)

    Xia, Ling; Pont, Sylvia C; Heynderickx, Ingrid

    2016-08-01

    The lighting and furnishing of an interior space (i.e., the reflectance of its materials, the geometries of the furnishings, and their arrangement) determine the appearance of this space. Conversely, human observers infer lighting properties from the space's appearance. We conducted two psychophysical experiments to investigate how the perception of the light direction is influenced by a scene's objects and their layout using real scenes. In the first experiment, we confirmed that the shape of the objects in the scene and the scene layout influence the perceived light direction. In the second experiment, we systematically investigated how specific shape properties influenced the estimation of the light direction. The results showed that increasing the number of visible faces of an object, ultimately using globally spherical shapes in the scene, supported the veridicality of the estimated light direction. Furthermore, symmetric arrangements in the scene improved the estimation of the tilt direction. Thus, human perception of light should integrally consider materials, scene content, and layout.

  5. Effects of Pre-Encoding Stress on Brain Correlates Associated with the Long-Term Memory for Emotional Scenes

    Science.gov (United States)

    Wirkner, Janine; Weymar, Mathias; Löw, Andreas; Hamm, Alfons O.

    2013-01-01

    Recent animal and human research indicates that stress around the time of encoding enhances long-term memory for emotionally arousing events but neural evidence remains unclear. In the present study we used the ERP old/new effect to investigate brain dynamics underlying the long-term effects of acute pre-encoding stress on memory for emotional and neutral scenes. Participants were exposed either to the Socially Evaluated Cold Pressure Test (SECPT) or a warm water control procedure before viewing 30 unpleasant, 30 neutral and 30 pleasant pictures. Two weeks after encoding, recognition memory was tested using 90 old and 90 new pictures. Emotional pictures were better recognized than neutral pictures in both groups and related to an enhanced centro-parietal ERP old/new difference (400–800 ms) during recognition, which suggests better recollection. Most interestingly, pre-encoding stress exposure specifically increased the ERP old/new-effect for emotional (unpleasant) pictures, but not for neutral pictures. These enhanced ERP/old new differences for emotional (unpleasant) scenes were particularly pronounced for those participants who reported high levels of stress during the SECPT. The results suggest that acute pre-encoding stress specifically strengthens brain signals of emotional memories, substantiating a facilitating role of stress on memory for emotional scenes. PMID:24039697

  6. Effects of pre-encoding stress on brain correlates associated with the long-term memory for emotional scenes.

    Directory of Open Access Journals (Sweden)

    Janine Wirkner

    Full Text Available Recent animal and human research indicates that stress around the time of encoding enhances long-term memory for emotionally arousing events but neural evidence remains unclear. In the present study we used the ERP old/new effect to investigate brain dynamics underlying the long-term effects of acute pre-encoding stress on memory for emotional and neutral scenes. Participants were exposed either to the Socially Evaluated Cold Pressure Test (SECPT or a warm water control procedure before viewing 30 unpleasant, 30 neutral and 30 pleasant pictures. Two weeks after encoding, recognition memory was tested using 90 old and 90 new pictures. Emotional pictures were better recognized than neutral pictures in both groups and related to an enhanced centro-parietal ERP old/new difference (400-800 ms during recognition, which suggests better recollection. Most interestingly, pre-encoding stress exposure specifically increased the ERP old/new-effect for emotional (unpleasant pictures, but not for neutral pictures. These enhanced ERP/old new differences for emotional (unpleasant scenes were particularly pronounced for those participants who reported high levels of stress during the SECPT. The results suggest that acute pre-encoding stress specifically strengthens brain signals of emotional memories, substantiating a facilitating role of stress on memory for emotional scenes.

  7. Rapid discrimination of visual scene content in the human brain

    Science.gov (United States)

    Anokhin, Andrey P.; Golosheykin, Simon; Sirevaag, Erik; Kristjansson, Sean; Rohrbaugh, John W.; Heath, Andrew C.

    2007-01-01

    The rapid evaluation of complex visual environments is critical for an organism's adaptation and survival. Previous studies have shown that emotionally significant visual scenes, both pleasant and unpleasant, elicit a larger late positive wave in the event-related brain potential (ERP) than emotionally neutral pictures. The purpose of the present study was to examine whether neuroelectric responses elicited by complex pictures discriminate between specific, biologically relevant contents of the visual scene and to determine how early in the picture processing this discrimination occurs. Subjects (n=264) viewed 55 color slides differing in both scene content and emotional significance. No categorical judgments or responses were required. Consistent with previous studies, we found that emotionally arousing pictures, regardless of their content, produce a larger late positive wave than neutral pictures. However, when pictures were further categorized by content, anterior ERP components in a time window between 200−600 ms following stimulus onset showed a high selectivity for pictures with erotic content compared to other pictures regardless of their emotional valence (pleasant, neutral, and unpleasant) or emotional arousal. The divergence of ERPs elicited by erotic and non-erotic contents started at 185 ms post-stimulus in the fronto-central midline regions, with a later onset in parietal regions. This rapid, selective, and content-specific processing of erotic materials and its dissociation from other pictures (including emotionally positive pictures) suggests the existence of a specialized neural network for prioritized processing of a distinct category of biologically relevant stimuli with high adaptive and evolutionary significance. PMID:16712815

  8. Navigating the auditory scene: an expert role for the hippocampus.

    Science.gov (United States)

    Teki, Sundeep; Kumar, Sukhbinder; von Kriegstein, Katharina; Stewart, Lauren; Lyness, C Rebecca; Moore, Brian C J; Capleton, Brian; Griffiths, Timothy D

    2012-08-29

    Over a typical career piano tuners spend tens of thousands of hours exploring a specialized acoustic environment. Tuning requires accurate perception and adjustment of beats in two-note chords that serve as a navigational device to move between points in previously learned acoustic scenes. It is a two-stage process that depends on the following: first, selective listening to beats within frequency windows, and, second, the subsequent use of those beats to navigate through a complex soundscape. The neuroanatomical substrates underlying brain specialization for such fundamental organization of sound scenes are unknown. Here, we demonstrate that professional piano tuners are significantly better than controls matched for age and musical ability on a psychophysical task simulating active listening to beats within frequency windows that is based on amplitude modulation rate discrimination. Tuners show a categorical increase in gray matter volume in the right frontal operculum and right superior temporal lobe. Tuners also show a striking enhancement of gray matter volume in the anterior hippocampus, parahippocampal gyrus, and superior temporal gyrus, and an increase in white matter volume in the posterior hippocampus as a function of years of tuning experience. The relationship with gray matter volume is sensitive to years of tuning experience and starting age but not actual age or level of musicality. Our findings support a role for a core set of regions in the hippocampus and superior temporal cortex in skilled exploration of complex sound scenes in which precise sound "templates" are encoded and consolidated into memory over time in an experience-dependent manner.

  9. Human matching performance of genuine crime scene latent fingerprints.

    Science.gov (United States)

    Thompson, Matthew B; Tangen, Jason M; McCarthy, Duncan J

    2014-02-01

    There has been very little research into the nature and development of fingerprint matching expertise. Here we present the results of an experiment testing the claimed matching expertise of fingerprint examiners. Expert (n = 37), intermediate trainee (n = 8), new trainee (n = 9), and novice (n = 37) participants performed a fingerprint discrimination task involving genuine crime scene latent fingerprints, their matches, and highly similar distractors, in a signal detection paradigm. Results show that qualified, court-practicing fingerprint experts were exceedingly accurate compared with novices. Experts showed a conservative response bias, tending to err on the side of caution by making more errors of the sort that could allow a guilty person to escape detection than errors of the sort that could falsely incriminate an innocent person. The superior performance of experts was not simply a function of their ability to match prints, per se, but a result of their ability to identify the highly similar, but nonmatching fingerprints as such. Comparing these results with previous experiments, experts were even more conservative in their decision making when dealing with these genuine crime scene prints than when dealing with simulated crime scene prints, and this conservatism made them relatively less accurate overall. Intermediate trainees-despite their lack of qualification and average 3.5 years experience-performed about as accurately as qualified experts who had an average 17.5 years experience. New trainees-despite their 5-week, full-time training course or their 6 months experience-were not any better than novices at discriminating matching and similar nonmatching prints, they were just more conservative. Further research is required to determine the precise nature of fingerprint matching expertise and the factors that influence performance. The findings of this representative, lab-based experiment may have implications for the way fingerprint examiners testify in

  10. The capture and recreation of 3D auditory scenes

    Science.gov (United States)

    Li, Zhiyun

    The main goal of this research is to develop the theory and implement practical tools (in both software and hardware) for the capture and recreation of 3D auditory scenes. Our research is expected to have applications in virtual reality, telepresence, film, music, video games, auditory user interfaces, and sound-based surveillance. The first part of our research is concerned with sound capture via a spherical microphone array. The advantage of this array is that it can be steered into any 3D directions digitally with the same beampattern. We develop design methodologies to achieve flexible microphone layouts, optimal beampattern approximation and robustness constraint. We also design novel hemispherical and circular microphone array layouts for more spatially constrained auditory scenes. Using the captured audio, we then propose a unified and simple approach for recreating them by exploring the reciprocity principle that is satisfied between the two processes. Our approach makes the system easy to build, and practical. Using this approach, we can capture the 3D sound field by a spherical microphone array and recreate it using a spherical loudspeaker array, and ensure that the recreated sound field matches the recorded field up to a high order of spherical harmonics. For some regular or semi-regular microphone layouts, we design an efficient parallel implementation of the multi-directional spherical beamformer by using the rotational symmetries of the beampattern and of the spherical microphone array. This can be implemented in either software or hardware and easily adapted for other regular or semi-regular layouts of microphones. In addition, we extend this approach for headphone-based system. Design examples and simulation results are presented to verify our algorithms. Prototypes are built and tested in real-world auditory scenes.

  11. Scene recognition and colorization for vehicle infrared images

    Science.gov (United States)

    Hou, Junjie; Sun, Shaoyuan; Shen, Zhenyi; Huang, Zhen; Zhao, Haitao

    2016-10-01

    In order to make better use of infrared technology for driving assistance system, a scene recognition and colorization method is proposed in this paper. Various objects in a queried infrared image are detected and labelled with proper categories by a combination of SIFT-Flow and MRF model. The queried image is then colorized by assigning corresponding colors according to the categories of the objects appeared. The results show that the strategy here emphasizes important information of the IR images for human vision and could be used to broaden the application of IR images for vehicle driving.

  12. The anatomy of the crime scene

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    simulated. The selected series range from more colourful and para-psychological based methods of investigation in series such as The Profiler and Medium to more realistic practises such as those found in series like Unit One and CSI. This analysis will be broadened by applying knowledge about how real...... scenes in order to reconstruct how the actual crime may have taken place. The profiling expert of the investigation team places herself in the role of the criminal, trying to gain insight into the criminal's psychology, way of thinking and reasoning and so on (like detective Lacour does in the Danish TV...

  13. Scenes of shame, social Roles, and the play with masks

    DEFF Research Database (Denmark)

    Welz, Claudia

    2014-01-01

    This article explores various scenes of shame, raising the questions of what shame discloses about the self and how this self-disclosure takes place. Thereby, the common idea that shame discloses the self’s debasement will be challenged. The dramatic dialectics of showing and hiding display a much...... reflected, the self’s active reflections on its shame are to be taken into account. As examples from Milan Kundera, Shakespeare’s King Lear, a line from Kingsley Amis, a speech by Vaclav Havel and Adam Smith’s Theory of Moral Sentiments indicate, self-(re)presentation in the public and the private sphere...

  14. Estimating the number of people in crowded scenes

    Science.gov (United States)

    Kim, Minjin; Kim, Wonjun; Kim, Changick

    2011-01-01

    This paper presents a method to estimate the number of people in crowded scenes without using explicit object segmentation or tracking. The proposed method consists of three steps as follows: (1) extracting space-time interest points using eigenvalues of the local spatio-temporal gradient matrix, (2) generating crowd regions based on space-time interest points, and (3) estimating the crowd density based on the multiple regression. In experimental results, the efficiency and robustness of our proposed method are demonstrated by using PETS 2009 dataset.

  15. Eye tracking to evaluate evidence recognition in crime scene investigations.

    Science.gov (United States)

    Watalingam, Renuka Devi; Richetelli, Nicole; Pelz, Jeff B; Speir, Jacqueline A

    2017-11-01

    Crime scene analysts are the core of criminal investigations; decisions made at the scene greatly affect the speed of analysis and the quality of conclusions, thereby directly impacting the successful resolution of a case. If an examiner fails to recognize the pertinence of an item on scene, the analyst's theory regarding the crime will be limited. Conversely, unselective evidence collection will most likely include irrelevant material, thus increasing a forensic laboratory's backlog and potentially sending the investigation into an unproductive and costly direction. Therefore, it is critical that analysts recognize and properly evaluate forensic evidence that can assess the relative support of differing hypotheses related to event reconstruction. With this in mind, the aim of this study was to determine if quantitative eye tracking data and qualitative reconstruction accuracy could be used to distinguish investigator expertise. In order to assess this, 32 participants were successfully recruited and categorized as experts or trained novices based on their practical experiences and educational backgrounds. Each volunteer then processed a mock crime scene while wearing a mobile eye tracker, wherein visual fixations, durations, search patterns, and reconstruction accuracy were evaluated. The eye tracking data (dwell time and task percentage on areas of interest or AOIs) were compared using Earth Mover's Distance (EMD) and the Needleman-Wunsch (N-W) algorithm, revealing significant group differences for both search duration (EMD), as well as search sequence (N-W). More specifically, experts exhibited greater dissimilarity in search duration, but greater similarity in search sequences than their novice counterparts. In addition to the quantitative visual assessment of examiner variability, each participant's reconstruction skill was assessed using a 22-point binary scoring system, in which significant group differences were detected as a function of total

  16. Stereo Scene Flow for 3D Motion Analysis

    CERN Document Server

    Wedel, Andreas

    2011-01-01

    This book presents methods for estimating optical flow and scene flow motion with high accuracy, focusing on the practical application of these methods in camera-based driver assistance systems. Clearly and logically structured, the book builds from basic themes to more advanced concepts, culminating in the development of a novel, accurate and robust optic flow method. Features: reviews the major advances in motion estimation and motion analysis, and the latest progress of dense optical flow algorithms; investigates the use of residual images for optical flow; examines methods for deriving mot

  17. Interaction between scene-based and array-based contextual cueing.

    Science.gov (United States)

    Rosenbaum, Gail M; Jiang, Yuhong V

    2013-07-01

    Contextual cueing refers to the cueing of spatial attention by repeated spatial context. Previous studies have demonstrated distinctive properties of contextual cueing by background scenes and by an array of search items. Whereas scene-based contextual cueing reflects explicit learning of the scene-target association, array-based contextual cueing is supported primarily by implicit learning. In this study, we investigated the interaction between scene-based and array-based contextual cueing. Participants searched for a target that was predicted by both the background scene and the locations of distractor items. We tested three possible patterns of interaction: (1) The scene and the array could be learned independently, in which case cueing should be expressed even when only one cue was preserved; (2) the scene and array could be learned jointly, in which case cueing should occur only when both cues were preserved; (3) overshadowing might occur, in which case learning of the stronger cue should preclude learning of the weaker cue. In several experiments, we manipulated the nature of the contextual cues present during training and testing. We also tested explicit awareness of scenes, scene-target associations, and arrays. The results supported the overshadowing account: Specifically, scene-based contextual cueing precluded array-based contextual cueing when both were predictive of the location of a search target. We suggest that explicit, endogenous cues dominate over implicit cues in guiding spatial attention.

  18. Colour agnosia impairs the recognition of natural but not of non-natural scenes.

    Science.gov (United States)

    Nijboer, Tanja C W; Van Der Smagt, Maarten J; Van Zandvoort, Martine J E; De Haan, Edward H F

    2007-03-01

    Scene recognition can be enhanced by appropriate colour information, yet the level of visual processing at which colour exerts its effects is still unclear. It has been suggested that colour supports low-level sensory processing, while others have claimed that colour information aids semantic categorization and recognition of objects and scenes. We investigated the effect of colour on scene recognition in a case of colour agnosia, M.A.H. In a scene identification task, participants had to name images of natural or non-natural scenes in six different formats. Irrespective of scene format, M.A.H. was much slower on the natural than on the non-natural scenes. As expected, neither M.A.H. nor control participants showed any difference in performance for the non-natural scenes. However, for the natural scenes, appropriate colour facilitated scene recognition in control participants (i.e., shorter reaction times), whereas M.A.H.'s performance did not differ across formats. Our data thus support the hypothesis that the effect of colour occurs at the level of learned associations.

  19. A view not to be missed: Salient scene content interferes with cognitive restoration.

    Directory of Open Access Journals (Sweden)

    Alexander P N Van der Jagt

    Full Text Available Attention Restoration Theory (ART states that built scenes place greater load on attentional resources than natural scenes. This is explained in terms of "hard" and "soft" fascination of built and natural scenes. Given a lack of direct empirical evidence for this assumption we propose that perceptual saliency of scene content can function as an empirically derived indicator of fascination. Saliency levels were established by measuring speed of scene category detection using a Go/No-Go detection paradigm. Experiment 1 shows that built scenes are more salient than natural scenes. Experiment 2 replicates these findings using greyscale images, ruling out a colour-based response strategy, and additionally shows that built objects in natural scenes affect saliency to a greater extent than the reverse. Experiment 3 demonstrates that the saliency of scene content is directly linked to cognitive restoration using an established restoration paradigm. Overall, these findings demonstrate an important link between the saliency of scene content and related cognitive restoration.

  20. Full-sky Ray-tracing Simulation of Weak Lensing Using ELUCID Simulations: Exploring Galaxy Intrinsic Alignment and Cosmic Shear Correlations

    Science.gov (United States)

    Wei, Chengliang; Li, Guoliang; Kang, Xi; Luo, Yu; Xia, Qianli; Wang, Peng; Yang, Xiaohu; Wang, Huiyuan; Jing, Yipeng; Mo, Houjun; Lin, Weipeng; Wang, Yang; Li, Shijie; Lu, Yi; Zhang, Youcai; Lim, S. H.; Tweed, Dylan; Cui, Weiguang

    2018-01-01

    The intrinsic alignment of galaxies is an important systematic effect in weak-lensing surveys, which can affect the derived cosmological parameters. One direct way to distinguish different alignment models and quantify their effects on the measurement is to produce mock weak-lensing surveys. In this work, we use the full-sky ray-tracing technique to produce mock images of galaxies from the ELUCID N-body simulation run with WMAP9 cosmology. In our model, we assume that the shape of the central elliptical galaxy follows that of the dark matter halo, and that of the spiral galaxy follows the halo spin. Using the mock galaxy images, a combination of galaxy intrinsic shape and the gravitational shear, we compare the predicted tomographic shear correlations to the results of the Kilo-Degree Survey (KiDS) and Deep Lens Survey (DLS). We find that our predictions stay between the KiDS and DLS results. We rule out a model in which the satellite galaxies are radially aligned with the center galaxy; otherwise, the shear correlations on small scales are too high. Most importantly, we find that although the intrinsic alignment of spiral galaxies is very weak, they induce a positive correlation between the gravitational shear signal and the intrinsic galaxy orientation (GI). This is because the spiral galaxy is tangentially aligned with the nearby large-scale overdensity, contrary to the radial alignment of the elliptical galaxy. Our results explain the origin of the detected positive GI term in the weak-lensing surveys. We conclude that in future analyses, the GI model must include the dependence on galaxy types in more detail.

  1. A hybrid multiview stereo algorithm for modeling urban scenes.

    Science.gov (United States)

    Lafarge, Florent; Keriven, Renaud; Brédif, Mathieu; Vu, Hoang-Hiep

    2013-01-01

    We present an original multiview stereo reconstruction algorithm which allows the 3D-modeling of urban scenes as a combination of meshes and geometric primitives. The method provides a compact model while preserving details: Irregular elements such as statues and ornaments are described by meshes, whereas regular structures such as columns and walls are described by primitives (planes, spheres, cylinders, cones, and tori). We adopt a two-step strategy consisting first in segmenting the initial meshbased surface using a multilabel Markov Random Field-based model and second in sampling primitive and mesh components simultaneously on the obtained partition by a Jump-Diffusion process. The quality of a reconstruction is measured by a multi-object energy model which takes into account both photo-consistency and semantic considerations (i.e., geometry and shape layout). The segmentation and sampling steps are embedded into an iterative refinement procedure which provides an increasingly accurate hybrid representation. Experimental results on complex urban structures and large scenes are presented and compared to state-of-the-art multiview stereo meshing algorithms.

  2. Estimating perception of scene layout properties from global image features.

    Science.gov (United States)

    Ross, Michael G; Oliva, Aude

    2010-01-08

    The relationship between image features and scene structure is central to the study of human visual perception and computer vision, but many of the specifics of real-world layout perception remain unknown. We do not know which image features are relevant to perceiving layout properties, or whether those features provide the same information for every type of image. Furthermore, we do not know the spatial resolutions required for perceiving different properties. This paper describes an experiment and a computational model that provides new insights on these issues. Humans perceive the global spatial layout properties such as dominant depth, openness, and perspective, from a single image. This work describes an algorithm that reliably predicts human layout judgments. This model's predictions are general, not specific to the observers it trained on. Analysis reveals that the optimal spatial resolutions for determining layout vary with the content of the space and the property being estimated. Openness is best estimated at high resolution, depth is best estimated at medium resolution, and perspective is best estimated at low resolution. Given the reliability and simplicity of estimating the global layout of real-world environments, this model could help resolve perceptual ambiguities encountered by more detailed scene reconstruction schemas.

  3. Evaluating color descriptors for object and scene recognition.

    Science.gov (United States)

    van de Sande, Koen E A; Gevers, Theo; Snoek, Cees G M

    2010-09-01

    Image category recognition is important to access visual information on the level of objects and scene types. So far, intensity-based descriptors have been widely used for feature extraction at salient points. To increase illumination invariance and discriminative power, color descriptors have been proposed. Because many different descriptors exist, a structured overview is required of color invariant descriptors in the context of image category recognition. Therefore, this paper studies the invariance properties and the distinctiveness of color descriptors (software to compute the color descriptors from this paper is available from http://www.colordescriptors.com) in a structured way. The analytical invariance properties of color descriptors are explored, using a taxonomy based on invariance properties with respect to photometric transformations, and tested experimentally using a data set with known illumination conditions. In addition, the distinctiveness of color descriptors is assessed experimentally using two benchmarks, one from the image domain and one from the video domain. From the theoretical and experimental results, it can be derived that invariance to light intensity changes and light color changes affects category recognition. The results further reveal that, for light intensity shifts, the usefulness of invariance is category-specific. Overall, when choosing a single descriptor and no prior knowledge about the data set and object and scene categories is available, the OpponentSIFT is recommended. Furthermore, a combined set of color descriptors outperforms intensity-based SIFT and improves category recognition by 8 percent on the PASCAL VOC 2007 and by 7 percent on the Mediamill Challenge.

  4. Text Detection in Natural Scene Images by Stroke Gabor Words.

    Science.gov (United States)

    Yi, Chucai; Tian, Yingli

    2011-01-01

    In this paper, we propose a novel algorithm, based on stroke components and descriptive Gabor filters, to detect text regions in natural scene images. Text characters and strings are constructed by stroke components as basic units. Gabor filters are used to describe and analyze the stroke components in text characters or strings. We define a suitability measurement to analyze the confidence of Gabor filters in describing stroke component and the suitability of Gabor filters on an image window. From the training set, we compute a set of Gabor filters that can describe principle stroke components of text by their parameters. Then a K -means algorithm is applied to cluster the descriptive Gabor filters. The clustering centers are defined as Stroke Gabor Words (SGWs) to provide a universal description of stroke components. By suitability evaluation on positive and negative training samples respectively, each SGW generates a pair of characteristic distributions of suitability measurements. On a testing natural scene image, heuristic layout analysis is applied first to extract candidate image windows. Then we compute the principle SGWs for each image window to describe its principle stroke components. Characteristic distributions generated by principle SGWs are used to classify text or nontext windows. Experimental results on benchmark datasets demonstrate that our algorithm can handle complex backgrounds and variant text patterns (font, color, scale, etc.).

  5. S3-2: Colorfulness Perception Adapting to Natural Scenes

    Directory of Open Access Journals (Sweden)

    Yoko Mizokami

    2012-10-01

    Full Text Available Our visual system has the ability to adapt to the color characteristics of environment and maintain stable color appearance. Many researches on chromatic adaptation and color constancy suggested that the different levels of visual processes involve the adaptation mechanism. In the case of colorfulness perception, it has been shown that the perception changes with adaptation to chromatic contrast modulation and to surrounding chromatic variance. However, it is still not clear how the perception changes in natural scenes and what levels of visual mechanisms contribute to the perception. Here, I will mainly present our recent work on colorfulness-adaptation in natural images. In the experiment, we examined whether the colorfulness perception of an image was influenced by the adaptation to natural images with different degrees of saturation. Natural and unnatural (shuffled or phase-scrambled images are used for adapting and test images, and all combinations of adapting and test images were tested (e.g., the combination of natural adapting images and a shuffled test image. The results show that colorfulness perception was influenced by adaptation to the saturation of images. A test image appeared less colorful after adaptation to saturated images, and vice versa. The effect of colorfulness adaptation was the strongest for the combination of natural adapting and natural test images. The fact that the naturalness of the spatial structure in an image affects the strength of the adaptation effect implies that the recognition of natural scene would play an important role in the adaptation mechanism.

  6. People detection in crowded scenes using active contour models

    Science.gov (United States)

    Sidla, Oliver

    2009-01-01

    The detection of pedestrians in real-world scenes is a daunting task, especially in crowded situations. Our experience over the last years has shown that active shape models (ASM) can contribute significantly to a robust pedestrian detection system. The paper starts with an overview of shape model approaches, it then explains our approach which builds on top of Eigenshape models which have been trained using real-world data. These models are placed over candidate regions and matched to image gradients using a scoring function which integrates i) point distribution, ii) local gradient orientations iii) local image gradient strengths. A matching and shape model update process is iteratively applied in order to fit the flexible models to the local image content. The weights of the scoring function have a significant impact on the ASM performance. We analyze different settings of scoring weights for gradient magnitude, relative orientation differences, distance between model and gradient in an experiment which uses real-world data. Although for only one pedestrian model in an image computation time is low, the number of necessary processing cycles which is needed to track many people in crowded scenes can become the bottleneck in a real-time application. We describe the measures which have been taken in order to improve the speed of the ASM implementation and make it real-time capable.

  7. The Influence of Familiarity on Affective Responses to Natural Scenes

    Science.gov (United States)

    Sanabria Z., Jorge C.; Cho, Youngil; Yamanaka, Toshimasa

    This kansei study explored how familiarity with image-word combinations influences affective states. Stimuli were obtained from Japanese print advertisements (ads), and consisted of images (e.g., natural-scene backgrounds) and their corresponding headlines (advertising copy). Initially, a group of subjects evaluated their level of familiarity with images and headlines independently, and stimuli were filtered based on the results. In the main experiment, a different group of subjects rated their pleasure and arousal to, and familiarity with, image-headline combinations. The Self-Assessment Manikin (SAM) scale was used to evaluate pleasure and arousal, and a bipolar scale was used to evaluate familiarity. The results showed a high correlation between familiarity and pleasure, but low correlation between familiarity and arousal. The characteristics of the stimuli, and their effect on the variables of pleasure, arousal and familiarity, were explored through ANOVA. It is suggested that, in the case of natural-scene ads, familiarity with image-headline combinations may increase the pleasure response to the ads, and that certain components in the images (e.g., water) may increase arousal levels.

  8. Accident or homicide--virtual crime scene reconstruction using 3D methods.

    Science.gov (United States)

    Buck, Ursula; Naether, Silvio; Räss, Beat; Jackowski, Christian; Thali, Michael J

    2013-02-10

    The analysis and reconstruction of forensically relevant events, such as traffic accidents, criminal assaults and homicides are based on external and internal morphological findings of the injured or deceased person. For this approach high-tech methods are gaining increasing importance in forensic investigations. The non-contact optical 3D digitising system GOM ATOS is applied as a suitable tool for whole body surface and wound documentation and analysis in order to identify injury-causing instruments and to reconstruct the course of event. In addition to the surface documentation, cross-sectional imaging methods deliver medical internal findings of the body. These 3D data are fused into a whole body model of the deceased. Additional to the findings of the bodies, the injury inflicting instruments and incident scene is documented in 3D. The 3D data of the incident scene, generated by 3D laser scanning and photogrammetry, is also included into the reconstruction. Two cases illustrate the methods. In the fist case a man was shot in his bedroom and the main question was, if the offender shot the man intentionally or accidentally, as he declared. In the second case a woman was hit by a car, driving backwards into a garage. It was unclear if the driver drove backwards once or twice, which would indicate that he willingly injured and killed the woman. With this work, we demonstrate how 3D documentation, data merging and animation enable to answer reconstructive questions regarding the dynamic development of patterned injuries, and how this leads to a real data based reconstruction of the course of event. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Designing and testing scene enhancement algorithms for patients with retina degenerative disorders

    Directory of Open Access Journals (Sweden)

    Downes Susan M

    2010-06-01

    Full Text Available Abstract Background Retina degenerative disorders represent the primary cause of blindness in UK and in the developed world. In particular, Age Related Macular Degeneration (AMD and Retina Pigmentosa (RP diseases are of interest to this study. We have therefore created new image processing algorithms for enhancing the visual scenes for them. Methods In this paper we present three novel image enhancement techniques aimed at enhancing the remaining visual information for patients suffering from retina dystrophies. Currently, the only effective way to test novel technology for visual enhancement is to undergo testing on large numbers of patients. To test our techniques, we have therefore built a retinal image processing model and compared the results to data from patient testing. In particular we focus on the ability of our image processing techniques to achieve improved face detection and enhanced edge perception. Results Results from our model are compared to actual data obtained from testing the performance of these algorithms on 27 patients with an average visual acuity of 0.63 and an average contrast sensitivity of 1.22. Results show that Tinted Reduced Outlined Nature (TRON and Edge Overlaying algorithms are most beneficial for dynamic scenes such as motion detection. Image Cartoonization was most beneficial for spatial feature detection such as face detection. Patient's stated that they would most like to see Cartoonized images for use in daily life. Conclusions Results obtained from our retinal model and from patients show that there is potential for these image processing techniques to improve visual function amongst the visually impaired community. In addition our methodology using face detection and efficiency of perceived edges in determining potential benefit derived from different image enhancement algorithms could also prove to be useful in quantitatively assessing algorithms in future studies.

  10. Semi-automatic scene generation using the Digital Anatomist Foundational Model.

    Science.gov (United States)

    Wong, B A; Rosse, C; Brinkley, J F

    1999-01-01

    A recent survey shows that a major impediment to more widespread use of computers in anatomy education is the inability to directly manipulate 3-D models, and to relate these to corresponding textual information. In the University of Washington Digital Anatomist Project we have developed a prototype Web-based scene generation program that combines the symbolic Foundational Model of Anatomy with 3-D models. A Web user can browse the Foundational Model (FM), then click to request that a 3-D scene be created of an object and its parts or branches. The scene is rendered by a graphics server, and a snapshot is sent to the Web client. The user can then manipulate the scene, adding new structures, deleting structures, rotating the scene, zooming, and saving the scene as a VRML file. Applications such as this, when fully realized with fast rendering and more anatomical content, have the potential to significantly change the way computers are used in anatomy education.

  11. Short report: the effect of expertise in hiking on recognition memory for mountain scenes.

    Science.gov (United States)

    Kawamura, Satoru; Suzuki, Sae; Morikawa, Kazunori

    2007-10-01

    The nature of an expert memory advantage that does not depend on stimulus structure or chunking was examined, using more ecologically valid stimuli in the context of a more natural activity than previously studied domains. Do expert hikers and novice hikers see and remember mountain scenes differently? In the present experiment, 18 novice hikers and 17 expert hikers were presented with 60 photographs of scenes from hiking trails. These scenes differed in the degree of functional aspects that implied some action possibilities or dangers. The recognition test revealed that the memory performance of experts was significantly superior to that of novices for scenes with highly functional aspects. The memory performance for the scenes with few functional aspects did not differ between novices and experts. These results suggest that experts pay more attention to, and thus remember better, scenes with functional meanings than do novices.

  12. Relationship between Childhood Meal Scenes at Home Remembered by University Students and their Current Personality

    OpenAIRE

    恩村, 咲希; Onmura, Saki

    2013-01-01

    This study examines the relationship between childhood meal scenes at home that are remembered by university students and their current personality. The meal scenes are analyzed in terms of companions, conversation content, conversation frequency, atmosphere, and consideration of meals. The scale of the conversation content in childhood meal scenes was prepared on the basis of the results of a preliminary survey. The result showed that a relationship was found between personality traits and c...

  13. Adaptive attunement of selective covert attention to evolutionary-relevant emotional visual scenes

    OpenAIRE

    Fernández-Martín, Andrés (UNIR); Gutiérrez-García, Aida; Capafons, Juan; Calvo, Manuel G

    2017-01-01

    We investigated selective attention to emotional scenes in peripheral vision, as a function of adaptive relevance of scene affective content for male and female observers. Pairs of emotional neutral images appeared peripherally with perceptual stimulus differences controlled while viewers were fixating on a different stimulus in central vision. Early selective orienting was assessed by the probability of directing the first fixation towards either scene, and the time until first fixation. Emo...

  14. Active visual search in non-stationary scenes: coping with temporal variability and uncertainty

    Science.gov (United States)

    Ušćumlić, Marija; Blankertz, Benjamin

    2016-02-01

    Objective. State-of-the-art experiments for studying neural processes underlying visual cognition often constrain sensory inputs (e.g., static images) and our behavior (e.g., fixed eye-gaze, long eye fixations), isolating or simplifying the interaction of neural processes. Motivated by the non-stationarity of our natural visual environment, we investigated the electroencephalography (EEG) correlates of visual recognition while participants overtly performed visual search in non-stationary scenes. We hypothesized that visual effects (such as those typically used in human-computer interfaces) may increase temporal uncertainty (with reference to fixation onset) of cognition-related EEG activity in an active search task and therefore require novel techniques for single-trial detection. Approach. We addressed fixation-related EEG activity in an active search task with respect to stimulus-appearance styles and dynamics. Alongside popping-up stimuli, our experimental study embraces two composite appearance styles based on fading-in, enlarging, and motion effects. Additionally, we explored whether the knowledge obtained in the pop-up experimental setting can be exploited to boost the EEG-based intention-decoding performance when facing transitional changes of visual content. Main results. The results confirmed our initial hypothesis that the dynamic of visual content can increase temporal uncertainty of the cognition-related EEG activity in active search with respect to fixation onset. This temporal uncertainty challenges the pivotal aim to keep the decoding performance constant irrespective of visual effects. Importantly, the proposed approach for EEG decoding based on knowledge transfer between the different experimental settings gave a promising performance. Significance. Our study demonstrates that the non-stationarity of visual scenes is an important factor in the evolution of cognitive processes, as well as in the dynamic of ocular behavior (i.e., dwell time and

  15. Scene perception in posterior cortical atrophy: categorization, description and fixation patterns.

    Science.gov (United States)

    Shakespeare, Timothy J; Yong, Keir X X; Frost, Chris; Kim, Lois G; Warrington, Elizabeth K; Crutch, Sebastian J

    2013-01-01

    Partial or complete Balint's syndrome is a core feature of the clinico-radiological syndrome of posterior cortical atrophy (PCA), in which individuals experience a progressive deterioration of cortical vision. Although multi-object arrays are frequently used to detect simultanagnosia in the clinical assessment and diagnosis of PCA, to date there have been no group studies of scene perception in patients with the syndrome. The current study involved three linked experiments conducted in PCA patients and healthy controls. Experiment 1 evaluated the accuracy and latency of complex scene perception relative to individual faces and objects (color and grayscale) using a categorization paradigm. PCA patients were both less accurate (faces < scenes < objects) and slower (scenes < objects < faces) than controls on all categories, with performance strongly associated with their level of basic visual processing impairment; patients also showed a small advantage for color over grayscale stimuli. Experiment 2 involved free description of real world scenes. PCA patients generated fewer features and more misperceptions than controls, though perceptual errors were always consistent with the patient's global understanding of the scene (whether correct or not). Experiment 3 used eye tracking measures to compare patient and control eye movements over initial and subsequent fixations of scenes. Patients' fixation patterns were significantly different to those of young and age-matched controls, with comparable group differences for both initial and subsequent fixations. Overall, these findings describe the variability in everyday scene perception exhibited by individuals with PCA, and indicate the importance of exposure duration in the perception of complex scenes.

  16. Parallel programming of saccades during natural scene viewing: evidence from eye movement positions.

    Science.gov (United States)

    Wu, Esther X W; Gilani, Syed Omer; van Boxtel, Jeroen J A; Amihai, Ido; Chua, Fook Kee; Yen, Shih-Cheng

    2013-10-24

    Previous studies have shown that saccade plans during natural scene viewing can be programmed in parallel. This evidence comes mainly from temporal indicators, i.e., fixation durations and latencies. In the current study, we asked whether eye movement positions recorded during scene viewing also reflect parallel programming of saccades. As participants viewed scenes in preparation for a memory task, their inspection of the scene was suddenly disrupted by a transition to another scene. We examined whether saccades after the transition were invariably directed immediately toward the center or were contingent on saccade onset times relative to the transition. The results, which showed a dissociation in eye movement behavior between two groups of saccades after the scene transition, supported the parallel programming account. Saccades with relatively long onset times (>100 ms) after the transition were directed immediately toward the center of the scene, probably to restart scene exploration. Saccades with short onset times (programming of saccades during scene viewing. Additionally, results from the analyses of intersaccadic intervals were also consistent with the parallel programming hypothesis.

  17. Accumulating and remembering the details of neutral and emotional natural scenes.

    Science.gov (United States)

    Melcher, David

    2010-01-01

    In contrast to our rich sensory experience with complex scenes in everyday life, the capacity of visual working memory is thought to be quite limited. Here our memory has been examined for the details of naturalistic scenes as a function of display duration, emotional valence of the scene, and delay before test. Individual differences in working memory and long-term memory for pictorial scenes were examined in experiment 1. The accumulation of memory for emotional scenes and the retention of these details in long-term memory were investigated in experiment 2. Although there were large individual differences in performance, memory for scene details generally exceeded the traditional working memory limit within a few seconds. Information about positive scenes was learned most quickly, while negative scenes showed the worst memory for details. The overall pattern of results was consistent with the idea that both short-term and long-term representations are mixed together in a medium-term 'online' memory for scenes.

  18. Viewing nature scenes positively affects recovery of autonomic function following acute-mental stress.

    Science.gov (United States)

    Brown, Daniel K; Barton, Jo L; Gladwell, Valerie F

    2013-06-04

    A randomized crossover study explored whether viewing different scenes prior to a stressor altered autonomic function during the recovery from the stressor. The two scenes were (a) nature (composed of trees, grass, fields) or (b) built (composed of man-made, urban scenes lacking natural characteristics) environments. Autonomic function was assessed using noninvasive techniques of heart rate variability; in particular, time domain analyses evaluated parasympathetic activity, using root-mean-square of successive differences (RMSSD). During stress, secondary cardiovascular markers (heart rate, systolic and diastolic blood pressure) showed significant increases from baseline which did not differ between the two viewing conditions. Parasympathetic activity, however, was significantly higher in recovery following the stressor in the viewing scenes of nature condition compared to viewing scenes depicting built environments (RMSSD; 50.0 ± 31.3 vs 34.8 ± 14.8 ms). Thus, viewing nature scenes prior to a stressor alters autonomic activity in the recovery period. The secondary aim was to examine autonomic function during viewing of the two scenes. Standard deviation of R-R intervals (SDRR), as change from baseline, during the first 5 min of viewing nature scenes was greater than during built scenes. Overall, this suggests that nature can elicit improvements in the recovery process following a stressor.

  19. Sub-basalt Imaging of Hydrocarbon-Bearing Mesozoic Sediments Using Ray-Trace Inversion of First-Arrival Seismic Data and Elastic Finite-Difference Full-Wave Modeling Along Sinor-Valod Profile of Deccan Syneclise, India

    Science.gov (United States)

    Talukdar, Karabi; Behera, Laxmidhar

    2018-03-01

    Imaging below the basalt for hydrocarbon exploration is a global problem because of poor penetration and significant loss of seismic energy due to scattering, attenuation, absorption and mode-conversion when the seismic waves encounter a highly heterogeneous and rugose basalt layer. The conventional (short offset) seismic data acquisition, processing and modeling techniques adopted by the oil industry generally fails to image hydrocarbon-bearing sub-trappean Mesozoic sediments hidden below the basalt and is considered as a serious problem for hydrocarbon exploration in the world. To overcome this difficulty of sub-basalt imaging, we have generated dense synthetic seismic data with the help of elastic finite-difference full-wave modeling using staggered-grid scheme for the model derived from ray-trace inversion using sparse wide-angle seismic data acquired along Sinor-Valod profile in the Deccan Volcanic Province of India. The full-wave synthetic seismic data generated have been processed and imaged using conventional seismic data processing technique with Kirchhoff pre-stack time and depth migrations. The seismic image obtained correlates with all the structural features of the model obtained through ray-trace inversion of wide-angle seismic data, validating the effectiveness of robust elastic finite-difference full-wave modeling approach for imaging below thick basalts. Using the full-wave modeling also allows us to decipher small-scale heterogeneities imposed in the model as a measure of the rugose basalt interfaces, which could not be dealt with ray-trace inversion. Furthermore, we were able to accurately image thin low-velocity hydrocarbon-bearing Mesozoic sediments sandwiched between and hidden below two thick sequences of high-velocity basalt layers lying above the basement.

  20. ADULT BASIC LIFE SUPPORT ON NEAR DROWNING AT THE SCENE

    Directory of Open Access Journals (Sweden)

    Gd. Harry Kurnia Prawedana

    2013-04-01

    Full Text Available Indonesia is a popular tourist destination which has potential for drowning cases. Therefore, required knowledge of adult basic life support to be able to deal with such cases in the field. Basic life support in an act to maintain airway and assist breathing and circulation without the use of tools other than simple breathing aids. The most important factor that determines the outcome of drowning event is the duration and severity of hypoxia induced. The management of near drowning at the scene include the rescue of victim from the water, rescue breathing, chest compression, cleaning the vomit substances which allowing blockage of the airway, prevent loss of body heat, and transport the victim to nearest emergency department for evaluation and monitoring.

  1. Behinds the scenes of GS: a DSO like no other

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    At CERN, Departmental Safety Officers (DSOs) are responsible for making the members of their department aware of safety issues. They’re our first point of call every time a problem arises relating to environmental matters or the safety of people and installations. In GS, this role is even more crucial as the Department’s activities are scattered across the Laboratory and affect everyone.   As we have pointed out in our article series "Behind the scenes of GS”, the GS Department is responsible for the construction, renovation and maintenance of buildings and related technical infrastructures. The latter include heating and toilet facilities; detection and alarm systems; the management of the hotels, stores, stocks, shuttle services and mail; and the development of technical and administrative databases. The activities of the Medical Service and the Fire and Rescue Service also come under the umbrella of GS, as do the many other daily activities that are pa...

  2. Text Line Detection from Rectangle Traffic Panels of Natural Scene

    Science.gov (United States)

    Wang, Shiyuan; Huang, Linlin; Hu, Jian

    2018-01-01

    Traffic sign detection and recognition is very important for Intelligent Transportation. Among traffic signs, traffic panel contains rich information. However, due to low resolution and blur in the rectangular traffic panel, it is difficult to extract the character and symbols. In this paper, we propose a coarse-to-fine method to detect the Chinese character on traffic panels from natural scenes. Given a traffic panel Color Quantization is applied to extract candidate regions of Chinese characters. Second, a multi-stage filter based on learning is applied to discard the non-character regions. Third, we aggregate the characters for text lines by Distance Metric Learning method. Experimental results on real traffic images from Baidu Street View demonstrate the effectiveness of the proposed method.

  3. Adaptive and Selective Time Averaging of Auditory Scenes

    DEFF Research Database (Denmark)

    McWalter, Richard Ian; McDermott, Josh H.

    2018-01-01

    longer than previously reported integration times in the auditory system. Integration also showed signs of being restricted to sound elements attributed to a common source. The results suggest an integration process that depends on stimulus characteristics, integrating over longer extents when......To overcome variability, estimate scene characteristics, and compress sensory input, perceptual systems pool data into statistical summaries. Despite growing evidence for statistical representations in perception, the underlying mechanisms remain poorly understood. One example...... it benefits statistical estimation of variable signals and selectively integrating stimulus components likely to have a common cause in the world. Our methodology could be naturally extended to examine statistical representations of other types of sensory signals. Sound texture perception is thought...

  4. Multiscale deep features learning for land-use scene recognition

    Science.gov (United States)

    Yuan, Baohua; Li, Shijin; Li, Ning

    2018-01-01

    The features extracted from deep convolutional neural networks (CNNs) have shown their promise as generic descriptors for land-use scene recognition. However, most of the work directly adopts the deep features for the classification of remote sensing images, and does not encode the deep features for improving their discriminative power, which can affect the performance of deep feature representations. To address this issue, we propose an effective framework, LASC-CNN, obtained by locality-constrained affine subspace coding (LASC) pooling of a CNN filter bank. LASC-CNN obtains more discriminative deep features than directly extracted from CNNs. Furthermore, LASC-CNN builds on the top convolutional layers of CNNs, which can incorporate multiscale information and regions of arbitrary resolution and sizes. Our experiments have been conducted using two widely used remote sensing image databases, and the results show that the proposed method significantly improves the performance when compared to other state-of-the-art methods.

  5. Sound Classification in Hearing Aids Inspired by Auditory Scene Analysis

    Science.gov (United States)

    Büchler, Michael; Allegro, Silvia; Launer, Stefan; Dillier, Norbert

    2005-12-01

    A sound classification system for the automatic recognition of the acoustic environment in a hearing aid is discussed. The system distinguishes the four sound classes "clean speech," "speech in noise," "noise," and "music." A number of features that are inspired by auditory scene analysis are extracted from the sound signal. These features describe amplitude modulations, spectral profile, harmonicity, amplitude onsets, and rhythm. They are evaluated together with different pattern classifiers. Simple classifiers, such as rule-based and minimum-distance classifiers, are compared with more complex approaches, such as Bayes classifier, neural network, and hidden Markov model. Sounds from a large database are employed for both training and testing of the system. The achieved recognition rates are very high except for the class "speech in noise." Problems arise in the classification of compressed pop music, strongly reverberated speech, and tonal or fluctuating noises.

  6. Luminance cues constrain chromatic blur discrimination in natural scene stimuli.

    Science.gov (United States)

    Sharman, Rebecca J; McGraw, Paul V; Peirce, Jonathan W

    2013-03-22

    Introducing blur into the color components of a natural scene has very little effect on its percept, whereas blur introduced into the luminance component is very noticeable. Here we quantify the dominance of luminance information in blur detection and examine a number of potential causes. We show that the interaction between chromatic and luminance information is not explained by reduced acuity or spatial resolution limitations for chromatic cues, the effective contrast of the luminance cue, or chromatic and achromatic statistical regularities in the images. Regardless of the quality of chromatic information, the visual system gives primacy to luminance signals when determining edge location. In natural viewing, luminance information appears to be specialized for detecting object boundaries while chromatic information may be used to determine surface properties.

  7. Attention, awareness, and the perception of auditory scenes

    Directory of Open Access Journals (Sweden)

    Joel S Snyder

    2012-02-01

    Full Text Available Auditory perception and cognition entails both low-level and high-level processes, which are likely to interact with each other to create our rich conscious experience of soundscapes. Recent research that we review has revealed numerous influences of high-level factors, such as attention, intention, and prior experience, on conscious auditory perception. And recently, studies have shown that auditory scene analysis tasks can exhibit multistability in a manner very similar to ambiguous visual stimuli, presenting a unique opportunity to study neural correlates of auditory awareness and the extent to which mechanisms of perception are shared across sensory modalities. Research has also led to a growing number of techniques through which auditory perception can be manipulated and even completely suppressed. Such findings have important consequences for our understanding of the mechanisms of perception and also should allow scientists to precisely distinguish the influences of different higher-level influences.

  8. "Undoing" (or Symbolic Reversal) at Homicide Crime Scenes.

    Science.gov (United States)

    Russell, Maria; Schlesinger, Louis B; Leon, Maria; Holdren, Samantha

    2018-03-01

    A closed case file review of a nonrandom national sample of 975 homicides disclosed 11 cases (1.13%) of undoing, wherein offenders engaged in crime scene behavior that has been considered an attempt to symbolically reverse the murder. The frequency of the various methods of undoing involved the use of blankets to cover the victim's body (55%), positioning the body (55%), use of a bed or couch (42%), washing the body (36%), using pillows (36%), as well as removing clothing and adding other types of adornments (27%). Ten of the 11 offenders were male, and one was female; all 12 victims were female. Ten of the 12 victims were family members or relationship intimates. These findings are consistent with prior reports which concluded that the motivation for undoing behavior is an attempt to compensate for guilt or remorse for having committed the homicide. © 2017 American Academy of Forensic Sciences.

  9. Optimized 3D Street Scene Reconstruction from Driving Recorder Images

    Directory of Open Access Journals (Sweden)

    Yongjun Zhang

    2015-07-01

    Full Text Available The paper presents an automatic region detection based method to reconstruct street scenes from driving recorder images. The driving recorder in this paper is a dashboard camera that collects images while the motor vehicle is moving. An enormous number of moving vehicles are included in the collected data because the typical recorders are often mounted in the front of moving vehicles and face the forward direction, which can make matching points on vehicles and guardrails unreliable. Believing that utilizing these image data can reduce street scene reconstruction and updating costs because of their low price, wide use, and extensive shooting coverage, we therefore proposed a new method, which is called the Mask automatic detecting method, to improve the structure results from the motion reconstruction. Note that we define vehicle and guardrail regions as “mask” in this paper since the features on them should be masked out to avoid poor matches. After removing the feature points in our new method, the camera poses and sparse 3D points that are reconstructed with the remaining matches. Our contrast experiments with the typical pipeline of structure from motion (SfM reconstruction methods, such as Photosynth and VisualSFM, demonstrated that the Mask decreased the root-mean-square error (RMSE of the pairwise matching results, which led to more accurate recovering results from the camera-relative poses. Removing features from the Mask also increased the accuracy of point clouds by nearly 30%–40% and corrected the problems of the typical methods on repeatedly reconstructing several buildings when there was only one target building.

  10. Assessment of the accuracy of the conventional ray-tracing technique: Implications in remote sensing and radiative transfer involving ice clouds

    International Nuclear Information System (INIS)

    Bi, Lei; Yang, Ping; Liu, Chao; Yi, Bingqi; Baum, Bryan A.; Diedenhoven, Bastiaan van; Iwabuchi, Hironobu

    2014-01-01

    A fundamental problem in remote sensing and radiative transfer simulations involving ice clouds is the ability to compute accurate optical properties for individual ice particles. While relatively simple and intuitively appealing, the conventional geometric-optics method (CGOM) is used frequently for the solution of light scattering by ice crystals. Due to the approximations in the ray-tracing technique, the CGOM accuracy is not well quantified. The result is that the uncertainties are introduced that can impact many applications. Improvements in the Invariant Imbedding T-matrix method (II-TM) and the Improved Geometric-Optics Method (IGOM) provide a mechanism to assess the aforementioned uncertainties. The results computed by the II-TM+IGOM are considered as a benchmark because the II-TM solves Maxwell's equations from first principles and is applicable to particle size parameters ranging into the domain at which the IGOM has reasonable accuracy. To assess the uncertainties with the CGOM in remote sensing and radiative transfer simulations, two independent optical property datasets of hexagonal columns are developed for sensitivity studies by using the CGOM and the II-TM+IGOM, respectively. Ice cloud bulk optical properties obtained from the two datasets are compared and subsequently applied to retrieve the optical thickness and effective diameter from Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. Additionally, the bulk optical properties are tested in broadband radiative transfer (RT) simulations using the general circulation model (GCM) version of the Rapid Radiative Transfer Model (RRTMG) that is adopted in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM, version 5.1). For MODIS retrievals, the mean bias of uncertainties of applying the CGOM in shortwave bands (0.86 and 2.13 μm) can be up to 5% in the optical thickness and as high as 20% in the effective diameter, depending on cloud optical

  11. Optimizing Raytracing Algorithm Using CUDA

    Directory of Open Access Journals (Sweden)

    Sayed Ahmadreza Razian

    2017-11-01

    The results show that one can generate at least 11 frames per second in HD (720p resolution by GPU processor and GT 840M graphic card, using trace method. If better graphic card employ, this algorithm and program can be used to generate real-time animation.

  12. Distinct contributions of functional and deep neural network features to representational similarity of scenes in human brain and behavior.

    Science.gov (United States)

    Groen, Iris Ia; Greene, Michelle R; Baldassano, Christopher; Fei-Fei, Li; Beck, Diane M; Baker, Chris I

    2018-03-07

    Inherent correlations between visual and semantic features in real-world scenes make it difficult to determine how different scene properties contribute to neural representations. Here, we assessed the contributions of multiple properties to scene representation by partitioning the variance explained in human behavioral and brain measurements by three feature models whose inter-correlations were minimized a priori through stimulus preselection. Behavioral assessments of scene similarity reflected unique contributions from a functional feature model indicating potential actions in scenes as well as high-level visual features from a deep neural network (DNN). In contrast, similarity of cortical responses in scene-selective areas was uniquely explained by mid- and high-level DNN features only, while an object label model did not contribute uniquely to either domain. The striking dissociation between functional and DNN features in their contribution to behavioral and brain representations of scenes indicates that scene-selective cortex represents only a subset of behaviorally relevant scene information.

  13. The roles of scene gist and spatial dependency among objects in the semantic guidance of attention in real-world scenes.

    Science.gov (United States)

    Wu, Chia-Chien; Wang, Hsueh-Cheng; Pomplun, Marc

    2014-12-01

    A previous study (Vision Research 51 (2011) 1192-1205) found evidence for semantic guidance of visual attention during the inspection of real-world scenes, i.e., an influence of semantic relationships among scene objects on overt shifts of attention. In particular, the results revealed an observer bias toward gaze transitions between semantically similar objects. However, this effect is not necessarily indicative of semantic processing of individual objects but may be mediated by knowledge of the scene gist, which does not require object recognition, or by known spatial dependency among objects. To examine the mechanisms underlying semantic guidance, in the present study, participants were asked to view a series of displays with the scene gist excluded and spatial dependency varied. Our results show that spatial dependency among objects seems to be sufficient to induce semantic guidance. Scene gist, on the other hand, does not seem to affect how observers use semantic information to guide attention while viewing natural scenes. Extracting semantic information mainly based on spatial dependency may be an efficient strategy of the visual system that only adds little cognitive load to the viewing task. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. [Perception of objects and scenes in age-related macular degeneration].

    Science.gov (United States)

    Tran, T H C; Boucart, M

    2012-01-01

    Vision related quality of life questionnaires suggest that patients with AMD exhibit difficulties in finding objects and in mobility. In the natural environment, objects seldom appear in isolation. They appear in a spatial context which may obscure them in part or place obstacles in the patient's path. Furthermore, the luminance of a natural scene varies as a function of the hour of the day and the light source, which can alter perception. This study aims to evaluate recognition of objects and natural scenes by patients with AMD, by using photographs of such scenes. Studies demonstrate that AMD patients are able to categorize scenes as nature scenes or urban scenes and to discriminate indoor from outdoor scenes with a high degree of precision. They detect objects better in isolation, in color, or against a white background than in their natural contexts. These patients encounter more difficulties than normally sighted individuals in detecting objects in a low-contrast, black-and-white scene. These results may have implications for rehabilitation, for layout of texts and magazines for the reading-impaired and for the rearrangement of the spatial environment of older AMD patients in order to facilitate mobility, finding objects and reducing the risk of falls. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  15. Places in the Brain: Bridging Layout and Object Geometry in Scene-Selective Cortex.

    Science.gov (United States)

    Dillon, Moira R; Persichetti, Andrew S; Spelke, Elizabeth S; Dilks, Daniel D

    2017-06-13

    Diverse animal species primarily rely on sense (left-right) and egocentric distance (proximal-distal) when navigating the environment. Recent neuroimaging studies with human adults show that this information is represented in 2 scene-selective cortical regions-the occipital place area (OPA) and retrosplenial complex (RSC)-but not in a third scene-selective region-the parahippocampal place area (PPA). What geometric properties, then, does the PPA represent, and what is its role in scene processing? Here we hypothesize that the PPA represents relative length and angle, the geometric properties classically associated with object recognition, but only in the context of large extended surfaces that compose the layout of a scene. Using functional magnetic resonance imaging adaptation, we found that the PPA is indeed sensitive to relative length and angle changes in pictures of scenes, but not pictures of objects that reliably elicited responses to the same geometric changes in object-selective cortical regions. Moreover, we found that the OPA is also sensitive to such changes, while the RSC is tolerant to such changes. Thus, the geometric information typically associated with object recognition is also used during some aspects of scene processing. These findings provide evidence that scene-selective cortex differentially represents the geometric properties guiding navigation versus scene categorization. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. A semi-interactive panorama based 3D reconstruction framework for indoor scenes

    NARCIS (Netherlands)

    Dang, T.K.; Worring, M.; Bui, T.D.

    2011-01-01

    We present a semi-interactive method for 3D reconstruction specialized for indoor scenes which combines computer vision techniques with efficient interaction. We use panoramas, popularly used for visualization of indoor scenes, but clearly not able to show depth, for their great field of view, as

  17. The ART of CSI: An augmented reality tool (ART) to annotate crime scenes in forensic investigation

    NARCIS (Netherlands)

    Streefkerk, J.W.; Houben, M.; Amerongen, P. van; Haar, F. ter; Dijk, J.

    2013-01-01

    Forensic professionals have to collect evidence at crime scenes quickly and without contamination. A handheld Augmented Reality (AR) annotation tool allows these users to virtually tag evidence traces at crime scenes and to review, share and export evidence lists. In an user walkthrough with this

  18. The Interplay of Episodic and Semantic Memory in Guiding Repeated Search in Scenes

    Science.gov (United States)

    Vo, Melissa L.-H.; Wolfe, Jeremy M.

    2013-01-01

    It seems intuitive to think that previous exposure or interaction with an environment should make it easier to search through it and, no doubt, this is true in many real-world situations. However, in a recent study, we demonstrated that previous exposure to a scene does not necessarily speed search within that scene. For instance, when observers…

  19. Automating the construction of scene classifiers for content-based video retrieval

    NARCIS (Netherlands)

    Khan, L.; Israël, Menno; Petrushin, V.A.; van den Broek, Egon; van der Putten, Peter

    2004-01-01

    This paper introduces a real time automatic scene classifier within content-based video retrieval. In our envisioned approach end users like documentalists, not image processing experts, build classifiers interactively, by simply indicating positive examples of a scene. Classification consists of a

  20. Panoramic Search: The Interaction of Memory and Vision in Search through a Familiar Scene

    Science.gov (United States)

    Oliva, Aude; Wolfe, Jeremy M. Arsenio, Helga C.

    2004-01-01

    How do observers search through familiar scenes? A novel panoramic search method is used to study the interaction of memory and vision in natural search behavior. In panoramic search, observers see part of an unchanging scene larger than their current field of view. A target object can be visible, present in the display but hidden from view, or…

  1. Motivational Objects in Natural Scenes (MONS: A Database of >800 Objects

    Directory of Open Access Journals (Sweden)

    Judith Schomaker

    2017-09-01

    Full Text Available In daily life, we are surrounded by objects with pre-existing motivational associations. However, these are rarely controlled for in experiments with natural stimuli. Research on natural stimuli would therefore benefit from stimuli with well-defined motivational properties; in turn, such stimuli also open new paths in research on motivation. Here we introduce a database of Motivational Objects in Natural Scenes (MONS. The database consists of 107 scenes. Each scene contains 2 to 7 objects placed at approximately equal distance from the scene center. Each scene was photographed creating 3 versions, with one object (“critical object” being replaced to vary the overall motivational value of the scene (appetitive, aversive, and neutral, while maintaining high visual similarity between the three versions. Ratings on motivation, valence, arousal and recognizability were obtained using internet-based questionnaires. Since the main objective was to provide stimuli of well-defined motivational value, three motivation scales were used: (1 Desire to own the object; (2 Approach/Avoid; (3 Desire to interact with the object. Three sets of ratings were obtained in independent sets of observers: for all 805 objects presented on a neutral background, for 321 critical objects presented in their scene context, and for the entire scenes. On the basis of the motivational ratings, objects were subdivided into aversive, neutral, and appetitive categories. The MONS database will provide a standardized basis for future studies on motivational value under realistic conditions.

  2. Anticipatory Scene Representation in Preschool Children's Recall and Recognition Memory

    Science.gov (United States)

    Kreindel, Erica; Intraub, Helene

    2017-01-01

    Behavioral and neuroscience research on boundary extension (false memory beyond the edges of a view of a scene) has provided new insights into the constructive nature of scene representation, and motivates questions about development. Early research with children (as young as 6-7 years) was consistent with boundary extension, but relied on an…

  3. Number 13 / Part I. Music. 3. Mad Scenes: A Warning against Overwhelming Passions

    Directory of Open Access Journals (Sweden)

    Marisi Rossella

    2017-03-01

    Full Text Available This study focuses on mad scenes in poetry and musical theatre, stressing that, according to Aristotle’s theory on catharsis and the Affektenlehre, they had a pedagogical role on the audience. Some mad scenes by J.S. Bach, Handel and Mozart are briefly analyzed, highlighting their most relevant textual and musical characteristics.

  4. Object Attention Patches for Text Detection and Recognition in Scene Images using SIFT

    NARCIS (Netherlands)

    Sriman, Bowornrat; Schomaker, Lambertus; De Marsico, Maria; Figueiredo, Mário; Fred, Ana

    2015-01-01

    Natural urban scene images contain many problems for character recognition such as luminance noise, varying font styles or cluttered backgrounds. Detecting and recognizing text in a natural scene is a difficult problem. Several techniques have been proposed to overcome these problems. These are,

  5. Eye Movement Control in Scene Viewing and Reading: Evidence from the Stimulus Onset Delay Paradigm

    Science.gov (United States)

    Luke, Steven G.; Nuthmann, Antje; Henderson, John M.

    2013-01-01

    The present study used the stimulus onset delay paradigm to investigate eye movement control in reading and in scene viewing in a within-participants design. Short onset delays (0, 25, 50, 200, and 350 ms) were chosen to simulate the type of natural processing difficulty encountered in reading and scene viewing. Fixation duration increased…

  6. Fundamental remote sensing science research program. Part 1: Scene radiation and atmospheric effects characterization project

    Science.gov (United States)

    Murphy, R. E.; Deering, D. W.

    1984-01-01

    Brief articles summarizing the status of research in the scene radiation and atmospheric effect characterization (SRAEC) project are presented. Research conducted within the SRAEC program is focused on the development of empirical characterizations and mathematical process models which relate the electromagnetic energy reflected or emitted from a scene to the biophysical parameters of interest.

  7. The Effect of Scene Variation on the Redundant Use of Color in Definite Reference

    Science.gov (United States)

    Koolen, Ruud; Goudbeek, Martijn; Krahmer, Emiel

    2013-01-01

    This study investigates to what extent the amount of variation in a visual scene causes speakers to mention the attribute color in their definite target descriptions, focusing on scenes in which this attribute is not needed for identification of the target. The results of our three experiments show that speakers are more likely to redundantly…

  8. Was That Levity or Livor Mortis? Crime Scene Investigators' Perspectives on Humor and Work

    Science.gov (United States)

    Vivona, Brian D.

    2012-01-01

    Humor is common and purposeful in most work settings. Although researchers have examined humor and joking behavior in various work settings, minimal research has been done on humor applications in the field of crime scene investigation. The crime scene investigator encounters death, trauma, and tragedy in a more intimate manner than any other…

  9. Motivational Objects in Natural Scenes (MONS): A Database of >800 Objects.

    Science.gov (United States)

    Schomaker, Judith; Rau, Elias M; Einhäuser, Wolfgang; Wittmann, Bianca C

    2017-01-01

    In daily life, we are surrounded by objects with pre-existing motivational associations. However, these are rarely controlled for in experiments with natural stimuli. Research on natural stimuli would therefore benefit from stimuli with well-defined motivational properties; in turn, such stimuli also open new paths in research on motivation. Here we introduce a database of Motivational Objects in Natural Scenes (MONS). The database consists of 107 scenes. Each scene contains 2 to 7 objects placed at approximately equal distance from the scene center. Each scene was photographed creating 3 versions, with one object ("critical object") being replaced to vary the overall motivational value of the scene (appetitive, aversive, and neutral), while maintaining high visual similarity between the three versions. Ratings on motivation, valence, arousal and recognizability were obtained using internet-based questionnaires. Since the main objective was to provide stimuli of well-defined motivational value, three motivation scales were used: (1) Desire to own the object; (2) Approach/Avoid; (3) Desire to interact with the object. Three sets of ratings were obtained in independent sets of observers: for all 805 objects presented on a neutral background, for 321 critical objects presented in their scene context, and for the entire scenes. On the basis of the motivational ratings, objects were subdivided into aversive, neutral, and appetitive categories. The MONS database will provide a standardized basis for future studies on motivational value under realistic conditions.

  10. Eye Movements when Looking at Unusual/Weird Scenes: Are There Cultural Differences?

    Science.gov (United States)

    Rayner, Keith; Castelhano, Monica S.; Yang, Jinmian

    2009-01-01

    Recent studies have suggested that eye movement patterns while viewing scenes differ for people from different cultural backgrounds and that these differences in how scenes are viewed are due to differences in the prioritization of information (background or foreground). The current study examined whether there are cultural differences in how…

  11. Face, Body, and Center of Gravity Mediate Person Detection in Natural Scenes

    Science.gov (United States)

    Bindemann, Markus; Scheepers, Christoph; Ferguson, Heather J.; Burton, A. Mike

    2010-01-01

    Person detection is an important prerequisite of social interaction, but is not well understood. Following suggestions that people in the visual field can capture a viewer's attention, this study examines the role of the face and the body for person detection in natural scenes. We observed that viewers tend first to look at the center of a scene,…

  12. Making a scene: exploring the dimensions of place through Dutch popular music, 1960-2010

    NARCIS (Netherlands)

    Brandellero, A.; Pfeffer, K.

    2015-01-01

    This paper applies a multi-layered conceptualisation of place to the analysis of particular music scenes in the Netherlands, 1960-2010. We focus on: the clustering of music-related activities in locations; the delineation of spatially tied music scenes, based on a shared identity, reproduced over

  13. Visual search in scenes involves selective and non-selective pathways

    Science.gov (United States)

    Wolfe, Jeremy M; Vo, Melissa L-H; Evans, Karla K; Greene, Michelle R

    2010-01-01

    How do we find objects in scenes? For decades, visual search models have been built on experiments in which observers search for targets, presented among distractor items, isolated and randomly arranged on blank backgrounds. Are these models relevant to search in continuous scenes? This paper argues that the mechanisms that govern artificial, laboratory search tasks do play a role in visual search in scenes. However, scene-based information is used to guide search in ways that had no place in earlier models. Search in scenes may be best explained by a dual-path model: A “selective” path in which candidate objects must be individually selected for recognition and a “non-selective” path in which information can be extracted from global / statistical information. PMID:21227734

  14. A hierarchical probabilistic model for rapid object categorization in natural scenes.

    Directory of Open Access Journals (Sweden)

    Xiaofu He

    Full Text Available Humans can categorize objects in complex natural scenes within 100-150 ms. This amazing ability of rapid categorization has motivated many computational models. Most of these models require extensive training to obtain a decision boundary in a very high dimensional (e.g., ∼6,000 in a leading model feature space and often categorize objects in natural scenes by categorizing the context that co-occurs with objects when objects do not occupy large portions of the scenes. It is thus unclear how humans achieve rapid scene categorization.To address this issue, we developed a hierarchical probabilistic model for rapid object categorization in natural scenes. In this model, a natural object category is represented by a coarse hierarchical probability distribution (PD, which includes PDs of object geometry and spatial configuration of object parts. Object parts are encoded by PDs of a set of natural object structures, each of which is a concatenation of local object features. Rapid categorization is performed as statistical inference. Since the model uses a very small number (∼100 of structures for even complex object categories such as animals and cars, it requires little training and is robust in the presence of large variations within object categories and in their occurrences in natural scenes. Remarkably, we found that the model categorized animals in natural scenes and cars in street scenes with a near human-level performance. We also found that the model located animals and cars in natural scenes, thus overcoming a flaw in many other models which is to categorize objects in natural context by categorizing contextual features. These results suggest that coarse PDs of object categories based on natural object structures and statistical operations on these PDs may underlie the human ability to rapidly categorize scenes.

  15. SCEGRAM: An image database for semantic and syntactic inconsistencies in scenes.

    Science.gov (United States)

    Öhlschläger, Sabine; Võ, Melissa Le-Hoa

    2017-10-01

    Our visual environment is not random, but follows compositional rules according to what objects are usually found where. Despite the growing interest in how such semantic and syntactic rules - a scene grammar - enable effective attentional guidance and object perception, no common image database containing highly-controlled object-scene modifications has been publically available. Such a database is essential in minimizing the risk that low-level features drive high-level effects of interest, which is being discussed as possible source of controversial study results. To generate the first database of this kind - SCEGRAM - we took photographs of 62 real-world indoor scenes in six consistency conditions that contain semantic and syntactic (both mild and extreme) violations as well as their combinations. Importantly, always two scenes were paired, so that an object was semantically consistent in one scene (e.g., ketchup in kitchen) and inconsistent in the other (e.g., ketchup in bathroom). Low-level salience did not differ between object-scene conditions and was generally moderate. Additionally, SCEGRAM contains consistency ratings for every object-scene condition, as well as object-absent scenes and object-only images. Finally, a cross-validation using eye-movements replicated previous results of longer dwell times for both semantic and syntactic inconsistencies compared to consistent controls. In sum, the SCEGRAM image database is the first to contain well-controlled semantic and syntactic object-scene inconsistencies that can be used in a broad range of cognitive paradigms (e.g., verbal and pictorial priming, change detection, object identification, etc.) including paradigms addressing developmental aspects of scene grammar. SCEGRAM can be retrieved for research purposes from http://www.scenegrammarlab.com/research/scegram-database/ .

  16. Falling out of time: enhanced memory for scenes presented at behaviorally irrelevant points in time in posttraumatic stress disorder (PTSD).

    Science.gov (United States)

    Levy-Gigi, Einat; Kéri, Szabolcs

    2012-01-01

    Spontaneous encoding of the visual environment depends on the behavioral relevance of the task performed simultaneously. If participants identify target letters or auditory tones while viewing a series of briefly presented natural and urban scenes, they demonstrate effective scene recognition only when a target, but not a behaviorally irrelevant distractor, appears together with the scene. Here, we show that individuals with posttraumatic stress disorder (PTSD), who witnessed the red sludge disaster in Hungary, show the opposite pattern of performance: enhanced recognition of scenes presented together with distractors and deficient recognition of scenes presented with targets. The recognition of trauma-related and neutral scenes was not different in individuals with PTSD. We found a positive correlation between memory for scenes presented with auditory distractors and re-experiencing symptoms (memory intrusions and flashbacks). These results suggest that abnormal encoding of visual scenes at behaviorally irrelevant events might be associated with intrusive experiences by disrupting the flow of time.

  17. Falling out of time: enhanced memory for scenes presented at behaviorally irrelevant points in time in posttraumatic stress disorder (PTSD.

    Directory of Open Access Journals (Sweden)

    Einat Levy-Gigi

    Full Text Available Spontaneous encoding of the visual environment depends on the behavioral relevance of the task performed simultaneously. If participants identify target letters or auditory tones while viewing a series of briefly presented natural and urban scenes, they demonstrate effective scene recognition only when a target, but not a behaviorally irrelevant distractor, appears together with the scene. Here, we show that individuals with posttraumatic stress disorder (PTSD, who witnessed the red sludge disaster in Hungary, show the opposite pattern of performance: enhanced recognition of scenes presented together with distractors and deficient recognition of scenes presented with targets. The recognition of trauma-related and neutral scenes was not different in individuals with PTSD. We found a positive correlation between memory for scenes presented with auditory distractors and re-experiencing symptoms (memory intrusions and flashbacks. These results suggest that abnormal encoding of visual scenes at behaviorally irrelevant events might be associated with intrusive experiences by disrupting the flow of time.

  18. Improving Scene Classifications with Combined Active/Passive Measurements

    Science.gov (United States)

    Hu, Y.; Rodier, S.; Vaughan, M.; McGill, M.

    The uncertainties in cloud and aerosol physical properties derived from passive instruments such as MODIS are not insignificant And the uncertainty increases when the optical depths decrease Lidar observations do much better for the thin clouds and aerosols Unfortunately space-based lidar measurements such as the one onboard CALIPSO satellites are limited to nadir view only and thus have limited spatial coverage To produce climatologically meaningful thin cloud and aerosol data products it is necessary to combine the spatial coverage of MODIS with the highly sensitive CALIPSO lidar measurements Can we improving the quality of cloud and aerosol remote sensing data products by extending the knowledge about thin clouds and aerosols learned from CALIPSO-type of lidar measurements to a larger portion of the off-nadir MODIS-like multi-spectral pixels To answer the question we studied the collocated Cloud Physics Lidar CPL with Modis-Airborne-Simulation MAS observations and established an effective data fusion technique that will be applied in the combined CALIPSO MODIS cloud aerosol product algorithms This technique performs k-mean and Kohonen self-organized map cluster analysis on the entire swath of MAS data as well as on the combined CPL MAS data at the nadir track Interestingly the clusters generated from the two approaches are almost identical It indicates that the MAS multi-spectral data may have already captured most of the cloud and aerosol scene types such as cloud ice water phase multi-layer information aerosols

  19. Intrinsic Scene Decomposition from RGB-D Images

    KAUST Repository

    Hachama, Mohammed; Ghanem, Bernard; Wonka, Peter

    2015-01-01

    In this paper, we address the problem of computing an intrinsic decomposition of the colors of a surface into an albedo and a shading term. The surface is reconstructed from a single or multiple RGB-D images of a static scene obtained from different views. We thereby extend and improve existing works in the area of intrinsic image decomposition. In a variational framework, we formulate the problem as a minimization of an energy composed of two terms: a data term and a regularity term. The first term is related to the image formation process and expresses the relation between the albedo, the surface normals, and the incident illumination. We use an affine shading model, a combination of a Lambertian model, and an ambient lighting term. This model is relevant for Lambertian surfaces. When available, multiple views can be used to handle view-dependent non-Lambertian reflections. The second term contains an efficient combination of l2 and l1-regularizers on the illumination vector field and albedo respectively. Unlike most previous approaches, especially Retinex-like techniques, these terms do not depend on the image gradient or texture, thus reducing the mixing shading/reflectance artifacts and leading to better results. The obtained non-linear optimization problem is efficiently solved using a cyclic block coordinate descent algorithm. Our method outperforms a range of state-of-the-art algorithms on a popular benchmark dataset.

  20. Saliency predicts change detection in pictures of natural scenes.

    Science.gov (United States)

    Wright, Michael J

    2005-01-01

    It has been proposed that the visual system encodes the salience of objects in the visual field in an explicit two-dimensional map that guides visual selective attention. Experiments were conducted to determine whether salience measurements applied to regions of pictures of outdoor scenes could predict the detection of changes in those regions. To obtain a quantitative measure of change detection, observers located changes in pairs of colour pictures presented across an interstimulus interval (ISI). Salience measurements were then obtained from different observers for image change regions using three independent methods, and all were positively correlated with change detection. Factor analysis extracted a single saliency factor that accounted for 62% of the variance contained in the four measures. Finally, estimates of the magnitude of the image change in each picture pair were obtained, using nine separate visual filters representing low-level vision features (luminance, colour, spatial frequency, orientation, edge density). None of the feature outputs was significantly associated with change detection or saliency. On the other hand it was shown that high-level (structural) properties of the changed region were related to saliency and to change detection: objects were more salient than shadows and more detectable when changed.

  1. Effects of mild cognitive impairment on emotional scene memory.

    Science.gov (United States)

    Waring, J D; Dimsdale-Zucker, H R; Flannery, S; Budson, A E; Kensinger, E A

    2017-02-01

    Young and older adults experience benefits in attention and memory for emotional compared to neutral information, but this memory benefit is greatly diminished in Alzheimer's disease (AD). Little is known about whether this impairment arises early or late in the time course between healthy aging and AD. This study compared memory for positive, negative, and neutral items with neutral backgrounds between patients with mild cognitive impairment (MCI) and healthy older adults. We also used a divided attention condition in older adults as a possible model for the deficits observed in MCI patients. Results showed a similar pattern of selective memory for emotional items while forgetting their backgrounds in older adults and MCI patients, but MCI patients had poorer memory overall. Dividing attention during encoding disproportionately reduced memory for backgrounds (versus items) relative to a full attention condition. Participants performing in the lower half on the divided attention task qualitatively and quantitatively mirrored the results in MCI patients. Exploratory analyses comparing lower- and higher-performing MCI patients showed that only higher-performing MCI patients had the characteristic scene memory pattern observed in healthy older adults. Together, these results suggest that the effects of emotion on memory are relatively well preserved for patients with MCI, although emotional memory patterns may start to be altered once memory deficits become more pronounced. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Ocfentanil overdose fatality in the recreational drug scene.

    Science.gov (United States)

    Coopman, Vera; Cordonnier, Jan; De Leeuw, Marc; Cirimele, Vincent

    2016-09-01

    This paper describes the first reported death involving ocfentanil, a potent synthetic opioid and structure analogue of fentanyl abused as a new psychoactive substance in the recreational drug scene. A 17-year-old man with a history of illegal substance abuse was found dead in his home after snorting a brown powder purchased over the internet with bitcoins. Acetaminophen, caffeine and ocfentanil were identified in the powder by gas chromatography mass spectrometry and reversed-phase liquid chromatography with diode array detector. Quantitation of ocfentanil in biological samples was performed using a target analysis based on liquid-liquid extraction and ultra performance liquid chromatography tandem mass spectrometry. In the femoral blood taken at the external body examination, the following concentrations were measured: ocfentanil 15.3μg/L, acetaminophen 45mg/L and caffeine 0.23mg/L. Tissues sampled at autopsy were analyzed to study the distribution of ocfentanil. The comprehensive systematic toxicological analysis on the post-mortem blood and tissue samples was negative for other compounds. Based on circumstantial evidence, autopsy findings and the results of the toxicological analysis, the medical examiner concluded that the cause of death was an acute intoxication with ocfentanil. The manner of death was assumed to be accidental after snorting the powder. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Repfinder: Finding approximately repeated scene elements for image editing

    KAUST Repository

    Cheng, Ming-Ming

    2010-07-26

    Repeated elements are ubiquitous and abundant in both manmade and natural scenes. Editing such images while preserving the repetitions and their relations is nontrivial due to overlap, missing parts, deformation across instances, illumination variation, etc. Manually enforcing such relations is laborious and error-prone. We propose a novel framework where user scribbles are used to guide detection and extraction of such repeated elements. Our detection process, which is based on a novel boundary band method, robustly extracts the repetitions along with their deformations. The algorithm only considers the shape of the elements, and ignores similarity based on color, texture, etc. We then use topological sorting to establish a partial depth ordering of overlapping repeated instances. Missing parts on occluded instances are completed using information from other instances. The extracted repeated instances can then be seamlessly edited and manipulated for a variety of high level tasks that are otherwise difficult to perform. We demonstrate the versatility of our framework on a large set of inputs of varying complexity, showing applications to image rearrangement, edit transfer, deformation propagation, and instance replacement. © 2010 ACM.

  4. Sleep Promotes Lasting Changes in Selective Memory for Emotional Scenes

    Directory of Open Access Journals (Sweden)

    Jessica ePayne

    2012-11-01

    Full Text Available Although we know that emotional events enjoy a privileged status in our memories, we still have much to learn about how emotional memories are processed, stored, and how they change over time. Here we show a positive association between REM sleep and the selective consolidation of central, negative aspects of complex scenes. Moreover, we show that the placement of sleep is critical for this selective emotional memory benefit. When testing occurred 24hr post-encoding, subjects who slept soon after learning (24hr Sleep First group had superior memory for emotional objects compared to subjects whose sleep was delayed for 16hr post-encoding following a full day of wakefulness (24hr Wake First group. However, this increase in memory for emotional objects corresponded with a decrease in memory for the neutral backgrounds on which these objects were placed. Furthermore, memory for emotional objects in the 24hr Sleep First group was comparable to performance after just a 12hr delay containing a night of sleep, suggesting that sleep soon after learning selectively stabilizes emotional memory. These results suggest that the sleeping brain preserves in long-term memory only what is emotionally salient and perhaps most adaptive to remember.

  5. Sleep promotes lasting changes in selective memory for emotional scenes.

    Science.gov (United States)

    Payne, Jessica D; Chambers, Alexis M; Kensinger, Elizabeth A

    2012-01-01

    Although we know that emotional events enjoy a privileged status in our memories, we still have much to learn about how emotional memories are processed, stored, and how they change over time. Here we show a positive association between REM sleep and the selective consolidation of central, negative aspects of complex scenes. Moreover, we show that the placement of sleep is critical for this selective emotional memory benefit. When testing occurred 24 h post-encoding, subjects who slept soon after learning (24 h Sleep First group) had superior memory for emotional objects compared to subjects whose sleep was delayed for 16 h post-encoding following a full day of wakefulness (24 h Wake First group). However, this increase in memory for emotional objects corresponded with a decrease in memory for the neutral backgrounds on which these objects were placed. Furthermore, memory for emotional objects in the 24 h Sleep First group was comparable to performance after just a 12 h delay containing a night of sleep, suggesting that sleep soon after learning selectively stabilizes emotional memory. These results suggest that the sleeping brain preserves in long-term memory only what is emotionally salient and perhaps most adaptive to remember.

  6. Intrinsic Scene Decomposition from RGB-D Images

    KAUST Repository

    Hachama, Mohammed

    2015-12-07

    In this paper, we address the problem of computing an intrinsic decomposition of the colors of a surface into an albedo and a shading term. The surface is reconstructed from a single or multiple RGB-D images of a static scene obtained from different views. We thereby extend and improve existing works in the area of intrinsic image decomposition. In a variational framework, we formulate the problem as a minimization of an energy composed of two terms: a data term and a regularity term. The first term is related to the image formation process and expresses the relation between the albedo, the surface normals, and the incident illumination. We use an affine shading model, a combination of a Lambertian model, and an ambient lighting term. This model is relevant for Lambertian surfaces. When available, multiple views can be used to handle view-dependent non-Lambertian reflections. The second term contains an efficient combination of l2 and l1-regularizers on the illumination vector field and albedo respectively. Unlike most previous approaches, especially Retinex-like techniques, these terms do not depend on the image gradient or texture, thus reducing the mixing shading/reflectance artifacts and leading to better results. The obtained non-linear optimization problem is efficiently solved using a cyclic block coordinate descent algorithm. Our method outperforms a range of state-of-the-art algorithms on a popular benchmark dataset.

  7. Napping and the Selective Consolidation of Negative Aspects of Scenes

    Science.gov (United States)

    Payne, Jessica D.; Kensinger, Elizabeth A.; Wamsley, Erin; Spreng, R. Nathan; Alger, Sara; Gibler, Kyle; Schacter, Daniel L.; Stickgold, Robert

    2018-01-01

    After information is encoded into memory, it undergoes an offline period of consolidation that occurs optimally during sleep. The consolidation process not only solidifies memories, but also selectively preserves aspects of experience that are emotionally salient and relevant for future use. Here, we provide evidence that an afternoon nap is sufficient to trigger preferential memory for emotional information contained in complex scenes. Selective memory for negative emotional information was enhanced after a nap compared to wakefulness in two control conditions designed to carefully address interference and time-of-day confounds. Although prior evidence has connected negative emotional memory formation to rapid eye movement (REM) sleep physiology, we found that non-REM delta activity and the amount of slow wave sleep (SWS) in the nap were robustly related to the selective consolidation of negative information. These findings suggest that the mechanisms underlying memory consolidation benefits associated with napping and nighttime sleep are not always the same. Finally, we provide preliminary evidence that the magnitude of the emotional memory benefit conferred by sleep is equivalent following a nap and a full night of sleep, suggesting that selective emotional remembering can be economically achieved by taking a nap. PMID:25706830

  8. Optimising crime scene temperature collection for forensic entomology casework.

    Science.gov (United States)

    Hofer, Ines M J; Hart, Andrew J; Martín-Vega, Daniel; Hall, Martin J R

    2017-01-01

    The value of minimum post-mortem interval (minPMI) estimations in suspicious death investigations from insect evidence using temperature modelling is indisputable. In order to investigate the reliability of the collected temperature data used for modelling minPMI, it is necessary to study the effects of data logger location on the accuracy and precision of measurements. Digital data logging devices are the most commonly used temperature measuring devices in forensic entomology, however, the relationship between ambient temperatures (measured by loggers) and body temperatures has been little studied. The placement of loggers in this study in three locations (two outdoors, one indoors) had measurable effects when compared with actual body temperature measurements (simulated with pig heads), some more significant than others depending on season, exposure to the environment and logger location. Overall, the study demonstrated the complexity of the question of optimal logger placement at a crime scene and the potential impact of inaccurate temperature data on minPMI estimations, showing the importance of further research in this area and development of a standard protocol. Initial recommendations are provided for data logger placement (within a Stevenson Screen where practical), situations to avoid (e.g. placement of logger in front of windows when measuring indoor temperatures), and a baseline for further research into producing standard guidelines for logger placement, to increase the accuracy of minPMI estimations and, thereby, the reliability of forensic entomology evidence in court. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. METRIC EVALUATION PIPELINE FOR 3D MODELING OF URBAN SCENES

    Directory of Open Access Journals (Sweden)

    M. Bosch

    2017-05-01

    Full Text Available Publicly available benchmark data and metric evaluation approaches have been instrumental in enabling research to advance state of the art methods for remote sensing applications in urban 3D modeling. Most publicly available benchmark datasets have consisted of high resolution airborne imagery and lidar suitable for 3D modeling on a relatively modest scale. To enable research in larger scale 3D mapping, we have recently released a public benchmark dataset with multi-view commercial satellite imagery and metrics to compare 3D point clouds with lidar ground truth. We now define a more complete metric evaluation pipeline developed as publicly available open source software to assess semantically labeled 3D models of complex urban scenes derived from multi-view commercial satellite imagery. Evaluation metrics in our pipeline include horizontal and vertical accuracy and completeness, volumetric completeness and correctness, perceptual quality, and model simplicity. Sources of ground truth include airborne lidar and overhead imagery, and we demonstrate a semi-automated process for producing accurate ground truth shape files to characterize building footprints. We validate our current metric evaluation pipeline using 3D models produced using open source multi-view stereo methods. Data and software is made publicly available to enable further research and planned benchmarking activities.

  10. Metric Evaluation Pipeline for 3d Modeling of Urban Scenes

    Science.gov (United States)

    Bosch, M.; Leichtman, A.; Chilcott, D.; Goldberg, H.; Brown, M.

    2017-05-01

    Publicly available benchmark data and metric evaluation approaches have been instrumental in enabling research to advance state of the art methods for remote sensing applications in urban 3D modeling. Most publicly available benchmark datasets have consisted of high resolution airborne imagery and lidar suitable for 3D modeling on a relatively modest scale. To enable research in larger scale 3D mapping, we have recently released a public benchmark dataset with multi-view commercial satellite imagery and metrics to compare 3D point clouds with lidar ground truth. We now define a more complete metric evaluation pipeline developed as publicly available open source software to assess semantically labeled 3D models of complex urban scenes derived from multi-view commercial satellite imagery. Evaluation metrics in our pipeline include horizontal and vertical accuracy and completeness, volumetric completeness and correctness, perceptual quality, and model simplicity. Sources of ground truth include airborne lidar and overhead imagery, and we demonstrate a semi-automated process for producing accurate ground truth shape files to characterize building footprints. We validate our current metric evaluation pipeline using 3D models produced using open source multi-view stereo methods. Data and software is made publicly available to enable further research and planned benchmarking activities.

  11. Depth estimation of complex geometry scenes from light fields

    Science.gov (United States)

    Si, Lipeng; Wang, Qing

    2018-01-01

    The surface camera (SCam) of light fields gathers angular sample rays passing through a 3D point. The consistency of SCams is evaluated to estimate the depth map of scene. But the consistency is affected by several limitations such as occlusions or non-Lambertian surfaces. To solve those limitations, the SCam is partitioned into two segments that one of them could satisfy the consistency constraint. The segmentation pattern of SCam is highly related to the texture of spatial patch, so we enforce a mask matching to describe the shape correlation between segments of SCam and spatial patch. To further address the ambiguity in textureless region, a global method with pixel-wise plane label is presented. Plane label inference at each pixel can recover not only depth value but also local geometry structure, that is suitable for light fields with sub-pixel disparities and continuous view variation. Our method is evaluated on public light field datasets and outperforms the state-of-the-art.

  12. Fitting boxes to Manhattan scenes using linear integer programming

    KAUST Repository

    Li, Minglei

    2016-02-19

    We propose an approach for automatic generation of building models by assembling a set of boxes using a Manhattan-world assumption. The method first aligns the point cloud with a per-building local coordinate system, and then fits axis-aligned planes to the point cloud through an iterative regularization process. The refined planes partition the space of the data into a series of compact cubic cells (candidate boxes) spanning the entire 3D space of the input data. We then choose to approximate the target building by the assembly of a subset of these candidate boxes using a binary linear programming formulation. The objective function is designed to maximize the point cloud coverage and the compactness of the final model. Finally, all selected boxes are merged into a lightweight polygonal mesh model, which is suitable for interactive visualization of large scale urban scenes. Experimental results and a comparison with state-of-the-art methods demonstrate the effectiveness of the proposed framework.

  13. Integration of Visual Information in Auditory Cortex Promotes Auditory Scene Analysis through Multisensory Binding.

    Science.gov (United States)

    Atilgan, Huriye; Town, Stephen M; Wood, Katherine C; Jones, Gareth P; Maddox, Ross K; Lee, Adrian K C; Bizley, Jennifer K

    2018-02-07

    How and where in the brain audio-visual signals are bound to create multimodal objects remains unknown. One hypothesis is that temporal coherence between dynamic multisensory signals provides a mechanism for binding stimulus features across sensory modalities. Here, we report that when the luminance of a visual stimulus is temporally coherent with the amplitude fluctuations of one sound in a mixture, the representation of that sound is enhanced in auditory cortex. Critically, this enhancement extends to include both binding and non-binding features of the sound. We demonstrate that visual information conveyed from visual cortex via the phase of the local field potential is combined with auditory information within auditory cortex. These data provide evidence that early cross-sensory binding provides a bottom-up mechanism for the formation of cross-sensory objects and that one role for multisensory binding in auditory cortex is to support auditory scene analysis. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  14. Influences of High-Level Features, Gaze, and Scene Transitions on the Reliability of BOLD Responses to Natural Movie Stimuli

    Science.gov (United States)

    Lu, Kun-Han; Hung, Shao-Chin; Wen, Haiguang; Marussich, Lauren; Liu, Zhongming

    2016-01-01

    Complex, sustained, dynamic, and naturalistic visual stimulation can evoke distributed brain activities that are highly reproducible within and across individuals. However, the precise origins of such reproducible responses remain incompletely understood. Here, we employed concurrent functional magnetic resonance imaging (fMRI) and eye tracking to investigate the experimental and behavioral factors that influence fMRI activity and its intra- and inter-subject reproducibility during repeated movie stimuli. We found that widely distributed and highly reproducible fMRI responses were attributed primarily to the high-level natural content in the movie. In the absence of such natural content, low-level visual features alone in a spatiotemporally scrambled control stimulus evoked significantly reduced degree and extent of reproducible responses, which were mostly confined to the primary visual cortex (V1). We also found that the varying gaze behavior affected the cortical response at the peripheral part of V1 and in the oculomotor network, with minor effects on the response reproducibility over the extrastriate visual areas. Lastly, scene transitions in the movie stimulus due to film editing partly caused the reproducible fMRI responses at widespread cortical areas, especially along the ventral visual pathway. Therefore, the naturalistic nature of a movie stimulus is necessary for driving highly reliable visual activations. In a movie-stimulation paradigm, scene transitions and individuals’ gaze behavior should be taken as potential confounding factors in order to properly interpret cortical activity that supports natural vision. PMID:27564573

  15. Semantic memory for contextual regularities within and across scene categories: evidence from eye movements.

    Science.gov (United States)

    Brockmole, James R; Le-Hoa Võ, Melissa

    2010-10-01

    When encountering familiar scenes, observers can use item-specific memory to facilitate the guidance of attention to objects appearing in known locations or configurations. Here, we investigated how memory for relational contingencies that emerge across different scenes can be exploited to guide attention. Participants searched for letter targets embedded in pictures of bedrooms. In a between-subjects manipulation, targets were either always on a bed pillow or randomly positioned. When targets were systematically located within scenes, search for targets became more efficient. Importantly, this learning transferred to bedrooms without pillows, ruling out learning that is based on perceptual contingencies. Learning also transferred to living room scenes, but it did not transfer to kitchen scenes, even though both scene types contained pillows. These results suggest that statistical regularities abstracted across a range of stimuli are governed by semantic expectations regarding the presence of target-predicting local landmarks. Moreover, explicit awareness of these contingencies led to a central tendency bias in recall memory for precise target positions that is similar to the spatial category effects observed in landmark memory. These results broaden the scope of conditions under which contextual cuing operates and demonstrate how semantic memory plays a causal and independent role in the learning of associations between objects in real-world scenes.

  16. Scene text recognition in mobile applications by character descriptor and structure configuration.

    Science.gov (United States)

    Yi, Chucai; Tian, Yingli

    2014-07-01

    Text characters and strings in natural scene can provide valuable information for many applications. Extracting text directly from natural scene images or videos is a challenging task because of diverse text patterns and variant background interferences. This paper proposes a method of scene text recognition from detected text regions. In text detection, our previously proposed algorithms are applied to obtain text regions from scene image. First, we design a discriminative character descriptor by combining several state-of-the-art feature detectors and descriptors. Second, we model character structure at each character class by designing stroke configuration maps. Our algorithm design is compatible with the application of scene text extraction in smart mobile devices. An Android-based demo system is developed to show the effectiveness of our proposed method on scene text information extraction from nearby objects. The demo system also provides us some insight into algorithm design and performance improvement of scene text extraction. The evaluation results on benchmark data sets demonstrate that our proposed scheme of text recognition is comparable with the best existing methods.

  17. Effects of aging on neural connectivity underlying selective memory for emotional scenes.

    Science.gov (United States)

    Waring, Jill D; Addis, Donna Rose; Kensinger, Elizabeth A

    2013-02-01

    Older adults show age-related reductions in memory for neutral items within complex visual scenes, but just like young adults, older adults exhibit a memory advantage for emotional items within scenes compared with the background scene information. The present study examined young and older adults' encoding-stage effective connectivity for selective memory of emotional items versus memory for both the emotional item and its background. In a functional magnetic resonance imaging (fMRI) study, participants viewed scenes containing either positive or negative items within neutral backgrounds. Outside the scanner, participants completed a memory test for items and backgrounds. Irrespective of scene content being emotionally positive or negative, older adults had stronger positive connections among frontal regions and from frontal regions to medial temporal lobe structures than did young adults, especially when items and backgrounds were subsequently remembered. These results suggest there are differences between young and older adults' connectivity accompanying the encoding of emotional scenes. Older adults may require more frontal connectivity to encode all elements of a scene rather than just encoding the emotional item. Published by Elsevier Inc.

  18. Oculomotor capture during real-world scene viewing depends on cognitive load.

    Science.gov (United States)

    Matsukura, Michi; Brockmole, James R; Boot, Walter R; Henderson, John M

    2011-03-25

    It has been claimed that gaze control during scene viewing is largely governed by stimulus-driven, bottom-up selection mechanisms. Recent research, however, has strongly suggested that observers' top-down control plays a dominant role in attentional prioritization in scenes. A notable exception to this strong top-down control is oculomotor capture, where visual transients in a scene draw the eyes. One way to test whether oculomotor capture during scene viewing is independent of an observer's top-down goal setting is to reduce observers' cognitive resource availability. In the present study, we examined whether increasing observers' cognitive load influences the frequency and speed of oculomotor capture during scene viewing. In Experiment 1, we tested whether increasing observers' cognitive load modulates the degree of oculomotor capture by a new object suddenly appeared in a scene. Similarly, in Experiment 2, we tested whether increasing observers' cognitive load modulates the degree of oculomotor capture by an object's color change. In both experiments, the degree of oculomotor capture decreased as observers' cognitive resources were reduced. These results suggest that oculomotor capture during scene viewing is dependent on observers' top-down selection mechanisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Hierarchy-associated semantic-rule inference framework for classifying indoor scenes

    Science.gov (United States)

    Yu, Dan; Liu, Peng; Ye, Zhipeng; Tang, Xianglong; Zhao, Wei

    2016-03-01

    Typically, the initial task of classifying indoor scenes is challenging, because the spatial layout and decoration of a scene can vary considerably. Recent efforts at classifying object relationships commonly depend on the results of scene annotation and predefined rules, making classification inflexible. Furthermore, annotation results are easily affected by external factors. Inspired by human cognition, a scene-classification framework was proposed using the empirically based annotation (EBA) and a match-over rule-based (MRB) inference system. The semantic hierarchy of images is exploited by EBA to construct rules empirically for MRB classification. The problem of scene classification is divided into low-level annotation and high-level inference from a macro perspective. Low-level annotation involves detecting the semantic hierarchy and annotating the scene with a deformable-parts model and a bag-of-visual-words model. In high-level inference, hierarchical rules are extracted to train the decision tree for classification. The categories of testing samples are generated from the parts to the whole. Compared with traditional classification strategies, the proposed semantic hierarchy and corresponding rules reduce the effect of a variable background and improve the classification performance. The proposed framework was evaluated on a popular indoor scene dataset, and the experimental results demonstrate its effectiveness.

  20. Medial Temporal Lobe Contributions to Episodic Future Thinking: Scene Construction or Future Projection?

    Science.gov (United States)

    Palombo, D J; Hayes, S M; Peterson, K M; Keane, M M; Verfaellie, M

    2018-02-01

    Previous research has shown that the medial temporal lobes (MTL) are more strongly engaged when individuals think about the future than about the present, leading to the suggestion that future projection drives MTL engagement. However, future thinking tasks often involve scene processing, leaving open the alternative possibility that scene-construction demands, rather than future projection, are responsible for the MTL differences observed in prior work. This study explores this alternative account. Using functional magnetic resonance imaging, we directly contrasted MTL activity in 1) high scene-construction and low scene-construction imagination conditions matched in future thinking demands and 2) future-oriented and present-oriented imagination conditions matched in scene-construction demands. Consistent with the alternative account, the MTL was more active for the high versus low scene-construction condition. By contrast, MTL differences were not observed when comparing the future versus present conditions. Moreover, the magnitude of MTL activation was associated with the extent to which participants imagined a scene but was not associated with the extent to which participants thought about the future. These findings help disambiguate which component processes of imagination specifically involve the MTL. Published by Oxford University Press 2016.

  1. Poetics of the Key Scenes of V. Pelevin’s Literary Historiosophy

    Directory of Open Access Journals (Sweden)

    Tatyana E. Sorokina

    2017-03-01

    Full Text Available The article studies the poetics of the key scenes of the artistic philosophy of history of Victor Pelevin. There is an attempt to identify the features of his rational creative manner. Firstly, in the novels and stories of the writer there is modernity, transformed into grotesque images «of our days». Secondly, dynamism of fable text formation is in the context of philosophical reflection and breakthroughs that allow the reader to feel attached to the «wisdom», without leaving the area of the plot that can be disclosed within mass culture. Thirdly, the component of the philosophical text does not require the reader’s own intellectual effort; humor, irony and sarcasm eliminate vector of didactic narrative complexity of the book. Fourthly, the frequent use of profanity, limit of the freedom of the narrator and the characters from the classic morality reinforce grotesque sound of works and stimulate the reader to go through a certain surge of marginality, however, not going beyond the act of reading. And fifthly, it is accomplished the introduction to Buddhist culture, which is «preached» by means of historical realities of modern Russia. The paradox of Pelevin’s poetics: the impossibility of history, but it is impossible not to talk about it. What it is not substantially constant appears in the dialogue of the novel. The ambiguity of chronotope, the duality of time and space, ironic attitude to the character – the basis of poetics is not only in the novel «Chapaev and Emptiness», which raises the question of the existence of history as a fact of consciousness, the reality existing outside our mind, but also the «Sacred Book of the Werewolf» and «Тhe Empire V». The key image – the image of the emptiness. Consequently, the poetics of the key scenes of artistic historiosophy of Pelevin is considered on the material of novels «Chapaev and Emptiness», «The Sacred Book of the Werewolf» and «The Empire V».

  2. Feedforward and recurrent processing in scene segmentation: electroencephalography and functional magnetic resonance imaging.

    Science.gov (United States)

    Scholte, H Steven; Jolij, Jacob; Fahrenfort, Johannes J; Lamme, Victor A F

    2008-11-01

    In texture segregation, an example of scene segmentation, we can discern two different processes: texture boundary detection and subsequent surface segregation [Lamme, V. A. F., Rodriguez-Rodriguez, V., & Spekreijse, H. Separate processing dynamics for texture elements, boundaries and surfaces in primary visual cortex of the macaque monkey. Cerebral Cortex, 9, 406-413, 1999]. Neural correlates of texture boundary detection have been found in monkey V1 [Sillito, A. M., Grieve, K. L., Jones, H. E., Cudeiro, J., & Davis, J. Visual cortical mechanisms detecting focal orientation discontinuities. Nature, 378, 492-496, 1995; Grosof, D. H., Shapley, R. M., & Hawken, M. J. Macaque-V1 neurons can signal illusory contours. Nature, 365, 550-552, 1993], but whether surface segregation occurs in monkey V1 [Rossi, A. F., Desimone, R., & Ungerleider, L. G. Contextual modulation in primary visual cortex of macaques. Journal of Neuroscience, 21, 1698-1709, 2001; Lamme, V. A. F. The neurophysiology of figure ground segregation in primary visual-cortex. Journal of Neuroscience, 15, 1605-1615, 1995], and whether boundary detection or surface segregation signals can also be measured in human V1, is more controversial [Kastner, S., De Weerd, P., & Ungerleider, L. G. Texture segregation in the human visual cortex: A functional MRI study. Journal of Neurophysiology, 83, 2453-2457, 2000]. Here we present electroencephalography (EEG) and functional magnetic resonance imaging data that have been recorded with a paradigm that makes it possible to differentiate between boundary detection and scene segmentation in humans. In this way, we were able to show with EEG that neural correlates of texture boundary detection are first present in the early visual cortex around 92 msec and then spread toward the parietal and temporal lobes. Correlates of surface segregation first appear in temporal areas (around 112 msec) and from there appear to spread to parietal, and back to occipital areas. After 208

  3. Framework of passive millimeter-wave scene simulation based on material classification

    Science.gov (United States)

    Park, Hyuk; Kim, Sung-Hyun; Lee, Ho-Jin; Kim, Yong-Hoon; Ki, Jae-Sug; Yoon, In-Bok; Lee, Jung-Min; Park, Soon-Jun

    2006-05-01

    Over the past few decades, passive millimeter-wave (PMMW) sensors have emerged as useful implements in transportation and military applications such as autonomous flight-landing system, smart weapons, night- and all weather vision system. As an efficient way to predict the performance of a PMMW sensor and apply it to system, it is required to test in SoftWare-In-the-Loop (SWIL). The PMMW scene simulation is a key component for implementation of this simulator. However, there is no commercial on-the-shelf available to construct the PMMW scene simulation; only there have been a few studies on this technology. We have studied the PMMW scene simulation method to develop the PMMW sensor SWIL simulator. This paper describes the framework of the PMMW scene simulation and the tentative results. The purpose of the PMMW scene simulation is to generate sensor outputs (or image) from a visible image and environmental conditions. We organize it into four parts; material classification mapping, PMMW environmental setting, PMMW scene forming, and millimeter-wave (MMW) sensorworks. The background and the objects in the scene are classified based on properties related with MMW radiation and reflectivity. The environmental setting part calculates the following PMMW phenomenology; atmospheric propagation and emission including sky temperature, weather conditions, and physical temperature. Then, PMMW raw images are formed with surface geometry. Finally, PMMW sensor outputs are generated from PMMW raw images by applying the sensor characteristics such as an aperture size and noise level. Through the simulation process, PMMW phenomenology and sensor characteristics are simulated on the output scene. We have finished the design of framework of the simulator, and are working on implementation in detail. As a tentative result, the flight observation was simulated in specific conditions. After implementation details, we plan to increase the reliability of the simulation by data collecting

  4. Scene perception in Posterior Cortical Atrophy: categorisation, description and fixation patterns

    Directory of Open Access Journals (Sweden)

    Timothy J Shakespeare

    2013-10-01

    Full Text Available Partial or complete Balint’s syndrome is a core feature of the clinico-radiological syndrome of posterior cortical atrophy (PCA, in which individuals experience a progressive deterioration of cortical vision. Although multi-object arrays are frequently used to detect simultanagnosia in the clinical assessment and diagnosis of PCA, to date there have been no group studies of scene perception in patients with the syndrome. The current study involved three linked experiments conducted in PCA patients and healthy controls. Experiment 1 evaluated the accuracy and latency of complex scene perception relative to individual faces and objects (colour and greyscale using a categorisation paradigm. PCA patients were both less accurate (faces<scenesscenesscenes. PCA patients generated fewer features and more misperceptions than controls, though perceptual errors were always consistent with the patient’s global understanding of the scene (whether correct or not. Experiment 3 used eye tracking measures to compare patient and control eye movements over initial and subsequent fixations of scenes. Patients’ fixation patterns were significantly different to those of young and age-matched controls, with comparable group differences for both initial and subsequent fixations. Overall, these findings describe the variability in everyday scene perception exhibited by individuals with PCA, and indicate the importance of exposure duration in the perception of complex scenes.

  5. CSIR optronic scene simulator finds real application in self-protection mechanisms of the South African Air Force

    CSIR Research Space (South Africa)

    Willers, CJ

    2010-09-01

    Full Text Available The Optronic Scene Simulator (OSSIM) is a second-generation scene simulator that creates synthetic images of arbitrary complex scenes in the visual and infrared (IR) bands, covering the 0.2 to 20 μm spectral region. These images are radiometrically...

  6. Representations and Techniques for 3D Object Recognition and Scene Interpretation

    CERN Document Server

    Hoiem, Derek

    2011-01-01

    One of the grand challenges of artificial intelligence is to enable computers to interpret 3D scenes and objects from imagery. This book organizes and introduces major concepts in 3D scene and object representation and inference from still images, with a focus on recent efforts to fuse models of geometry and perspective with statistical machine learning. The book is organized into three sections: (1) Interpretation of Physical Space; (2) Recognition of 3D Objects; and (3) Integrated 3D Scene Interpretation. The first discusses representations of spatial layout and techniques to interpret physi

  7. Hierarchical Model for the Similarity Measurement of a Complex Holed-Region Entity Scene

    Directory of Open Access Journals (Sweden)

    Zhanlong Chen

    2017-11-01

    Full Text Available Complex multi-holed-region entity scenes (i.e., sets of random region with holes are common in spatial database systems, spatial query languages, and the Geographic Information System (GIS. A multi-holed-region (region with an arbitrary number of holes is an abstraction of the real world that primarily represents geographic objects that have more than one interior boundary, such as areas that contain several lakes or lakes that contain islands. When the similarity of the two complex holed-region entity scenes is measured, the number of regions in the scenes and the number of holes in the regions are usually different between the two scenes, which complicates the matching relationships of holed-regions and holes. The aim of this research is to develop several holed-region similarity metrics and propose a hierarchical model to measure comprehensively the similarity between two complex holed-region entity scenes. The procedure first divides a complex entity scene into three layers: a complex scene, a micro-spatial-scene, and a simple entity (hole. The relationships between the adjacent layers are considered to be sets of relationships, and each level of similarity measurements is nested with the adjacent one. Next, entity matching is performed from top to bottom, while the similarity results are calculated from local to global. In addition, we utilize position graphs to describe the distribution of the holed-regions and subsequently describe the directions between the holes using a feature matrix. A case study that uses the Great Lakes in North America in 1986 and 2015 as experimental data illustrates the entire similarity measurement process between two complex holed-region entity scenes. The experimental results show that the hierarchical model accounts for the relationships of the different layers in the entire complex holed-region entity scene. The model can effectively calculate the similarity of complex holed-region entity scenes, even if the

  8. Eye movements and attention in reading, scene perception, and visual search.

    Science.gov (United States)

    Rayner, Keith

    2009-08-01

    Eye movements are now widely used to investigate cognitive processes during reading, scene perception, and visual search. In this article, research on the following topics is reviewed with respect to reading: (a) the perceptual span (or span of effective vision), (b) preview benefit, (c) eye movement control, and (d) models of eye movements. Related issues with respect to eye movements during scene perception and visual search are also reviewed. It is argued that research on eye movements during reading has been somewhat advanced over research on eye movements in scene perception and visual search and that some of the paradigms developed to study reading should be more widely adopted in the study of scene perception and visual search. Research dealing with "real-world" tasks and research utilizing the visual-world paradigm are also briefly discussed.

  9. "Biennale en scene" keskendus hääle erinevatele võimalustele / Diana Kiivit

    Index Scriptorium Estoniae

    Kiivit, Diana

    2006-01-01

    7. - 26. märtsil Lyonis toimunud festivalist "Biennale en scene" ja seal etendunud kolmest ooperist: G. Aperghis "Entre chien et loup", C. Ambrosini "Il canbto della pelle", P. Dusapini "Faustus, la derniere nuit"

  10. Signature modelling and radiometric rendering equations in infrared scene simulation systems

    CSIR Research Space (South Africa)

    Willers, CJ

    2011-09-01

    Full Text Available The development and optimisation of modern infrared systems necessitates the use of simulation systems to create radiometrically realistic representations (e.g. images) of infrared scenes. Such simulation systems are used in signature prediction...

  11. Quantitative assessment of similarity between randomly acquired characteristics on high quality exemplars and crime scene impressions via analysis of feature size and shape.

    Science.gov (United States)

    Richetelli, Nicole; Nobel, Madonna; Bodziak, William J; Speir, Jacqueline A

    2017-01-01

    Forensic footwear evidence can prove invaluable to the resolution of a criminal investigation. Naturally, the value of a comparison varies with the rarity of the evidence, which is a function of both manufactured as well as randomly acquired characteristics (RACs). When focused specifically on the latter of these two types of features, empirical evidence demonstrates high discriminating power for the differentiation of known match and known non-match samples when presented with exemplars of high quality and exhibiting a sufficient number of clear and complex RACs. However, given the dynamic and unpredictable nature of the media, substrate, and deposition process encountered during the commission of a crime, RACs on crime scene prints are expected to exhibit a large range of variability in terms of reproducibility, clarity, and quality. Although the pattern recognition skill of the expert examiner is adept at recognizing and evaluating this type of natural variation, there is little research to suggest that objective and numerical metrics can globally process this variation when presented with RACs from degraded crime scene quality prints. As such, the goal of this study was to mathematically compare the loss and similarity of RACs in high quality exemplars versus crime-scene-like quality impressions as a function of RAC shape, perimeter, area, and common source. Results indicate that the unpredictable conditions associated with crime scene print production promotes RAC loss that varies between 33% and 100% with an average of 85%, and that when the entire outsole is taken as a constellation of features (or a RAC map), 64% of the crime-scene-like impressions exhibited 10 or fewer RACs, resulting in a 0.72 probability of stochastic dominance. Given this, individual RAC description and correspondence were further explored using five simple, but objective, numerical metrics of similarity. Statistically significant differences in similarity scores for RAC shape and size

  12. Combined Influence of Visual Scene and Body Tilt on Arm Pointing Movements: Gravity Matters!

    Science.gov (United States)

    Scotto Di Cesare, Cécile; Sarlegna, Fabrice R.; Bourdin, Christophe; Mestre, Daniel R.; Bringoux, Lionel

    2014-01-01

    Performing accurate actions such as goal-directed arm movements requires taking into account visual and body orientation cues to localize the target in space and produce appropriate reaching motor commands. We experimentally tilted the body and/or the visual scene to investigate how visual and body orientation cues are combined for the control of unseen arm movements. Subjects were asked to point toward a visual target using an upward movement during slow body and/or visual scene tilts. When the scene was tilted, final pointing errors varied as a function of the direction of the scene tilt (forward or backward). Actual forward body tilt resulted in systematic target undershoots, suggesting that the brain may have overcompensated for the biomechanical movement facilitation arising from body tilt. Combined body and visual scene tilts also affected final pointing errors according to the orientation of the visual scene. The data were further analysed using either a body-centered or a gravity-centered reference frame to encode visual scene orientation with simple additive models (i.e., ‘combined’ tilts equal to the sum of ‘single’ tilts). We found that the body-centered model could account only for some of the data regarding kinematic parameters and final errors. In contrast, the gravity-centered modeling in which the body and visual scene orientations were referred to vertical could explain all of these data. Therefore, our findings suggest that the brain uses gravity, thanks to its invariant properties, as a reference for the combination of visual and non-visual cues. PMID:24925371

  13. The elephant in the room: inconsistency in scene viewing and representation

    OpenAIRE

    Spotorno, Sara; Tatler, Benjamin W.

    2017-01-01

    We examined the extent to which semantic informativeness, consistency with expectations and perceptual salience contribute to object prioritization in scene viewing and representation. In scene viewing (Experiments 1–2), semantic guidance overshadowed perceptual guidance in determining fixation order, with the greatest prioritization for objects that were diagnostic of the scene’s depicted event. Perceptual properties affected selection of consistent objects (regardless of their informativene...

  14. Virtual Relighting of a Virtualized Scene by Estimating Surface Reflectance Properties

    OpenAIRE

    福富, 弘敦; 町田, 貴史; 横矢, 直和

    2011-01-01

    In mixed reality that merges real and virtual worlds, it is required to interactively manipulate the illumination conditions in a virtualized space. In general, specular reflections in a scene make it difficult to interactively manipulate the illumination conditions. Our goal is to provide an opportunity to simulate the original scene, including diffuse and specular relfections, with novel viewpoints and illumination conditions. Thus, we propose a new method for estimating diffuse and specula...

  15. Knowledge Guided Disambiguation for Large-Scale Scene Classification With Multi-Resolution CNNs

    Science.gov (United States)

    Wang, Limin; Guo, Sheng; Huang, Weilin; Xiong, Yuanjun; Qiao, Yu

    2017-04-01

    Convolutional Neural Networks (CNNs) have made remarkable progress on scene recognition, partially due to these recent large-scale scene datasets, such as the Places and Places2. Scene categories are often defined by multi-level information, including local objects, global layout, and background environment, thus leading to large intra-class variations. In addition, with the increasing number of scene categories, label ambiguity has become another crucial issue in large-scale classification. This paper focuses on large-scale scene recognition and makes two major contributions to tackle these issues. First, we propose a multi-resolution CNN architecture that captures visual content and structure at multiple levels. The multi-resolution CNNs are composed of coarse resolution CNNs and fine resolution CNNs, which are complementary to each other. Second, we design two knowledge guided disambiguation techniques to deal with the problem of label ambiguity. (i) We exploit the knowledge from the confusion matrix computed on validation data to merge ambiguous classes into a super category. (ii) We utilize the knowledge of extra networks to produce a soft label for each image. Then the super categories or soft labels are employed to guide CNN training on the Places2. We conduct extensive experiments on three large-scale image datasets (ImageNet, Places, and Places2), demonstrating the effectiveness of our approach. Furthermore, our method takes part in two major scene recognition challenges, and achieves the second place at the Places2 challenge in ILSVRC 2015, and the first place at the LSUN challenge in CVPR 2016. Finally, we directly test the learned representations on other scene benchmarks, and obtain the new state-of-the-art results on the MIT Indoor67 (86.7\\%) and SUN397 (72.0\\%). We release the code and models at~\\url{https://github.com/wanglimin/MRCNN-Scene-Recognition}.

  16. Contribution to the reconstruction of scenes made of cylindrical and polyhedral objects from sequences of images obtained by a moving camera

    International Nuclear Information System (INIS)

    Viala, Marc

    1992-01-01

    Environment perception is an important process which enables a robot to perform actions in an unknown scene. Although many sensors exist to 'give sight', the camera seems to play a leading part. This thesis deals with the reconstruction of scenes made of cylindrical and polyhedral objects from sequences of images provided by a moving camera. Two methods are presented. Both are based on the evolution of apparent contours of objects in a sequence. The first approach has been developed considering that camera motion is known. Despite the good results obtained by this method, the specific conditions it requires makes its use limited. In order to avoid an accurate evaluation of camera motion, we introduce another method allowing, at the same time, to estimate the object parameters and camera positions. In this approach, only is needed a 'poor' knowledge of camera displacements supplied by the control system of the robotic platform, in which the camera is embedded. An optimal integration of a priori information, as well as the dynamic feature of the state model to estimate, lead us to use the Kalman filter. Experiments conducted with synthetic and real images proved the reliability of these methods. Camera calibration set-up is also suggested to achieve the most accurate scene models resulting from reconstruction processes. (author) [fr

  17. Cybersickness in the presence of scene rotational movements along different axes.

    Science.gov (United States)

    Lo, W T; So, R H

    2001-02-01

    Compelling scene movements in a virtual reality (VR) system can cause symptoms of motion sickness (i.e., cybersickness). A within-subject experiment has been conducted to investigate the effects of scene oscillations along different axes on the level of cybersickness. Sixteen male participants were exposed to four 20-min VR simulation sessions. The four sessions used the same virtual environment but with scene oscillations along different axes, i.e., pitch, yaw, roll, or no oscillation (speed: 30 degrees/s, range: +/- 60 degrees). Verbal ratings of the level of nausea were taken at 5-min intervals during the sessions and sickness symptoms were also measured before and after the sessions using the Simulator Sickness Questionnaire (SSQ). In the presence of scene oscillation, both nausea ratings and SSQ scores increased at significantly higher rates than with no oscillation. While individual participants exhibited different susceptibilities to nausea associated with VR simulation containing scene oscillations along different rotational axes, the overall effects of axis among our group of 16 randomly selected participants were not significant. The main effects of, and interactions among, scene oscillation, duration, and participants are discussed in the paper.

  18. Performance Benefits with Scene-Linked HUD Symbology: An Attentional Phenomenon?

    Science.gov (United States)

    Levy, Jonathan L.; Foyle, David C.; McCann, Robert S.; Null, Cynthia H. (Technical Monitor)

    1999-01-01

    Previous research has shown that in a simulated flight task, navigating a path defined by ground markers while maintaining a target altitude is more accurate when an altitude indicator appears in a virtual "scenelinked" format (projected symbology moving as if it were part of the out-the-window environment) compared to the fixed-location, superimposed format found on present-day HUDs (Foyle, McCann & Shelden, 1995). One explanation of the scene-linked performance advantage is that attention can be divided between scene-linked symbology and the outside world more efficiently than between standard (fixed-position) HUD symbology and the outside world. The present study tested two alternative explanations by manipulating the location of the scene-linked HUD symbology relative to the ground path markers. Scene-linked symbology yielded better ground path-following performance than standard fixed-location superimposed symbology regardless of whether the scene-linked symbology appeared directly along the ground path or at various distances off the path. The results support the explanation that the performance benefits found with scene-linked symbology are attentional.

  19. Gist in time: Scene semantics and structure enhance recall of searched objects.

    Science.gov (United States)

    Josephs, Emilie L; Draschkow, Dejan; Wolfe, Jeremy M; Võ, Melissa L-H

    2016-09-01

    Previous work has shown that recall of objects that are incidentally encountered as targets in visual search is better than recall of objects that have been intentionally memorized (Draschkow, Wolfe, & Võ, 2014). However, this counter-intuitive result is not seen when these tasks are performed with non-scene stimuli. The goal of the current paper is to determine what features of search in a scene contribute to higher recall rates when compared to a memorization task. In each of four experiments, we compare the free recall rate for target objects following a search to the rate following a memorization task. Across the experiments, the stimuli include progressively more scene-related information. Experiment 1 provides the spatial relations between objects. Experiment 2 adds relative size and depth of objects. Experiments 3 and 4 include scene layout and semantic information. We find that search leads to better recall than explicit memorization in cases where scene layout and semantic information are present, as long as the participant has ample time (2500ms) to integrate this information with knowledge about the target object (Exp. 4). These results suggest that the integration of scene and target information not only leads to more efficient search, but can also contribute to stronger memory representations than intentional memorization. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Out of Mind, Out of Sight: Unexpected Scene Elements Frequently Go Unnoticed Until Primed.

    Science.gov (United States)

    Slavich, George M; Zimbardo, Philip G

    2013-12-01

    The human visual system employs a sophisticated set of strategies for scanning the environment and directing attention to stimuli that can be expected given the context and a person's past experience. Although these strategies enable us to navigate a very complex physical and social environment, they can also cause highly salient, but unexpected stimuli to go completely unnoticed. To examine the generality of this phenomenon, we conducted eight studies that included 15 different experimental conditions and 1,577 participants in all. These studies revealed that a large majority of participants do not report having seen a woman in the center of an urban scene who was photographed in midair as she was committing suicide. Despite seeing the scene repeatedly, 46 % of all participants failed to report seeing a central figure and only 4.8 % reported seeing a falling person. Frequency of noticing the suicidal woman was highest for participants who read a narrative priming story that increased the extent to which she was schematically congruent with the scene. In contrast to this robust effect of inattentional blindness , a majority of participants reported seeing other peripheral objects in the visual scene that were equally difficult to detect, yet more consistent with the scene. Follow-up qualitative analyses revealed that participants reported seeing many elements that were not actually present, but which could have been expected given the overall context of the scene. Together, these findings demonstrate the robustness of inattentional blindness and highlight the specificity with which different visual primes may increase noticing behavior.

  1. Scene grammar shapes the way we interact with objects, strengthens memories, and speeds search.

    Science.gov (United States)

    Draschkow, Dejan; Võ, Melissa L-H

    2017-11-28

    Predictions of environmental rules (here referred to as "scene grammar") can come in different forms: seeing a toilet in a living room would violate semantic predictions, while finding a toilet brush next to the toothpaste would violate syntactic predictions. The existence of such predictions has usually been investigated by showing observers images containing such grammatical violations. Conversely, the generative process of creating an environment according to one's scene grammar and its effects on behavior and memory has received little attention. In a virtual reality paradigm, we either instructed participants to arrange objects according to their scene grammar or against it. Subsequently, participants' memory for the arrangements was probed using a surprise recall (Exp1), or repeated search (Exp2) task. As a result, participants' construction behavior showed strategic use of larger, static objects to anchor the location of smaller objects which are generally the goals of everyday actions. Further analysis of this scene construction data revealed possible commonalities between the rules governing word usage in language and object usage in naturalistic environments. Taken together, we revealed some of the building blocks of scene grammar necessary for efficient behavior, which differentially influence how we interact with objects and what we remember about scenes.

  2. A Two-Stream Deep Fusion Framework for High-Resolution Aerial Scene Classification

    Directory of Open Access Journals (Sweden)

    Yunlong Yu

    2018-01-01

    Full Text Available One of the challenging problems in understanding high-resolution remote sensing images is aerial scene classification. A well-designed feature representation method and classifier can improve classification accuracy. In this paper, we construct a new two-stream deep architecture for aerial scene classification. First, we use two pretrained convolutional neural networks (CNNs as feature extractor to learn deep features from the original aerial image and the processed aerial image through saliency detection, respectively. Second, two feature fusion strategies are adopted to fuse the two different types of deep convolutional features extracted by the original RGB stream and the saliency stream. Finally, we use the extreme learning machine (ELM classifier for final classification with the fused features. The effectiveness of the proposed architecture is tested on four challenging datasets: UC-Merced dataset with 21 scene categories, WHU-RS dataset with 19 scene categories, AID dataset with 30 scene categories, and NWPU-RESISC45 dataset with 45 challenging scene categories. The experimental results demonstrate that our architecture gets a significant classification accuracy improvement over all state-of-the-art references.

  3. Z-depth integration: a new technique for manipulating z-depth properties in composited scenes

    Science.gov (United States)

    Steckel, Kayla; Whittinghill, David

    2014-02-01

    This paper presents a new technique in the production pipeline of asset creation for virtual environments called Z-Depth Integration (ZeDI). ZeDI is intended to reduce the time required to place elements at the appropriate z-depth within a scene. Though ZeDI is intended for use primarily in two-dimensional scene composition, depth-dependent "flat" animated objects are often critical elements of augmented and virtual reality applications (AR/VR). ZeDI is derived from "deep image compositing", a capacity implemented within the OpenEXR file format. In order to trick the human eye into perceiving overlapping scene elements as being in front of or behind one another, the developer must manually manipulate which pixels of an element are visible in relation to other objects embedded within the environment's image sequence. ZeDI improves on this process by providing a means for interacting with procedurally extracted z-depth data from a virtual environment scene. By streamlining the process of defining objects' depth characteristics, it is expected that the time and energy required for developers to create compelling AR/VR scenes will be reduced. In the proof of concept presented in this manuscript, ZeDI is implemented for pre-rendered virtual scene construction via an AfterEffects software plug-in.

  4. The development of brain systems associated with successful memory retrieval of scenes.

    Science.gov (United States)

    Ofen, Noa; Chai, Xiaoqian J; Schuil, Karen D I; Whitfield-Gabrieli, Susan; Gabrieli, John D E

    2012-07-18

    Neuroanatomical and psychological evidence suggests prolonged maturation of declarative memory systems in the human brain from childhood into young adulthood. Here, we examine functional brain development during successful memory retrieval of scenes in children, adolescents, and young adults ages 8-21 via functional magnetic resonance imaging. Recognition memory improved with age, specifically for accurate identification of studied scenes (hits). Successful retrieval (correct old-new decisions for studied vs unstudied scenes) was associated with activations in frontal, parietal, and medial temporal lobe (MTL) regions. Activations associated with successful retrieval increased with age in left parietal cortex (BA7), bilateral prefrontal, and bilateral caudate regions. In contrast, activations associated with successful retrieval did not change with age in the MTL. Psychophysiological interaction analysis revealed that there were, however, age-relate changes in differential connectivity for successful retrieval between MTL and prefrontal regions. These results suggest that neocortical regions related to attentional or strategic control show the greatest developmental changes for memory retrieval of scenes. Furthermore, these results suggest that functional interactions between MTL and prefrontal regions during memory retrieval also develop into young adulthood. The developmental increase of memory-related activations in frontal and parietal regions for retrieval of scenes and the absence of such an increase in MTL regions parallels what has been observed for memory encoding of scenes.

  5. Using selected scenes from Brazilian films to teach about substance use disorders, within medical education

    Directory of Open Access Journals (Sweden)

    João Mauricio Castaldelli-Maia

    Full Text Available CONTEXT AND OBJECTIVES: Themes like alcohol and drug abuse, relationship difficulties, psychoses, autism and personality dissociation disorders have been widely used in films. Psychiatry and psychiatric conditions in various cultural settings are increasingly taught using films. Many articles on cinema and psychiatry have been published but none have presented any methodology on how to select material. Here, the authors look at the portrayal of abusive use of alcohol and drugs during the Brazilian cinema revival period (1994 to 2008. DESIGN AND SETTING: Qualitative study at two universities in the state of São Paulo. METHODS: Scenes were selected from films available at rental stores and were analyzed using a specifically designed protocol. We assessed how realistic these scenes were and their applicability for teaching. One author selected 70 scenes from 50 films (graded for realism and teaching applicability > 8. These were then rated by another two judges. Rating differences among the three judges were assessed using nonparametric tests (P 8 were defined as "quality scenes". RESULTS: Thirty-nine scenes from 27 films were identified as "quality scenes". Alcohol, cannabis, cocaine, hallucinogens and inhalants were included in these. Signs and symptoms of intoxication, abusive/harmful use and dependence were shown. CONCLUSIONS: We have produced rich teaching material for discussing psychopathology relating to alcohol and drug use that can be used both at undergraduate and at postgraduate level. Moreover, it could be seen that certain drug use behavioral patterns are deeply rooted in some Brazilian films and groups.

  6. Using selected scenes from Brazilian films to teach about substance use disorders, within medical education.

    Science.gov (United States)

    Castaldelli-Maia, João Mauricio; Oliveira, Hercílio Pereira; Andrade, Arthur Guerra; Lotufo-Neto, Francisco; Bhugra, Dinesh

    2012-01-01

    Themes like alcohol and drug abuse, relationship difficulties, psychoses, autism and personality dissociation disorders have been widely used in films. Psychiatry and psychiatric conditions in various cultural settings are increasingly taught using films. Many articles on cinema and psychiatry have been published but none have presented any methodology on how to select material. Here, the authors look at the portrayal of abusive use of alcohol and drugs during the Brazilian cinema revival period (1994 to 2008). Qualitative study at two universities in the state of São Paulo. Scenes were selected from films available at rental stores and were analyzed using a specifically designed protocol. We assessed how realistic these scenes were and their applicability for teaching. One author selected 70 scenes from 50 films (graded for realism and teaching applicability > 8). These were then rated by another two judges. Rating differences among the three judges were assessed using nonparametric tests (P 8) were defined as "quality scenes". Thirty-nine scenes from 27 films were identified as "quality scenes". Alcohol, cannabis, cocaine, hallucinogens and inhalants were included in these. Signs and symptoms of intoxication, abusive/harmful use and dependence were shown. We have produced rich teaching material for discussing psychopathology relating to alcohol and drug use that can be used both at undergraduate and at postgraduate level. Moreover, it could be seen that certain drug use behavioral patterns are deeply rooted in some Brazilian films and groups.

  7. SCENES OF HAPPINESS IN THE NOVELS OF DOSTOEVSKY

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    Rita Osipovna Mazel

    2013-11-01

    Full Text Available This article presents Dostoyevsky to readers as an author praising happiness and felicity. Having lived through deep sorrows he acquired insight into another dimension of life. Like a longing pathfinder, he states the unfeigned grace of life. “Life is a gift, life is mercy, and any minute may be the age of happiness”, – this is the essence of his great novels. People are not lonesome on Earth; they are bound by invisible threads. A loner may not succeed. One heart or one consciousness attracts another one like a magnet, as if claiming: thou art... Christ, with his Love and his Sacrifice, the greatest miracle on the Earth. It is impossible to be aware of Christ’s existence and not to be joyful. Dostoyevsky reveals one of the main principles of life: when you love someone and sacrifice yourself to this person you satisfy your aspiration for a beau ideal and feel like in heavens. In this article the author analyzes selected scenes of happiness in Dostoevsky’s novels: Arkady’s and his sister Liza’s admiration for the sacrifice of their father Versilov; Alyosha and Grushen’ka, saving each other instead of committing sins and transgressing moral standards; Alyosha’s dream about the Christ’s first miracle in Cana of Galilee; Stavrogin’s dream of the Golden Age of the blessed mankind... In Dostoyevsky’s tragic novel The Possessed (The Devils, or Demons a reader faces an image of love – mutual, sacrificial, fulfilling, and blithe. There is probably nothing similar in the history of the world literature. One can eminently feel the interconnectedness of Dostoevsky’s heroes with another, higher world that penetrates into every aspect of their lives. All of his creatures are illumed by the light of other worlds. It is clear that there cannot be darkness, despair, or hopelessness in Dostoevsky’s works, because even in the hell full of demons there is a place for righteous people, luminous (as Nikolai Berdyaev called them and

  8. Microscopic 3D measurement of dynamic scene using optimized pulse-width-modulation binary fringe

    Science.gov (United States)

    Hu, Yan; Chen, Qian; Feng, Shijie; Tao, Tianyang; Li, Hui; Zuo, Chao

    2017-10-01

    Microscopic 3-D shape measurement can supply accurate metrology of the delicacy and complexity of MEMS components of the final devices to ensure their proper performance. Fringe projection profilometry (FPP) has the advantages of noncontactness and high accuracy, making it widely used in 3-D measurement. Recently, tremendous advance of electronics development promotes 3-D measurements to be more accurate and faster. However, research about real-time microscopic 3-D measurement is still rarely reported. In this work, we effectively combine optimized binary structured pattern with number-theoretical phase unwrapping algorithm to realize real-time 3-D shape measurement. A slight defocusing of our proposed binary patterns can considerably alleviate the measurement error based on phase-shifting FPP, making the binary patterns have the comparable performance with ideal sinusoidal patterns. Real-time 3-D measurement about 120 frames per second (FPS) is achieved, and experimental result of a vibrating earphone is presented.

  9. Thermal-depth matching in dynamic scene based on affine projection and feature registration

    Science.gov (United States)

    Wang, Hongyu; Jia, Tong; Wu, Chengdong; Li, Yongqiang

    2018-03-01

    This paper aims to study the construction of 3D temperature distribution reconstruction system based on depth and thermal infrared information. Initially, a traditional calibration method cannot be directly used, because the depth and thermal infrared camera is not sensitive to the color calibration board. Therefore, this paper aims to design a depth and thermal infrared camera calibration board to complete the calibration of the depth and thermal infrared camera. Meanwhile a local feature descriptors in thermal and depth images is proposed. The belief propagation matching algorithm is also investigated based on the space affine transformation matching and local feature matching. The 3D temperature distribution model is built based on the matching of 3D point cloud and 2D thermal infrared information. Experimental results show that the method can accurately construct the 3D temperature distribution model, and has strong robustness.

  10. Influence of semantic consistency and perceptual features on visual attention during scene viewing in toddlers.

    Science.gov (United States)

    Helo, Andrea; van Ommen, Sandrien; Pannasch, Sebastian; Danteny-Dordoigne, Lucile; Rämä, Pia

    2017-11-01

    Conceptual representations of everyday scenes are built in interaction with visual environment and these representations guide our visual attention. Perceptual features and object-scene semantic consistency have been found to attract our attention during scene exploration. The present study examined how visual attention in 24-month-old toddlers is attracted by semantic violations and how perceptual features (i. e. saliency, centre distance, clutter and object size) and linguistic properties (i. e. object label frequency and label length) affect gaze distribution. We compared eye movements of 24-month-old toddlers and adults while exploring everyday scenes which either contained an inconsistent (e.g., soap on a breakfast table) or consistent (e.g., soap in a bathroom) object. Perceptual features such as saliency, centre distance and clutter of the scene affected looking times in the toddler group during the whole viewing time whereas looking times in adults were affected only by centre distance during the early viewing time. Adults looked longer to inconsistent than consistent objects either if the objects had a high or a low saliency. In contrast, toddlers presented semantic consistency effect only when objects were highly salient. Additionally, toddlers with lower vocabulary skills looked longer to inconsistent objects while toddlers with higher vocabulary skills look equally long to both consistent and inconsistent objects. Our results indicate that 24-month-old children use scene context to guide visual attention when exploring the visual environment. However, perceptual features have a stronger influence in eye movement guidance in toddlers than in adults. Our results also indicate that language skills influence cognitive but not perceptual guidance of eye movements during scene perception in toddlers. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Clandestine laboratory scene investigation and processing using portable GC/MS

    Science.gov (United States)

    Matejczyk, Raymond J.

    1997-02-01

    This presentation describes the use of portable gas chromatography/mass spectrometry for on-scene investigation and processing of clandestine laboratories. Clandestine laboratory investigations present special problems to forensic investigators. These crime scenes contain many chemical hazards that must be detected, identified and collected as evidence. Gas chromatography/mass spectrometry performed on-scene with a rugged, portable unit is capable of analyzing a variety of matrices for drugs and chemicals used in the manufacture of illicit drugs, such as methamphetamine. Technologies used to detect various materials at a scene have particular applications but do not address the wide range of samples, chemicals, matrices and mixtures that exist in clan labs. Typical analyses performed by GC/MS are for the purpose of positively establishing the identity of starting materials, chemicals and end-product collected from clandestine laboratories. Concerns for the public and investigator safety and the environment are also important factors for rapid on-scene data generation. Here is described the implementation of a portable multiple-inlet GC/MS system designed for rapid deployment to a scene to perform forensic investigations of clandestine drug manufacturing laboratories. GC/MS has long been held as the 'gold standard' in performing forensic chemical analyses. With the capability of GC/MS to separate and produce a 'chemical fingerprint' of compounds, it is utilized as an essential technique for detecting and positively identifying chemical evidence. Rapid and conclusive on-scene analysis of evidence will assist the forensic investigators in collecting only pertinent evidence thereby reducing the amount of evidence to be transported, reducing chain of custody concerns, reducing costs and hazards, maintaining sample integrity and speeding the completion of the investigative process.

  12. Study on general design of dual-DMD based infrared two-band scene simulation system

    Science.gov (United States)

    Pan, Yue; Qiao, Yang; Xu, Xi-ping

    2017-02-01

    Mid-wave infrared(MWIR) and long-wave infrared(LWIR) two-band scene simulation system is a kind of testing equipment that used for infrared two-band imaging seeker. Not only it would be qualified for working waveband, but also realize the essence requests that infrared radiation characteristics should correspond to the real scene. Past single-digital micromirror device (DMD) based infrared scene simulation system does not take the huge difference between targets and background radiation into account, and it cannot realize the separated modulation to two-band light beam. Consequently, single-DMD based infrared scene simulation system cannot accurately express the thermal scene model that upper-computer built, and it is not that practical. To solve the problem, we design a dual-DMD based, dual-channel, co-aperture, compact-structure infrared two-band scene simulation system. The operating principle of the system is introduced in detail, and energy transfer process of the hardware-in-the-loop simulation experiment is analyzed as well. Also, it builds the equation about the signal-to-noise ratio of infrared detector in the seeker, directing the system overall design. The general design scheme of system is given, including the creation of infrared scene model, overall control, optical-mechanical structure design and image registration. By analyzing and comparing the past designs, we discuss the arrangement of optical engine framework in the system. According to the main content of working principle and overall design, we summarize each key techniques in the system.

  13. Binary patterns encoded convolutional neural networks for texture recognition and remote sensing scene classification

    Science.gov (United States)

    Anwer, Rao Muhammad; Khan, Fahad Shahbaz; van de Weijer, Joost; Molinier, Matthieu; Laaksonen, Jorma

    2018-04-01

    Designing discriminative powerful texture features robust to realistic imaging conditions is a challenging computer vision problem with many applications, including material recognition and analysis of satellite or aerial imagery. In the past, most texture description approaches were based on dense orderless statistical distribution of local features. However, most recent approaches to texture recognition and remote sensing scene classification are based on Convolutional Neural Networks (CNNs). The de facto practice when learning these CNN models is to use RGB patches as input with training performed on large amounts of labeled data (ImageNet). In this paper, we show that Local Binary Patterns (LBP) encoded CNN models, codenamed TEX-Nets, trained using mapped coded images with explicit LBP based texture information provide complementary information to the standard RGB deep models. Additionally, two deep architectures, namely early and late fusion, are investigated to combine the texture and color information. To the best of our knowledge, we are the first to investigate Binary Patterns encoded CNNs and different deep network fusion architectures for texture recognition and remote sensing scene classification. We perform comprehensive experiments on four texture recognition datasets and four remote sensing scene classification benchmarks: UC-Merced with 21 scene categories, WHU-RS19 with 19 scene classes, RSSCN7 with 7 categories and the recently introduced large scale aerial image dataset (AID) with 30 aerial scene types. We demonstrate that TEX-Nets provide complementary information to standard RGB deep model of the same network architecture. Our late fusion TEX-Net architecture always improves the overall performance compared to the standard RGB network on both recognition problems. Furthermore, our final combination leads to consistent improvement over the state-of-the-art for remote sensing scene classification.

  14. Emotional event-related potentials are larger to figures than scenes but are similarly reduced by inattention

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    Nordström Henrik

    2012-05-01

    Full Text Available Abstract Background In research on event-related potentials (ERP to emotional pictures, greater attention to emotional than neutral stimuli (i.e., motivated attention is commonly indexed by two difference waves between emotional and neutral stimuli: the early posterior negativity (EPN and the late positive potential (LPP. Evidence suggests that if attention is directed away from the pictures, then the emotional effects on EPN and LPP are eliminated. However, a few studies have found residual, emotional effects on EPN and LPP. In these studies, pictures were shown at fixation, and picture composition was that of simple figures rather than that of complex scenes. Because figures elicit larger LPP than do scenes, figures might capture and hold attention more strongly than do scenes. Here, we showed negative and neutral pictures of figures and scenes and tested first, whether emotional effects are larger to figures than scenes for both EPN and LPP, and second, whether emotional effects on EPN and LPP are reduced less for unattended figures than scenes. Results Emotional effects on EPN and LPP were larger for figures than scenes. When pictures were unattended, emotional effects on EPN increased for scenes but tended to decrease for figures, whereas emotional effects on LPP decreased similarly for figures and scenes. Conclusions Emotional effects on EPN and LPP were larger for figures than scenes, but these effects did not resist manipulations of attention more strongly for figures than scenes. These findings imply that the emotional content captures attention more strongly for figures than scenes, but that the emotional content does not hold attention more strongly for figures than scenes.

  15. Emotional event-related potentials are larger to figures than scenes but are similarly reduced by inattention

    Science.gov (United States)

    2012-01-01

    Background In research on event-related potentials (ERP) to emotional pictures, greater attention to emotional than neutral stimuli (i.e., motivated attention) is commonly indexed by two difference waves between emotional and neutral stimuli: the early posterior negativity (EPN) and the late positive potential (LPP). Evidence suggests that if attention is directed away from the pictures, then the emotional effects on EPN and LPP are eliminated. However, a few studies have found residual, emotional effects on EPN and LPP. In these studies, pictures were shown at fixation, and picture composition was that of simple figures rather than that of complex scenes. Because figures elicit larger LPP than do scenes, figures might capture and hold attention more strongly than do scenes. Here, we showed negative and neutral pictures of figures and scenes and tested first, whether emotional effects are larger to figures than scenes for both EPN and LPP, and second, whether emotional effects on EPN and LPP are reduced less for unattended figures than scenes. Results Emotional effects on EPN and LPP were larger for figures than scenes. When pictures were unattended, emotional effects on EPN increased for scenes but tended to decrease for figures, whereas emotional effects on LPP decreased similarly for figures and scenes. Conclusions Emotional effects on EPN and LPP were larger for figures than scenes, but these effects did not resist manipulations of attention more strongly for figures than scenes. These findings imply that the emotional content captures attention more strongly for figures than scenes, but that the emotional content does not hold attention more strongly for figures than scenes. PMID:22607397

  16. Scene Recognition for Indoor Localization Using a Multi-Sensor Fusion Approach

    Directory of Open Access Journals (Sweden)

    Mengyun Liu

    2017-12-01

    Full Text Available After decades of research, there is still no solution for indoor localization like the GNSS (Global Navigation Satellite System solution for outdoor environments. The major reasons for this phenomenon are the complex spatial topology and RF transmission environment. To deal with these problems, an indoor scene constrained method for localization is proposed in this paper, which is inspired by the visual cognition ability of the human brain and the progress in the computer vision field regarding high-level image understanding. Furthermore, a multi-sensor fusion method is implemented on a commercial smartphone including cameras, WiFi and inertial sensors. Compared to former research, the camera on a smartphone is used to “see” which scene the user is in. With this information, a particle filter algorithm constrained by scene information is adopted to determine the final location. For indoor scene recognition, we take advantage of deep learning that has been proven to be highly effective in the computer vision community. For particle filter, both WiFi and magnetic field signals are used to update the weights of particles. Similar to other fingerprinting localization methods, there are two stages in the proposed system, offline training and online localization. In the offline stage, an indoor scene model is trained by Caffe (one of the most popular open source frameworks for deep learning and a fingerprint database is constructed by user trajectories in different scenes. To reduce the volume requirement of training data for deep learning, a fine-tuned method is adopted for model training. In the online stage, a camera in a smartphone is used to recognize the initial scene. Then a particle filter algorithm is used to fuse the sensor data and determine the final location. To prove the effectiveness of the proposed method, an Android client and a web server are implemented. The Android client is used to collect data and locate a user. The web

  17. Error Detection, Factorization and Correction for Multi-View Scene Reconstruction from Aerial Imagery

    Energy Technology Data Exchange (ETDEWEB)

    Hess-Flores, Mauricio [Univ. of California, Davis, CA (United States)

    2011-11-10

    Scene reconstruction from video sequences has become a prominent computer vision research area in recent years, due to its large number of applications in fields such as security, robotics and virtual reality. Despite recent progress in this field, there are still a number of issues that manifest as incomplete, incorrect or computationally-expensive reconstructions. The engine behind achieving reconstruction is the matching of features between images, where common conditions such as occlusions, lighting changes and texture-less regions can all affect matching accuracy. Subsequent processes that rely on matching accuracy, such as camera parameter estimation, structure computation and non-linear parameter optimization, are also vulnerable to additional sources of error, such as degeneracies and mathematical instability. Detection and correction of errors, along with robustness in parameter solvers, are a must in order to achieve a very accurate final scene reconstruction. However, error detection is in general difficult due to the lack of ground-truth information about the given scene, such as the absolute position of scene points or GPS/IMU coordinates for the camera(s) viewing the scene. In this dissertation, methods are presented for the detection, factorization and correction of error sources present in all stages of a scene reconstruction pipeline from video, in the absence of ground-truth knowledge. Two main applications are discussed. The first set of algorithms derive total structural error measurements after an initial scene structure computation and factorize errors into those related to the underlying feature matching process and those related to camera parameter estimation. A brute-force local correction of inaccurate feature matches is presented, as well as an improved conditioning scheme for non-linear parameter optimization which applies weights on input parameters in proportion to estimated camera parameter errors. Another application is in

  18. Deconstructing visual scenes in cortex: gradients of object and spatial layout information.

    Science.gov (United States)

    Harel, Assaf; Kravitz, Dwight J; Baker, Chris I

    2013-04-01

    Real-world visual scenes are complex cluttered, and heterogeneous stimuli engaging scene- and object-selective cortical regions including parahippocampal place area (PPA), retrosplenial complex (RSC), and lateral occipital complex (LOC). To understand the unique contribution of each region to distributed scene representations, we generated predictions based on a neuroanatomical framework adapted from monkey and tested them using minimal scenes in which we independently manipulated both spatial layout (open, closed, and gradient) and object content (furniture, e.g., bed, dresser). Commensurate with its strong connectivity with posterior parietal cortex, RSC evidenced strong spatial layout information but no object information, and its response was not even modulated by object presence. In contrast, LOC, which lies within the ventral visual pathway, contained strong object information but no background information. Finally, PPA, which is connected with both the dorsal and the ventral visual pathway, showed information about both objects and spatial backgrounds and was sensitive to the presence or absence of either. These results suggest that 1) LOC, PPA, and RSC have distinct representations, emphasizing different aspects of scenes, 2) the specific representations in each region are predictable from their patterns of connectivity, and 3) PPA combines both spatial layout and object information as predicted by connectivity.

  19. Reconstruction and simplification of urban scene models based on oblique images

    Science.gov (United States)

    Liu, J.; Guo, B.

    2014-08-01

    We describe a multi-view stereo reconstruction and simplification algorithms for urban scene models based on oblique images. The complexity, diversity, and density within the urban scene, it increases the difficulty to build the city models using the oblique images. But there are a lot of flat surfaces existing in the urban scene. One of our key contributions is that a dense matching algorithm based on Self-Adaptive Patch in view of the urban scene is proposed. The basic idea of matching propagating based on Self-Adaptive Patch is to build patches centred by seed points which are already matched. The extent and shape of the patches can adapt to the objects of urban scene automatically: when the surface is flat, the extent of the patch would become bigger; while the surface is very rough, the extent of the patch would become smaller. The other contribution is that the mesh generated by Graph Cuts is 2-manifold surface satisfied the half edge data structure. It is solved by clustering and re-marking tetrahedrons in s-t graph. The purpose of getting 2- manifold surface is to simply the mesh by edge collapse algorithm which can preserve and stand out the features of buildings.

  20. Qualitative spatial logic descriptors from 3D indoor scenes to generate explanations in natural language.

    Science.gov (United States)

    Falomir, Zoe; Kluth, Thomas

    2018-05-01

    The challenge of describing 3D real scenes is tackled in this paper using qualitative spatial descriptors. A key point to study is which qualitative descriptors to use and how these qualitative descriptors must be organized to produce a suitable cognitive explanation. In order to find answers, a survey test was carried out with human participants which openly described a scene containing some pieces of furniture. The data obtained in this survey are analysed, and taking this into account, the QSn3D computational approach was developed which uses a XBox 360 Kinect to obtain 3D data from a real indoor scene. Object features are computed on these 3D data to identify objects in indoor scenes. The object orientation is computed, and qualitative spatial relations between the objects are extracted. These qualitative spatial relations are the input to a grammar which applies saliency rules obtained from the survey study and generates cognitive natural language descriptions of scenes. Moreover, these qualitative descriptors can be expressed as first-order logical facts in Prolog for further reasoning. Finally, a validation study is carried out to test whether the descriptions provided by QSn3D approach are human readable. The obtained results show that their acceptability is higher than 82%.

  1. The perception of naturalness correlates with low-level visual features of environmental scenes.

    Directory of Open Access Journals (Sweden)

    Marc G Berman

    Full Text Available Previous research has shown that interacting with natural environments vs. more urban or built environments can have salubrious psychological effects, such as improvements in attention and memory. Even viewing pictures of nature vs. pictures of built environments can produce similar effects. A major question is: What is it about natural environments that produces these benefits? Problematically, there are many differing qualities between natural and urban environments, making it difficult to narrow down the dimensions of nature that may lead to these benefits. In this study, we set out to uncover visual features that related to individuals' perceptions of naturalness in images. We quantified naturalness in two ways: first, implicitly using a multidimensional scaling analysis and second, explicitly with direct naturalness ratings. Features that seemed most related to perceptions of naturalness were related to the density of contrast changes in the scene, the density of straight lines in the scene, the average color saturation in the scene and the average hue diversity in the scene. We then trained a machine-learning algorithm to predict whether a scene was perceived as being natural or not based on these low-level visual features and we could do so with 81% accuracy. As such we were able to reliably predict subjective perceptions of naturalness with objective low-level visual features. Our results can be used in future studies to determine if these features, which are related to naturalness, may also lead to the benefits attained from interacting with nature.

  2. Parietal cortex integrates contextual and saliency signals during the encoding of natural scenes in working memory.

    Science.gov (United States)

    Santangelo, Valerio; Di Francesco, Simona Arianna; Mastroberardino, Serena; Macaluso, Emiliano

    2015-12-01

    The Brief presentation of a complex scene entails that only a few objects can be selected, processed indepth, and stored in memory. Both low-level sensory salience and high-level context-related factors (e.g., the conceptual match/mismatch between objects and scene context) contribute to this selection process, but how the interplay between these factors affects memory encoding is largely unexplored. Here, during fMRI we presented participants with pictures of everyday scenes. After a short retention interval, participants judged the position of a target object extracted from the initial scene. The target object could be either congruent or incongruent with the context of the scene, and could be located in a region of the image with maximal or minimal salience. Behaviourally, we found a reduced impact of saliency on visuospatial working memory performance when the target was out-of-context. Encoding-related fMRI results showed that context-congruent targets activated dorsoparietal regions, while context-incongruent targets de-activated the ventroparietal cortex. Saliency modulated activity both in dorsal and ventral regions, with larger context-related effects for salient targets. These findings demonstrate the joint contribution of knowledge-based and saliency-driven attention for memory encoding, highlighting a dissociation between dorsal and ventral parietal regions. © 2015 Wiley Periodicals, Inc.

  3. History of Reading Struggles Linked to Enhanced Learning in Low Spatial Frequency Scenes

    Science.gov (United States)

    Schneps, Matthew H.; Brockmole, James R.; Sonnert, Gerhard; Pomplun, Marc

    2012-01-01

    People with dyslexia, who face lifelong struggles with reading, exhibit numerous associated low-level sensory deficits including deficits in focal attention. Countering this, studies have shown that struggling readers outperform typical readers in some visual tasks that integrate distributed information across an expanse. Though such abilities would be expected to facilitate scene memory, prior investigations using the contextual cueing paradigm failed to find corresponding advantages in dyslexia. We suggest that these studies were confounded by task-dependent effects exaggerating known focal attention deficits in dyslexia, and that, if natural scenes were used as the context, advantages would emerge. Here, we investigate this hypothesis by comparing college students with histories of severe lifelong reading difficulties (SR) and typical readers (TR) in contexts that vary attention load. We find no differences in contextual-cueing when spatial contexts are letter-like objects, or when contexts are natural scenes. However, the SR group significantly outperforms the TR group when contexts are low-pass filtered natural scenes [F(3, 39) = 3.15, p<.05]. These findings suggest that perception or memory for low spatial frequency components in scenes is enhanced in dyslexia. These findings are important because they suggest strengths for spatial learning in a population otherwise impaired, carrying implications for the education and support of students who face challenges in school. PMID:22558210

  4. History of reading struggles linked to enhanced learning in low spatial frequency scenes.

    Directory of Open Access Journals (Sweden)

    Matthew H Schneps

    Full Text Available People with dyslexia, who face lifelong struggles with reading, exhibit numerous associated low-level sensory deficits including deficits in focal attention. Countering this, studies have shown that struggling readers outperform typical readers in some visual tasks that integrate distributed information across an expanse. Though such abilities would be expected to facilitate scene memory, prior investigations using the contextual cueing paradigm failed to find corresponding advantages in dyslexia. We suggest that these studies were confounded by task-dependent effects exaggerating known focal attention deficits in dyslexia, and that, if natural scenes were used as the context, advantages would emerge. Here, we investigate this hypothesis by comparing college students with histories of severe lifelong reading difficulties (SR and typical readers (TR in contexts that vary attention load. We find no differences in contextual-cueing when spatial contexts are letter-like objects, or when contexts are natural scenes. However, the SR group significantly outperforms the TR group when contexts are low-pass filtered natural scenes [F(3, 39 = 3.15, p<.05]. These findings suggest that perception or memory for low spatial frequency components in scenes is enhanced in dyslexia. These findings are important because they suggest strengths for spatial learning in a population otherwise impaired, carrying implications for the education and support of students who face challenges in school.

  5. Three-dimensional model-based object recognition and segmentation in cluttered scenes.

    Science.gov (United States)

    Mian, Ajmal S; Bennamoun, Mohammed; Owens, Robyn

    2006-10-01

    Viewpoint independent recognition of free-form objects and their segmentation in the presence of clutter and occlusions is a challenging task. We present a novel 3D model-based algorithm which performs this task automatically and efficiently. A 3D model of an object is automatically constructed offline from its multiple unordered range images (views). These views are converted into multidimensional table representations (which we refer to as tensors). Correspondences are automatically established between these views by simultaneously matching the tensors of a view with those of the remaining views using a hash table-based voting scheme. This results in a graph of relative transformations used to register the views before they are integrated into a seamless 3D model. These models and their tensor representations constitute the model library. During online recognition, a tensor from the scene is simultaneously matched with those in the library by casting votes. Similarity measures are calculated for the model tensors which receive the most votes. The model with the highest similarity is transformed to the scene and, if it aligns accurately with an object in the scene, that object is declared as recognized and is segmented. This process is repeated until the scene is completely segmented. Experiments were performed on real and synthetic data comprised of 55 models and 610 scenes and an overall recognition rate of 95 percent was achieved. Comparison with the spin images revealed that our algorithm is superior in terms of recognition rate and efficiency.

  6. Single-View 3D Scene Reconstruction and Parsing by Attribute Grammar.

    Science.gov (United States)

    Liu, Xiaobai; Zhao, Yibiao; Zhu, Song-Chun

    2018-03-01

    In this paper, we present an attribute grammar for solving two coupled tasks: i) parsing a 2D image into semantic regions; and ii) recovering the 3D scene structures of all regions. The proposed grammar consists of a set of production rules, each describing a kind of spatial relation between planar surfaces in 3D scenes. These production rules are used to decompose an input image into a hierarchical parse graph representation where each graph node indicates a planar surface or a composite surface. Different from other stochastic image grammars, the proposed grammar augments each graph node with a set of attribute variables to depict scene-level global geometry, e.g., camera focal length, or local geometry, e.g., surface normal, contact lines between surfaces. These geometric attributes impose constraints between a node and its off-springs in the parse graph. Under a probabilistic framework, we develop a Markov Chain Monte Carlo method to construct a parse graph that optimizes the 2D image recognition and 3D scene reconstruction purposes simultaneously. We evaluated our method on both public benchmarks and newly collected datasets. Experiments demonstrate that the proposed method is capable of achieving state-of-the-art scene reconstruction of a single image.

  7. Adaptive attunement of selective covert attention to evolutionary-relevant emotional visual scenes.

    Science.gov (United States)

    Fernández-Martín, Andrés; Gutiérrez-García, Aída; Capafons, Juan; Calvo, Manuel G

    2017-05-01

    We investigated selective attention to emotional scenes in peripheral vision, as a function of adaptive relevance of scene affective content for male and female observers. Pairs of emotional-neutral images appeared peripherally-with perceptual stimulus differences controlled-while viewers were fixating on a different stimulus in central vision. Early selective orienting was assessed by the probability of directing the first fixation towards either scene, and the time until first fixation. Emotional scenes selectively captured covert attention even when they were task-irrelevant, thus revealing involuntary, automatic processing. Sex of observers and specific emotional scene content (e.g., male-to-female-aggression, families and babies, etc.) interactively modulated covert attention, depending on adaptive priorities and goals for each sex, both for pleasant and unpleasant content. The attentional system exhibits domain-specific and sex-specific biases and attunements, probably rooted in evolutionary pressures to enhance reproductive and protective success. Emotional cues selectively capture covert attention based on their bio-social significance. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The elephant in the room: Inconsistency in scene viewing and representation.

    Science.gov (United States)

    Spotorno, Sara; Tatler, Benjamin W

    2017-10-01

    We examined the extent to which semantic informativeness, consistency with expectations and perceptual salience contribute to object prioritization in scene viewing and representation. In scene viewing (Experiments 1-2), semantic guidance overshadowed perceptual guidance in determining fixation order, with the greatest prioritization for objects that were diagnostic of the scene's depicted event. Perceptual properties affected selection of consistent objects (regardless of their informativeness) but not of inconsistent objects. Semantic and perceptual properties also interacted in influencing foveal inspection, as inconsistent objects were fixated longer than low but not high salience diagnostic objects. While not studied in direct competition with each other (each studied in competition with diagnostic objects), we found that inconsistent objects were fixated earlier and for longer than consistent but marginally informative objects. In change detection (Experiment 3), perceptual guidance overshadowed semantic guidance, promoting detection of highly salient changes. A residual advantage for diagnosticity over inconsistency emerged only when selection prioritization could not be based on low-level features. Overall these findings show that semantic inconsistency is not prioritized within a scene when competing with other relevant information that is essential to scene understanding and respects observers' expectations. Moreover, they reveal that the relative dominance of semantic or perceptual properties during selection depends on ongoing task requirements. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  9. Acute stress influences the discrimination of complex scenes and complex faces in young healthy men.

    Science.gov (United States)

    Paul, M; Lech, R K; Scheil, J; Dierolf, A M; Suchan, B; Wolf, O T

    2016-04-01

    The stress-induced release of glucocorticoids has been demonstrated to influence hippocampal functions via the modulation of specific receptors. At the behavioral level stress is known to influence hippocampus dependent long-term memory. In recent years, studies have consistently associated the hippocampus with the non-mnemonic perception of scenes, while adjacent regions in the medial temporal lobe were associated with the perception of objects, and faces. So far it is not known whether and how stress influences non-mnemonic perceptual processes. In a behavioral study, fifty male participants were subjected either to the stressful socially evaluated cold-pressor test or to a non-stressful control procedure, before they completed a visual discrimination task, comprising scenes and faces. The complexity of the face and scene stimuli was manipulated in easy and difficult conditions. A significant three way interaction between stress, stimulus type and complexity was found. Stressed participants tended to commit more errors in the complex scenes condition. For complex faces a descriptive tendency in the opposite direction (fewer errors under stress) was observed. As a result the difference between the number of errors for scenes and errors for faces was significantly larger in the stress group. These results indicate that, beyond the effects of stress on long-term memory, stress influences the discrimination of spatial information, especially when the perception is characterized by a high complexity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Fuzzy Classification of High Resolution Remote Sensing Scenes Using Visual Attention Features

    Directory of Open Access Journals (Sweden)

    Linyi Li

    2017-01-01

    Full Text Available In recent years the spatial resolutions of remote sensing images have been improved greatly. However, a higher spatial resolution image does not always lead to a better result of automatic scene classification. Visual attention is an important characteristic of the human visual system, which can effectively help to classify remote sensing scenes. In this study, a novel visual attention feature extraction algorithm was proposed, which extracted visual attention features through a multiscale process. And a fuzzy classification method using visual attention features (FC-VAF was developed to perform high resolution remote sensing scene classification. FC-VAF was evaluated by using remote sensing scenes from widely used high resolution remote sensing images, including IKONOS, QuickBird, and ZY-3 images. FC-VAF achieved more accurate classification results than the others according to the quantitative accuracy evaluation indices. We also discussed the role and impacts of different decomposition levels and different wavelets on the classification accuracy. FC-VAF improves the accuracy of high resolution scene classification and therefore advances the research of digital image analysis and the applications of high resolution remote sensing images.

  11. The effects of scene characteristics, resolution, and compression on the ability to recognize objects in video

    Science.gov (United States)

    Dumke, Joel; Ford, Carolyn G.; Stange, Irena W.

    2011-03-01

    Public safety practitioners increasingly use video for object recognition tasks. These end users need guidance regarding how to identify the level of video quality necessary for their application. The quality of video used in public safety applications must be evaluated in terms of its usability for specific tasks performed by the end user. The Public Safety Communication Research (PSCR) project performed a subjective test as one of the first in a series to explore visual intelligibility in video-a user's ability to recognize an object in a video stream given various conditions. The test sought to measure the effects on visual intelligibility of three scene parameters (target size, scene motion, scene lighting), several compression rates, and two resolutions (VGA (640x480) and CIF (352x288)). Seven similarly sized objects were used as targets in nine sets of near-identical source scenes, where each set was created using a different combination of the parameters under study. Viewers were asked to identify the objects via multiple choice questions. Objective measurements were performed on each of the scenes, and the ability of the measurement to predict visual intelligibility was studied.

  12. Modification of computational auditory scene analysis (CASA) for noise-robust acoustic feature

    Science.gov (United States)

    Kwon, Minseok

    While there have been many attempts to mitigate interferences of background noise, the performance of automatic speech recognition (ASR) still can be deteriorated by various factors with ease. However, normal hearing listeners can accurately perceive sounds of their interests, which is believed to be a result of Auditory Scene Analysis (ASA). As a first attempt, the simulation of the human auditory processing, called computational auditory scene analysis (CASA), was fulfilled through physiological and psychological investigations of ASA. CASA comprised of Zilany-Bruce auditory model, followed by tracking fundamental frequency for voice segmentation and detecting pairs of onset/offset at each characteristic frequency (CF) for unvoiced segmentation. The resulting Time-Frequency (T-F) representation of acoustic stimulation was converted into acoustic feature, gammachirp-tone frequency cepstral coefficients (GFCC). 11 keywords with various environmental conditions are used and the robustness of GFCC was evaluated by spectral distance (SD) and dynamic time warping distance (DTW). In "clean" and "noisy" conditions, the application of CASA generally improved noise robustness of the acoustic feature compared to a conventional method with or without noise suppression using MMSE estimator. The intial study, however, not only showed the noise-type dependency at low SNR, but also called the evaluation methods in question. Some modifications were made to capture better spectral continuity from an acoustic feature matrix, to obtain faster processing speed, and to describe the human auditory system more precisely. The proposed framework includes: 1) multi-scale integration to capture more accurate continuity in feature extraction, 2) contrast enhancement (CE) of each CF by competition with neighboring frequency bands, and 3) auditory model modifications. The model modifications contain the introduction of higher Q factor, middle ear filter more analogous to human auditory system

  13. Combination of Morphological Operations with Structure based Partitioning and grouping for Text String detection from Natural Scenes

    OpenAIRE

    Vyankatesh V. Rampurkar; Gyankamal J. Chhajed

    2014-01-01

    Text information in natural scene images serves as important clues for many image-based applications such as scene perceptive, content-based image retrieval, assistive direction-finding and automatic geocoding. Now days different approaches like countours based, Image binarization and enhancement based, Gradient based and colour reduction based techniques can be used for the text detection from natural scenes. In this paper the combination of morphological operations with structure based part...

  14. Application of composite small calibration objects in traffic accident scene photogrammetry.

    Science.gov (United States)

    Chen, Qiang; Xu, Hongguo; Tan, Lidong

    2015-01-01

    In order to address the difficulty of arranging large calibration objects and the low measurement accuracy of small calibration objects in traffic accident scene photogrammetry, a photogrammetric method based on a composite of small calibration objects is proposed. Several small calibration objects are placed around the traffic accident scene, and the coordinate system of the composite calibration object is given based on one of them. By maintaining the relative position and coplanar relationship of the small calibration objects, the local coordinate system of each small calibration object is transformed into the coordinate system of the composite calibration object. The two-dimensional direct linear transformation method is improved based on minimizing the reprojection error of the calibration points of all objects. A rectified image is obtained using the nonlinear optimization method. The increased accuracy of traffic accident scene photogrammetry using a composite small calibration object is demonstrated through the analysis of field experiments and case studies.

  15. The singular nature of auditory and visual scene analysis in autism.

    Science.gov (United States)

    Lin, I-Fan; Shirama, Aya; Kato, Nobumasa; Kashino, Makio

    2017-02-19

    Individuals with autism spectrum disorder often have difficulty acquiring relevant auditory and visual information in daily environments, despite not being diagnosed as hearing impaired or having low vision. Resent psychophysical and neurophysiological studies have shown that autistic individuals have highly specific individual differences at various levels of information processing, including feature extraction, automatic grouping and top-down modulation in auditory and visual scene analysis. Comparison of the characteristics of scene analysis between auditory and visual modalities reveals some essential commonalities, which could provide clues about the underlying neural mechanisms. Further progress in this line of research may suggest effective methods for diagnosing and supporting autistic individuals.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Author(s).

  16. Molecular identification of blow flies recovered from human cadavers during crime scene investigations in Malaysia.

    Science.gov (United States)

    Kavitha, Rajagopal; Nazni, Wasi Ahmad; Tan, Tian Chye; Lee, Han Lim; Isa, Mohd Noor Mat; Azirun, Mohd Sofian

    2012-12-01

    Forensic entomology applies knowledge about insects associated with decedent in crime scene investigation. It is possible to calculate a minimum postmortem interval (PMI) by determining the age and species of the oldest blow fly larvae feeding on decedent. This study was conducted in Malaysia to identify maggot specimens collected during crime scene investigations. The usefulness of the molecular and morphological approach in species identifications was evaluated in 10 morphologically identified blow fly larvae sampled from 10 different crime scenes in Malaysia. The molecular identification method involved the sequencing of a total length of 2.2 kilo base pairs encompassing the 'barcode' fragments of the mitochondrial cytochrome oxidase I (COI), cytochrome oxidase II (COII) and t-RNA leucine genes. Phylogenetic analyses confirmed the presence of Chrysomya megacephala, Chrysomya rufifacies and Chrysomya nigripes. In addition, one unidentified blow fly species was found based on phylogenetic tree analysis.

  17. Desirable and undesirable future thoughts call for different scene construction processes.

    Science.gov (United States)

    de Vito, S; Neroni, M A; Gamboz, N; Della Sala, S; Brandimonte, M A

    2015-01-01

    Despite the growing interest in the ability of foreseeing (episodic future thinking), it is still unclear how healthy people construct possible future scenarios. We suggest that different future thoughts require different processes of scene construction. Thirty-five participants were asked to imagine desirable and less desirable future events. Imagining desirable events increased the ease of scene construction, the frequency of life scripts, the number of internal details, and the clarity of sensorial and spatial temporal information. The initial description of general personal knowledge lasted longer in undesirable than in desirable anticipations. Finally, participants were more prone to explicitly indicate autobiographical memory as the main source of their simulations of undesirable episodes, whereas they equally related the simulations of desirable events to autobiographical events or semantic knowledge. These findings show that desirable and undesirable scenarios call for different mechanisms of scene construction. The present study emphasizes that future thinking cannot be considered as a monolithic entity.

  18. Three-dimensional scene encryption and display based on computer-generated holograms.

    Science.gov (United States)

    Kong, Dezhao; Cao, Liangcai; Jin, Guofan; Javidi, Bahram

    2016-10-10

    An optical encryption and display method for a three-dimensional (3D) scene is proposed based on computer-generated holograms (CGHs) using a single phase-only spatial light modulator. The 3D scene is encoded as one complex Fourier CGH. The Fourier CGH is then decomposed into two phase-only CGHs with random distributions by the vector stochastic decomposition algorithm. Two CGHs are interleaved as one final phase-only CGH for optical encryption and reconstruction. The proposed method can support high-level nonlinear optical 3D scene security and complex amplitude modulation of the optical field. The exclusive phase key offers strong resistances of decryption attacks. Experimental results demonstrate the validity of the novel method.

  19. The Role of Binocular Disparity in Rapid Scene and Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Matteo Valsecchi

    2013-04-01

    Full Text Available We investigated the contribution of binocular disparity to the rapid recognition of scenes and simpler spatial patterns using a paradigm combining backward masked stimulus presentation and short-term match-to-sample recognition. First, we showed that binocular disparity did not contribute significantly to the recognition of briefly presented natural and artificial scenes, even when the availability of monocular cues was reduced. Subsequently, using dense random dot stereograms as stimuli, we showed that observers were in principle able to extract spatial patterns defined only by disparity under brief, masked presentations. Comparing our results with the predictions from a cue-summation model, we showed that combining disparity with luminance did not per se disrupt the processing of disparity. Our results suggest that the rapid recognition of scenes is mediated mostly by a monocular comparison of the images, although we can rely on stereo in fast pattern recognition.

  20. Application of composite small calibration objects in traffic accident scene photogrammetry.

    Directory of Open Access Journals (Sweden)

    Qiang Chen

    Full Text Available In order to address the difficulty of arranging large calibration objects and the low measurement accuracy of small calibration objects in traffic accident scene photogrammetry, a photogrammetric method based on a composite of small calibration objects is proposed. Several small calibration objects are placed around the traffic accident scene, and the coordinate system of the composite calibration object is given based on one of them. By maintaining the relative position and coplanar relationship of the small calibration objects, the local coordinate system of each small calibration object is transformed into the coordinate system of the composite calibration object. The two-dimensional direct linear transformation method is improved based on minimizing the reprojection error of the calibration points of all objects. A rectified image is obtained using the nonlinear optimization method. The increased accuracy of traffic accident scene photogrammetry using a composite small calibration object is demonstrated through the analysis of field experiments and case studies.

  1. How children remember neutral and emotional pictures: boundary extension in children's scene memories.

    Science.gov (United States)

    Candel, Ingrid; Merckelbach, Harald; Houben, Katrijn; Vandyck, Inne

    2004-01-01

    Boundary extension is the tendency to remember more of a scene than was actually shown. The dominant interpretation of this memory illusion is that it originates from schemata that people construct when viewing a scene. Evidence of boundary extension has been obtained primarily with adult participants who remember neutral pictures. The current study addressed the developmental stability of this phenomenon. Therefore, we investigated whether children aged 10-12 years display boundary extension for neutral pictures. Moreover, we examined emotional scene memory. Eighty-seven children drew pictures from memory after they had seen either neutral or emotional pictures. Both their neutral and emotional drawings revealed boundary extension. Apparently, the schema construction that underlies boundary extension is a robust and ubiquitous process.

  2. Using 3D range cameras for crime scene documentation and legal medicine

    Science.gov (United States)

    Cavagnini, Gianluca; Sansoni, Giovanna; Trebeschi, Marco

    2009-01-01

    Crime scene documentation and legal medicine analysis are part of a very complex process which is aimed at identifying the offender starting from the collection of the evidences on the scene. This part of the investigation is very critical, since the crime scene is extremely volatile, and once it is removed, it can not be precisely created again. For this reason, the documentation process should be as complete as possible, with minimum invasiveness. The use of optical 3D imaging sensors has been considered as a possible aid to perform the documentation step, since (i) the measurement is contactless and (ii) the process required to editing and modeling the 3D data is quite similar to the reverse engineering procedures originally developed for the manufacturing field. In this paper we show the most important results obtained in the experimentation.

  3. The formation of music-scenes in Manchester and their relation to urban space and the image of the city

    DEFF Research Database (Denmark)

    Nielsen, Tom

    2013-01-01

    and the image of the city. This image has later been utilised in the branding of Manchester as a creative city. The case is interesting in relation to the current ideals of planning ‘creative cities’ and local cultural scenes. The music scenes cannot be seen as participatory projects and has developed in more......The formation of music-scenes in Manchester and their relation to urban space and the image of the city The paper I would like to present derives from a study of the relation between the atmospheric qualities of a city and the formation of music scenes. I have studied Manchester which is a known...

  4. Cross-cultural differences in item and background memory: examining the influence of emotional intensity and scene congruency.

    Science.gov (United States)

    Mickley Steinmetz, Katherine R; Sturkie, Charlee M; Rochester, Nina M; Liu, Xiaodong; Gutchess, Angela H

    2018-07-01

    After viewing a scene, individuals differ in what they prioritise and remember. Culture may be one factor that influences scene memory, as Westerners have been shown to be more item-focused than Easterners (see Masuda, T., & Nisbett, R. E. (2001). Attending holistically versus analytically: Comparing the context sensitivity of Japanese and Americans. Journal of Personality and Social Psychology, 81, 922-934). However, cultures may differ in their sensitivity to scene incongruences and emotion processing, which may account for cross-cultural differences in scene memory. The current study uses hierarchical linear modeling (HLM) to examine scene memory while controlling for scene congruency and the perceived emotional intensity of the images. American and East Asian participants encoded pictures that included a positive, negative, or neutral item placed on a neutral background. After a 20-min delay, participants were shown the item and background separately along with similar and new items and backgrounds to assess memory specificity. Results indicated that even when congruency and emotional intensity were controlled, there was evidence that Americans had better item memory than East Asians. Incongruent scenes were better remembered than congruent scenes. However, this effect did not differ by culture. This suggests that Americans' item focus may result in memory changes that are robust despite variations in scene congruency and perceived emotion.

  5. Negotiating place and gendered violence in Canada's largest open drug scene.

    Science.gov (United States)

    McNeil, Ryan; Shannon, Kate; Shaver, Laura; Kerr, Thomas; Small, Will

    2014-05-01

    Vancouver's Downtown Eastside is home to Canada's largest street-based drug scene and only supervised injection facility (Insite). High levels of violence among men and women have been documented in this neighbourhood. This study was undertaken to explore the role of violence in shaping the socio-spatial relations of women and 'marginal men' (i.e., those occupying subordinate positions within the drug scene) in the Downtown Eastside, including access to Insite. Semi-structured qualitative interviews were conducted with 23 people who inject drugs (PWID) recruited through the Vancouver Area Network of Drug Users, a local drug user organization. Interviews included a mapping exercise. Interview transcripts and maps were analyzed thematically, with an emphasis on how gendered violence shaped participants' spatial practices. Hegemonic forms of masculinity operating within the Downtown Eastside framed the everyday violence experienced by women and marginal men. This violence shaped the spatial practices of women and marginal men, in that they avoided drug scene milieus where they had experienced violence or that they perceived to be dangerous. Some men linked their spatial restrictions to the perceived 'dope quality' of neighbourhood drug dealers to maintain claims to dominant masculinities while enacting spatial strategies to promote safety. Environmental supports provided by health and social care agencies were critical in enabling women and marginal men to negotiate place and survival within the context of drug scene violence. Access to Insite did not motivate participants to enter into "dangerous" drug scene milieus but they did venture into these areas if necessary to obtain drugs or generate income. Gendered violence is critical in restricting the geographies of men and marginal men within the street-based drug scene. There is a need to scale up existing environmental interventions, including supervised injection services, to minimize violence and potential drug

  6. NEGOTIATING PLACE AND GENDERED VIOLENCE IN CANADA’S LARGEST OPEN DRUG SCENE

    Science.gov (United States)

    McNeil, Ryan; Shannon, Kate; Shaver, Laura; Kerr, Thomas; Small, Will

    2014-01-01

    Background Vancouver’s Downtown Eastside is home to Canada’s largest street-based drug scene and only supervised injection facility (Insite). High levels of violence among men and women have been documented in this neighbourhood. This study was undertaken to explore the role of violence in shaping the socio-spatial relations of women and ‘marginal men’ (i.e., those occupying subordinate positions within the drug scene) in the Downtown Eastside, including access to Insite. Methods Semi-structured qualitative interviews were conducted with 23 people who inject drugs (PWID) recruited through the Vancouver Area Network of Drug Users, a local drug user organization. Interviews included a mapping exercise. Interview transcripts and maps were analyzed thematically, with an emphasis on how gendered violence shaped participants’ spatial practices. Results Hegemonic forms of masculinity operating within the Downtown Eastside framed the everyday violence experienced by women and marginal men. This violence shaped the spatial practices of women and marginal men, in that they avoided drug scene milieus where they had experienced violence or that they perceived to be dangerous. Some men linked their spatial restrictions to the perceived 'dope quality' of neighbourhood drug dealers to maintain claims to dominant masculinities while enacting spatial strategies to promote safety. Environmental supports provided by health and social care agencies were critical in enabling women and marginal men to negotiate place and survival within the context of drug scene violence. Access to Insite did not motivate participants to enter into “dangerous” drug scene milieus but they did venture into these areas if necessary to obtain drugs or generate income. Conclusion Gendered violence is critical in restricting the geographies of men and marginal men within the street-based drug scene. There is a need to scale up existing environmental interventions, including supervised injection

  7. Deep Salient Feature Based Anti-Noise Transfer Network for Scene Classification of Remote Sensing Imagery

    Directory of Open Access Journals (Sweden)

    Xi Gong

    2018-03-01

    Full Text Available Remote sensing (RS scene classification is important for RS imagery semantic interpretation. Although tremendous strides have been made in RS scene classification, one of the remaining open challenges is recognizing RS scenes in low quality variance (e.g., various scales and noises. This paper proposes a deep salient feature based anti-noise transfer network (DSFATN method that effectively enhances and explores the high-level features for RS scene classification in different scales and noise conditions. In DSFATN, a novel discriminative deep salient feature (DSF is introduced by saliency-guided DSF extraction, which conducts a patch-based visual saliency (PBVS algorithm using “visual attention” mechanisms to guide pre-trained CNNs for producing the discriminative high-level features. Then, an anti-noise network is proposed to learn and enhance the robust and anti-noise structure information of RS scene by directly propagating the label information to fully-connected layers. A joint loss is used to minimize the anti-noise network by integrating anti-noise constraint and a softmax classification loss. The proposed network architecture can be easily trained with a limited amount of training data. The experiments conducted on three different scale RS scene datasets show that the DSFATN method has achieved excellent performance and great robustness in different scales and noise conditions. It obtains classification accuracy of 98.25%, 98.46%, and 98.80%, respectively, on the UC Merced Land Use Dataset (UCM, the Google image dataset of SIRI-WHU, and the SAT-6 dataset, advancing the state-of-the-art substantially.

  8. Surface-illuminant ambiguity and color constancy: effects of scene complexity and depth cues.

    Science.gov (United States)

    Kraft, James M; Maloney, Shannon I; Brainard, David H

    2002-01-01

    Two experiments were conducted to study how scene complexity and cues to depth affect human color constancy. Specifically, two levels of scene complexity were compared. The low-complexity scene contained two walls with the same surface reflectance and a test patch which provided no information about the illuminant. In addition to the surfaces visible in the low-complexity scene, the high-complexity scene contained two rectangular solid objects and 24 paper samples with diverse surface reflectances. Observers viewed illuminated objects in an experimental chamber and adjusted the test patch until it appeared achromatic. Achromatic settings made tinder two different illuminants were used to compute an index that quantified the degree of constancy. Two experiments were conducted: one in which observers viewed the stimuli directly, and one in which they viewed the scenes through an optical system that reduced cues to depth. In each experiment, constancy was assessed for two conditions. In the valid-cue condition, many cues provided valid information about the illuminant change. In the invalid-cue condition, some image cues provided invalid information. Four broad conclusions are drawn from the data: (a) constancy is generally better in the valid-cue condition than in the invalid-cue condition: (b) for the stimulus configuration used, increasing image complexity has little effect in the valid-cue condition but leads to increased constancy in the invalid-cue condition; (c) for the stimulus configuration used, reducing cues to depth has little effect for either constancy condition: and (d) there is moderate individual variation in the degree of constancy exhibited, particularly in the degree to which the complexity manipulation affects performance.

  9. Fast Binary Coding for the Scene Classification of High-Resolution Remote Sensing Imagery

    Directory of Open Access Journals (Sweden)

    Fan Hu

    2016-06-01

    Full Text Available Scene classification of high-resolution remote sensing (HRRS imagery is an important task in the intelligent processing of remote sensing images and has attracted much attention in recent years. Although the existing scene classification methods, e.g., the bag-of-words (BOW model and its variants, can achieve acceptable performance, these approaches strongly rely on the extraction of local features and the complicated coding strategy, which are usually time consuming and demand much expert effort. In this paper, we propose a fast binary coding (FBC method, to effectively generate efficient discriminative scene representations of HRRS images. The main idea is inspired by the unsupervised feature learning technique and the binary feature descriptions. More precisely, equipped with the unsupervised feature learning technique, we first learn a set of optimal “filters” from large quantities of randomly-sampled image patches and then obtain feature maps by convolving the image scene with the learned filters. After binarizing the feature maps, we perform a simple hashing step to convert the binary-valued feature map to the integer-valued feature map. Finally, statistical histograms computed on the integer-valued feature map are used as global feature representations of the scenes of HRRS images, similar to the conventional BOW model. The analysis of the algorithm complexity and experiments on HRRS image datasets demonstrate that, in contrast with existing scene classification approaches, the proposed FBC has much faster computational speed and achieves comparable classification performance. In addition, we also propose two extensions to FBC, i.e., the spatial co-occurrence matrix and different visual saliency maps, for further improving its final classification accuracy.

  10. Spectral feature characterization methods for blood stain detection in crime scene backgrounds

    Science.gov (United States)

    Yang, Jie; Mathew, Jobin J.; Dube, Roger R.; Messinger, David W.

    2016-05-01

    Blood stains are one of the most important types of evidence for forensic investigation. They contain valuable DNA information, and the pattern of the stains can suggest specifics about the nature of the violence that transpired at the scene. Blood spectral signatures containing unique reflectance or absorption features are important both for forensic on-site investigation and laboratory testing. They can be used for target detection and identification applied to crime scene hyperspectral imagery, and also be utilized to analyze the spectral variation of blood on various backgrounds. Non-blood stains often mislead the detection and can generate false alarms at a real crime scene, especially for dark and red backgrounds. This paper measured the reflectance of liquid blood and 9 kinds of non-blood samples in the range of 350 nm - 2500 nm in various crime scene backgrounds, such as pure samples contained in petri dish with various thicknesses, mixed samples with different colors and materials of fabrics, and mixed samples with wood, all of which are examined to provide sub-visual evidence for detecting and recognizing blood from non-blood samples in a realistic crime scene. The spectral difference between blood and non-blood samples are examined and spectral features such as "peaks" and "depths" of reflectance are selected. Two blood stain detection methods are proposed in this paper. The first method uses index to denote the ratio of "depth" minus "peak" over"depth" add"peak" within a wavelength range of the reflectance spectrum. The second method uses relative band depth of the selected wavelength ranges of the reflectance spectrum. Results show that the index method is able to discriminate blood from non-blood samples in most tested crime scene backgrounds, but is not able to detect it from black felt. Whereas the relative band depth method is able to discriminate blood from non-blood samples on all of the tested background material types and colors.

  11. Assembling a game development scene? Uncovering Finland’s largest demo party

    Directory of Open Access Journals (Sweden)

    Heikki Tyni

    2014-03-01

    Full Text Available The study takes look at Assembly, a large-scale LAN and demo party founded in 1992 and organized annually in Helsinki, Finland. Assembly is used as a case study to explore the relationship between computer hobbyism – including gaming, demoscene and other related activities – and professional game development. Drawing from expert interviews, a visitor query and news coverage we ask what kind of functions Assembly has played for the scene in general, and on the formation and fostering of the Finnish game industry in particular. The conceptual contribution of the paper is constructed around the interrelated concepts of scene, technicity and gaming capital.

  12. Binary Format for Scene (BIFS): combining MPEG-4 media to build rich multimedia services

    Science.gov (United States)

    Signes, Julien

    1998-12-01

    In this paper, we analyze the design concepts and some technical details behind the MPEG-4 standard, particularly the scene description layer, commonly known as the Binary Format for Scene (BIFS). We show how MPEG-4 may ease multimedia proliferation by offering a unique, optimized multimedia platform. Lastly, we analyze the potential of the technology for creating rich multimedia applications on various networks and platforms. An e-commerce application example is detailed, highlighting the benefits of the technology. Compression results show how rich applications may be built even on very low bit rate connections.

  13. CSRNet: Dilated Convolutional Neural Networks for Understanding the Highly Congested Scenes

    OpenAIRE

    Li, Yuhong; Zhang, Xiaofan; Chen, Deming

    2018-01-01

    We propose a network for Congested Scene Recognition called CSRNet to provide a data-driven and deep learning method that can understand highly congested scenes and perform accurate count estimation as well as present high-quality density maps. The proposed CSRNet is composed of two major components: a convolutional neural network (CNN) as the front-end for 2D feature extraction and a dilated CNN for the back-end, which uses dilated kernels to deliver larger reception fields and to replace po...

  14. New scenes and houses for literature - a challenge for cultural and public library policy?

    DEFF Research Database (Denmark)

    Lund, Niels D.

    2012-01-01

    The paper focuses on the emergence of new initiatives and undertakings in the field of promotion and use of literature in comparison with the possibilities and practices of the traditional public library institutions and of public cultural policy. First a description of a dual development...... of the public library and of UNESCO’s agenda City of literature makes a setting; then three parts mention different scenes and initiatives: small scenes for performance of literature, festivals of literature as a mode, and – more detailed – the various types of houses of literature - with primarily Danish...... questions of subsiding and relations to libraries and civil society....

  15. Sustained change blindness to incremental scene rotation: a dissociation between explicit change detection and visual memory.

    Science.gov (United States)

    Hollingworth, Andrew; Henderson, John M

    2004-07-01

    In a change detection paradigm, the global orientation of a natural scene was incrementally changed in 1 degree intervals. In Experiments 1 and 2, participants demonstrated sustained change blindness to incremental rotation, often coming to consider a significantly different scene viewpoint as an unchanged continuation of the original view. Experiment 3 showed that participants who failed to detect the incremental rotation nevertheless reliably detected a single-step rotation back to the initial view. Together, these results demonstrate an important dissociation between explicit change detection and visual memory. Following a change, visual memory is updated to reflect the changed state of the environment, even if the change was not detected.

  16. Contribution to the tracking and the 3D reconstruction of scenes composed of torus from image sequences a acquired by a moving camera

    International Nuclear Information System (INIS)

    Naudet, S.

    1997-01-01

    The three-dimensional perception of the environment is often necessary for a robot to correctly perform its tasks. One solution, based on the dynamic vision, consists in analysing time-varying monocular images to estimate the spatial geometry of the scene. This thesis deals with the reconstruction of torus by dynamic vision. Though this object class is restrictive, it enables to tackle the problem of reconstruction of bent pipes usually encountered in industrial environments. The proposed method is based on the evolution of apparent contours of objects in the sequence. Using the expression of torus limb boundaries, it is possible to recursively estimate the object three-dimensional parameters by minimising the error between the predicted projected contours and the image contours. This process, which is performed by a Kalman filter, does not need a precise knowledge of the camera displacement or any matching of the tow limbs belonging to the same object. To complete this work, temporal tracking of objects which deals with occlusion situations is proposed. The approach consists in modeling and interpreting the apparent motion of objects in the successive images. The motion interpretation, based on a simplified representation of the scene, allows to recover pertinent three-dimensional information which is used to manage occlusion situations. Experiments, on synthetic and real images, proves he validity of the tracking and the reconstruction processes. (author)

  17. Active listening for spatial orientation in a complex auditory scene.

    Science.gov (United States)

    Moss, Cynthia F; Bohn, Kari; Gilkenson, Hannah; Surlykke, Annemarie

    2006-04-01

    To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration) cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.

  18. Active listening for spatial orientation in a complex auditory scene.

    Directory of Open Access Journals (Sweden)

    Cynthia F Moss

    2006-04-01

    Full Text Available To successfully negotiate a complex environment, an animal must control the timing of motor behaviors in coordination with dynamic sensory information. Here, we report on adaptive temporal control of vocal-motor behavior in an echolocating bat, Eptesicus fuscus, as it captured tethered insects close to background vegetation. Recordings of the bat's sonar vocalizations were synchronized with high-speed video images that were used to reconstruct the bat's three-dimensional flight path and the positions of target and vegetation. When the bat encountered the difficult task of taking insects as close as 10-20 cm from the vegetation, its behavior changed significantly from that under open room conditions. Its success rate decreased by about 50%, its time to initiate interception increased by a factor of ten, and its high repetition rate "terminal buzz" decreased in duration by a factor of three. Under all conditions, the bat produced prominent sonar "strobe groups," clusters of echolocation pulses with stable intervals. In the final stages of insect capture, the bat produced strobe groups at a higher incidence when the insect was positioned near clutter. Strobe groups occurred at all phases of the wingbeat (and inferred respiration cycle, challenging the hypothesis of strict synchronization between respiration and sound production in echolocating bats. The results of this study provide a clear demonstration of temporal vocal-motor control that directly impacts the signals used for perception.

  19. Explicit and spontaneous retrieval of emotional scenes: Electrophysiological correlates

    Science.gov (United States)

    Weymar, Mathias; Bradley, Margaret M.; El-Hinnawi, Nasryn; Lang, Peter J.

    2014-01-01

    When event-related potentials are measured during a recognition task, items that have previously been presented typically elicit a larger late (400–800 ms) positive potential than new items. Recent data, however, suggest that emotional, but not neutral, pictures show ERP evidence of spontaneous retrieval when presented in a free-viewing task (Ferrari, Bradley, Codispoti & Lang, 2012). In two experiments, we further investigated the brain dynamics of implicit and explicit retrieval. In Experiment 1, brain potentials were measured during a semantic categorization task, which did not explicitly probe episodic memory, but which, like a recognition task, required an active decision and a button press, and were compared to those elicited during recognition and free viewing. Explicit recognition prompted a late enhanced positivity for previously presented, compared to new, pictures regardless of hedonic content. In contrast, only emotional pictures showed an old-new difference when the task did not explicitly probe episodic memory, either when either making an active categorization decision regarding picture content, or when simply viewing pictures. In Experiment 2, however, neutral pictures did prompt a significant old-new ERP difference during subsequent free viewing when emotionally arousing pictures were not included in the encoding set. These data suggest that spontaneous retrieval is heightened for salient cues, perhaps reflecting heightened attention and elaborative processing at encoding. PMID:23795588

  20. Improving Remote Sensing Scene Classification by Integrating Global-Context and Local-Object Features

    Directory of Open Access Journals (Sweden)

    Dan Zeng

    2018-05-01

    Full Text Available Recently, many researchers have been dedicated to using convolutional neural networks (CNNs to extract global-context features (GCFs for remote-sensing scene classification. Commonly, accurate classification of scenes requires knowledge about both the global context and local objects. However, unlike the natural images in which the objects cover most of the image, objects in remote-sensing images are generally small and decentralized. Thus, it is hard for vanilla CNNs to focus on both global context and small local objects. To address this issue, this paper proposes a novel end-to-end CNN by integrating the GCFs and local-object-level features (LOFs. The proposed network includes two branches, the local object branch (LOB and global semantic branch (GSB, which are used to generate the LOFs and GCFs, respectively. Then, the concatenation of features extracted from the two branches allows our method to be more discriminative in scene classification. Three challenging benchmark remote-sensing datasets were extensively experimented on; the proposed approach outperformed the existing scene classification methods and achieved state-of-the-art results for all three datasets.

  1. Attention Switching during Scene Perception: How Goals Influence the Time Course of Eye Movements across Advertisements

    Science.gov (United States)

    Wedel, Michel; Pieters, Rik; Liechty, John

    2008-01-01

    Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a…

  2. Naturalness and image quality : chroma and hue variation in color images of natural scenes

    NARCIS (Netherlands)

    Ridder, de H.; Blommaert, F.J.J.; Fedorovskaya, E.A.; Rogowitz, B.E.; Allebach, J.P.

    1995-01-01

    The relation between perceptual image quality and naturalness was investigated by varying the colorfulness and hue of color images of natural scenes. These variations were created by digitizing the images, subsequently determining their color point distributions in the CIELUV color space and finally

  3. Naturalness and image quality: Chroma and hue variation in color images of natural scenes

    NARCIS (Netherlands)

    Ridder, de H.; Blommaert, F.J.J.; Fedorovskaya, E.A.; Eschbach, R.; Braun, K.

    1997-01-01

    The relation between perceptual image quality and natural ness was investigated by varying the colorfulness and hue of color images of natural scenes. These variations were created by digitizing the images, subsequently determining their color point distributions in the CIELUV color space and

  4. The effects of alcohol intoxication on attention and memory for visual scenes.

    Science.gov (United States)

    Harvey, Alistair J; Kneller, Wendy; Campbell, Alison C

    2013-01-01

    This study tests the claim that alcohol intoxication narrows the focus of visual attention on to the more salient features of a visual scene. A group of alcohol intoxicated and sober participants had their eye movements recorded as they encoded a photographic image featuring a central event of either high or low salience. All participants then recalled the details of the image the following day when sober. We sought to determine whether the alcohol group would pay less attention to the peripheral features of the encoded scene than their sober counterparts, whether this effect of attentional narrowing was stronger for the high-salience event than for the low-salience event, and whether it would lead to a corresponding deficit in peripheral recall. Alcohol was found to narrow the focus of foveal attention to the central features of both images but did not facilitate recall from this region. It also reduced the overall amount of information accurately recalled from each scene. These findings demonstrate that the concept of alcohol myopia originally posited to explain the social consequences of intoxication (Steele & Josephs, 1990) may be extended to explain the relative neglect of peripheral information during the processing of visual scenes.

  5. Cultural adaptation of visual attention: calibration of the oculomotor control system in accordance with cultural scenes.

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Ueda

    Full Text Available Previous studies have found that Westerners are more likely than East Asians to attend to central objects (i.e., analytic attention, whereas East Asians are more likely than Westerners to focus on background objects or context (i.e., holistic attention. Recently, it has been proposed that the physical environment of a given culture influences the cultural form of scene cognition, although the underlying mechanism is yet unclear. This study examined whether the physical environment influences oculomotor control. Participants saw culturally neutral stimuli (e.g., a dog in a park as a baseline, followed by Japanese or United States scenes, and finally culturally neutral stimuli again. The results showed that participants primed with Japanese scenes were more likely to move their eyes within a broader area and they were less likely to fixate on central objects compared with the baseline, whereas there were no significant differences in the eye movements of participants primed with American scenes. These results suggest that culturally specific patterns in eye movements are partly caused by the physical environment.

  6. Anticipation in Real-world Scenes: The Role of Visual Context and Visual Memory

    Science.gov (United States)

    Coco, Moreno I.; Keller, Frank; Malcolm, George L.

    2016-01-01

    The human sentence processor is able to make rapid predictions about upcoming linguistic input. For example, upon hearing the verb eat, anticipatory eye-movements are launched toward edible objects in a visual scene (Altmann & Kamide, 1999). However, the cognitive mechanisms that underlie anticipation remain to be elucidated in ecologically…

  7. Staging Scenes of Co-Cultural Communication: Acting out Aspects of Marginalized and Dominant Identities

    Science.gov (United States)

    Root, Elizabeth

    2018-01-01

    Courses: Intercultural Communication, Interracial Communication, or an Interpersonal Communication class that covers co-cultural theory. Objectives: Students will be able to demonstrate a practical application of co-cultural theory by creating scenes that illustrate different communicative approaches and desired outcomes based on communication…

  8. Campaign Documentaries: Behind-the-Scenes Perspectives Make Useful Teaching Tools

    Science.gov (United States)

    Wolfford, David

    2012-01-01

    Over the last 20 years, independent filmmakers have produced insightful documentaries of high profile political campaigns with behind-the-scenes footage. These documentaries offer inside looks and unique perspectives on electoral politics. This campaign season, consider "The War Room"; "A Perfect Candidate"; "Journeys With George;" "Chisholm '72";…

  9. Scene matching based on non-linear pre-processing on reference image and sensed image

    Institute of Scientific and Technical Information of China (English)

    Zhong Sheng; Zhang Tianxu; Sang Nong

    2005-01-01

    To solve the heterogeneous image scene matching problem, a non-linear pre-processing method for the original images before intensity-based correlation is proposed. The result shows that the proper matching probability is raised greatly. Especially for the low S/N image pairs, the effect is more remarkable.

  10. 77 FR 45378 - Guidelines for Cases Requiring On-Scene Death Investigation

    Science.gov (United States)

    2012-07-31

    ... DEPARTMENT OF JUSTICE Office of Justice Programs [OJP (NIJ) Docket No. 1600] Guidelines for Cases... entitled, ``Guidelines for Cases Requiring On-Scene Death Investigation''. The opportunity to provide comments on this document is open to coroner/medical examiner office representatives, law enforcement...

  11. Segmentation of RGB-D indoor scenes by stacking random forests and conditional random fields

    DEFF Research Database (Denmark)

    Thøgersen, Mikkel; Guerrero, Sergio Escalera; Gonzàlez, Jordi

    2016-01-01

    Depth images have granted new possibilities to computer vision researchers across the field. A prominent task is scene understanding and segmentation on which the present work is concerned. In this paper, we present a procedure combining well known methods in a unified learning framework based on...

  12. Explicit Foreground and Background Modeling in The Classification of Text Blocks in Scene Images

    NARCIS (Netherlands)

    Sriman, Bowornrat; Schomaker, Lambertus

    2015-01-01

    Achieving high accuracy for classifying foreground and background is an interesting challenge in the field of scene image analysis because of the wide range of illumination, complex background, and scale changes. Classifying fore- ground and background using bag-of-feature model gives a good result.

  13. General Text-Chunk Localization in Scene Images using a Codebook-based Classifier

    NARCIS (Netherlands)

    Sriman, Bowornrat; Schomaker, Lambertus; Pruksasri, Potchara

    Text localization is a main portal to character recognition in scene images. The detection of text regions in an image is a great challenge. However, many locating methods use a bottom-up scheme that consumes relatively high computation to identify the text regions. Therefore, this paper presents a

  14. Fixation and saliency during search of natural scenes: the case of visual agnosia.

    Science.gov (United States)

    Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

    2009-07-01

    Models of eye movement control in natural scenes often distinguish between stimulus-driven processes (which guide the eyes to visually salient regions) and those based on task and object knowledge (which depend on expectations or identification of objects and scene gist). In the present investigation, the eye movements of a patient with visual agnosia were recorded while she searched for objects within photographs of natural scenes and compared to those made by students and age-matched controls. Agnosia is assumed to disrupt the top-down knowledge available in this task, and so may increase the reliance on bottom-up cues. The patient's deficit in object recognition was seen in poor search performance and inefficient scanning. The low-level saliency of target objects had an effect on responses in visual agnosia, and the most salient region in the scene was more likely to be fixated by the patient than by controls. An analysis of model-predicted saliency at fixation locations indicated a closer match between fixations and low-level saliency in agnosia than in controls. These findings are discussed in relation to saliency-map models and the balance between high and low-level factors in eye guidance.

  15. Using Science Fiction Movie Scenes to Support Critical Analysis of Science

    Science.gov (United States)

    Barnett, Michael; Kafka, Alan

    2007-01-01

    This paper discusses pedagogical advantages and challenges of using science-fiction movies and television shows in an introductory science class for elementary teachers. The authors describe two instructional episodes in which scenes from the movies "Red Planet" and "The Core" were used to engage students in critiquing science as presented in…

  16. Training Small Networks for Scene Classification of Remote Sensing Images via Knowledge Distillation

    Directory of Open Access Journals (Sweden)

    Guanzhou Chen

    2018-05-01

    Full Text Available Scene classification, aiming to identify the land-cover categories of remotely sensed image patches, is now a fundamental task in the remote sensing image analysis field. Deep-learning-model-based algorithms are widely applied in scene classification and achieve remarkable performance, but these high-level methods are computationally expensive and time-consuming. Consequently in this paper, we introduce a knowledge distillation framework, currently a mainstream model compression method, into remote sensing scene classification to improve the performance of smaller and shallower network models. Our knowledge distillation training method makes the high-temperature softmax output of a small and shallow student model match the large and deep teacher model. In our experiments, we evaluate knowledge distillation training method for remote sensing scene classification on four public datasets: AID dataset, UCMerced dataset, NWPU-RESISC dataset, and EuroSAT dataset. Results show that our proposed training method was effective and increased overall accuracy (3% in AID experiments, 5% in UCMerced experiments, 1% in NWPU-RESISC and EuroSAT experiments for small and shallow models. We further explored the performance of the student model on small and unbalanced datasets. Our findings indicate that knowledge distillation can improve the performance of small network models on datasets with lower spatial resolution images, numerous categories, as well as fewer training samples.

  17. The Processing Speed of Scene Categorization at Multiple Levels of Description: The Superordinate Advantage Revisited.

    Science.gov (United States)

    Banno, Hayaki; Saiki, Jun

    2015-03-01

    Recent studies have sought to determine which levels of categories are processed first in visual scene categorization and have shown that the natural and man-made superordinate-level categories are understood faster than are basic-level categories. The current study examined the robustness of the superordinate-level advantage in a visual scene categorization task. A go/no-go categorization task was evaluated with response time distribution analysis using an ex-Gaussian template. A visual scene was categorized as either superordinate or basic level, and two basic-level categories forming a superordinate category were judged as either similar or dissimilar to each other. First, outdoor/ indoor groups and natural/man-made were used as superordinate categories to investigate whether the advantage could be generalized beyond the natural/man-made boundary. Second, a set of images forming a superordinate category was manipulated. We predicted that decreasing image set similarity within the superordinate-level category would work against the speed advantage. We found that basic-level categorization was faster than outdoor/indoor categorization when the outdoor category comprised dissimilar basic-level categories. Our results indicate that the superordinate-level advantage in visual scene categorization is labile across different categories and category structures. © 2015 SAGE Publications.

  18. Finding the Cause: Verbal Framing Helps Children Extract Causal Evidence Embedded in a Complex Scene

    Science.gov (United States)

    Butler, Lucas P.; Markman, Ellen M.

    2012-01-01

    In making causal inferences, children must both identify a causal problem and selectively attend to meaningful evidence. Four experiments demonstrate that verbally framing an event ("Which animals make Lion laugh?") helps 4-year-olds extract evidence from a complex scene to make accurate causal inferences. Whereas framing was unnecessary when…

  19. Something for everyone? Changes and choices in the ethno-party scene in urban nightlife

    NARCIS (Netherlands)

    de Bruin, S.

    2011-01-01

    The urban population is becoming increasingly diverse and growing (ethnic) diversity is having a singular effect on nightlife in Dutch cities. By studying the motivation behind and nightlife choices of the young people who participate in ethno-party scenes, Boogaarts-de Bruin investigates how the

  20. Detection of moving objects from a moving platform in urban scenes

    NARCIS (Netherlands)

    Haar, F.B. ter; Hollander, R.J.M. den; Dijk, J.

    2010-01-01

    Moving object detection in urban scenes is important for the guidance of autonomous vehicles, robot navigation, and monitoring. In this paper moving objects are automatically detected using three sequential frames and tracked over a longer period. To this extend we modify the plane+parallax,