WorldWideScience

Sample records for public domain image

  1. Public-domain software for root image analysis

    Directory of Open Access Journals (Sweden)

    Mirian Cristina Gomes Costa

    2014-10-01

    Full Text Available In the search for high efficiency in root studies, computational systems have been developed to analyze digital images. ImageJ and Safira are public-domain systems that may be used for image analysis of washed roots. However, differences in root properties measured using ImageJ and Safira are supposed. This study compared values of root length and surface area obtained with public-domain systems with values obtained by a reference method. Root samples were collected in a banana plantation in an area of a shallower Typic Carbonatic Haplic Cambisol (CXk, and an area of a deeper Typic Haplic Ta Eutrophic Cambisol (CXve, at six depths in five replications. Root images were digitized and the systems ImageJ and Safira used to determine root length and surface area. The line-intersect method modified by Tennant was used as reference; values of root length and surface area measured with the different systems were analyzed by Pearson's correlation coefficient and compared by the confidence interval and t-test. Both systems ImageJ and Safira had positive correlation coefficients with the reference method for root length and surface area data in CXk and CXve. The correlation coefficient ranged from 0.54 to 0.80, with lowest value observed for ImageJ in the measurement of surface area of roots sampled in CXve. The IC (95 % revealed that root length measurements with Safira did not differ from that with the reference method in CXk (-77.3 to 244.0 mm. Regarding surface area measurements, Safira did not differ from the reference method for samples collected in CXk (-530.6 to 565.8 mm² as well as in CXve (-4231 to 612.1 mm². However, measurements with ImageJ were different from those obtained by the reference method, underestimating length and surface area in samples collected in CXk and CXve. Both ImageJ and Safira allow an identification of increases or decreases in root length and surface area. However, Safira results for root length and surface area are

  2. Monitoring Urban Tree Cover Using Object-Based Image Analysis and Public Domain Remotely Sensed Data

    Directory of Open Access Journals (Sweden)

    Meghan Halabisky

    2011-10-01

    Full Text Available Urban forest ecosystems provide a range of social and ecological services, but due to the heterogeneity of these canopies their spatial extent is difficult to quantify and monitor. Traditional per-pixel classification methods have been used to map urban canopies, however, such techniques are not generally appropriate for assessing these highly variable landscapes. Landsat imagery has historically been used for per-pixel driven land use/land cover (LULC classifications, but the spatial resolution limits our ability to map small urban features. In such cases, hyperspatial resolution imagery such as aerial or satellite imagery with a resolution of 1 meter or below is preferred. Object-based image analysis (OBIA allows for use of additional variables such as texture, shape, context, and other cognitive information provided by the image analyst to segment and classify image features, and thus, improve classifications. As part of this research we created LULC classifications for a pilot study area in Seattle, WA, USA, using OBIA techniques and freely available public aerial photography. We analyzed the differences in accuracies which can be achieved with OBIA using multispectral and true-color imagery. We also compared our results to a satellite based OBIA LULC and discussed the implications of per-pixel driven vs. OBIA-driven field sampling campaigns. We demonstrated that the OBIA approach can generate good and repeatable LULC classifications suitable for tree cover assessment in urban areas. Another important finding is that spectral content appeared to be more important than spatial detail of hyperspatial data when it comes to an OBIA-driven LULC.

  3. PUBLIC DOMAIN PROTECTION. USES AND REUSES OF PUBLIC DOMAIN WORKS

    OpenAIRE

    Monica Adriana LUPAȘCU

    2015-01-01

    This study tries to highlight the necessity of an awareness of the right of access to the public domain, particularly using the example of works whose protection period has expired, as well as the ones which the law considers to be excluded from protection. Such works are used not only by large libraries from around the world, but also by rights holders, via different means of use, including incorporations into original works or adaptations. However, the reuse that follows these uses often on...

  4. Integrating NASA's Land Analysis System (LAS) image processing software with an appropriate Geographic Information System (GIS): A review of candidates in the public domain

    Science.gov (United States)

    Rochon, Gilbert L.

    1989-01-01

    A user requirements analysis (URA) was undertaken to determine and appropriate public domain Geographic Information System (GIS) software package for potential integration with NASA's LAS (Land Analysis System) 5.0 image processing system. The necessity for a public domain system was underscored due to the perceived need for source code access and flexibility in tailoring the GIS system to the needs of a heterogenous group of end-users, and to specific constraints imposed by LAS and its user interface, Transportable Applications Executive (TAE). Subsequently, a review was conducted of a variety of public domain GIS candidates, including GRASS 3.0, MOSS, IEMIS, and two university-based packages, IDRISI and KBGIS. The review method was a modified version of the GIS evaluation process, development by the Federal Interagency Coordinating Committee on Digital Cartography. One IEMIS-derivative product, the ALBE (AirLand Battlefield Environment) GIS, emerged as the most promising candidate for integration with LAS. IEMIS (Integrated Emergency Management Information System) was developed by the Federal Emergency Management Agency (FEMA). ALBE GIS is currently under development at the Pacific Northwest Laboratory under contract with the U.S. Army Corps of Engineers' Engineering Topographic Laboratory (ETL). Accordingly, recommendations are offered with respect to a potential LAS/ALBE GIS linkage and with respect to further system enhancements, including coordination with the development of the Spatial Analysis and Modeling System (SAMS) GIS in Goddard's IDM (Intelligent Data Management) developments in Goddard's National Space Science Data Center.

  5. NAIP Public Image Services

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — This map provides a preview and information about the National Agriculture Imagery Program (NAIP) image services available on the APFO public image server. Click on...

  6. MIVIS image geocoding experience on merging position attitude system data and public domain GPS stream (ASI-GeoDAF

    Directory of Open Access Journals (Sweden)

    S. Pignatti

    2006-06-01

    Full Text Available The use of airborne scanners involves geo-referencing problems, which are difficult because of the need to know the exact platform position and attitude for each scan line. The errors of the onboard navigation system are normally corrected using ground control point on the image. This post-processing correction procedure is too long in case of multiple flight campaigns, and besides it implies the need to have available 1:10000 orthophotoimages or maps in digital format. To optimize the above procedure a new method to correct MIVIS navigational data in the post-processing phase has been implemented. The procedure takes into consideration the GPS stream in Rinex format of common knowledge and findable on the web, acquired at the ground stations of the Geodetic Data Archiving Facilities provided by ASI. The application of this correction entails the assumption that the environmental variables affecting both onboard and geodetic GPS equally affect the position measurements. The airborne data correction was carried out merging the two data sets (onboard and ground station GPS to achieve a more precise aircraft trajectory. The present study compares the geo-coded images obtained by means of the two post-processing methods.

  7. Magnified time-domain ghost imaging

    Science.gov (United States)

    Ryczkowski, Piotr; Barbier, Margaux; Friberg, Ari T.; Dudley, John M.; Genty, Goëry

    2017-04-01

    Ghost imaging allows the imaging of an object without directly seeing this object. Originally demonstrated in the spatial domain, it was recently shown that ghost imaging can be transposed into the time domain to detect ultrafast signals, even in the presence of distortion. We propose and experimentally demonstrate a temporal ghost imaging scheme which generates a 5× magnified ghost image of an ultrafast waveform. Inspired by shadow imaging in the spatial domain and building on the dispersive Fourier transform of an incoherent supercontinuum in an optical fiber, the approach overcomes the resolution limit of standard time-domain ghost imaging generally imposed by the detectors speed. The method can be scaled up to higher magnification factors using longer fiber lengths and light source with shorter duration.

  8. Cultural Heritage and the Public Domain

    Directory of Open Access Journals (Sweden)

    Bas Savenije

    2012-09-01

    by providing their resources on the Internet” (Berlin Declaration 2003. Therefore, in the spirit of the Berlin Declaration, the ARL encourages its members’ libraries to grant all non-commercial users “a free, irrevocable, worldwide, right of access to, and a license to copy, use, distribute, transmit and display the work publicly and to make and distribute derivative works, in any digital medium for any responsible purpose, subject to proper attribution of authorship”. And: “If fees are to be assessed for the use of digitised public domain works, those fees should only apply to commercial uses” (ARL Principles July 2010. In our view, cultural heritage institutions should make public domain material digitised with public funding as widely available as possible for access and reuse. The public sector has the primary responsibility to fund digitisation. The involvement of private partners, however, is encouraged by ARL as well as the Comité des Sages. Private funding for digitisation is a complement to the necessary public investment, especially in times of economic crisis, but should not be seen as a substitute for public funding. As we can see from these reports there are a number of arguments in favour of digitisation and also of providing maximum accessibility to the digitised cultural heritage. In this paper we will investigate the legal aspects of digitisation of cultural heritage, especially public domain material. On the basis of these we will make an inventory of policy considerations regarding reuse. Furthermore, we will describe the conclusions the National Library of the Netherlands (hereafter: KB has formulated and the arguments that support these. In this context we will review public-private partnerships and also the policy of the KB. We will conclude with recommendations for cultural heritage institutions concerning a reuse policy for digitised public domain material.

  9. Image sharpening in the JPEG domain.

    Science.gov (United States)

    Konstantinides, K; Bhaskaran, V; Beretta, G

    1999-01-01

    We present a new technique for sharpening compressed images in the discrete-cosine-transform domain. For images compressed using the JPEG standard, image sharpening is achieved by suitably scaling each element of the encoding quantization table to enhance the high-frequency characteristics of the image. The modified version of the encoding table is then transmitted in lieu of the original. Experimental results with scanned images show improved text and image quality with no additional computation cost and without affecting compressibility.

  10. Domain imaging in FINEMET ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Silveyra, J.M., E-mail: jsilveyra@fi.uba.a [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, UBA-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina); Vlasak, G.; Svec, P.; Janickovic, D. [Institute of Physics, Slovak Academy of Sciences, Dubravska cesta 9, 845 11 Bratislava (Slovakia); Cremaschi, V.J., E-mail: vcremas@gmail.co [Laboratorio de Solidos Amorfos, INTECIN, Facultad de Ingenieria, UBA-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina); Member of Carrera del Investigador, CONICET (Argentina)

    2010-09-15

    The magnetization behaviour of a ferromagnetic material depends on its domain structure, which in turn is largely determined by magnetic anisotropies. In this work, domain patterns were observed by a quite forgotten but still the simplest and the cheapest technique: the Bitter method. A systematic study of the evolution of the domain structure in FINEMET ribbons after thermal annealing is presented, correlating the results with the crystalline structure, magnetostriction and coercivity measurements.

  11. Frequency Domain Image Filtering Using CUDA

    Directory of Open Access Journals (Sweden)

    Muhammad Awais Rajput

    2014-10-01

    Full Text Available In this paper, we investigate the implementation of image filtering in frequency domain using NVIDIA?s CUDA (Compute Unified Device Architecture. In contrast to signal and image filtering in spatial domain which uses convolution operations and hence is more compute-intensive for filters having larger spatial extent, the frequency domain filtering uses FFT (Fast Fourier Transform which is much faster and significantly reduces the computational complexity of the filtering. We implement the frequency domain filtering on CPU and GPU respectively and analyze the speed-up obtained from the CUDA?s parallel processing paradigm. In order to demonstrate the efficiency of frequency domain filtering on CUDA, we implement three frequency domain filters, i.e., Butterworth, low-pass and Gaussian for processing different sizes of images on CPU and GPU respectively and perform the GPU vs. CPU benchmarks. The results presented in this paper show that the frequency domain filtering with CUDA achieves significant speed-up over the CPU processing in frequency domain with the same level of (output image quality on both the processing architectures

  12. Preserving the positive functions of the public domain in science

    Directory of Open Access Journals (Sweden)

    Pamela Samuelson

    2003-11-01

    Full Text Available Science has advanced in part because data and scientific methodologies have traditionally not been subject to intellectual property protection. In recent years, intellectual property has played a greater role in scientific work. While intellectual property rights may have a positive role to play in some fields of science, so does the public domain. This paper will discuss some of the positive functions of the public domain and ways in which certain legal developments may negatively impact the public domain. It suggests some steps that scientists can take to preserve the positive functions of the public domain for science.

  13. Differential ghost imaging in time domain

    Science.gov (United States)

    O-oka, Yoshiki; Fukatsu, Susumu

    2017-08-01

    Differential ghost imaging is attempted in time domain, i.e., temporal differential ghost imaging (TDGI), using pseudo-randomized light pulses and a temporal object consisting of no-return-to-zero bit patterns of varying duty. Evaluation of the signal-to-noise characteristics by taking into account errors due to false cross-correlation between the reference and the bucket detector readings indicates that the TDGI outperforms its non-differential counterpart, i.e., time-domain GI, in terms of consistently high and even duty-independent signal-to-noise ratios that are achieved.

  14. Robust color image hiding method in DCT domain

    Institute of Scientific and Technical Information of China (English)

    LI Qing-zhong; YU Chen; CHU Dong-sheng

    2006-01-01

    This paper presents a robust color image hiding method based on YCbCr color system in discrete cosine transform (DCT) domain,which can hide a secret color image behind a public color cover image and is compatible with the international image compression standard of JPEG.To overcome the grave distortion problem in the restored secret image,this paper proposes a new embedding scheme consisting of reasonable partition of a pixel value and sign embedding.Moreover,based on human visual system (HVS) and fuzzy theory,this paper also presents a fuzzy classification method for DCT sub-blocks to realize the adaptive selection of embedding strength.The experimental results show that the maximum distortion error in pixel value for the extracted secret image is ±1.And the color cover image can provide good quality after embedding large amount of data.

  15. Bregmanized Domain Decomposition for Image Restoration

    KAUST Repository

    Langer, Andreas

    2012-05-22

    Computational problems of large-scale data are gaining attention recently due to better hardware and hence, higher dimensionality of images and data sets acquired in applications. In the last couple of years non-smooth minimization problems such as total variation minimization became increasingly important for the solution of these tasks. While being favorable due to the improved enhancement of images compared to smooth imaging approaches, non-smooth minimization problems typically scale badly with the dimension of the data. Hence, for large imaging problems solved by total variation minimization domain decomposition algorithms have been proposed, aiming to split one large problem into N > 1 smaller problems which can be solved on parallel CPUs. The N subproblems constitute constrained minimization problems, where the constraint enforces the support of the minimizer to be the respective subdomain. In this paper we discuss a fast computational algorithm to solve domain decomposition for total variation minimization. In particular, we accelerate the computation of the subproblems by nested Bregman iterations. We propose a Bregmanized Operator Splitting-Split Bregman (BOS-SB) algorithm, which enforces the restriction onto the respective subdomain by a Bregman iteration that is subsequently solved by a Split Bregman strategy. The computational performance of this new approach is discussed for its application to image inpainting and image deblurring. It turns out that the proposed new solution technique is up to three times faster than the iterative algorithm currently used in domain decomposition methods for total variation minimization. © Springer Science+Business Media, LLC 2012.

  16. The Definition, Dimensions, and Domain of Public Relations.

    Science.gov (United States)

    Hutton, James G.

    1999-01-01

    Discusses how the field of public relations has left itself vulnerable to other fields that are making inroads into public relations' traditional domain, and to critics who are filling in their own definitions of public relations. Proposes a definition and a three-dimensional framework to compare competing philosophies of public relations and to…

  17. A Secure Public-key Image Authentication Plan

    Institute of Scientific and Technical Information of China (English)

    YANG Qing; CHEN Ke-fei

    2005-01-01

    Digital watermark can be used for image ownership verification or authentication. In this paper, we propose a new image authentication plan concentrating on its security performance. Digital watermark is first turbo coded, scaled and then processed in wavelet domain. To enhance security level, public key cryptosystem is utilized to replace traditional watermark key. Simulation results are finally given by experiment.

  18. Navigation domain representation for interactive multiview imaging.

    Science.gov (United States)

    Maugey, Thomas; Daribo, Ismael; Cheung, Gene; Frossard, Pascal

    2013-09-01

    Enabling users to interactively navigate through different viewpoints of a static scene is a new interesting functionality in 3D streaming systems. While it opens exciting perspectives toward rich multimedia applications, it requires the design of novel representations and coding techniques to solve the new challenges imposed by the interactive navigation. In particular, the encoder must prepare a priori a compressed media stream that is flexible enough to enable the free selection of multiview navigation paths by different streaming media clients. Interactivity clearly brings new design constraints: the encoder is unaware of the exact decoding process, while the decoder has to reconstruct information from incomplete subsets of data since the server generally cannot transmit images for all possible viewpoints due to resource constrains. In this paper, we propose a novel multiview data representation that permits us to satisfy bandwidth and storage constraints in an interactive multiview streaming system. In particular, we partition the multiview navigation domain into segments, each of which is described by a reference image (color and depth data) and some auxiliary information. The auxiliary information enables the client to recreate any viewpoint in the navigation segment via view synthesis. The decoder is then able to navigate freely in the segment without further data request to the server; it requests additional data only when it moves to a different segment. We discuss the benefits of this novel representation in interactive navigation systems and further propose a method to optimize the partitioning of the navigation domain into independent segments, under bandwidth and storage constraints. Experimental results confirm the potential of the proposed representation; namely, our system leads to similar compression performance as classical inter-view coding, while it provides the high level of flexibility that is required for interactive streaming. Because of

  19. Image and video processing in the compressed domain

    CERN Document Server

    Mukhopadhyay, Jayanta

    2011-01-01

    As more images and videos are becoming available in compressed formats, researchers have begun designing algorithms for different image operations directly in their domains of representation, leading to faster computation and lower buffer requirements. Image and Video Processing in the Compressed Domain presents the fundamentals, properties, and applications of a variety of image transforms used in image and video compression. It illustrates the development of algorithms for processing images and videos in the compressed domain. Developing concepts from first principles, the book introduces po

  20. Development and Initial Validation of Public Domain Basic Interest Markers

    Science.gov (United States)

    Liao, Hsin-Ya; Armstrong, Patrick Ian; Rounds, James

    2008-01-01

    Goldberg (Goldberg, L. R. (1999). "A broad-bandwidth, public-domain, personality inventory measuring the lower-level facets of several five-factor models." In: I. Mervielde, I. Deary, F. De Fruyt, & F. Ostendorf (Eds.), "Personality psychology in Europe" (Vol. 7, pp. 7-28). Tilburg, The Netherlands: Tilburg University Press) has argued that the…

  1. Imaging scattering orientation with spatial frequency domain imaging.

    Science.gov (United States)

    Konecky, Soren D; Rice, Tyler; Durkin, Anthony J; Tromberg, Bruce J

    2011-12-01

    Optical imaging techniques based on multiple light scattering generally have poor sensitivity to the orientation and direction of microscopic light scattering structures. In order to address this limitation, we introduce a spatial frequency domain method for imaging contrast from oriented scattering structures by measuring the angular-dependence of structured light reflectance. The measurement is made by projecting sinusoidal patterns of light intensity on a sample, and measuring the degree to which the patterns are blurred as a function of the projection angle. We derive a spatial Fourier domain solution to an anisotropic diffusion model. This solution predicts the effects of bulk scattering orientation on the amplitude and phase of the projected patterns. We introduce a new contrast function based on a scattering orientation index (SOI) which is sensitive to the degree to which light scattering is directionally dependent. We validate the technique using tissue simulating phantoms, and ex vivo samples of muscle and brain. Our results show that SOI is independent of the overall amount of bulk light scattering and absorption, and that isotropic versus oriented scattering structures can be clearly distinguished. We determine the orientation of subsurface microscopic scattering structures located up to 600 μm beneath highly scattering (μ(') (s) = 1.5 mm(-1)) material.

  2. Second-harmonic imaging of ferroelectric domain walls

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Hvam, Jørn Märcher; Pedersen, Kjeld;

    1998-01-01

    Domain walls in periodically poled ferroelectric KTiOPO4 and LiNbO3 crystals are observed by making use of second-harmonic (SH) generation enhancement in the transition regions between neighboring domains. SH images of domain walls obtained with various samples for different polarization...

  3. Copyright and the Value of the Public Domain

    OpenAIRE

    Erickson, Kristofer; Heald, Paul; Homberg, Fabian; Kretschmer, Martin; Mendis, Dinusha

    2015-01-01

    This research report documents the results of a year-long knowledge exchange initiative undertaken between the Intellectual Property Office, researchers at the University of Glasgow CREATe Centre, and more than two dozen UK businesses and innovators, to explore how value is generated from the public domain. The study was supported by the Economic and Social Research Council (ESRC) and the Intellectual Property Office (IPO). The core research team consisted of Dr. Kristofer Erickson (Lord Kelv...

  4. Comparison of Satellite Image Enhancement Techniques in Wavelet Domain

    Directory of Open Access Journals (Sweden)

    K. Narasimhan

    2012-12-01

    Full Text Available In this study, a comparison of various existing satellite image resolution enhancement techniques in wavelet domain is done. Each method is analysed quantitatively and visually. There are various wavelet domain based methods such as Wavelet Zero Padding, Dual Tree-Complex Wavelet Transform, Discrete Wavelet Transform, Cycle Spinning and Undecimated Wavelet Transform. On the basis of analysis, the most efficient method is proposed. The algorithms take the low resolution image as the input image and then wavelet transformation using daubechies (db3 is used to decompose the input image into different sub band images containing high and low frequency component. Then these subband images along with the input image are interpolated followed by combining all these images to generate a new resolution enhanced image by an inverse process.

  5. Image Fusion Using Pca in Cs Domain

    Directory of Open Access Journals (Sweden)

    M. T. Sadeghi

    2012-09-01

    Full Text Available Compressive sampling (CS, also called Compressed Sensing, has generated a tremendous amount of excitement in the image processing community. It provides an alternative to Shannon/Nyquist sampling when the signal under acquisition is known to be sparse or compressible. In this paper, we propose a new efficient image fusion method for compressed sensing imaging. In this method, we calculate the twodimensional discrete cosine transform of multiple input images, these achieved measurements are multiplied with sampling filter, so compressed images are obtained. we take inverse discrete cosine transform of them. Finally, fused image achieves from these results by using PCA fusion method. This approach also is implemented for multi-focus and noisy images. Simulation results show that our methodprovides promising fusion performance in both visual comparison and comparison using objective measures. Moreover, because this method does not need to recovery process the computational time is decreased very much.

  6. Image Credibility Analysis with Effective Domain Transferred Deep Networks

    OpenAIRE

    Jin, Zhiwei; Cao, Juan; Luo, Jiebo; Zhang, Yongdong

    2016-01-01

    Numerous fake images spread on social media today and can severely jeopardize the credibility of online content to public. In this paper, we employ deep networks to learn distinct fake image related features. In contrast to authentic images, fake images tend to be eye-catching and visually striking. Compared with traditional visual recognition tasks, it is extremely challenging to understand these psychologically triggered visual patterns in fake images. Traditional general image classificati...

  7. Agents unleashed a public domain look at agent technology

    CERN Document Server

    Wayner, Peter

    1995-01-01

    Agents Unleashed: A Public Domain Look at Agent Technology covers details of building a secure agent realm. The book discusses the technology for creating seamlessly integrated networks that allow programs to move from machine to machine without leaving a trail of havoc; as well as the technical details of how an agent will move through the network, prove its identity, and execute its code without endangering the host. The text also describes the organization of the host's work processing an agent; error messages, bad agent expulsion, and errors in XLISP-agents; and the simulators of errors, f

  8. Fourier domain OCT imaging of American cockroach nervous system

    Science.gov (United States)

    Wyszkowska, Joanna; Gorczynska, Iwona; Ruminski, Daniel; Karnowski, Karol; Kowalczyk, Andrzej; Stankiewicz, Maria; Wojtkowski, Maciej

    2012-01-01

    In this pilot study we demonstrate results of structural Fourier domain OCT imaging of the nervous system of Periplaneta americana L. (American cockroach). The purpose of this research is to develop an OCT apparatus enabling structural imaging of insect neural system. Secondary purpose of the presented research is to develop methods of the sample preparation and handling during the OCT imaging experiments. We have performed imaging in the abdominal nerve cord excised from the American cockroach. For this purpose we have developed a Fourier domain / spectral OCT system operating at 820 nm wavelength range.

  9. Low energy electron imaging of domains and domain walls in magnesium-doped lithium niobate

    Science.gov (United States)

    Nataf, G. F.; Grysan, P.; Guennou, M.; Kreisel, J.; Martinotti, D.; Rountree, C. L.; Mathieu, C.; Barrett, N.

    2016-09-01

    The understanding of domain structures, specifically domain walls, currently attracts a significant attention in the field of (multi)-ferroic materials. In this article, we analyze contrast formation in full field electron microscopy applied to domains and domain walls in the uniaxial ferroelectric lithium niobate, which presents a large 3.8 eV band gap and for which conductive domain walls have been reported. We show that the transition from Mirror Electron Microscopy (MEM - electrons reflected) to Low Energy Electron Microscopy (LEEM - electrons backscattered) gives rise to a robust contrast between domains with upwards (Pup) and downwards (Pdown) polarization, and provides a measure of the difference in surface potential between the domains. We demonstrate that out-of-focus conditions of imaging produce contrast inversion, due to image distortion induced by charged surfaces, and also carry information on the polarization direction in the domains. Finally, we show that the intensity profile at domain walls provides experimental evidence for a local stray, lateral electric field.

  10. Low energy electron imaging of domains and domain walls in magnesium-doped lithium niobate

    Science.gov (United States)

    Nataf, G. F.; Grysan, P.; Guennou, M.; Kreisel, J.; Martinotti, D.; Rountree, C. L.; Mathieu, C.; Barrett, N.

    2016-01-01

    The understanding of domain structures, specifically domain walls, currently attracts a significant attention in the field of (multi)-ferroic materials. In this article, we analyze contrast formation in full field electron microscopy applied to domains and domain walls in the uniaxial ferroelectric lithium niobate, which presents a large 3.8 eV band gap and for which conductive domain walls have been reported. We show that the transition from Mirror Electron Microscopy (MEM – electrons reflected) to Low Energy Electron Microscopy (LEEM – electrons backscattered) gives rise to a robust contrast between domains with upwards (Pup) and downwards (Pdown) polarization, and provides a measure of the difference in surface potential between the domains. We demonstrate that out-of-focus conditions of imaging produce contrast inversion, due to image distortion induced by charged surfaces, and also carry information on the polarization direction in the domains. Finally, we show that the intensity profile at domain walls provides experimental evidence for a local stray, lateral electric field. PMID:27608605

  11. A novel statistical fusion rule for image fusion and its comparison in non subsampled contourlet transform domain and wavelet domain

    CERN Document Server

    T, Manu V

    2012-01-01

    Image fusion produces a single fused image from a set of input images. A new method for image fusion is proposed based on Weighted Average Merging Method (WAMM) in the NonSubsampled Contourlet Transform (NSCT) domain. A performance analysis on various statistical fusion rules are also analysed both in NSCT and Wavelet domain. Analysis has been made on medical images, remote sensing images and multi focus images. Experimental results shows that the proposed method, WAMM obtained better results in NSCT domain than the wavelet domain as it preserves more edges and keeps the visual quality intact in the fused image.

  12. Image-domain full waveform inversion: Field data example

    KAUST Repository

    Zhang, Sanzong

    2014-08-05

    The main difficulty with the data-domain full waveform inversion (FWI) is that it tends to get stuck in the local minima associated with the waveform misfit function. This is the result of cycle skipping which degrades the low-wavenumber update in the absence of low-frequencies and long-offset data. An image-domain objective function is defined as the normed difference between the predicted and observed common image gathers (CIGs) in the subsurface offset domain. This new objective function is not constrained by cycle skipping at the far subsurface offsets. To test the effectiveness of this method, we apply it to marine data recorded in the Gulf of Mexico. Results show that image-domain FWI is less sensitive to the initial model and the absence of low-frequency data compared with conventional FWI. The liability, however, is that it is almost an order of magnitude more expensive than standard FWI.

  13. A Visible Watermarking Scheme for Digital Images in Frequency Domain

    Directory of Open Access Journals (Sweden)

    D.R.Denslin Brabin

    2012-11-01

    Full Text Available A novel method is proposed for visible watermarking of digital image in frequency domain. The method is based on DCT modification of original image with respect to watermark image. The host image pixels are transformed into frequency coefficients as well as the watermark image pixels are also transformed into frequency coefficients using DCT. The compound mapping function is used to adjust the pixel values close to those of desired visible watermarks. Thus the watermarking is done in frequency domain using compound mapping function. One who has the watermark image and mapping function parameters only can remove the watermark. Thus it enhances the security. Experimental results demonstrate the effectiveness of the proposed approach.

  14. Imaging domains in transmission electron microscopy (invited) (abstract)

    Science.gov (United States)

    Mishra, R. K.

    1987-04-01

    Magnetic domain walls and domains inside thin electron transparent specimens of ferromagnetic materials can be imaged using the Fresnel and Focault techniques in a transmission electron microscope. Combined with the diffraction, microstructural and microchemical capabilities of modern microscopes, Lorentz microscopy offers one of the most powerful tools to study structure-property relationships in magnetic materials. In addition, using this technique, it is possible to deduce the local magnetization distribution around inhomogeneities and complex Bloch and Néel walls. Lorentz images can be used to quantitatively measure domain wall thickness and estimate domain wall energy. With modified sample holders and pole pieces, one can study in situ domain wall motion and the interaction of domains with microstructural features such as second phases, grain boundaries, structural defects, etc. All these will be illustrated with examples of Lorentz images from soft and hard magnets with special emphasis on the Nd-Fe-B hard magnets. Finally, the limitations of the Lorentz imaging technique utilizing the deflected electron intensities will be outlined and a new technique which utilizes the phase changes in the electron beam as it passes through the material in a scanning transmission microscope will be reviewed.

  15. A novel statistical fusion rule for image fusion and its comparison in non subsampled contourlet transform domain and wavelet domain

    OpenAIRE

    Manu V T; Philomina Simon

    2012-01-01

    Image fusion produces a single fused image from a set of input images. A new method for image fusion is proposed based on Weighted Average Merging Method (WAMM) in the Non Subsampled Contourlet Transform (NSCT) domain. A performance analysis on various statistical fusion rules are also analysed both in NSCT and Wavelet domain. Analysis has been made on medical images, remote sensing images and multi focus images. Experimental results shows that the proposed method, WAMM obtained better resu...

  16. Transparent Image Watermarking in the Wavelet Domain

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Digital watermarking has been proposed as a viable solution to protect the copyright of multime-dia data in a networked environment, since it makes possible to embed identification codes into a digital docu-ment. This paper proposes a new scheme for image watermarking in which a watermark is embedded in a se-lected set of wavelet transform coefficients. To ensure the watermark invisibility with high robustness, a bi-nary pseudo-random sequence is embedded into significant wavelet coefficients by exploiting Embedded Ze-rotree Wavelet (EZW) coding algorithm. Experimental results show the effectiveness of this technique.

  17. Materialities of Law: Celebrity Production and the Public Domain

    Directory of Open Access Journals (Sweden)

    Esther Milne

    2009-12-01

    Full Text Available Celebrity production and consumption are powerful socio-economic forces. The celebrity functions as a significant economic resource for the commercial sector and plays a fundamental symbolic role within culture by providing a shared ‘vocabulary’ through which to understand contemporary social relations. A pivotal element of this allure is the process by which the celebrity figure is able to forge an intimate link with its audience, often producing public expressions of profound compassion, respect or revulsion. This process, however, is complicated by emerging participatory media forms whose impact is experienced as new conditions of possibility for celebrity production and consumption. As Marshall argues, video mash-ups of celebrity interviews, such as those of Christian Bale or Tom Cruise, are dramatically changing the relation between celebrity and audience (Marshall, 2006: 640. Meanings produced by these audience remixes challenge the extent to which a celebrity might control her image. So is the celebrity personality, therefore, a public or private commodity? Who owns the celebrity image within remix culture? Although the celebrity figure has been thoroughly researched in relation to its patterns of consumption; semiotic power; and industry construction; less attention has been focused on the forms of celebrity governance enabled by legislative and case law settings. How might the law deal with the significant economic and cultural power exercised within celebrity culture?

  18. High-speed optical frequency-domain imaging

    OpenAIRE

    Yun, S. H.; Tearney, G. J.; Boer; Iftimia, N. V.; Bouma, B. E.

    2003-01-01

    We demonstrate high-speed, high-sensitivity, high-resolution optical imaging based on optical frequency-domain interferometry using a rapidly-tuned wavelength-swept laser. We derive and show experimentally that frequency-domain ranging provides a superior signal-to-noise ratio compared with conventional time-domain ranging as used in optical coherence tomography. A high sensitivity of −110 dB was obtained with a 6 mW source at an axial resolution of 13.5 µm and an A-line rate of 15.7 kHz, rep...

  19. Image Resolution Enhancement using DWT and Spatial Domain Interpolation Technique

    Directory of Open Access Journals (Sweden)

    Mrs. G. Padma Priya

    2016-02-01

    Full Text Available Image Resolution is one of the important quality metrics of images. Images with high resolution are required in many fields. In this paper, a new resolution enhancement technique is proposed based on the interpolation of four sub band images generated by Discrete Wavelet Transform (DWT and the original Low Resolution (LR input image. In this technique, the four sub band images generated by DWT and the input LR image are interpolated with scaling factor, α and then performed inverse DWT to obtain the intermediate High Resolution (HR Image. The difference between the intermediate HR image and the interpolated LR input image is added to the intermediate HR image to obtain final output HR Image. Lanczos interpolation is used in this technique. The proposed technique is tested on well known bench mark images. The quantitative and visual results shows the superiority of the proposed technique over the conventional and state of art image resolution enhancement techniques in wavelet domain using haar wavelet filter.

  20. Social Media Image Analysis for Public Health

    OpenAIRE

    2015-01-01

    Several projects have shown the feasibility to use textual social media data to track public health concerns, such as temporal influenza patterns or geographical obesity patterns. In this paper, we look at whether geo-tagged images from Instagram also provide a viable data source. Especially for "lifestyle" diseases, such as obesity, drinking or smoking, images of social gatherings could provide information that is not necessarily shared in, say, tweets. In this study, we explore whether (i) ...

  1. PCNN-Based Image Fusion in Compressed Domain

    Directory of Open Access Journals (Sweden)

    Yang Chen

    2015-01-01

    Full Text Available This paper addresses a novel method of image fusion problem for different application scenarios, employing compressive sensing (CS as the image sparse representation method and pulse-coupled neural network (PCNN as the fusion rule. Firstly, source images are compressed through scrambled block Hadamard ensemble (SBHE for its compression capability and computational simplicity on the sensor side. Local standard variance is input to motivate PCNN and coefficients with large firing times are selected as the fusion coefficients in compressed domain. Fusion coefficients are smoothed by sliding window in order to avoid blocking effect. Experimental results demonstrate that the proposed fusion method outperforms other fusion methods in compressed domain and is effective and adaptive in different image fusion applications.

  2. RADIANCE DOMAIN COMPOSITING FOR HIGH DYNAMIC RANGE IMAGING

    Directory of Open Access Journals (Sweden)

    M.R. Renu

    2013-02-01

    Full Text Available High dynamic range imaging aims at creating an image with a range of intensity variations larger than the range supported by a camera sensor. Most commonly used methods combine multiple exposure low dynamic range (LDR images, to obtain the high dynamic range (HDR image. Available methods typically neglect the noise term while finding appropriate weighting functions to estimate the camera response function as well as the radiance map. We look at the HDR imaging problem in a denoising frame work and aim at reconstructing a low noise radiance map from noisy low dynamic range images, which is tone mapped to get the LDR equivalent of the HDR image. We propose a maximum aposteriori probability (MAP based reconstruction of the HDR image using Gibb’s prior to model the radiance map, with total variation (TV as the prior to avoid unnecessary smoothing of the radiance field. To make the computation with TV prior efficient, we extend the majorize-minimize method of upper bounding the total variation by a quadratic function to our case which has a nonlinear term arising from the camera response function. A theoretical justification for doing radiance domain denoising as opposed to image domain denoising is also provided.

  3. Medical Image Steganography: Study of Medical Image Quality Degradation when Embedding Data in the Frequency Domain

    Directory of Open Access Journals (Sweden)

    M.I.Khalil

    2017-02-01

    Full Text Available Steganography is the discipline of invisible communication by hiding the exchanged secret information (message in another digital information media (image, video or audio. The existence of the message is kept indiscernible in sense that no one, other than the intended recipient, suspects the existence of the message. The majority of steganography techniques are implemented either in spatial domain or in frequency domain of the digital images while the embedded information can be in the form of plain or cipher message. Medical image steganography is classified as a distinctive case of image steganography in such a way that both the image and the embedded information have special requirements such as achieving utmost clarity reading of the medical images and the embedded messages. There is a contention between the amount of hidden information and the caused detectable distortion of image. The current paper studies the degradation of the medical image when undergoes the steganography process in the frequency domain.

  4. An efficient multiple exposure image fusion in JPEG domain

    Science.gov (United States)

    Hebbalaguppe, Ramya; Kakarala, Ramakrishna

    2012-01-01

    In this paper, we describe a method to fuse multiple images taken with varying exposure times in the JPEG domain. The proposed algorithm finds its application in HDR image acquisition and image stabilization for hand-held devices like mobile phones, music players with cameras, digital cameras etc. Image acquisition at low light typically results in blurry and noisy images for hand-held camera's. Altering camera settings like ISO sensitivity, exposure times and aperture for low light image capture results in noise amplification, motion blur and reduction of depth-of-field respectively. The purpose of fusing multiple exposures is to combine the sharp details of the shorter exposure images with high signal-to-noise-ratio (SNR) of the longer exposure images. The algorithm requires only a single pass over all images, making it efficient. It comprises of - sigmoidal boosting of shorter exposed images, image fusion, artifact removal and saturation detection. Algorithm does not need more memory than a single JPEG macro block to be kept in memory making it feasible to be implemented as the part of a digital cameras hardware image processing engine. The Artifact removal step reuses the JPEGs built-in frequency analysis and hence benefits from the considerable optimization and design experience that is available for JPEG.

  5. Finite homomorphic images of Bezout duo-domains

    Directory of Open Access Journals (Sweden)

    O. S. Sorokin

    2014-12-01

    Full Text Available It is proved that for a quasi-duo Bezout ring of stable range 1 the duo-ring condition is equivalent to being an elementary divisor ring. As an application of this result a couple of useful properties are obtained for finite homomorphic images of Bezout duo-domains: they are coherent morphic rings, all injective modules over them are flat, their weak global dimension is either 0 or infinity. Moreover, we introduce the notion of square-free element in noncommutativecase and it is shown that they are adequate elements of Bezout duo-domains. In addition, we are going to prove that these elements are elements of almost stable range 1, as well as necessary and sufficient conditions for being square-free element are found in terms of regularity, Jacobson semisimplicity, and boundness of weak global dimension of finite homomorphic images of Bezout duo-domains.

  6. Natural language processing and visualization in the molecular imaging domain.

    Science.gov (United States)

    Tulipano, P Karina; Tao, Ying; Millar, William S; Zanzonico, Pat; Kolbert, Katherine; Xu, Hua; Yu, Hong; Chen, Lifeng; Lussier, Yves A; Friedman, Carol

    2007-06-01

    Molecular imaging is at the crossroads of genomic sciences and medical imaging. Information within the molecular imaging literature could be used to link to genomic and imaging information resources and to organize and index images in a way that is potentially useful to researchers. A number of natural language processing (NLP) systems are available to automatically extract information from genomic literature. One existing NLP system, known as BioMedLEE, automatically extracts biological information consisting of biomolecular substances and phenotypic data. This paper focuses on the adaptation, evaluation, and application of BioMedLEE to the molecular imaging domain. In order to adapt BioMedLEE for this domain, we extend an existing molecular imaging terminology and incorporate it into BioMedLEE. BioMedLEE's performance is assessed with a formal evaluation study. The system's performance, measured as recall and precision, is 0.74 (95% CI: [.70-.76]) and 0.70 (95% CI [.63-.76]), respectively. We adapt a JAVA viewer known as PGviewer for the simultaneous visualization of images with NLP extracted information.

  7. Enhancement of Hyperspectral Real World Images Using Hybrid Domain Approach

    Directory of Open Access Journals (Sweden)

    Shyam Lal

    2013-04-01

    Full Text Available This paper presents enhancement of hyperspectral real world images using hybrid domain approach. The proposed method consists of three phases: In first phase the discrete wavelet transform is applied and approximation coefficient is selected. In second phase approximation coefficient of discrete wavelet transform of image is process by automatic contrast adjustment technique and in third phase it takes logarithmic of output of second phase and after that adaptive filtering is applied for image enhancement in frequency domain. To judge the superiority of proposed method the image quality parameters such as measure of enhancement (EME and measure of enhancement factor (EMF is evaluated. Therefore, a better value of EME and EMF implies that the visual quality of the enhanced image is good. Simulation results indicates that proposed method provides better results as compared to other state-of-art contrast enhancement algorithms for hyperspectral real world images. The proposed method is efficient and very effective method for contrast enhancement of hyperspectral real world images. This method can also be used in different applications where images are suffering from different contrast problems.

  8. Millimeter wave imaging system modeling: spatial frequency domain calculation versus spatial domain calculation.

    Science.gov (United States)

    Qi, Feng; Tavakol, Vahid; Ocket, Ilja; Xu, Peng; Schreurs, Dominique; Wang, Jinkuan; Nauwelaers, Bart

    2010-01-01

    Active millimeter wave imaging systems have become a promising candidate for indoor security applications and industrial inspection. However, there is a lack of simulation tools at the system level. We introduce and evaluate two modeling approaches that are applied to active millimeter wave imaging systems. The first approach originates in Fourier optics and concerns the calculation in the spatial frequency domain. The second approach is based on wave propagation and corresponds to calculation in the spatial domain. We compare the two approaches in the case of both rough and smooth objects and point out that the spatial frequency domain calculation may suffer from a large error in amplitude of 50% in the case of rough objects. The comparison demonstrates that the concepts of point-spread function and f-number should be applied with careful consideration in coherent millimeter wave imaging systems. In the case of indoor applications, the near-field effect should be considered, and this is included in the spatial domain calculation.

  9. Secured color image watermarking technique in DWT-DCT domain

    CERN Document Server

    Gunjal, Baisa L

    2011-01-01

    The multilayer secured DWT-DCT and YIQ color space based image watermarking technique with robustness and better correlation is presented here. The security levels are increased by using multiple pn sequences, Arnold scrambling, DWT domain, DCT domain and color space conversions. Peak signal to noise ratio and Normalized correlations are used as measurement metrics. The 512x512 sized color images with different histograms are used for testing and watermark of size 64x64 is embedded in HL region of DWT and 4x4 DCT is used. 'Haar' wavelet is used for decomposition and direct flexing factor is used. We got PSNR value is 63.9988 for flexing factor k=1 for Lena image and the maximum NC 0.9781 for flexing factor k=4 in Q color space. The comparative performance in Y, I and Q color space is presented. The technique is robust for different attacks like scaling, compression, rotation etc.

  10. Multiscale Stategies in Automatic Image-Domain Waveform Tomography

    Institute of Scientific and Technical Information of China (English)

    Yujin Liu; Zhenchun Li

    2015-01-01

    Multiscale strategies are very important in the successful application of waveform-based velocity inversion. The strategy that sequentially preceeds from long to short scale of velocity model, has been well developed in full waveform inversion (FWI) to solve the local mininum problem. In contrast, it’s not well understood in the image-domain waveform tomography (IWT), which back-projects incoherent waveform components of the common image gather into velocity updates. IWT is less prone to local minimum problem but tends to build long-scale model with low resolution. In order to build both long- and short-scale model by IWT, we discuss several multiscale strategies restricted in the image domain. The strategies include model reparameterization, objective function switching and gradient rescaling. Numerical tests on Marmsousi model and real data demonstrate that our proposed multiscale IWT is effective in buidling velocity model with wide wavenumber spectrum.

  11. Microcirculation monitoring with real time spatial frequency domain imaging

    Science.gov (United States)

    Chen, Xinlin; Cao, Zili; Lin, Weihao; Zhu, Danfeng; Zhu, Xiuwei; Zeng, Bixin; Xu, M.

    2017-01-01

    We present a spatial frequency domain imaging (SFDI) study of local hemodynamics in the forearm of healthy volunteers performing paced breathing. Real time Single Snapshot Multiple Frequency Demodulation - Spatial Frequency Domain Imaging (SSMD-SFDI) was used to map the optical properties of the subsurface of the forearm continuously. The oscillations of the concentrations of deoxy- and oxyhemoglobin at the subsurface of the forearm induced by paced breathing are found to be close to out-of-phase, attributed to the dominance of the blood flow modulation by paced breathing. The properties of local microcirculation including the blood transit times through capillaries and venules are extracted by fitting to Simplified Hemodynamics Model. Our preliminary results suggest that the real time SSMD-SFDI platform may serve as one effective imaging modality for microcirculation monitoring.

  12. Domain decomposition methods for solving an image problem

    Energy Technology Data Exchange (ETDEWEB)

    Tsui, W.K.; Tong, C.S. [Hong Kong Baptist College (Hong Kong)

    1994-12-31

    The domain decomposition method is a technique to break up a problem so that ensuing sub-problems can be solved on a parallel computer. In order to improve the convergence rate of the capacitance systems, pre-conditioned conjugate gradient methods are commonly used. In the last decade, most of the efficient preconditioners are based on elliptic partial differential equations which are particularly useful for solving elliptic partial differential equations. In this paper, the authors apply the so called covering preconditioner, which is based on the information of the operator under investigation. Therefore, it is good for various kinds of applications, specifically, they shall apply the preconditioned domain decomposition method for solving an image restoration problem. The image restoration problem is to extract an original image which has been degraded by a known convolution process and additive Gaussian noise.

  13. Microwave Frequency Ferroelectric Domain Imaging of Deuterated Triglycine Sulfate Crystals

    Science.gov (United States)

    Steinhauer, David E.; Anlage, Steven M.

    2001-03-01

    We have used a near-field scanning microwave microscope(D. E. Steinhauer, C. P. Vlahacos, F. C. Wellstood, Steven M. Anlage, C. Canedy, R. Ramesh, A. Stanishevsky, and J. Melngailis, "Quantitative Imaging of Dielectric Permittivity and Tunability with a Near-Field Scanning Microwave Microscope," Rev. Sci. Instrum. 71), 2751-2758 (2000). to image domain structure and quantitatively measure dielectric permittivity and nonlinearity in ferroelectric crystals at 8.1 GHz with a spatial resolution of 1 μm. We imaged ferroelectric domains in periodically-poled LiNbO_3, BaTiO_3, and deuterated triglycine sulfate (DTGS) with a signal-to-noise ratio of 7. Measurement of the permittivity and nonlinearity of DTGS in the temperature range 300--400 K shows a peak at the Curie temperature, TC ≈ 340 K, as well as reasonable agreement with thermodynamic theory. In addition, the domain growth relaxation time shows a minimum near T_C. We observe coarsening of ferroelectric domains in DTGS after a temperature quench from 360 K to 330 K, and evaluate the structure factor.

  14. Image Denoising using Adaptive Thresholding in Framelet Transform Domain

    Directory of Open Access Journals (Sweden)

    R.Vidhya

    2012-09-01

    Full Text Available Noise will be unavoidable during image acquisition process and denosing is an essential step to improve the image quality. Image denoising involves the manipulation of the image data to produce a visually high quality image. Finding efficient image denoising methods is still valid challenge in image processing. Wavelet denoising attempts to remove the noise present in the imagery while preserving the image characteristics, regardless of its frequency content. Many of the wavelet based denoising algorithms use DWT (Discrete Wavelet Transform in the decomposition stage which is suffering from shift variance. To overcome this, in this paper we proposed the denoising method which uses Framelet transform to decompose the image and performed shrinkage operation to eliminate the noise .The framework describes a comparative study of different thresholding techniques for image denoising in Framelet transform domain. The idea is to transform the data into the Framelet basis, example shrinkage followed by the inverse transform. In this work different shrinkage rules such as universal shrink(US,Visu shrink (VS, Minmax shrink(MS, Sure shrink(SS , Bayes shrink(BS and Normal shrink(NS were incorporated . Results based on different noise such as Gausssian noise, Poission noise , Salt and pepper noise and Speckle noise at (??=10,20 performed in this paper and peak signal to noise ratio (PSNR and Structural similarity index measure(SSIM as a measure of the quality of denoising was performed.

  15. Image recovery from double amplitudes in fractional Fourier domain

    Institute of Scientific and Technical Information of China (English)

    Liao Tian-He; Gao Qiong

    2006-01-01

    The classical Gerchberg-Saxton algorithm is introduced into the image recovery in fractional Fourier domain after adaptation. When this algorithm is applied directly, its performance is good for smoothed image, but bad for unsmoothed image. Based on the diversity of fractional Fourier transform on its orders, this paper suggests a novel iterative algorithm, which extracts the information of the original image from amplitudes of its fractional Fourier transform at two orders. This new algorithm consists of two independent Gerchberg-Saxton procedures and an averaging operation in each circle. Numerical simulations are carried out to show its validity for both smoothed and unsmoothed images with most pairs of orders in the interval [0,1] .

  16. Assessment of current cybersecurity practices in the public domain : cyber indications and warnings domain.

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Keliiaa, Curtis M.

    2010-09-01

    This report assesses current public domain cyber security practices with respect to cyber indications and warnings. It describes cybersecurity industry and government activities, including cybersecurity tools, methods, practices, and international and government-wide initiatives known to be impacting current practice. Of particular note are the U.S. Government's Trusted Internet Connection (TIC) and 'Einstein' programs, which are serving to consolidate the Government's internet access points and to provide some capability to monitor and mitigate cyber attacks. Next, this report catalogs activities undertaken by various industry and government entities. In addition, it assesses the benchmarks of HPC capability and other HPC attributes that may lend themselves to assist in the solution of this problem. This report draws few conclusions, as it is intended to assess current practice in preparation for future work, however, no explicit references to HPC usage for the purpose of analyzing cyber infrastructure in near-real-time were found in the current practice. This report and a related SAND2010-4766 National Cyber Defense High Performance Computing and Analysis: Concepts, Planning and Roadmap report are intended to provoke discussion throughout a broad audience about developing a cohesive HPC centric solution to wide-area cybersecurity problems.

  17. Secure image transform domain technique for steganographic applications

    Science.gov (United States)

    Alturki, Faisal T.; Mersereau, Russell M.

    2001-08-01

    Digital steganography is the art of secretly hiding information inside a multimedia signal in such a way that its very existence is concealed. In this paper, we present a new steganographic technique for covert communications. The technique embeds the hidden information in the transform domain after decorrelating the image samples in the spatial domain using a key. This results in a significant increase in the number of transform coefficients that can be used to transmit the hidden information, and therefore, increases the data embedding capacity. The hidden information is embedded in the transform domain after taking a block DCT of the decorrelated image. A quantization technique is used to embed the hidden data. The decoding process requires the availability of the same key that was used to decorrelate the image samples. By using quantization techniques, the hidden information can be recovered reliably. If the key is not available at the decoder it is impossible to recover the hidden information. Hence, this system is secure against removal attacks. The statistical properties of the cover and the stego image remain identical for small quantization steps. Therefore, the hidden data cannot be detected. The data embedding system is modeled as transmitting information through a Gaussian channel.

  18. Classification of similar medical images in the lifting domain

    Science.gov (United States)

    Sallee, Chad W.; Tashakkori, Rahman

    2002-03-01

    In this paper lifting is used for similarity analysis and classification of sets of similar medical images. The lifting scheme is an invertible wavelet transform that maps integers to integers. Lifting provides efficient in-place calculation of transfer coefficients and is widely used for analysis of similar image sets. Images of a similar set show high degrees of correlation with one another. The inter-set redundancy can be exploited for the purposes of prediction, compression, feature extraction, and classification. This research intends to show that there is a higher degree of correlation between images of a similar set in the lifting domain than in the pixel domain. Such a high correlation will result in more accurate classification and prediction of images in a similar set. Several lifting schemes from Calderbank-Daubechies-Fauveue's family were used in this research. The research shows that some of these lifting schemes decorrelates the images of similar sets more effectively than others. The research presents the statistical analysis of the data in scatter plots and regression models.

  19. Resonant Doppler imaging with Fourier domain optical coherence tomography

    Science.gov (United States)

    Leitgeb, Rainer A.; Szklumowska, Anna; Pircher, Michael; Gotzinger, Erich; Fercher, Adolf F.

    2005-04-01

    Fourier Domain Optical Coherene Tomography (FD OCT) is a high speed imaging modality with increased sensitivity as compared to standard time domain (TD) OCT. The higher sensitivity is especially important, if strongly scattering tissue such as blood is investigated. Recently it could be shown that retinal blood flow can be assessed in-vivo by high speed FD OCT. However the detection bandwidth of color Doppler (CD) FDOCT is strongly limited due to blurring of the detected interference fringes during exposure. This leads to a loss of sensitivity for detection of fast changes in tissue. Using a moving mirror as a reference one can effectively increase the detection bandwidth for CD FDOCT and perform perfusion sectioning. The modality is called resonant CD FDOCT imaging. The principle of the method is presented and experimentally verified.

  20. Time Domain Terahertz (T-Ray) Subsurface and Structural Imaging

    Science.gov (United States)

    Zimdars, David; White, Jeffrey S.; Stuk, G.; Chernovsky, A.; Fichter, G.; Sucha, G.; Williamson, S.

    2007-03-01

    The technology, methods, and examples of high speed time domain terahertz (T-Ray) imaging non-destructive examination (NDE) for 2 and 3 dimensional structural and material content characterization are discussed. T-Ray imaging can be utilized for non-contact transmission and/or monostatic reflection inspection of non-conductive materials such as plastics, foam, composites, ceramics, paper, wood and glass. Example subsurface homeland security images of concealed items in baggage and on personnel are shown. We tabulate attenuation and penetration characteristics through a selection of building materials, and demonstrate the ability of T-ray instrumentation to sub-surface image building structures such as wall framing and interior wiring and conduits.

  1. An outlook on the nature of mental creations after belonging to public domain

    Directory of Open Access Journals (Sweden)

    Pedjman Mohammadi

    2015-05-01

    Full Text Available The public domain of copyright which considers the end of protection period, attempts to cause balance among the rights of authors, society and third parties. So at the end of financial rights of author’s protection period the possibility of free utilization of these literary works will be possible. But in this situation one of the controversial difficulties is the nature of these kinds of literary works which, according to some scholars, after belonging to public domain, they will change in to the Allowable. To approve their idea, they focus on common features existing in these literary works(works relating to public domain and the Allowable. On the other hand it is believed that literary works after belonging to public domain essentially works after belonging to public domain essentially due to lacking of scarcity element are not considered property at all.

  2. New Optimal DWT Domain Image Watermarking Technique via Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHONG Ning; KUANG Jing-ming; HE Zun-wen

    2007-01-01

    A novel optimal image watermarking scheme is proposed in which the genetic algor ithm (GA) is employed to obtain the improvement of algorithm performance. Arnold transform is utilized to obtain the scrambled watermark, and then the embedding and extraction of watermark are implemented in digital wavelet transform (DWT) domain. During the watermarking process, GA is employed to search optimal parame ters of embedding strength and times of Arnold transform to gain the optimization of watermarking performance. Simulation results show that the proposed method can improve the quality of watermarked image and give almost the same robustness of the watermark.

  3. Robust Image Watermarking in the Wavelet Domain for Copyright Protection

    CERN Document Server

    Dehghan, Hamed

    2010-01-01

    In this paper a new approach to image watermarking in wavelet domain is presented. The idea is to hide the watermark data in blocks of the block segmented image. Two schemes are presented based on this idea by embedding the watermark data in the low pass wavelet coefficients of each block. Due to low computational complexity of the proposed approach, this algorithm can be implemented in real time. Experimental results demonstrate the impercepti-bility of the proposed method and its high robustness against various attacks such as filtering, JPEG compres-sion, cropping, noise addition and geometric distortions.

  4. A symmetrical image encryption scheme in wavelet and time domain

    Science.gov (United States)

    Luo, Yuling; Du, Minghui; Liu, Junxiu

    2015-02-01

    There has been an increasing concern for effective storages and secure transactions of multimedia information over the Internet. Then a great variety of encryption schemes have been proposed to ensure the information security while transmitting, but most of current approaches are designed to diffuse the data only in spatial domain which result in reducing storage efficiency. A lightweight image encryption strategy based on chaos is proposed in this paper. The encryption process is designed in transform domain. The original image is decomposed into approximation and detail components using integer wavelet transform (IWT); then as the more important component of the image, the approximation coefficients are diffused by secret keys generated from a spatiotemporal chaotic system followed by inverse IWT to construct the diffused image; finally a plain permutation is performed for diffusion image by the Logistic mapping in order to reduce the correlation between adjacent pixels further. Experimental results and performance analysis demonstrate the proposed scheme is an efficient, secure and robust encryption mechanism and it realizes effective coding compression to satisfy desirable storage.

  5. Multiscale Seismic Inversion in the Data and Image Domains

    KAUST Repository

    Zhang, Sanzong

    2015-12-01

    I present a general methodology for inverting seismic data in either the data or image domains. It partially overcomes one of the most serious problems with current waveform inversion methods, which is the tendency to converge to models far from the actual one. The key idea is to develop a multiscale misfit function that is composed of both a simplified version of the data and one associated with the complex part of the data. Misfit functions based on simple data are characterized by many fewer local minima so that a gradient optimization method can make quick progress in getting to the general vicinity of the actual model. Once we are near the actual model, we then use the gradient based on the more complex data. Below, we describe two implementations of this multiscale strategy: wave equation traveltime inversion in the data domain and generalized differential semblance optimization in the image domain. • Wave Equation Traveltime Inversion in the Data Domain (WT): The main difficulty with iterative waveform inversion is that it tends to get stuck in local minima associated with the waveform misfit function. To mitigate this problem and avoid the need to fit amplitudes in the data, we present a waveequation method that inverts the traveltimes of reflection events, and so is less prone to the local minima problem. Instead of a waveform misfit function, the penalty function is a crosscorrelation of the downgoing direct wave and the upgoing reflection wave at the trial image point. The time lag which maximizes the crosscorrelation amplitude represents the reflection-traveltime residual that is back-projected along the reflection wavepath to update the velocity. Shot- and angle-domain crosscorrelation functions are introduced to estimate the reflection-traveltime residual by semblance analysis and scanning. In theory, only the traveltime information is inverted and there is no need to precisely fit the amplitudes or assume a high-frequency approximation. Results

  6. IDEAL: Images Across Domains, Experiments, Algorithms and Learning

    Science.gov (United States)

    Ushizima, Daniela M.; Bale, Hrishikesh A.; Bethel, E. Wes; Ercius, Peter; Helms, Brett A.; Krishnan, Harinarayan; Grinberg, Lea T.; Haranczyk, Maciej; Macdowell, Alastair A.; Odziomek, Katarzyna; Parkinson, Dilworth Y.; Perciano, Talita; Ritchie, Robert O.; Yang, Chao

    2016-09-01

    Research across science domains is increasingly reliant on image-centric data. Software tools are in high demand to uncover relevant, but hidden, information in digital images, such as those coming from faster next generation high-throughput imaging platforms. The challenge is to analyze the data torrent generated by the advanced instruments efficiently, and provide insights such as measurements for decision-making. In this paper, we overview work performed by an interdisciplinary team of computational and materials scientists, aimed at designing software applications and coordinating research efforts connecting (1) emerging algorithms for dealing with large and complex datasets; (2) data analysis methods with emphasis in pattern recognition and machine learning; and (3) advances in evolving computer architectures. Engineering tools around these efforts accelerate the analyses of image-based recordings, improve reusability and reproducibility, scale scientific procedures by reducing time between experiments, increase efficiency, and open opportunities for more users of the imaging facilities. This paper describes our algorithms and software tools, showing results across image scales, demonstrating how our framework plays a role in improving image understanding for quality control of existent materials and discovery of new compounds.

  7. IDEAL: Images Across Domains, Experiments, Algorithms and Learning

    Science.gov (United States)

    Ushizima, Daniela M.; Bale, Hrishikesh A.; Bethel, E. Wes; Ercius, Peter; Helms, Brett A.; Krishnan, Harinarayan; Grinberg, Lea T.; Haranczyk, Maciej; Macdowell, Alastair A.; Odziomek, Katarzyna; Parkinson, Dilworth Y.; Perciano, Talita; Ritchie, Robert O.; Yang, Chao

    2016-11-01

    Research across science domains is increasingly reliant on image-centric data. Software tools are in high demand to uncover relevant, but hidden, information in digital images, such as those coming from faster next generation high-throughput imaging platforms. The challenge is to analyze the data torrent generated by the advanced instruments efficiently, and provide insights such as measurements for decision-making. In this paper, we overview work performed by an interdisciplinary team of computational and materials scientists, aimed at designing software applications and coordinating research efforts connecting (1) emerging algorithms for dealing with large and complex datasets; (2) data analysis methods with emphasis in pattern recognition and machine learning; and (3) advances in evolving computer architectures. Engineering tools around these efforts accelerate the analyses of image-based recordings, improve reusability and reproducibility, scale scientific procedures by reducing time between experiments, increase efficiency, and open opportunities for more users of the imaging facilities. This paper describes our algorithms and software tools, showing results across image scales, demonstrating how our framework plays a role in improving image understanding for quality control of existent materials and discovery of new compounds.

  8. Chaotic CDMA watermarking algorithm for digital image in FRFT domain

    Science.gov (United States)

    Liu, Weizhong; Yang, Wentao; Feng, Zhuoming; Zou, Xuecheng

    2007-11-01

    A digital image-watermarking algorithm based on fractional Fourier transform (FRFT) domain is presented by utilizing chaotic CDMA technique in this paper. As a popular and typical transmission technique, CDMA has many advantages such as privacy, anti-jamming and low power spectral density, which can provide robustness against image distortions and malicious attempts to remove or tamper with the watermark. A super-hybrid chaotic map, with good auto-correlation and cross-correlation characteristics, is adopted to produce many quasi-orthogonal codes (QOC) that can replace the periodic PN-code used in traditional CDAM system. The watermarking data is divided into a lot of segments that correspond to different chaotic QOC respectively and are modulated into the CDMA watermarking data embedded into low-frequency amplitude coefficients of FRFT domain of the cover image. During watermark detection, each chaotic QOC extracts its corresponding watermarking segment by calculating correlation coefficients between chaotic QOC and watermarked data of the detected image. The CDMA technique not only can enhance the robustness of watermark but also can compress the data of the modulated watermark. Experimental results show that the watermarking algorithm has good performances in three aspects: better imperceptibility, anti-attack robustness and security.

  9. Spatial frequency domain imaging for monitoring palpable breast lesions

    Science.gov (United States)

    Robbins, Constance M.; Antaki, James F.; Kainerstorfer, Jana M.

    2017-02-01

    We describe a novel approach for monitoring breast lesions, utilizing spatial frequency domain imaging, a diffuse optical imaging method to detect hemoglobin contrast, in combination with mechanical compression of the tissue. The project is motivated by the growing rate of unnecessary breast biopsies, caused by uncertainty in X-ray mammographic diagnoses. We believe there is a need for an alternate means of tracking the progression palpable lesions exhibiting probably benign features, that can be performed non-invasively and hence frequently: at home or in the clinic. The proposed approach capitalizes on two distinguishing properties of cancerous lesions, namely the relative stiffness with respect to surrounding tissue and the optical absorption due to the greater vascularization, hence hemoglobin concentration. The current research project is a pilot study to evaluate the principle on soft, breast tissue-mimicking phantoms containing stiffer, more highly absorbing inclusions. Spatial frequency domain imaging was performed by projecting onto the phantom a series of wide-field patterns at multiple spatial frequencies. Image analysis then was performed to map absorption and scattering properties. The results of the study demonstrate that compression significantly increases the optical contrast observed for inclusions located 10 and 15 mm beneath the surface. In the latter case, the inclusion was not detectable without compression.

  10. Perfect imaging in the optical domain using dielectric materials

    CERN Document Server

    Gabrielli, Lucas H; Lipson, Michal

    2010-01-01

    The promise of perfect imaging in the optical domain, where light can be imaged without aberrations and with ultra-high resolution, could revolutionize technology and nanofabrication [1, 2, 3, 4, 5, 6]. Recently it has been shown theoretically that perfect imaging can be achieved in a dielectric medium with spatially varying refractive index [7, 8]. The lens geometry is defined using transformation optics [9, 10, 11, 12, 13, 14, 15] for projecting a spherical space onto a real plane space, forming Maxwells fish eye [16, 17, 18, 19]. Most transformation optics demonstrations have been achieved for Euclidean spaces and in the microwave regime, due to ease of fabrication. Here we demonstrate a transformation to a non-Euclidean space [20] in the optical regime using silicon nanophotonic structures.

  11. Spatial Domain Image Steganography based on Security and Randomization

    Directory of Open Access Journals (Sweden)

    Namita Tiwari

    2014-01-01

    Full Text Available In the present digital scenario secure communication is the prime requirement. Commonly, cryptography used for the said purpose. Another method related to cryptography is used for the above objective is Steganography. Steganography is the art of hiding information in some medium. Here we are using image as a means for covering information. Spatial domain image Steganography has been used for the work because of its compatibility to images. Objective of the paper is to increase the capacity of hidden data in a way that security could be maintained. In the current work MSB of the randomly selected pixel have been used as indicator. Result analysis has been performed on the basis of different parameters like PSNR, MSE and capacity.

  12. Perceptual image quality in normalized LOG domain for Adaptive Optics image post-processing

    Science.gov (United States)

    Guo, Shiping; Zhang, Rongzhi; Li, Jisheng; Zou, Jianhua; Liu, Changhai; Gao, Weizhe

    2015-08-01

    Adaptive Optics together with subsequent post-processing techniques obviously improve the resolution of turbulencedegraded images in ground-based space objects detection and identification. The most common method for frame selection and stopping iteration in post-processing has always been subjective viewing of the images due to a lack of widely agreed-upon objective quality metric. Full reference metrics are not applicable for assessing the field data, no-reference metrics tend to perform poor sensitivity for Adaptive Optics images. In the present work, based on the Laplacian of Gaussian (LOG) local contrast feature, a nonlinear normalization is applied to transform the input image into a normalized LOG domain; a quantitative index is then extracted in this domain to assess the perceptual image quality. Experiments show this no-reference quality index is highly consistent with the subjective evaluation of input images for different blur degree and different iteration number.

  13. A Review of Various Transform Domain Digital Image Fusion for Multifocus Colored Images

    Directory of Open Access Journals (Sweden)

    Arun Begill

    2015-11-01

    Full Text Available Image fusion is the idea to enhance the image content by fusing two or more images obtained from visual sensor network. The main goal of image fusion is to eliminate redundant information and merging more useful information from source images. Various transform domain image fusion methods like DWT, SIDWT and DCT, ACMax DCT etc. are developed in recent years. Every method has its own advantages and disadvantages. ACMax Discrete cosine transform (DCT is very efficient approach for image fusion because of its energy compaction property as well as improve quality of image. Furthermore, this technique has also some disadvantages like color artifacts, noise and degrade the sharpness of edges. In this paper ACMax DCT method is integrated with saturation weighting and Joint Trilateral filter to get the high quality image and compare with traditional methods. The results have shown that ACMax DCT with Saturation weighting and Joint Trilateral filter method has outperformed the state of art techniques.

  14. Fourier domain image fusion for differential X-ray phase-contrast breast imaging.

    Science.gov (United States)

    Coello, Eduardo; Sperl, Jonathan I; Bequé, Dirk; Benz, Tobias; Scherer, Kai; Herzen, Julia; Sztrókay-Gaul, Anikó; Hellerhoff, Karin; Pfeiffer, Franz; Cozzini, Cristina; Grandl, Susanne

    2017-04-01

    X-Ray Phase-Contrast (XPC) imaging is a novel technology with a great potential for applications in clinical practice, with breast imaging being of special interest. This work introduces an intuitive methodology to combine and visualize relevant diagnostic features, present in the X-ray attenuation, phase shift and scattering information retrieved in XPC imaging, using a Fourier domain fusion algorithm. The method allows to present complementary information from the three acquired signals in one single image, minimizing the noise component and maintaining visual similarity to a conventional X-ray image, but with noticeable enhancement in diagnostic features, details and resolution. Radiologists experienced in mammography applied the image fusion method to XPC measurements of mastectomy samples and evaluated the feature content of each input and the fused image. This assessment validated that the combination of all the relevant diagnostic features, contained in the XPC images, was present in the fused image as well.

  15. CHOROIDAL IMAGING USING SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY

    Science.gov (United States)

    Regatieri, Caio V.; Branchini, Lauren; Fujimoto, James G.; Duker, Jay S.

    2012-01-01

    Background A structurally and functionally normal choroidal vasculature is essential for retinal function. Therefore, a precise clinical understanding of choroidal morphology should be important for understanding many retinal and choroidal diseases. Methods PUBMED (http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed) was used for most of the literature search for this article. The criterion for inclusion of an article in the references for this review was that it included materials about both the clinical and the basic properties of choroidal imaging using spectral-domain optical coherence tomography. Results Recent reports show successful examination and accurate measurement of choroidal thickness in normal and pathologic states using spectral-domain optical coherence tomography systems. This review focuses on the principles of the new technology that make choroidal imaging using optical coherence tomography possible and on the changes that subsequently have been documented to occur in the choroid in various diseases. Additionally, it outlines future directions in choroidal imaging. Conclusion Optical coherence tomography is now proven to be an effective noninvasive tool to evaluate the choroid and to detect choroidal changes in pathologic states. Additionally, choroidal evaluation using optical coherence tomography can be used as a parameter for diagnosis and follow-up. PMID:22487582

  16. Aperture domain model image reconstruction (ADMIRE) with plane wave synthesis

    Science.gov (United States)

    Dei, Kazuyuki; Tierney, Jaime; Byram, Brett

    2017-03-01

    In our previous studies, we demonstrated that our aperture domain model-based clutter suppression algorithm improved image quality of in vivo B-mode data obtained from focused transmit beam sequences. Our approach suppresses off-axis clutter and reverberation and tackles limitations of related algorithms because it preserves RF channel signals and speckle statistics. We call the algorithm aperture domain model image reconstruction (ADMIRE). We previously focused on reverberation suppression, but ADMIRE is also effective at suppressing off-axis clutter. We are interested in how ADMIRE performs on plane wave sequences and the impact of AD- MIRE applied before and after synthetic beamforming of steered plane wave sequences. We employed simulated phantoms using Field II and tissue-mimicking phantoms to evaluate ADMIRE applied to plane wave sequencing. We generated images acquired from plane waves with and without synthetic aperture synthesis and measured contrast and contrast-to-noise ratio (CNR). For simulated cyst images formed from single plane waves, the contrast for delay-and-sum (DAS) and ADMIRE are 15.64 dB and 28.34 dB, respectively, while the CNR are 1.76 dB and 3.90 dB, respectively. Based on these findings, ADMIRE improves plane wave image quality. We also applied ADMIRE to resolution phantoms having a point target at 3 cm depth on-axis, simulating the point spread functions from data obtained from 1 and 75 steered plane waves, along with linear scan at focus of 3 and 4 cm depth. We then examined the outcome of applying ADMIRE before and after synthetic aperture processing. Finally, we applied this to an in vivo carotid artery.

  17. Encryption of color images using MSVD in DCST domain

    Science.gov (United States)

    Kumar, Manoj; Vaish, Ankita

    2017-01-01

    In this paper, a new image encryption and decryption algorithm based on Multiresolution Singular Value Decomposition (MSVD) and Discrete Cosine Stockwell Transform (DCST) is proposed. An original image is first transformed in DCST domain and then decomposed into four subbands using MSVD, all the four subbands are further decomposed into four subimages according to their indexing and masked by the parameters generated by MSVD. We have used number of bands of DCST, arrangement of MSVD subbands, arrangement of various subimages obtained from MSVD subbands, values and arrangement of a 4×4 matrix generated by MSVD and the arrangement of masked subimages as encryption and decryption keys. To ensure the correct decryption of encrypted image, it is indeed necessary to have correct knowledge of all keys in correct order along with their exact values. If all the keys are correct but a single key is wrong even though it would be almost impossible to guess the original image. The efficiency of proposed algorithm is evaluated by comparing it with some recent published works and it is evident from the experimental results and analysis that the proposed algorithm can transmit the images more securely and efficiently over the network.

  18. Optical color-image encryption and synthesis using coherent diffractive imaging in the Fresnel domain.

    Science.gov (United States)

    Chen, Wen; Chen, Xudong; Sheppard, Colin J R

    2012-02-13

    We propose a new method using coherent diffractive imaging for optical color-image encryption and synthesis in the Fresnel domain. An optical multiple-random-phase-mask encryption system is applied, and a strategy based on lateral translations of a phase-only mask is employed during image encryption. For the decryption, an iterative phase retrieval algorithm is applied to extract high-quality decrypted color images from diffraction intensity maps (i.e., ciphertexts). In addition, optical color-image synthesis is also investigated based on coherent diffractive imaging. Numerical results are presented to demonstrate feasibility and effectiveness of the proposed method. Compared with conventional interference methods, coherent diffractive imaging approach may open up a new research perspective or can provide an effective alternative for optical color-image encryption and synthesis.

  19. Multiwavelets domain singular value features for image texture classification

    Institute of Scientific and Technical Information of China (English)

    RAMAKRISHNAN S.; SELVAN S.

    2007-01-01

    A new approach based on multiwavelets transformation and singular value decomposition (SVD) is proposed for the classification of image textures. Lower singular values are truncated based on its energy distribution to classify the textures in the presence of additive white Gaussian noise (AWGN). The proposed approach extracts features such as energy, entropy, local homogeneity and max-min ratio from the selected singular values of multiwavelets transformation coefficients of image textures.The classification was carried out using probabilistic neural network (PNN). Performance of the proposed approach was compared with conventional wavelet domain gray level co-occurrence matrix (GLCM) based features, discrete multiwavelets transformation energy based approach, and HMM based approach. Experimental results showed the superiority of the proposed algorithms when compared with existing algorithms.

  20. Image encryption using random sequence generated from generalized information domain

    Science.gov (United States)

    Xia-Yan, Zhang; Guo-Ji, Zhang; Xuan, Li; Ya-Zhou, Ren; Jie-Hua, Wu

    2016-05-01

    A novel image encryption method based on the random sequence generated from the generalized information domain and permutation-diffusion architecture is proposed. The random sequence is generated by reconstruction from the generalized information file and discrete trajectory extraction from the data stream. The trajectory address sequence is used to generate a P-box to shuffle the plain image while random sequences are treated as keystreams. A new factor called drift factor is employed to accelerate and enhance the performance of the random sequence generator. An initial value is introduced to make the encryption method an approximately one-time pad. Experimental results show that the random sequences pass the NIST statistical test with a high ratio and extensive analysis demonstrates that the new encryption scheme has superior security.

  1. Microball lens integrated fiber probe for optical frequency domain imaging

    Institute of Scientific and Technical Information of China (English)

    Jae-Ho Han; J.U.Kang

    2011-01-01

    An integrated microball lens fiber catheter probe is demonstrated, which has better lateral resolution and longer working distance than a corresponding bare fiber probe with diverging beam for Fourier domain optical coherence tomography (FDOCT). Simulation results are shown to gain the effect of the distance between the microball lens and the bare fiber to the focusing plane and beam width. The freedom of modifying the working distance and lateral resolution is shown. This is achieved by changing the gap distance between the single-mode fiber and the microball lens within the packaged surgical needle catheter without using an additional beam expander having a fixed length. The probe successfully acquired cross-sectional images of ocular tissues from an animal sample with the proposed miniaturized imaging probe.%@@ An integrated microball lens fiber catheter probe is demonstrated,which has better lateral resolution and longer working distance than a corresponding bare fiber probe with diverging beam for Fourier domain optical coherence tomography(FDOCT).Simulation results are shown to gain the effect of the distance between the microball lens and the bare fiber to the focusing plane and beam width.The freedom of modifying the working distance and lateral resolution is shown.This is achieved by changing the gap distance between the single-mode fiber and the microball lens within the packaged surgical needle catheter without using an additional beam expander having a fixed length.The probe successfully acquired crosssectional images of ocular tissues from an animal sample with the proposed miniaturized imaging probe.

  2. A new image cipher in time and frequency domains

    Science.gov (United States)

    Abd El-Latif, Ahmed A.; Niu, Xiamu; Amin, Mohamed

    2012-10-01

    Recently, various encryption techniques based on chaos have been proposed. However, most existing chaotic encryption schemes still suffer from fundamental problems such as small key space, weak security function and slow performance speed. This paper introduces an efficient encryption scheme for still visual data that overcome these disadvantages. The proposed scheme is based on hybrid Linear Feedback Shift Register (LFSR) and chaotic systems in hybrid domains. The core idea is to scramble the pixel positions based on 2D chaotic systems in frequency domain. Then, the diffusion is done on the scrambled image based on cryptographic primitive operations and the incorporation of LFSR and chaotic systems as round keys. The hybrid compound of LFSR, chaotic system and cryptographic primitive operations strengthen the encryption performance and enlarge the key space required to resist the brute force attacks. Results of statistical and differential analysis show that the proposed algorithm has high security for secure digital images. Furthermore, it has key sensitivity together with a large key space and is very fast compared to other competitive algorithms.

  3. Automatic view synthesis by image-domain-warping.

    Science.gov (United States)

    Stefanoski, Nikolce; Wang, Oliver; Lang, Manuel; Greisen, Pierre; Heinzle, Simon; Smolic, Aljosa

    2013-09-01

    Today, stereoscopic 3D (S3D) cinema is already mainstream, and almost all new display devices for the home support S3D content. S3D distribution infrastructure to the home is already established partly in the form of 3D Blu-ray discs, video on demand services, or television channels. The necessity to wear glasses is, however, often considered as an obstacle, which hinders broader acceptance of this technology in the home. Multiviewautostereoscopic displays enable a glasses free perception of S3D content for several observers simultaneously, and support head motion parallax in a limited range. To support multiviewautostereoscopic displays in an already established S3D distribution infrastructure, a synthesis of new views from S3D video is needed. In this paper, a view synthesis method based on image-domain-warping (IDW) is presented that automatically synthesizes new views directly from S3D video and functions completely. IDW relies on an automatic and robust estimation of sparse disparities and image saliency information, and enforces target disparities in synthesized images using an image warping framework. Two configurations of the view synthesizer in the scope of a transmission and view synthesis framework are analyzed and evaluated. A transmission and view synthesis system that uses IDW is recently submitted to MPEG's call for proposals on 3D video technology, where it is ranked among the four best performing proposals.

  4. The Use and Abuse of Research in the Public Domain

    Science.gov (United States)

    Reid, Alan

    2016-01-01

    In Australia, education think tanks have become increasingly influential in policy circles through "reports" to government, and in public debate through the mainstream media. Invariably think-tanks draw on educational research to lend authority and legitimacy to their work. This is desirable if the research deepens understandings about…

  5. Comparison of sinogram- and image-domain penalized-likelihood image reconstruction estimators.

    Science.gov (United States)

    Vargas, Phillip A; La Rivière, Patrick J

    2011-08-01

    In recent years, the authors and others have been exploring the use of penalized-likelihood sinogram-domain smoothing and restoration approaches for emission and transmission tomography. The motivation for this strategy was initially pragmatic: to provide a more computationally feasible alternative to fully iterative penalized-likelihood image reconstruction involving expensive backprojections and reprojections, while still obtaining some of the benefits of the statistical modeling employed in penalized-likelihood approaches. In this work, the authors seek to compare the two approaches in greater detail. The sinogram-domain strategy entails estimating the "ideal" line integrals needed for reconstruction of an activity or attenuation distribution from the set of noisy, potentially degraded tomographic measurements by maximizing a penalized-likelihood objective function. The objective function models the data statistics as well as any degradation that can be represented in the sinogram domain. The estimated line integrals can then be input to analytic reconstruction algorithms such as filtered backprojection (FBP). The authors compare this to fully iterative approaches maximizing similar objective functions. The authors present mathematical analyses based on so-called equivalent optimization problems that establish that the approaches can be made precisely equivalent under certain restrictive conditions. More significantly, by use of resolution-variance tradeoff studies, the authors show that they can yield very similar performance under more relaxed, realistic conditions. The sinogram- and image-domain approaches are equivalent under certain restrictive conditions and can perform very similarly under more relaxed conditions. The match is particularly good for fully sampled, high-resolution CT geometries. One limitation of the sinogram-domain approach relative to the image-domain approach is the difficulty of imposing additional constraints, such as image non-negativity.

  6. Suburban development – a search for public domains in Danish suburban neighbourhoods

    DEFF Research Database (Denmark)

    Melgaard, Bente; Bech-Danielsen, Claus

    , potentials for bridge-building across the enclaves of the suburb are looked for through a combined architectural-anthropological mapping of public spaces in a specific suburb in Denmark, the analyses being carried out in the light of Hajer & Reijndorp’s definition of public domains and the term exchange....... The results so far show that suburban spaces with a potential for creating bridge-building across the segregated enclaves do exist but that, among other things, focus on spatial design is needed before actual public domains creating the basis for exchange are achieved....

  7. Stereo matching and view interpolation based on image domain triangulation.

    Science.gov (United States)

    Fickel, Guilherme Pinto; Jung, Claudio R; Malzbender, Tom; Samadani, Ramin; Culbertson, Bruce

    2013-09-01

    This paper presents a new approach for stereo matching and view interpolation problems based on triangular tessellations suitable for a linear array of rectified cameras. The domain of the reference image is initially partitioned into triangular regions using edge and scale information, aiming to place vertices along image edges and increase the number of triangles in textured regions. A region-based matching algorithm is then used to find an initial disparity for each triangle, and a refinement stage is applied to change the disparity at the vertices of the triangles, generating a piecewise linear disparity map. A simple post-processing procedure is applied to connect triangles with similar disparities generating a full 3D mesh related to each camera (view), which are used to generate new synthesized views along the linear camera array. With the proposed framework, view interpolation reduces to the trivial task of rendering polygonal meshes, which can be done very fast, particularly when GPUs are employed. Furthermore, the generated views are hole-free, unlike most point-based view interpolation schemes that require some kind of post-processing procedures to fill holes.

  8. Retinal Imaging of Infants on Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Anand Vinekar

    2015-01-01

    Full Text Available Spectral domain coherence tomography (SD OCT has become an important tool in the management of pediatric retinal diseases. It is a noncontact imaging device that provides detailed assessment of the microanatomy and pathology of the infant retina with a short acquisition time allowing office examination without the requirement of anesthesia. Our understanding of the development and maturation of the infant fovea has been enhanced by SD OCT allowing an in vivo assessment that correlates with histopathology. This has helped us understand the critical correlation of foveal development with visual potential in the first year of life and beyond. In this review, we summarize the recent literature on the clinical applications of SD OCT in studying the pathoanatomy of the infant macula, its ability to detect subclinical features, and its correlation with disease and vision. Retinopathy of prematurity and macular edema have been discussed in detail. The review also summarizes the current status of SD OCT in other infant retinal conditions, imaging the optic nerve, the choroid, and the retinal nerve fibre in infants and children, and suggests future areas of research.

  9. Far- and near-field second harmonic imaging of ferroelectric domain walls

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.; Pedersen, Kjeld; Skettrup, Torben

    1998-01-01

    Domain walls in periodically poled ferroelectric LiNbO3 crystals are observed with both far- and near-field imaging techniques that make use of second harmonic generation in the transition regions between neighbouring domains. Second harmonic images of domain walls represent bright lines of about.......5 micrometers in width (as measured with the near-field microscope) for the polarization of the second harmonic radiation perpendicular to the domain walls. Origin and selection rules for the constrast in second harmonic images of domain walls are discussed....

  10. THE PUBLIC IMAGE – FACETS AND STAGES IN ITS CREATION

    Directory of Open Access Journals (Sweden)

    Corina RADULESCU

    2011-12-01

    Full Text Available Public image is the representation or the idea that the public envisages as to an institution/organization and that special literature coins as: institutional image, enterprise image, prestige publicity, brand image, product image, institutional communication – all of these phrases representing multiple ”facets” of the public image whose unique goal is to create a positive representation of an institution. These facets – which are essentially different – often overlap.Thus, in this paper, we intend to distinguish between the multiple facets that the public image implies and, in order to do this, we firstly refer to the definition, characteristics and structure of the public image, so that we separately analyse its forms of manifestation and reveal the specific difference of the institutional image – which in its pure form aims at creating in the consumer’s/citizen’s mind an identity and a clear organizational representation, which is particularly different from commercial mark images. In the conclusion section to our paper, we indicate the steps that have to be followed in order to create a positive image for an organization.

  11. 76 FR 58281 - Magnetic Resonance Imaging Safety; Public Workshop

    Science.gov (United States)

    2011-09-20

    ... HUMAN SERVICES Food and Drug Administration Magnetic Resonance Imaging Safety; Public Workshop AGENCY... the safe use of magnetic resonance imaging (MRI) and approaches to mitigate risks. The overall goal is...: The Food and Drug Administration (FDA) is announcing a public workshop entitled: ``Magnetic...

  12. Problems with Permatrace: a note on digital image publication

    Directory of Open Access Journals (Sweden)

    Guy Hopkinson

    2004-01-01

    Full Text Available The methodology presented here developed out of work required to convert the hard-copy illustrations submitted to Internet Archaeology for publication of the 1975 excavations at Cricklade. The publication (and digital image preparatory work was funded by English Heritage and was, in part, an experiment designed to explore some of the possibilities presented by digital image publication. Various challenges in how to transform the drawings on permatrace to a digital format were encountered. While a full exploration of the potential of all areas of digital image preparation and publication was not possible, some interesting technical options were evaluated. This short article explains the processes applied in creating the images that were finally incorporated within the publication. It also examines some other avenues regarding the presentation of archaeological drawings that could be explored in both future Internet Archaeology content and other digital publications.

  13. A simple technique for morphological measurement of cerebral arterial circle variations using public domain software (Osiris).

    Science.gov (United States)

    Ansari, Saeed; Dadmehr, Majid; Eftekhar, Behzad; McConnell, Douglas J; Ganji, Sarah; Azari, Hassan; Kamali-Ardakani, Shahab; Hoh, Brian L; Mocco, J

    2011-12-01

    This article describes a straightforward method to measure the dimensions and identify morphological variations in the cerebral arterial circle using the general-purpose software program Osiris. This user-friendly and portable program displays, manipulates, and analyzes medical digital images, and it has the capability to determine morphometric properties of selected blood vessels (or other anatomical structures) in humans and animals. To ascertain morphometric variations in the cerebral arterial circle, 132 brains of recently deceased fetuses, infants, and adults were dissected. The dissection procedure was first digitized, and then the dimensions were measured with Osiris software. Measurements of each vessel's length and external diameters were used to identify and classify morphological variations in the cerebral arterial circle. The most commonly observed anatomical variations were uni- and bilateral hypoplasia of the posterior communicating artery. This study demonstrates that public domain software can be used to measure and classify cerebral arterial circle vessels. This method could be extended to examine other anatomical regions or to study other animals. Additionally, knowledge of variations within the circle could be applied clinically to enhance diagnostic and treatment specificity.

  14. Creating a brand image for public health nursing.

    Science.gov (United States)

    Baldwin, Kathleen A; Lyons, Roberta L; Issel, L Michele

    2011-01-01

    Public health nurses (PHNs) have declined as a proportion of both the nursing and the public health workforces in the past 2 decades. This decline comes as 30 states report public health nursing as the sector most affected in the overall public health shortage. Taken together, these data point to a need for renewed recruitment efforts. However, the current public images of nurses are primarily those of professionals employed in hospital settings. Therefore, this paper describes the development of a marketable image aimed at increasing the visibility and public awareness of PHNs and their work. Such a brand image was seen as a precursor to increasing applications for PHN positions. A multimethod qualitative sequential approach guided the branding endeavor. From the thoughts of public health nursing students, faculty, and practitioners came artists' renditions of four award-winning posters. These posters portray public health nursing-incorporating its image, location of practice, and levels of protection afforded the community. Since their initial unveiling, these posters have been distributed by request throughout the United States and Canada. The overwhelming response serves to underline the previous void of current professional images of public health nursing and the need for brand images to aid with recruitment.

  15. Deep subwavelength nanometric image reconstruction using Fourier domain optical normalization

    Institute of Scientific and Technical Information of China (English)

    Jing Qin; Richard M Silver; Bryan M Barnes; Hui Zhou; Ronald G Dixson; Mark-Alexander Henn

    2016-01-01

    Quantitative optical measurements of deep subwavelength,three-dimensional (3D),nanometric structures with sensitivity to sub-nanometer details address a ubiquitous measurement challenge.A Fourier domain normalization approach is used in the Fourier optical imaging code to simulate the full 3D scattered light field of nominally 15 nm-sized structures,accurately replicating the light field as a function of the focus position.Using the full 3D light field,nanometer scale details such as a 2 nm thin conformal oxide and nanometer topography are rigorously fitted for features less than one-thirtiethof the wavelength in size.The densely packed structures are positioned nearly an order of magnitude closer than the conventional Rayleigh resolution limit and can be measured with sub-nanometer parametric uncertainties.This approach enables a practical measurement sensitivity to size variations of only a few atoms in size using a high-throughput optical configuration with broad application in measuring nanometric structures and nanoelectronic devices.

  16. A Review of Domain Modelling and Domain Imaging Techniques in Ferroelectric Crystals

    Directory of Open Access Journals (Sweden)

    John E. Huber

    2011-02-01

    Full Text Available The present paper reviews models of domain structure in ferroelectric crystals, thin films and bulk materials. Common crystal structures in ferroelectric materials are described and the theory of compatible domain patterns is introduced. Applications to multi-rank laminates are presented. Alternative models employing phase-field and related techniques are reviewed. The paper then presents methods of observing ferroelectric domain structure, including optical, polarized light, scanning electron microscopy, X-ray and neutron diffraction, atomic force microscopy and piezo-force microscopy. Use of more than one technique for unambiguous identification of the domain structure is also described.

  17. Image Deblurring and Super-resolution by Adaptive Sparse Domain Selection and Adaptive Regularization

    CERN Document Server

    Dong, Weisheng; Shi, Guangming; Wu, Xiaolin

    2010-01-01

    As a powerful statistical image modeling technique, sparse representation has been successfully used in various image restoration applications. The success of sparse representation owes to the development of l1-norm optimization techniques, and the fact that natural images are intrinsically sparse in some domain. The image restoration quality largely depends on whether the employed sparse domain can represent well the underlying image. Considering that the contents can vary significantly across different images or different patches in a single image, we propose to learn various sets of bases from a pre-collected dataset of example image patches, and then for a given patch to be processed, one set of bases are adaptively selected to characterize the local sparse domain. We further introduce two adaptive regularization terms into the sparse representation framework. First, a set of autoregressive (AR) models are learned from the dataset of example image patches. The best fitted AR models to a given patch are ad...

  18. Safety features in nuclear power plants to eliminate the need of emergency planning in public domain

    Indian Academy of Sciences (India)

    P K Vijayan; M T Kamble; A K Nayak; K K Vaze; R K Sinha

    2013-10-01

    Following the Fukushima accident, the safety features of Nuclear Power Plants (NPP) are being re-examined worldwide including India to demonstrate capabilities to cope with severe accidents. In order to restore public confidence and support for nuclear power, it is felt necessary to design future NPPs with near zero impact outside the plant boundary and thus enabling elimination of emergency planning in public domain. Authors have identified a set of safety features which are needed to be incorporated in advanced reactors to achieve this goal. These features enabling prevention, termination, mitigation and containment of radioactivity for beyond design basis accidents arising from extreme natural events are essential for achieving the goal of elimination of emergency planning in public domain. Inherent safety characteristics, passive and engineered safety features to achieve these functions are discussed in this paper. Present trends and future developments in this direction are also described briefly.

  19. An adaptive nonlocal filtering for low-dose CT in both image and projection domains

    Directory of Open Access Journals (Sweden)

    Yingmei Wang

    2015-04-01

    Full Text Available An important problem in low-dose CT is the image quality degradation caused by photon starvation. There are a lot of algorithms in sinogram domain or image domain to solve this problem. In view of strong self-similarity contained in the special sinusoid-like strip data in the sinogram space, we propose a novel non-local filtering, whose average weights are related to both the image FBP (filtered backprojection reconstructed from restored sinogram data and the image directly FBP reconstructed from noisy sinogram data. In the process of sinogram restoration, we apply a non-local method with smoothness parameters adjusted adaptively to the variance of noisy sinogram data, which makes the method much effective for noise reduction in sinogram domain. Simulation experiments show that our proposed method by filtering in both image and projection domains has a better performance in noise reduction and details preservation in reconstructed images.

  20. Image authentication based on double-image encryption and partial phase decryption in nonseparable fractional Fourier domain

    Science.gov (United States)

    Yuan, Lin; Ran, Qiwen; Zhao, Tieyu

    2017-02-01

    In this paper an image authentication scheme is proposed based on double-image encryption and partial phase decryption in nonseparable Fractional Fourier transform domain. Two original images are combined and transformed into the nonseparable fractional Fourier domain. Only part of the phase information of the encrypted result is kept for decryption while the rest part of phase and all the amplitude information are discarded. The two recovered images are hardly recognized by visual inspection but can be authenticated by the nonlinear correlation algorithm. The numerical simulations demonstrate the viability and validity of the proposed image authentication scheme.

  1. The public image of nursing: a profession to learn about

    National Research Council Canada - National Science Library

    Errasti-Ibarrondo, B; Arantzamendi-Solabarrieta, M; Canga-Armayor, A

    2012-01-01

    .... As a result, this review of the literature has tried to identify the image of nursing held by the population, the prevailing stereotypes related to it, and what the public considers that nurses do...

  2. Images and Reflections: Photography in the Pursuit of Public Health

    National Research Council Canada - National Science Library

    Nigel Bruce

    2000-01-01

    .... Yet, who knows how much images such as Nick Ut's celebrated photograph of a naked, napalm burned girl running from the smoking remains of her village contributed to the change in public opinion...

  3. Computers in Public Schools: Changing the Image with Image Processing.

    Science.gov (United States)

    Raphael, Jacqueline; Greenberg, Richard

    1995-01-01

    The kinds of educational technologies selected can make the difference between uninspired, rote computer use and challenging learning experiences. University of Arizona's Image Processing for Teaching Project has worked with over 1,000 teachers to develop image-processing techniques that provide students with exciting, open-ended opportunities for…

  4. 37 CFR 201.26 - Recordation of documents pertaining to computer shareware and donation of public domain computer...

    Science.gov (United States)

    2010-07-01

    ... pertaining to computer shareware and donation of public domain computer software. 201.26 Section 201.26... GENERAL PROVISIONS § 201.26 Recordation of documents pertaining to computer shareware and donation of public domain computer software. (a) General. This section prescribes the procedures for submission of...

  5. 32 CFR 644.24 - Acquisition by Transfer from other Government Departments or Agencies (except Public Domain).

    Science.gov (United States)

    2010-07-01

    ... Departments or Agencies (except Public Domain). 644.24 Section 644.24 National Defense Department of Defense... Departments or Agencies (except Public Domain). When a requirement develops for the acquisition of Government... of existing improvements, the estimated cost of the proposed construction, attitude of the...

  6. A NEW TECHNIQUE BASED ON CHAOTIC STEGANOGRAPHY AND ENCRYPTION TEXT IN DCT DOMAIN FOR COLOR IMAGE

    Directory of Open Access Journals (Sweden)

    MELAD J. SAEED

    2013-10-01

    Full Text Available Image steganography is the art of hiding information into a cover image. This paper presents a new technique based on chaotic steganography and encryption text in DCT domain for color image, where DCT is used to transform original image (cover image from spatial domain to frequency domain. This technique used chaotic function in two phases; firstly; for encryption secret message, second; for embedding in DCT cover image. With this new technique, good results are obtained through satisfying the important properties of steganography such as: imperceptibility; improved by having mean square error (MSE, peak signal to noise ratio (PSNR and normalized correlation (NC, to phase and capacity; improved by encoding the secret message characters with variable length codes and embedding the secret message in one level of color image only.

  7. Co-registration of ultrasound and frequency-domain photoacoustic radar images and image improvement for tumor detection

    Science.gov (United States)

    Dovlo, Edem; Lashkari, Bahman; Choi, Sung soo Sean; Mandelis, Andreas

    2015-03-01

    This paper demonstrates the co-registration of ultrasound (US) and frequency domain photoacoustic radar (FD-PAR) images with significant image improvement from applying image normalization, filtering and amplification techniques. Achieving PA imaging functionality on a commercial Ultrasound instrument could accelerate clinical acceptance and use. Experimental results presented demonstrate live animal testing and show enhancements in signal-to-noise ratio (SNR), contrast and spatial resolution. The co-registered image produced from the US and phase PA images, provides more information than both images independently.

  8. Combining Public Domain and Professional Panoramic Imagery for the Accurate and Dense 3d Reconstruction of the Destroyed Bel Temple in Palmyra

    Science.gov (United States)

    Wahbeh, W.; Nebiker, S.; Fangi, G.

    2016-06-01

    This paper exploits the potential of dense multi-image 3d reconstruction of destroyed cultural heritage monuments by either using public domain touristic imagery only or by combining the public domain imagery with professional panoramic imagery. The focus of our work is placed on the reconstruction of the temple of Bel, one of the Syrian heritage monuments, which was destroyed in September 2015 by the so called "Islamic State". The great temple of Bel is considered as one of the most important religious buildings of the 1st century AD in the East with a unique design. The investigations and the reconstruction were carried out using two types of imagery. The first are freely available generic touristic photos collected from the web. The second are panoramic images captured in 2010 for documenting those monuments. In the paper we present a 3d reconstruction workflow for both types of imagery using state-of-the art dense image matching software, addressing the non-trivial challenges of combining uncalibrated public domain imagery with panoramic images with very wide base-lines. We subsequently investigate the aspects of accuracy and completeness obtainable from the public domain touristic images alone and from the combination with spherical panoramas. We furthermore discuss the challenges of co-registering the weakly connected 3d point cloud fragments resulting from the limited coverage of the touristic photos. We then describe an approach using spherical photogrammetry as a virtual topographic survey allowing the co-registration of a detailed and accurate single 3d model of the temple interior and exterior.

  9. A Digital Image Watermarking Method in the Discrete Cosine Transformation Domain

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Khammar

    2012-01-01

    Full Text Available In this paper, a watermarking method has been proposed based on Discrete Cosine Transform(DCT which can be used in order to protect copyrighting and to provide right of image ownership. In this method, the original image transferred to DCT domain after dividing into non-overlapped blocks 8×8 and to the same method, watermark image which can be whether a firm mark or any desired image from owner of the art work, after dividing into non-overlapped blocks 4×4, transferred to DCT domain. Watermark image coefficients after one step coding composed with low frequency coefficients of original image and create the final watermark image. On the other hand, the process of reforming watermarked image and extracting the original watermark on the secondary side is extractable by using original image and with reverse mechanism. Experiments show that this method in encountering with a number of routine attacks has a good resistance.

  10. Towards development of a high quality public domain global roads database

    Directory of Open Access Journals (Sweden)

    Andrew Nelson

    2006-12-01

    Full Text Available There is clear demand for a global spatial public domain roads data set with improved geographic and temporal coverage, consistent coding of road types, and clear documentation of sources. The currently best available global public domain product covers only one-quarter to one-third of the existing road networks, and this varies considerably by region. Applications for such a data set span multiple sectors and would be particularly valuable for the international economic development, disaster relief, and biodiversity conservation communities, not to mention national and regional agencies and organizations around the world. The building blocks for such a global product are available for many countries and regions, yet thus far there has been neither strategy nor leadership for developing it. This paper evaluates the best available public domain and commercial data sets, assesses the gaps in global coverage, and proposes a number of strategies for filling them. It also identifies stakeholder organizations with an interest in such a data set that might either provide leadership or funding for its development. It closes with a proposed set of actions to begin the process.

  11. Direct imaging of structural domains in iron pnictides

    Science.gov (United States)

    Tanatar, Makariy

    2010-03-01

    The parent compounds of iron-arsenide superconductors undergo first order structural transition between tetragonal and orthorhombic phases at a temperature, TS. In AFe2As2 (122) compounds (A=Ca,Sr,Ba) this occurs simultaneously with magnetic transition at TM. Using a combination of polarized light microscopy and spatially-resolved high-energy synchrotron x-ray diffraction we show the orthorhombic distortion leads to the formation of 45^o-type structural domains in both 122 and 1111 single crystals. Domains penetrate through the sample thickness in the c-direction and are not affected by crystal imperfections such as growth terraces. The domains form regular stripe patterns in the plane with a characteristic dimension of 10-50 μm. In a range of low Co-doped compositions structural domains and superconductivity coexist. With the increasing doping level the domain structure becomes more intertwined and fine due to a decrease in the orthorhombic distortion. This results in an energy landscape with maze-like spatial modulations favorable for pinning and intrinsically high critical current densities in the underdoped regime. M.A.Tanatar et al. Phys. Rev. B 79, 180508 (R) (2009). R. Prozorov et al. arxiv: 0909.0923, Phys. Rev.B accepted.

  12. Common-image gathers in the offset domain from reverse-time migration

    KAUST Repository

    Zhan, Ge

    2014-04-01

    Kirchhoff migration is flexible to output common-image gathers (CIGs) in the offset domain by imaging data with different offsets separately. These CIGs supply important information for velocity model updates and amplitude-variation-with-offset (AVO) analysis. Reverse-time migration (RTM) offers more insights into complex geology than Kirchhoff migration by accurately describing wave propagation using the two-way wave equation. But, it has difficulty to produce offset domain CIGs like Kirchhoff migration. In this paper, we develop a method for obtaining offset domain CIGs from RTM. The method first computes the RTM operator of an offset gather, followed by a dot product of the operator and the offset data to form a common-offset RTM image. The offset domain CIGs are then achieved after separately migrating data with different offsets. We generate offset domain CIGs on both the Marmousi synthetic data and 2D Gulf of Mexico real data using this approach. © 2014.

  13. New algorithms for processing images in the transform-compressed domain

    Science.gov (United States)

    Chang, Shih-Fu

    1995-04-01

    Future multimedia applications involving images and video will require technologies enabling users to manipulate image and video data as flexibly as traditional text and numerical data. However, vast amounts of image and video data mandate the use of image compression, which makes direct manipulation and editing of image data difficult. To explore the maximum synergistic relationships between image manipulation and compression, we extend our prior study of transform-domain image manipulation techniques to more complicated image operations such as rotation, shearing, and line-wise special effects. We propose to extract the individual image rows (columns) first and then apply the previously proposed transform-domain filtering and scaling techniques. The transform-domain rotation and line-wise operations can be accomplished by calculating the summation of products of nonzero transform coefficients and some precalculated special matrices. The overall computational complexity depends on the compression rate of the input images. For highly-compressed images, the transform-domain technique provides great potential for improving the computation speed.

  14. Multifocus Image Fusion with PCNN in Shearlet Domain

    Directory of Open Access Journals (Sweden)

    Peng Geng

    2012-08-01

    Full Text Available The Shearlet form a tight frame at various scales and directions and are optimally sparse in representing images with edges. In this study, an image fusion method is proposed based on the Shearlet transform. Firstly, transform the image A and image B by the Shearlet transform. Secondly, PCNN is used for the every frequency subbands, which uses the number of output pulses from the PCNN’s neurons to select fusion coefficients. Finally an inverse Shearlet is applied on the new fused coefficients to reconstruct the fused image. Some experiments are performed, comparing the new algorithm with the DWT, Contourlet and NSCT method based on the PCNN. The experiment results show that the proposed fusion rule is effective and the new algorithm can provide better performance in fusing images.

  15. Optical image encryption in Fresnel domain using spiral phase transform

    Science.gov (United States)

    Kumar, Ravi; Bhaduri, Basanta

    2017-09-01

    In this study, we propose a new nonlinear optical image encryption technique using spiral phase transform (SPT). First, the primary image is phase encoded and multiplied with a random amplitude mask (RAM), and using power function, the product is then powered to m. This powered output is Fresnel propagated with distance z 1 and then modulated with a random phase mask (RPM). The modulated image is further Fresnel propagated with distance z 2. Similarly, a security image is also modulated with another RAM and then Fresnel propagated with distance z 3. Next, the two modulated images after Fresnel propagations, are interfered and further Fresnel propagated with distance z 4 to get a complex image. Finally, this complex image is SPT with particular spiral phase function (SPF), to get the final encrypted image for transmission. In the proposed technique, the security keys are Fresnel propagation distances, the security image, RPM, RAMs, power order, m, and order of SPF, q. Numerical simulation results confirm the validity and effectiveness of the proposed technique. The proposed technique is robust against noise and brutal force attacks.

  16. Synthesis of Disparate Optical Imaging Data for Space Domain Awareness

    CERN Document Server

    Schneider, Michael D

    2016-01-01

    We present a Bayesian algorithm to combine optical imaging of unresolved objects from distinct epochs and observation platforms for orbit determination and tracking. By propagating the non-Gaussian uncertainties we are able to optimally combine imaging of arbitrary signal-to-noise ratios, allowing the integration of data from low-cost sensors. Our Bayesian approach to image characterization also allows large compression of imaging data without loss of statistical information. With a computationally efficient algorithm to combine multiple observation epochs and multiple telescopes, we show statistically optimal orbit inferences.

  17. Wide-field quantitative imaging of tissue microstructure using sub-diffuse spatial frequency domain imaging.

    Science.gov (United States)

    McClatchy, David M; Rizzo, Elizabeth J; Wells, Wendy A; Cheney, Philip P; Hwang, Jeeseong C; Paulsen, Keith D; Pogue, Brian W; Kanick, Stephen C

    2016-06-20

    Localized measurements of scattering in biological tissue provide sensitivity to microstructural morphology but have limited utility to wide-field applications, such as surgical guidance. This study introduces sub-diffusive spatial frequency domain imaging (sd-SFDI), which uses high spatial frequency illumination to achieve wide-field sampling of localized reflectances. Model-based inversion recovers macroscopic variations in the reduced scattering coefficient [Formula: see text] and the phase function backscatter parameter (γ). Measurements in optical phantoms show quantitative imaging of user-tuned phase-function-based contrast with accurate decoupling of parameters that define both the density and the size-scale distribution of scatterers. Measurements of fresh ex vivo breast tissue samples revealed, for the first time, unique clustering of sub-diffusive scattering properties for different tissue types. The results support that sd-SFDI provides maps of microscopic structural biomarkers that cannot be obtained with diffuse wide-field imaging and characterizes spatial variations not resolved by point-based optical sampling.

  18. Frequency-domain imaging algorithm for ultrasonic testing by application of matrix phased arrays

    Directory of Open Access Journals (Sweden)

    Dolmatov Dmitry

    2017-01-01

    Full Text Available Constantly increasing demand for high-performance materials and systems in aerospace industry requires advanced methods of nondestructive testing. One of the most promising methods is ultrasonic imaging by using matrix phased arrays. This technique allows to create three-dimensional ultrasonic imaging with high lateral resolution. Further progress in matrix phased array ultrasonic testing is determined by the development of fast imaging algorithms. In this article imaging algorithm based on frequency domain calculations is proposed. This approach is computationally efficient in comparison with time domain algorithms. Performance of the proposed algorithm was tested via computer simulations for planar specimen with flat bottom holes.

  19. A novel algorithm for fractional resizing of digital image in DCT domain

    Institute of Scientific and Technical Information of China (English)

    Wang Ci; Zhang Wenjun; Zheng Meng

    2005-01-01

    Fractional resizing of digital images is needed in various applications, such as displaying at different resolution depending on that of display device, building image index for an image database, and changing resolution according to the transmission channel bandwidth. With the wide use of JPEG and MPEG, almost all digital images are stored and transferred in DCT compressed format. Inorder to save the computation and memory cost, it is desirable to do resizing in DCT domain directly. This paper presents a fast and efficient method, which possesses the capability of fractional resizing in DCT domain. Experimental results confirm that this scheme can achieve significant computation cost reduction while maintain better quality.

  20. Phase image encryption in the fractional Hartley domain using Arnold transform and singular value decomposition

    Science.gov (United States)

    Singh, Phool; Yadav, A. K.; Singh, Kehar

    2017-04-01

    A novel scheme for image encryption of phase images is proposed, using fractional Hartley transform followed by Arnold transform and singular value decomposition in the frequency domain. Since the plaintext is a phase image, the mask used in the spatial domain is a random amplitude mask. The proposed scheme has been validated for grayscale images and is sensitive to the encryption parameters such as the order of the Arnold transform and the fractional orders of the Hartley transform. We have also evaluated the scheme's resistance to the well-known noise and occlusion attacks.

  1. Terahertz time-domain spectroscopy and imaging of artificial RNA

    DEFF Research Database (Denmark)

    Fischer, Bernd M.; Hoffmann, Matthias; Helm, Hanspeter

    2005-01-01

    We use terahertz time-domain spectroscopy (THz-TDS) to measure the far-infrared dielectric function of two artificial RNA single strands, composed of polyadenylic acid (poly-A) and polycytidylic acid (poly-C). We find a significant difference in the absorption between the two types of RNA strands...... in the absorption spectra....

  2. Terahertz time-domain spectroscopy and imaging of artificial RNA

    DEFF Research Database (Denmark)

    Fischer, Bernd M.; Hoffmann, Matthias; Helm, Hanspeter

    2005-01-01

    We use terahertz time-domain spectroscopy (THz-TDS) to measure the far-infrared dielectric function of two artificial RNA single strands, composed of polyadenylic acid (poly-A) and polycytidylic acid (poly-C). We find a significant difference in the absorption between the two types of RNA strands...

  3. A novel end-to-end classifier using domain transferred deep convolutional neural networks for biomedical images.

    Science.gov (United States)

    Pang, Shuchao; Yu, Zhezhou; Orgun, Mehmet A

    2017-03-01

    Highly accurate classification of biomedical images is an essential task in the clinical diagnosis of numerous medical diseases identified from those images. Traditional image classification methods combined with hand-crafted image feature descriptors and various classifiers are not able to effectively improve the accuracy rate and meet the high requirements of classification of biomedical images. The same also holds true for artificial neural network models directly trained with limited biomedical images used as training data or directly used as a black box to extract the deep features based on another distant dataset. In this study, we propose a highly reliable and accurate end-to-end classifier for all kinds of biomedical images via deep learning and transfer learning. We first apply domain transferred deep convolutional neural network for building a deep model; and then develop an overall deep learning architecture based on the raw pixels of original biomedical images using supervised training. In our model, we do not need the manual design of the feature space, seek an effective feature vector classifier or segment specific detection object and image patches, which are the main technological difficulties in the adoption of traditional image classification methods. Moreover, we do not need to be concerned with whether there are large training sets of annotated biomedical images, affordable parallel computing resources featuring GPUs or long times to wait for training a perfect deep model, which are the main problems to train deep neural networks for biomedical image classification as observed in recent works. With the utilization of a simple data augmentation method and fast convergence speed, our algorithm can achieve the best accuracy rate and outstanding classification ability for biomedical images. We have evaluated our classifier on several well-known public biomedical datasets and compared it with several state-of-the-art approaches. We propose a robust

  4. Tomographic imaging with ultra-wideband noise radar using time-domain data

    Science.gov (United States)

    Shin, Hee Jung; Narayanan, Ram M.; Rangaswamy, Muralidhar

    2013-05-01

    This paper investigates the feasibility of using a noise waveform in an ultra-wideband (UWB) radar system for two-dimensional tomographic imaging of a stationary object with a multistatic tomographic geometry. Multiple UWB transmitters and receivers are positioned along each side of the imaging area. We perform several numerical simulations in time-domain, and the successful imaging of the target is achieved by visual inspection of the formed images.

  5. Image Encryption Using Differential Evolution Approach in Frequency Domain

    CERN Document Server

    Hassan, Maaly Awad S; 10.5121/sipij.2011.2105

    2011-01-01

    This paper presents a new effective method for image encryption which employs magnitude and phase manipulation using Differential Evolution (DE) approach. The novelty of this work lies in deploying the concept of keyed discrete Fourier transform (DFT) followed by DE operations for encryption purpose. To this end, a secret key is shared between both encryption and decryption sides. Firstly two dimensional (2-D) keyed discrete Fourier transform is carried out on the original image to be encrypted. Secondly crossover is performed between two components of the encrypted image, which are selected based on Linear Feedback Shift Register (LFSR) index generator. Similarly, keyed mutation is performed on the real parts of a certain components selected based on LFSR index generator. The LFSR index generator initializes it seed with the shared secret key to ensure the security of the resulting indices. The process shuffles the positions of image pixels. A new image encryption scheme based on the DE approach is developed...

  6. Dual Modality Noncontact Photoacoustic and Spectral Domain OCT Imaging.

    Science.gov (United States)

    Leiss-Holzinger, Elisabeth; Bauer-Marschallinger, Johannes; Hochreiner, Armin; Hollinger, Philipp; Berer, Thomas

    2016-01-01

    We developed a multimodal imaging system, combining noncontact photoacoustic imaging and optical coherence tomography (OCT). Photoacoustic signals are recorded without contact to the specimens' surface by using an interferometric technique. The interferometer is realized within a fiber-optic network using a fiber laser at 1550 nm as source. The fiber-optic network allows the integration of a fiber-based OCT system operating at a wavelength region around 1310 nm. Light from the fiber laser and the OCT source are multiplexed into one fiber using wavelength-division multiplexing. The same focusing optics is used for both modalities. Back-reflected light from the sample is demultiplexed and guided to the respective imaging systems. As the same optical components are used for OCT and photoacoustic imaging, the obtained images are co-registered intrinsically in lateral direction. Three-dimensional imaging is implemented by hybrid galvanometer and mechanical scanning. To allow fast B-scan measurements, scanning of the interrogation beam along one dimension is executed by a galvanometer scanner. Slow-axis scanning, perpendicular to the fast axis, is performed utilizing a linear translational stage. We demonstrate two-dimensional and three-dimensional imaging on agarose phantoms.

  7. Image characterization by fractal descriptors in variational mode decomposition domain: Application to brain magnetic resonance

    Science.gov (United States)

    Lahmiri, Salim

    2016-08-01

    The main purpose of this work is to explore the usefulness of fractal descriptors estimated in multi-resolution domains to characterize biomedical digital image texture. In this regard, three multi-resolution techniques are considered: the well-known discrete wavelet transform (DWT) and the empirical mode decomposition (EMD), and; the newly introduced; variational mode decomposition mode (VMD). The original image is decomposed by the DWT, EMD, and VMD into different scales. Then, Fourier spectrum based fractal descriptors is estimated at specific scales and directions to characterize the image. The support vector machine (SVM) was used to perform supervised classification. The empirical study was applied to the problem of distinguishing between normal and abnormal brain magnetic resonance images (MRI) affected with Alzheimer disease (AD). Our results demonstrate that fractal descriptors estimated in VMD domain outperform those estimated in DWT and EMD domains; and also those directly estimated from the original image.

  8. The image of the public institutions and new technologies

    OpenAIRE

    Mihaela PĂUN; Coman, Cristina

    2010-01-01

    During the recent past decades, a new technology and a new kind of media emerged: the social media. It created a huge communication area that houses the interactions and debate between creators of social images and messages. In public relations, the emergence of social media challenges the traditional instruments of government public relations. Responding to development of information and communication technology (ICT), social media is considered as an alternative communication channel of gov...

  9. A New Hybrid Watermarking Algorithm for Images in Frequency Domain

    Directory of Open Access Journals (Sweden)

    AhmadReza Naghsh-Nilchi

    2008-03-01

    Full Text Available In recent years, digital watermarking has become a popular technique for digital images by hiding secret information which can protect the copyright. The goal of this paper is to develop a hybrid watermarking algorithm. This algorithm used DCT coefficient and DWT coefficient to embedding watermark, and the extracting procedure is blind. The proposed approach is robust to a variety of signal distortions, such as JPEG, image cropping and scaling.

  10. Measurement of magnetic domain wall width using energy-filtered Fresnel images.

    Science.gov (United States)

    Lloyd, S J; Loudon, J C; Midgley, P A

    2002-08-01

    Magnetic domain walls in Nd2Fe14B have been examined using a series of energy-filtered Fresnel images in the field emission gun transmission electron microscope (FEGTEM). We describe the changes in the intensity distribution of the convergent wall image as a function of defocus, foil thickness and domain wall width. The effect of tilted domain walls and beam convergence on the fringe pattern is also discussed. A comparison of the experimental intensity profile with that from simulations allows the domain wall width to be determined. Measurement of very narrow walls is made possible only by using a relatively thick foil, which necessitates energy-filtering to allow quantitative comparison with simulations. The magnetic domain wall width in Nd2Fe14B was found to be 3 +/- 2 nm.

  11. Direct imaging of topological edge states at a bilayer graphene domain wall

    Science.gov (United States)

    Yin, Long-Jing; Jiang, Hua; Qiao, Jia-Bin; He, Lin

    2016-06-01

    The AB-BA domain wall in gapped graphene bilayers is a rare naked structure hosting topological electronic states. Although it has been extensively studied in theory, a direct imaging of its topological edge states is still missing. Here we image the topological edge states at the graphene bilayer domain wall by using scanning tunnelling microscope. The simultaneously obtained atomic-resolution images of the domain wall provide us unprecedented opportunities to measure the spatially varying edge states within it. The one-dimensional conducting channels are observed to be mainly located around the two edges of the domain wall, which is reproduced quite well by our theoretical calculations. Our experiment further demonstrates that the one-dimensional topological states are quite robust even in the presence of high magnetic fields. The result reported here may raise hopes of graphene-based electronics with ultra-low dissipation.

  12. Molecular scaffold analysis of natural products databases in the public domain.

    Science.gov (United States)

    Yongye, Austin B; Waddell, Jacob; Medina-Franco, José L

    2012-11-01

    Natural products represent important sources of bioactive compounds in drug discovery efforts. In this work, we compiled five natural products databases available in the public domain and performed a comprehensive chemoinformatic analysis focused on the content and diversity of the scaffolds with an overview of the diversity based on molecular fingerprints. The natural products databases were compared with each other and with a set of molecules obtained from in-house combinatorial libraries, and with a general screening commercial library. It was found that publicly available natural products databases have different scaffold diversity. In contrast to the common concept that larger libraries have the largest scaffold diversity, the largest natural products collection analyzed in this work was not the most diverse. The general screening library showed, overall, the highest scaffold diversity. However, considering the most frequent scaffolds, the general reference library was the least diverse. In general, natural products databases in the public domain showed low molecule overlap. In addition to benzene and acyclic compounds, flavones, coumarins, and flavanones were identified as the most frequent molecular scaffolds across the different natural products collections. The results of this work have direct implications in the computational and experimental screening of natural product databases for drug discovery.

  13. A Frequency Domain Approach to Registration of Aliased Images with Application to Super-resolution

    Directory of Open Access Journals (Sweden)

    Vandewalle Patrick

    2006-01-01

    Full Text Available Super-resolution algorithms reconstruct a high-resolution image from a set of low-resolution images of a scene. Precise alignment of the input images is an essential part of such algorithms. If the low-resolution images are undersampled and have aliasing artifacts, the performance of standard registration algorithms decreases. We propose a frequency domain technique to precisely register a set of aliased images, based on their low-frequency, aliasing-free part. A high-resolution image is then reconstructed using cubic interpolation. Our algorithm is compared to other algorithms in simulations and practical experiments using real aliased images. Both show very good visual results and prove the attractivity of our approach in the case of aliased input images. A possible application is to digital cameras where a set of rapidly acquired images can be used to recover a higher-resolution final image.

  14. Using anisotropic diffusion equations in pixon domain for image de-noising

    DEFF Research Database (Denmark)

    Nadernejad, Ehsan; Forchhammer, Søren; Sharifzadeh, Sara

    2013-01-01

    Image enhancement is an essential phase in many image processing algorithms. In any image de-noising algorithm, it is a major concern to keep the interesting structures of the image. Such interesting structures in an image often correspond to the discontinuities in the image (edges). In this paper......, we propose a new algorithm for image de-noising using anisotropic diffusion equations in pixon domain. In this approach, diffusion equations are applied on the pixonal model of the image. The algorithm has been examined on a variety of standard images and the performance has been compared...... with algorithms known from the literature. The experimental results show that in comparison with the other existing methods, the proposed algorithm has a better performance in de-noising and preserving image edges....

  15. Optical double image security using random phase fractional Fourier domain encoding and phase-retrieval algorithm

    Science.gov (United States)

    Rajput, Sudheesh K.; Nishchal, Naveen K.

    2017-04-01

    We propose a novel security scheme based on the double random phase fractional domain encoding (DRPE) and modified Gerchberg-Saxton (G-S) phase retrieval algorithm for securing two images simultaneously. Any one of the images to be encrypted is converted into a phase-only image using modified G-S algorithm and this function is used as a key for encrypting another image. The original images are retrieved employing the concept of known-plaintext attack and following the DRPE decryption steps with all correct keys. The proposed scheme is also used for encryption of two color images with the help of convolution theorem and phase-truncated fractional Fourier transform. With some modification, the scheme is extended for simultaneous encryption of gray-scale and color images. As a proof-of-concept, simulation results have been presented for securing two gray-scale images, two color images, and simultaneous gray-scale and color images.

  16. FEEDBACK ON A PUBLICLY DISTRIBUTED IMAGE DATABASE: THE MESSIDOR DATABASE

    Directory of Open Access Journals (Sweden)

    Etienne Decencière

    2014-08-01

    Full Text Available The Messidor database, which contains hundreds of eye fundus images, has been publicly distributed since 2008. It was created by the Messidor project in order to evaluate automatic lesion segmentation and diabetic retinopathy grading methods. Designing, producing and maintaining such a database entails significant costs. By publicly sharing it, one hopes to bring a valuable resource to the public research community. However, the real interest and benefit of the research community is not easy to quantify. We analyse here the feedback on the Messidor database, after more than 6 years of diffusion. This analysis should apply to other similar research databases.

  17. New image of psychiatry, mass media impact and public relations.

    Science.gov (United States)

    Jakovljević, Miro; Tomić, Zoran; Maslov, Boris; Skoko, Iko

    2010-06-01

    The mass media has a powerful impact on public attitudes about mental health and psychiatry. The question of identity of psychiatry as a medical profession as well as of the future of psychiatry has been the subject of much controversial discussion. Psychiatry today has the historical opportunity to shape the future of mental health care, medicine and society. It has gained in scientific and professional status by the tremendous increase of knowledge and treatment skills. Psychiatry should build up new transdisciplinary and integrative image of a specialized profession, promote it and make it public. Good public relations are very important for the future of psychiatry.

  18. Combination of a spinning disc confocal unit with frequency-domain fluorescence lifetime imaging microscopy.

    NARCIS (Netherlands)

    van Munster, E.B.; Goedhart, J.; Kremers, G.J.; Manders, E.M.M.; Gadella, Th.W.J.

    2007-01-01

    BACKGROUND: Wide-field frequency-domain fluorescence lifetime imaging microscopy (FLIM) is an established technique to determine fluorescence lifetimes. Disadvantage of wide-field imaging is that measurements are compromised by out-of-focus blur. Conventional scanning confocal typically means long

  19. HTGRAPPA: real-time B1-weighted image domain TGRAPPA reconstruction.

    Science.gov (United States)

    Saybasili, Haris; Kellman, Peter; Griswold, Mark A; Derbyshire, J Andrew; Guttman, Michael A

    2009-06-01

    The temporal generalized autocalibrating partially parallel acquisitions (TGRAPPA) algorithm for parallel MRI was modified for real-time low latency imaging in interventional procedures using image domain, B(1)-weighted reconstruction. GRAPPA coefficients were calculated in k-space, but applied in the image domain after appropriate transformation. Convolution-like operations in k-space were thus avoided, resulting in improved reconstruction speed. Image domain GRAPPA weights were combined into composite unmixing coefficients using adaptive B(1)-map estimates and optimal noise weighting. Images were reconstructed by pixel-by-pixel multiplication in the image domain, rather than time-consuming convolution operations in k-space. Reconstruction and weight-set calculation computations were parallelized and implemented on a general-purpose multicore architecture. The weight calculation was performed asynchronously to the real-time image reconstruction using a dedicated parallel processing thread. The weight-set coefficients were computed in an adaptive manner with updates linked to changes in the imaging scan plane. In this implementation, reconstruction speed is not dependent on acceleration rate or GRAPPA kernel size.

  20. Extracting and compensating dispersion mismatch in ultrahigh-resolution Fourier domain OCT imaging of the retina

    Science.gov (United States)

    Choi, WooJhon; Baumann, Bernhard; Swanson, Eric A.; Fujimoto, James G.

    2012-01-01

    We present a numerical approach to extract the dispersion mismatch in ultrahigh-resolution Fourier domain optical coherence tomography (OCT) imaging of the retina. The method draws upon an analogy with a Shack-Hartmann wavefront sensor. By exploiting mathematical similarities between the expressions for aberration in optical imaging and dispersion mismatch in spectral / Fourier domain OCT, Shack-Hartmann principles can be extended from the two-dimensional paraxial wavevector space (or the x-y plane in the spatial domain) to the one-dimensional wavenumber space (or the z-axis in the spatial domain). For OCT imaging of the retina, different retinal layers, such as the retinal nerve fiber layer (RNFL), the photoreceptor inner and outer segment junction (IS/OS), or all the retinal layers near the retinal pigment epithelium (RPE) can be used as point source beacons in the axial direction, analogous to point source beacons used in conventional two-dimensional Shack-Hartman wavefront sensors for aberration characterization. Subtleties regarding speckle phenomena in optical imaging, which affect the Shack-Hartmann wavefront sensor used in adaptive optics, also occur analogously in this application. Using this approach and carefully suppressing speckle, the dispersion mismatch in spectral / Fourier domain OCT retinal imaging can be successfully extracted numerically and used for numerical dispersion compensation to generate sharper, ultrahigh-resolution OCT images. PMID:23187353

  1. 3D Image Modelling and Specific Treatments in Orthodontics Domain

    Directory of Open Access Journals (Sweden)

    Dionysis Goularas

    2007-01-01

    Full Text Available In this article, we present a 3D specific dental plaster treatment system for orthodontics. From computer tomography scanner images, we propose first a 3D image modelling and reconstruction method of the Mandible and Maxillary based on an adaptive triangulation allowing management of contours meant for the complex topologies. Secondly, we present two specific treatment methods directly achieved on obtained 3D model allowing the automatic correction for the setting in occlusion of the Mandible and the Maxillary, and the teeth segmentation allowing more specific dental examinations. Finally, these specific treatments are presented via a client/server application with the aim of allowing a telediagnosis and treatment.

  2. INTERACTIVE DOMAIN ADAPTION FOR THE CLASSIFICATION OF REMOTE SENSING IMAGES USING ACTIVE LEARNING

    Directory of Open Access Journals (Sweden)

    U.Pushpa Lingam

    2015-11-01

    Full Text Available Interactive Domain Adaptation (IDA technique based on active learning for the classification of remote sensing images. Interactive domain adaptation method is used for adapting the supervised classifier trained on a given remote sensing source image to make it suitable for classifying a different but related target image. The two images can be acquired in different locations and at different times. This method iteratively selects the most informative samples of the target image to be labeled and included in the training set and the source image samples are reweighted or removed from the training set on the basis of their disagreement with the target image classification problem. The consistent information available from the source image can be effectively exploited for the classification of the target image and for guiding the selection of new samples to be labeled, whereas the inconsistent information is automatically detected and removed. This approach significantly reduces the number of new labeled samples to be collected from the target image. Experimental results on both a multispectral very high resolution and a hyper spectral data set confirm the effectiveness of the interactive domain adaptation for theclassification of remote sensing using active learning method.

  3. Quality metric in matched Laplacian of Gaussian response domain for blind adaptive optics image deconvolution

    Science.gov (United States)

    Guo, Shiping; Zhang, Rongzhi; Yang, Yikang; Xu, Rong; Liu, Changhai; Li, Jisheng

    2016-04-01

    Adaptive optics (AO) in conjunction with subsequent postprocessing techniques have obviously improved the resolution of turbulence-degraded images in ground-based astronomical observations or artificial space objects detection and identification. However, important tasks involved in AO image postprocessing, such as frame selection, stopping iterative deconvolution, and algorithm comparison, commonly need manual intervention and cannot be performed automatically due to a lack of widely agreed on image quality metrics. In this work, based on the Laplacian of Gaussian (LoG) local contrast feature detection operator, we propose a LoG domain matching operation to perceive effective and universal image quality statistics. Further, we extract two no-reference quality assessment indices in the matched LoG domain that can be used for a variety of postprocessing tasks. Three typical space object images with distinct structural features are tested to verify the consistency of the proposed metric with perceptual image quality through subjective evaluation.

  4. CT Image Reconstruction by Spatial-Radon Domain Data-Driven Tight Frame Regularization

    CERN Document Server

    Zhan, Ruohan

    2016-01-01

    This paper proposes a spatial-Radon domain CT image reconstruction model based on data-driven tight frames (SRD-DDTF). The proposed SRD-DDTF model combines the idea of joint image and Radon domain inpainting model of \\cite{Dong2013X} and that of the data-driven tight frames for image denoising \\cite{cai2014data}. It is different from existing models in that both CT image and its corresponding high quality projection image are reconstructed simultaneously using sparsity priors by tight frames that are adaptively learned from the data to provide optimal sparse approximations. An alternative minimization algorithm is designed to solve the proposed model which is nonsmooth and nonconvex. Convergence analysis of the algorithm is provided. Numerical experiments showed that the SRD-DDTF model is superior to the model by \\cite{Dong2013X} especially in recovering some subtle structures in the images.

  5. Quantum Image Encryption Based on Iterative Framework of Frequency-Spatial Domain Transforms

    Science.gov (United States)

    Wang, Han; Wang, Jian; Geng, Ya-Cong; Song, Yan; Liu, Ji-Qiang

    2017-10-01

    A novel quantum image encryption and decryption algorithm based on iteration framework of frequency-spatial domain transforms is proposed. In this paper, the images are represented in the flexible representation for quantum images (FRQI). Previous quantum image encryption algorithms are realized by spatial domain transform to scramble the position information of original images and frequency domain transform to encode the color information of images. But there are some problems such as the periodicity of spatial domain transform, which will make it easy to recover the original images. Hence, we present the iterative framework of frequency-spatial domain transforms. Based on the iterative framework, the novel encryption algorithm uses Fibonacci transform and geometric transform for many times to scramble the position information of the original images and double random-phase encoding to encode the color information of the images. The encryption keys include the iterative time t of the Fibonacci transform, the iterative time l of the geometric transform, the geometric transform matrix G i which is n × n matrix, the classical binary sequences K (k0k1{\\ldots } k_{2^{2n}-1}) and D(d0d1{\\ldots } d_{2^{2n}-1}). Here the key space of Fibonacci transform and geometric transform are both estimated to be 226. The key space of binary sequences is (2 n× n ) × (2 n× n ). Then the key space of the entire algorithm is about 2^{2{n2}+52}. Since all quantum operations are invertible, the quantum image decryption algorithm is the inverse of the encryption algorithm. The results of numerical simulation and analysis indicate that the proposed algorithm has high security and high sensitivity.

  6. Answer These Questions, and Polish Your Board's Public Image.

    Science.gov (United States)

    Freund, Sidney A.

    1984-01-01

    The public image of a school board can be enhanced if it handles business in a manner that inspires confidence. Seven suggestions are presented on topics such as location of meetings, procedures, agenda, handling audience comments, establishing priorities, handling complaints, and superintendent support. (TE)

  7. Daas: A Web-based System for User-specific Dietary Analysis and Advice for the Public Healthcare Domain

    Institute of Scientific and Technical Information of China (English)

    Deirdre Nugent; Kudakwashe Dube; Wu Bing

    2003-01-01

    This paper presents a Dietary Analysis and Advice System (DAAS), a web-based system for providing, within the public healthcare domain, user-specific diet advice based on a preliminary analysis of current diet or eating habits and lifestyle, using knowledge from domain expertise and experts' interpretation of national dietary guidelines.

  8. Texture-based medical image retrieval in compressed domain using compressive sensing.

    Science.gov (United States)

    Yadav, Kuldeep; Srivastava, Avi; Mittal, Ankush; Ansari, M A

    2014-01-01

    Content-based image retrieval has gained considerable attention in today's scenario as a useful tool in many applications; texture is one of them. In this paper, we focus on texture-based image retrieval in compressed domain using compressive sensing with the help of DC coefficients. Medical imaging is one of the fields which have been affected most, as there had been huge size of image database and getting out the concerned image had been a daunting task. Considering this, in this paper we propose a new model of image retrieval process using compressive sampling, since it allows accurate recovery of image from far fewer samples of unknowns and it does not require a close relation of matching between sampling pattern and characteristic image structure with increase acquisition speed and enhanced image quality.

  9. Emotional textile image classification based on cross-domain convolutional sparse autoencoders with feature selection

    Science.gov (United States)

    Li, Zuhe; Fan, Yangyu; Liu, Weihua; Yu, Zeqi; Wang, Fengqin

    2017-01-01

    We aim to apply sparse autoencoder-based unsupervised feature learning to emotional semantic analysis for textile images. To tackle the problem of limited training data, we present a cross-domain feature learning scheme for emotional textile image classification using convolutional autoencoders. We further propose a correlation-analysis-based feature selection method for the weights learned by sparse autoencoders to reduce the number of features extracted from large size images. First, we randomly collect image patches on an unlabeled image dataset in the source domain and learn local features with a sparse autoencoder. We then conduct feature selection according to the correlation between different weight vectors corresponding to the autoencoder's hidden units. We finally adopt a convolutional neural network including a pooling layer to obtain global feature activations of textile images in the target domain and send these global feature vectors into logistic regression models for emotional image classification. The cross-domain unsupervised feature learning method achieves 65% to 78% average accuracy in the cross-validation experiments corresponding to eight emotional categories and performs better than conventional methods. Feature selection can reduce the computational cost of global feature extraction by about 50% while improving classification performance.

  10. Open access high throughput drug discovery in the public domain: a Mount Everest in the making.

    Science.gov (United States)

    Roy, Anuradha; McDonald, Peter R; Sittampalam, Sitta; Chaguturu, Rathnam

    2010-11-01

    High throughput screening (HTS) facilitates screening large numbers of compounds against a biochemical target of interest using validated biological or biophysical assays. In recent years, a significant number of drugs in clinical trails originated from HTS campaigns, validating HTS as a bona fide mechanism for hit finding. In the current drug discovery landscape, the pharmaceutical industry is embracing open innovation strategies with academia to maximize their research capabilities and to feed their drug discovery pipeline. The goals of academic research have therefore expanded from target identification and validation to probe discovery, chemical genomics, and compound library screening. This trend is reflected in the emergence of HTS centers in the public domain over the past decade, ranging in size from modestly equipped academic screening centers to well endowed Molecular Libraries Probe Centers Network (MLPCN) centers funded by the NIH Roadmap initiative. These centers facilitate a comprehensive approach to probe discovery in academia and utilize both classical and cutting-edge assay technologies for executing primary and secondary screening campaigns. The various facets of academic HTS centers as well as their implications on technology transfer and drug discovery are discussed, and a roadmap for successful drug discovery in the public domain is presented. New lead discovery against therapeutic targets, especially those involving the rare and neglected diseases, is indeed a Mount Everestonian size task, and requires diligent implementation of pharmaceutical industry's best practices for a successful outcome.

  11. Fast Fractal Compression of Satellite and Medical Images Based on Domain-Range Entropy

    Directory of Open Access Journals (Sweden)

    Ramesh Babu Inampudi

    2010-01-01

    Full Text Available Fractal image Compression is a lossy compression technique developed in the early 1990s. It makes use of the local self-similarity property existing in an image and finds a contractive mapping affine transformation (fractal transformT, such that the fixed point of T is close to the given image in a suitable metric. It has generated much interest due to its promise of high compression ratios with good decompression quality. The other advantage is its multi resolution property, i.e. an image can be decoded at higher or lower resolutions than the original without much degradation in quality. However, the encoding time is computationally intensive. In this paper, a fast fractal image compression method based on the domain-range entropy is proposed to reduce the encoding time, while maintaining the fidelity and compression ratio of the decoded image. The method is a two-step process. First, domains that are similar i.e. domains having nearly equal variances are eliminated from the domain pool. Second, during the encoding phase, only domains and ranges having equal entropies (with an adaptive error threshold, λdepth for each quadtree depth are compared for a match within the rms error tolerance. As a result, many unqualified domains are removed from comparison and a significant reduction in encoding time is expected. The method is applied for compression of satellite and medical images (512x512, 8-bit gray scale. Experimental results show that the proposed method yields superior performance over Fisher’s classified search and other methods.

  12. Imaging and characterization of conducting ferroelectric domain walls by photoemission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schaab, J.; Meier, D., E-mail: dennis.meier@mat.ethz.ch [Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 4, 8093 Zurich (Switzerland); Krug, I. P. [Institut für Optik und Atomare Physik, TU Berlin, Hardenbergstrasse 36, 10623 Berlin (Germany); Forschungszentrum Jülich Peter Grünberg Institute (PGI-6), Leo-Brandt-Strasse, 52425 Jülich (Germany); Nickel, F.; Gottlob, D. M.; Doğanay, H.; Schneider, C. M. [Forschungszentrum Jülich Peter Grünberg Institute (PGI-6), Leo-Brandt-Strasse, 52425 Jülich (Germany); Cano, A. [CNRS, Univ. Bordeaux, ICMCB, UPR 9048, F-33600 Pessac (France); Hentschel, M. [4th Physics Institute and Research Center SCoPE, University of Suttgart, Pfaffenwaldring 57, 70659 Stuttgart (Germany); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Yan, Z.; Bourret, E. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Ramesh, R. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States)

    2014-06-09

    High-resolution X-ray photoemission electron microscopy (X-PEEM) is a well-established method for imaging ferroelectric domain structures. Here, we expand the scope of application of X-PEEM and demonstrate its capability for imaging and investigating domain walls in ferroelectrics with high spatial resolution. Using ErMnO{sub 3} as test system, we show that ferroelectric domain walls can be visualized based on photo-induced charging effects and local variations in their electronic conductance can be mapped by analyzing the energy distribution of photoelectrons. Our results open the door for non-destructive, contact-free, and element-specific studies of the electronic and chemical structure at domain walls in ferroelectrics.

  13. Noncontact imaging of burn depth and extent in a porcine model using spatial frequency domain imaging.

    Science.gov (United States)

    Mazhar, Amaan; Saggese, Steve; Pollins, Alonda C; Cardwell, Nancy L; Nanney, Lillian; Cuccia, David J

    2014-08-01

    The standard of care for clinical assessment of burn severity and extent lacks a quantitative measurement. In this work, spatial frequency domain imaging (SFDI) was used to measure 48 thermal burns of graded severity (superficial partial, deep partial, and full thickness) in a porcine model. Functional (total hemoglobin and tissue oxygen saturation) and structural parameters (tissue scattering) derived from the SFDI measurements were monitored over 72 h for each burn type and compared to gold standard histological measurements of burn depth. Tissue oxygen saturation (stO₂) and total hemoglobin (ctHbT) differentiated superficial partial thickness burns from more severe burn types after 2 and 72 h, respectively (p burns from all burn types immediately after injury (p burn types from each other after 24 h (p burn depth as measured by vimentin immunostain (r² > 0.89). These results show promise for the use of SFDI-derived tissue scattering as a correlation to burn depth and the potential to assess burn depth via a combination of SFDI functional and structural parameters.

  14. Edge detection algorithm based on ICA-domain shrinkage in noisy images

    Institute of Scientific and Technical Information of China (English)

    HAN XianHua; DAI ShuiYan; LI Jian; XIA GuoRong

    2008-01-01

    We propose a robust edge detection method based on ICA-domain shrinkage (independent component analysis). It is known that most basis functions extracted from natural images by ICA are sparse and similar to localized and oriented receptive fields, and in the proposed edge detection method, a target image is first transformed by ICA basis functions and then the edges are detected or reconstructed with sparse components. Furthermore, by applying a shrinkage algorithm to filter out the components of noise in ICA-domain, we can readily obtain the sparse components of the original image, resulting in a kind of robust edge detection even for a noisy image with a very low SN ratio. The efficiency of the proposed method is demonstrated by experiments with some natural images.

  15. Ferroelectric Domain Imaging Mechanism in High-Vacuum Scanning Force Microscopy

    Institute of Scientific and Technical Information of China (English)

    ZENG Hua-Rong; YU Han-Feng; CHU Rui-Qing; LI Guo-Rong; YIN Qing-Rui

    2005-01-01

    @@ High-vacuum scanning force microscopy of the domain structures in PMN-PT single crystals is investigated. It has been shown that under high vacuum conditions, the polarization charges are not effectively compensated for by intrinsic screening charges from the ferroelectrics. This result suggests that the electrostatic tip-sample interaction plays a great contribution to the domain imaging mechanism in PMN-PT ferroelectric single crystals under high vacuum conditions.

  16. Optical double image encryption employing a pseudo image technique in the Fourier domain

    Science.gov (United States)

    Guo, Changliang; Liu, Shi; Sheridan, John T.

    2014-06-01

    A novel optical encryption method is proposed involving double image encryption in which one image is introduced as the pseudo image while the other is the original object image. The Double Random Phase Encoding technique is used to encrypt both the pseudo and object images into complex images. A unique binary image is then employed to first generate the random phase key for the object image encryption and then to embed the encrypted object image into the encrypted pseudo image, which acts as host image. Both the second random phase mask used for encoding the pseudo image and the binary image act as encryption keys. If an attacker attempts to crack the random phase key and decrypt the original object image, the pseudo image will be obtained instead. Simulation results and robustness tests are performed which demonstrate the feasibility of the algorithm.

  17. Time-domain imaging with quench-based fluorescent contrast agents

    Science.gov (United States)

    Akers, Walter J.; Solomon, Metasebya; Sudlow, Gail P.; Berezin, Mikhail; Achilefu, Samuel

    2012-03-01

    Quench-based probes utilize unique characteristics of fluorescence resonance energy transfer (FRET) to enhance contrast upon de-quenching. This mechanism has been used in a variety of molecular probes for imaging of cancer related enzyme activity such as matrix metalloproteinases, cathepsins and caspases. While non-fluorescent upon administration, fluorescence can be restored by separation of donor and acceptor, resulting in higher intensity in the presence of activator. Along with decreased quantum yield, FRET also results in altered fluorescence lifetime. Time-domain imaging can further enhance contrast and information yield from quench-based probes. We present in vivo time-domain imaging for detecting activation of quench-based probes. Quench-based probes utilize unique characteristics of fluorescence resonance energy transfer (FRET) to enhance contrast upon de-quenching. This mechanism has been used in a variety of molecular probes for imaging of cancer related enzyme activity such as matrix metalloproteinases, cathepsins and caspases. While non-fluorescent upon administration, fluorescence can be restored by separation of donor and acceptor, resulting in higher intensity in the presence of activator. Along with decreased quantum yield, FRET also results in altered fluorescence lifetime. Time-domain imaging can further enhance contrast and information yield from quench-based probes. We present in vivo time-domain imaging for detecting activation of quench-based probes. Time-domain diffuse optical imaging was performed to assess the FRET and quenching in living mice with orthotopic breast cancer. Tumor contrast enhancement was accompanied by increased fluorescence lifetime after administration of quenched probes selective for matrix metalloproteinases while no significant change was observed for non-quenched probes for integrin receptors. These results demonstrate the utility of timedomain imaging for detection of cancer-related enzyme activity in vivo.

  18. Simultaneous storage of medical images in the spatial and frequency domain: A comparative study

    Directory of Open Access Journals (Sweden)

    Acharya U Rajendra

    2004-06-01

    Full Text Available Abstract Background Digital watermarking is a technique of hiding specific identification data for copyright authentication. This technique is adapted here for interleaving patient information with medical images, to reduce storage and transmission overheads. Methods The patient information is encrypted before interleaving with images to ensure greater security. The bio-signals are compressed and subsequently interleaved with the image. This interleaving is carried out in the spatial domain and Frequency domain. The performance of interleaving in the spatial, Discrete Fourier Transform (DFT, Discrete Cosine Transform (DCT and Discrete Wavelet Transform (DWT coefficients is studied. Differential pulse code modulation (DPCM is employed for data compression as well as encryption and results are tabulated for a specific example. Results It can be seen from results, the process does not affect the picture quality. This is attributed to the fact that the change in LSB of a pixel changes its brightness by 1 part in 256. Spatial and DFT domain interleaving gave very less %NRMSE as compared to DCT and DWT domain. Conclusion The Results show that spatial domain the interleaving, the %NRMSE was less than 0.25% for 8-bit encoded pixel intensity. Among the frequency domain interleaving methods, DFT was found to be very efficient.

  19. Feature extraction for magnetic domain images of magneto-optical recording films using gradient feature segmentation

    Science.gov (United States)

    Quanqing, Zhu; Xinsai, Wang; Xuecheng, Zou; Haihua, Li; Xiaofei, Yang

    2002-07-01

    In this paper, we present a method to realize feature extraction on low contrast magnetic domain images of magneto-optical recording films. The method is based on the following three steps: first, Lee-filtering method is adopted to realize pre-filtering and noise reduction; this is followed by gradient feature segmentation, which separates the object area from the background area; finally the common linking method is adopted and the characteristic parameters of magnetic domain are calculated. We describe these steps with particular emphasis on the gradient feature segmentation. The results show that this method has advantages over other traditional ones for feature extraction of low contrast images.

  20. Secure public cloud platform for medical images sharing.

    Science.gov (United States)

    Pan, Wei; Coatrieux, Gouenou; Bouslimi, Dalel; Prigent, Nicolas

    2015-01-01

    Cloud computing promises medical imaging services offering large storage and computing capabilities for limited costs. In this data outsourcing framework, one of the greatest issues to deal with is data security. To do so, we propose to secure a public cloud platform devoted to medical image sharing by defining and deploying a security policy so as to control various security mechanisms. This policy stands on a risk assessment we conducted so as to identify security objectives with a special interest for digital content protection. These objectives are addressed by means of different security mechanisms like access and usage control policy, partial-encryption and watermarking.

  1. Towards spatial frequency domain optical imaging of neurovascular coupling in a mouse model of Alzheimer's disease

    Science.gov (United States)

    Lin, Alexander J.; Konecky, Soren D.; Rice, Tyler B.; Green, Kim N.; Choi, Bernard; Durkin, Anthony J.; Tromberg, Bruce J.

    2012-02-01

    Early neurovascular coupling (NVC) changes in Alzheimer's disease can potentially provide imaging biomarkers to assist with diagnosis and treatment. Previous efforts to quantify NVC with intrinsic signal imaging have required assumptions of baseline optical pathlength to calculate changes in oxy- and deoxy-hemoglobin concentrations during evoked stimuli. In this work, we present an economical spatial frequency domain imaging (SFDI) platform utilizing a commercially available LED projector, camera, and off-the-shelf optical components suitable for imaging dynamic optical properties. The fast acquisition platform described in this work is validated on silicone phantoms and demonstrated in neuroimaging of a mouse model.

  2. Double color image encryption using iterative phase retrieval algorithm in quaternion gyrator domain.

    Science.gov (United States)

    Shao, Zhuhong; Shu, Huazhong; Wu, Jiasong; Dong, Zhifang; Coatrieux, Gouenou; Coatrieux, Jean Louis

    2014-03-10

    This paper describes a novel algorithm to encrypt double color images into a single undistinguishable image in quaternion gyrator domain. By using an iterative phase retrieval algorithm, the phase masks used for encryption are obtained. Subsequently, the encrypted image is generated via cascaded quaternion gyrator transforms with different rotation angles. The parameters in quaternion gyrator transforms and phases serve as encryption keys. By knowing these keys, the original color images can be fully restituted. Numerical simulations have demonstrated the validity of the proposed encryption system as well as its robustness against loss of data and additive Gaussian noise.

  3. Frequency-domain fluorescence lifetime imaging system (pco.flim) based on a in-pixel dual tap control CMOS image sensor

    Science.gov (United States)

    Franke, Robert; Holst, Gerhard A.

    2015-03-01

    The luminescence lifetime as a beneficial analytical parameter is known for many years and is well described by a large variety of publications. Many instruments including 2D measuring systems with cameras have been developed and applied in the past years. However, since the current instrumentation to perform either time- or frequency-domain lifetime measurements is rather complex, new developments in CMOS image sensor technology have achieved to create new image sensors, which can efficiently be integrated into easier-to-handle luminescence lifetime measuring systems. The principle of these modulatable CMOS image sensors, while initially being designed for distance measurements, shows a clear analogy to frequency-domain FLIM measurements, which was proven by researchers [1, 2]. Based on this principle a new CMOS image sensor has been developed, integrated into a camera system and has been investigated within a research project. The image sensor has a resolution of 1024 × 1024 pixels with a 5.6 μm pitch and can be modulated up to 50 MHz. First measurements show an effective dynamic range of larger than 1:1024 (corresponding to 10 bit dynamic). The maximum frame rate is in the range of 90 frames/s in dual-tap mode, resulting in an effective lifetime image frame rate for realistic measurements of approximately 22 frames/s. The camera system pco.flim, featuring that image sensor, generates all required modulation signals from 5 kHz to 50 MHz (sinusoidal and rectangular). It performs advanced pixel correction to generate linear and high-quality images, while the basic lifetime image processing is done in the computer. The modulation frequency can be freely adjusted within the specified range. The characteristics of the camera systems are presented, and first results are discussed using different representations of the data like for example the phasor approach [3], which has been established to provide a more global view to pixelwise fluorescence lifetime data and

  4. A Novel Medical Image Watermarking in Three-dimensional Fourier Compressed Domain

    Directory of Open Access Journals (Sweden)

    Baoru Han

    2015-09-01

    Full Text Available Digital watermarking is a research hotspot in the field of image security, which is protected digital image copyright. In order to ensure medical image information security, a novel medical image digital watermarking algorithm in three-dimensional Fourier compressed domain is proposed. The novel medical image digital watermarking algorithm takes advantage of three-dimensional Fourier compressed domain characteristics, Legendre chaotic neural network encryption features and robust characteristics of differences hashing, which is a robust zero-watermarking algorithm. On one hand, the original watermarking image is encrypted in order to enhance security. It makes use of Legendre chaotic neural network implementation. On the other hand, the construction of zero-watermarking adopts differences hashing in three-dimensional Fourier compressed domain. The novel watermarking algorithm does not need to select a region of interest, can solve the problem of medical image content affected. The specific implementation of the algorithm and the experimental results are given in the paper. The simulation results testify that the novel algorithm possesses a desirable robustness to common attack and geometric attack.

  5. Graph Laplacian Regularization for Image Denoising: Analysis in the Continuous Domain.

    Science.gov (United States)

    Pang, Jiahao; Cheung, Gene

    2017-04-01

    Inverse imaging problems are inherently underdetermined, and hence, it is important to employ appropriate image priors for regularization. One recent popular prior-the graph Laplacian regularizer-assumes that the target pixel patch is smooth with respect to an appropriately chosen graph. However, the mechanisms and implications of imposing the graph Laplacian regularizer on the original inverse problem are not well understood. To address this problem, in this paper, we interpret neighborhood graphs of pixel patches as discrete counterparts of Riemannian manifolds and perform analysis in the continuous domain, providing insights into several fundamental aspects of graph Laplacian regularization for image denoising. Specifically, we first show the convergence of the graph Laplacian regularizer to a continuous-domain functional, integrating a norm measured in a locally adaptive metric space. Focusing on image denoising, we derive an optimal metric space assuming non-local self-similarity of pixel patches, leading to an optimal graph Laplacian regularizer for denoising in the discrete domain. We then interpret graph Laplacian regularization as an anisotropic diffusion scheme to explain its behavior during iterations, e.g., its tendency to promote piecewise smooth signals under certain settings. To verify our analysis, an iterative image denoising algorithm is developed. Experimental results show that our algorithm performs competitively with state-of-the-art denoising methods, such as BM3D for natural images, and outperforms them significantly for piecewise smooth images.

  6. Domain imaging on multiferroic BiFeO{sub 3}(001) by linear and circular dichroism in threshold photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Sander, Anke; Christl, Maik [Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle(Saale) (Germany); Chiang, Cheng-Tien [Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle(Saale) (Germany); Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle(Saale) (Germany); Alexe, Marin [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Widdra, Wolf, E-mail: wolf.widdra@physik.uni-halle.de [Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, 06120 Halle(Saale) (Germany); Max Planck Institute of Microstructure Physics, Weinberg 2, 06120 Halle(Saale) (Germany)

    2015-12-14

    We demonstrate ferroelectric domain imaging at BiFeO{sub 3}(001) single crystal surfaces with laser-based threshold photoemission electron microscopy (PEEM). Work function differences and linear dichroism allow for the identification of the eight independent ferroelectric domain configurations in the PEEM images. There, the determined domain structure is consistent with piezoresponse force microscopy of the sample surface and can also be related to the circular dichroic PEEM images. Our results provide a method for efficient mapping of complex ferroelectric domains with laser-excited PEEM and may allow lab-based time-resolved studies of the domain dynamics in the future.

  7. An Extended DCT Domain Watermarking for Robot Vision against Geometric Image Attacks

    Directory of Open Access Journals (Sweden)

    Okkyung Choi

    2013-01-01

    Full Text Available With the rapid development of the Internet and the mobile service robot, the digital services are becoming important factors for robots to recognize things in the real world. Advances in computer technology and the risk of copyright infringement have increased in the way that anyone replicates and copies digital media easily. Therefore, ways to prevent and suppress copyright infringement, digital watermarking technologies that insert copyrights information into the work, are being researched. Digital watermark, depending on the actual insert domain, can be categorized into the spatial domain and transform domain. In this paper, we propose an extended DCT domain watermarking for robot vision. The suggested method is by distributing and duplicating watermark images that are including copyright information on the original images. By doing this, it can be strong on geometric image attacks such as partial cutting, resizing, rotating, and so forth. For the success of watermark extraction, invertible process can be used to recover a disfigured image. Experimental results are provided to support these methods, through the process of recombination by complete image pieces.

  8. Private anonymous fingerprinting for color images in the wavelet domain

    Science.gov (United States)

    Abdul, W.; Gaborit, P.; Carré, P.

    2010-01-01

    An online buyer of multimedia content does not want to reveal his identity or his choice of multimedia content whereas the seller or owner of the content does not want the buyer to further distribute the content illegally. To address these issues we present a new private anonymous fingerprinting protocol. It is based on superposed sending for communication security, group signature for anonymity and traceability and single database private information retrieval (PIR) to allow the user to get an element of the database without giving any information about the acquired element. In the presence of a semi-honest model, the protocol is implemented using a blind, wavelet based color image watermarking scheme. The main advantage of the proposed protocol is that both the user identity and the acquired database element are unknown to any third party and in the case of piracy, the pirate can be identified using the group signature scheme. The robustness of the watermarking scheme against Additive White Gaussian Noise is also shown.

  9. Real-time spatial frequency domain imaging by single snapshot multiple frequency demodulation technique

    Science.gov (United States)

    Cao, Zili; Lin, Weihao; Chen, Xinlin; Zeng, Bixin; Xu, Min

    2017-02-01

    We have presented a novel Single Snapshot Multiple Frequency Demodulation (SSMD) method enabling single snapshot wide field imaging of optical properties of turbid media in the Spatial Frequency Domain. SSMD makes use of the orthogonality of harmonic functions and extracts the modulation transfer function (MTF) at multiple modulation frequencies and of arbitrary orientations and amplitudes simultaneously from a single structured-illuminated image at once. SSMD not only increases significantly the data acquisition speed and reduces motion artifacts but also exhibits excellent noise suppression in imaging as well. The performance of SSMD-SFDI is demonstrated with experiments on both tissue mimicking phantoms and in vivo for recovering optical properties. SSMD is ideal in the implementation of a real-time spatial frequency domain imaging platform, which will open up SFDI for vast applications in, for example, mapping the optical properties of a dynamic turbid medium or monitoring fast temporal evolutions.

  10. Domain adaptation of image classification based on collective target nearest-neighbor representation

    Science.gov (United States)

    Tang, Song; Ye, Mao; Liu, Qihe; Li, Fan

    2016-05-01

    In many practical applications, we frequently face the awkward problem in which an image classifier trained in a scenario is difficult to use in a new scenario. Traditionally, the probability inference-based methods are used to solve this problem. From the point of image representation, we propose an approach for domain adaption of image classification. First, all source samples are supposed to form the dictionary. Then, we encode the target sample by combining this dictionary and the local geometric information. Based on this new representation, called target nearest-neighbor representation, image classification can obtain good performance in the target domain. Our core contribution is that the nearest-neighbor information of the target sample is technically exploited to form more robust representation. Experimental results confirm the effectiveness of our method.

  11. Image quality evaluation of iterative CT reconstruction algorithms: a perspective from spatial domain noise texture measures

    Science.gov (United States)

    Pachon, Jan H.; Yadava, Girijesh; Pal, Debashish; Hsieh, Jiang

    2012-03-01

    Non-linear iterative reconstruction (IR) algorithms have shown promising improvements in image quality at reduced dose levels. However, IR images sometimes may be perceived as having different image noise texture than traditional filtered back projection (FBP) reconstruction. Standard linear-systems-based image quality evaluation metrics are limited in characterizing such textural differences and non-linear image-quality vs. dose trade-off behavior, hence limited in predicting potential impact of such texture differences in diagnostic task. In an attempt to objectively characterize and measure dose dependent image noise texture and statistical properties of IR and FBP images, we have investigated higher order moments and Haralicks Gray Level Co-occurrence Matrices (GLCM) based texture features on phantom images reconstructed by an iterative and a traditional FBP method. In this study, the first 4 central order moments, and multiple texture features from Haralick GLCM in 4 directions at 6 different ROI sizes and four dose levels were computed. For resolution, noise and texture trade-off analysis, spatial frequency domain NPS and contrastdependent MTF were also computed. Preliminary results of the study indicate that higher order moments, along with spatial domain measures of energy, contrast, correlation, homogeneity, and entropy consistently capture the textural differences between FBP and IR as dose changes. These metrics may be useful in describing the perceptual differences in randomness, coarseness, contrast, and smoothness of images reconstructed by non-linear algorithms.

  12. A dual adaptive watermarking scheme in contourlet domain for DICOM images

    Directory of Open Access Journals (Sweden)

    Rabbani Hossein

    2011-06-01

    Full Text Available Abstract Background Nowadays, medical imaging equipments produce digital form of medical images. In a modern health care environment, new systems such as PACS (picture archiving and communication systems, use the digital form of medical image too. The digital form of medical images has lots of advantages over its analog form such as ease in storage and transmission. Medical images in digital form must be stored in a secured environment to preserve patient privacy. It is also important to detect modifications on the image. These objectives are obtained by watermarking in medical image. Methods In this paper, we present a dual and oblivious (blind watermarking scheme in the contourlet domain. Because of importance of ROI (region of interest in interpretation by medical doctors rather than RONI (region of non-interest, we propose an adaptive dual watermarking scheme with different embedding strength in ROI and RONI. We embed watermark bits in singular value vectors of the embedded blocks within lowpass subband in contourlet domain. Results The values of PSNR (peak signal-to-noise ratio and SSIM (structural similarity measure index of ROI for proposed DICOM (digital imaging and communications in medicine images in this paper are respectively larger than 64 and 0.997. These values confirm that our algorithm has good transparency. Because of different embedding strength, BER (bit error rate values of signature watermark are less than BER values of caption watermark. Our results show that watermarked images in contourlet domain have greater robustness against attacks than wavelet domain. In addition, the qualitative analysis of our method shows it has good invisibility. Conclusions The proposed contourlet-based watermarking algorithm in this paper uses an automatically selection for ROI and embeds the watermark in the singular values of contourlet subbands that makes the algorithm more efficient, and robust against noise attacks than other transform

  13. The Creative Commons. A Third Way between Public Domain and Community ?

    Directory of Open Access Journals (Sweden)

    Clément Bert-Erboul

    2016-04-01

    Full Text Available How have the Creative Commons’ ownership rules used by free websites like Wikipedia or Flickr and in 3D printer projects or in alternative kitchen gardens, been develo­ped? Internet users and technological experimentation communities rely heavily on these free tools, but the ideologies of the public domain and online communities that allowed their birth often remain obscure. In this article we used American legal doctri­ne, the scientific literature and specialized press archives. From these sources we analyzed the links between Copyright reforms and the institutionalization of the activity of free software developers, at the origin of Creative Commons licenses. The case of intangible goods property applied to tangibles goods shows how the community members and institutions legitimize their IT practices by means of several producers of norms, such as States or communities.

  14. Systematic analysis of public domain compound potency data identifies selective molecular scaffolds across druggable target families.

    Science.gov (United States)

    Hu, Ye; Wassermann, Anne Mai; Lounkine, Eugen; Bajorath, Jürgen

    2010-01-28

    Molecular scaffolds that yield target family-selective compounds are of high interest in pharmaceutical research. There continues to be considerable debate in the field as to whether chemotypes with a priori selectivity for given target families and/or targets exist and how they might be identified. What do currently available data tell us? We present a systematic and comprehensive selectivity-centric analysis of public domain target-ligand interactions. More than 200 molecular scaffolds are identified in currently available active compounds that are selective for established target families. A subset of these scaffolds is found to produce compounds with high selectivity for individual targets among closely related ones. These scaffolds are currently underrepresented in approved drugs.

  15. Frequency-domain photoacoustic phased array probe for biomedical imaging applications.

    Science.gov (United States)

    Telenkov, Sergey; Alwi, Rudolf; Mandelis, Andreas; Worthington, Arthur

    2011-12-01

    We report the development of a frequency-domain biomedical photoacoustic imaging system that utilizes a continuous-wave laser source with a custom intensity modulation pattern, ultrasonic phased array for signal detection, and processing coupled with a beam-forming algorithm for reconstruction of photoacoustic correlation images. Sensitivity to optical contrast was demonstrated using tissue-mimicking phantoms and in-vivo tissue samples.

  16. The international river interface cooperative: Public domain flow and morphodynamics software for education and applications

    Science.gov (United States)

    Nelson, Jonathan M.; Shimizu, Yasuyuki; Abe, Takaaki; Asahi, Kazutake; Gamou, Mineyuki; Inoue, Takuya; Iwasaki, Toshiki; Kakinuma, Takaharu; Kawamura, Satomi; Kimura, Ichiro; Kyuka, Tomoko; McDonald, Richard R.; Nabi, Mohamed; Nakatsugawa, Makoto; Simões, Francisco R.; Takebayashi, Hiroshi; Watanabe, Yasunori

    2016-07-01

    This paper describes a new, public-domain interface for modeling flow, sediment transport and morphodynamics in rivers and other geophysical flows. The interface is named after the International River Interface Cooperative (iRIC), the group that constructed the interface and many of the current solvers included in iRIC. The interface is entirely free to any user and currently houses thirteen models ranging from simple one-dimensional models through three-dimensional large-eddy simulation models. Solvers are only loosely coupled to the interface so it is straightforward to modify existing solvers or to introduce other solvers into the system. Six of the most widely-used solvers are described in detail including example calculations to serve as an aid for users choosing what approach might be most appropriate for their own applications. The example calculations range from practical computations of bed evolution in natural rivers to highly detailed predictions of the development of small-scale bedforms on an initially flat bed. The remaining solvers are also briefly described. Although the focus of most solvers is coupled flow and morphodynamics, several of the solvers are also specifically aimed at providing flood inundation predictions over large spatial domains. Potential users can download the application, solvers, manuals, and educational materials including detailed tutorials at www.-i-ric.org. The iRIC development group encourages scientists and engineers to use the tool and to consider adding their own methods to the iRIC suite of tools.

  17. The international river interface cooperative: Public domain flow and morphodynamics software for education and applications

    Science.gov (United States)

    Nelson, Jonathan M.; Shimizu, Yasuyuki; Abe, Takaaki; Asahi, Kazutake; Gamou, Mineyuki; Inoue, Takuya; Iwasaki, Toshiki; Kakinuma, Takaharu; Kawamura, Satomi; Kimura, Ichiro; Kyuka, Tomoko; McDonald, Richard R.; Nabi, Mohamed; Nakatsugawa, Makoto; Simoes, Francisco J.; Takebayashi, Hiroshi; Watanabe, Yasunori

    2016-01-01

    This paper describes a new, public-domain interface for modeling flow, sediment transport and morphodynamics in rivers and other geophysical flows. The interface is named after the International River Interface Cooperative (iRIC), the group that constructed the interface and many of the current solvers included in iRIC. The interface is entirely free to any user and currently houses thirteen models ranging from simple one-dimensional models through three-dimensional large-eddy simulation models. Solvers are only loosely coupled to the interface so it is straightforward to modify existing solvers or to introduce other solvers into the system. Six of the most widely-used solvers are described in detail including example calculations to serve as an aid for users choosing what approach might be most appropriate for their own applications. The example calculations range from practical computations of bed evolution in natural rivers to highly detailed predictions of the development of small-scale bedforms on an initially flat bed. The remaining solvers are also briefly described. Although the focus of most solvers is coupled flow and morphodynamics, several of the solvers are also specifically aimed at providing flood inundation predictions over large spatial domains. Potential users can download the application, solvers, manuals, and educational materials including detailed tutorials at www.-i-ric.org. The iRIC development group encourages scientists and engineers to use the tool and to consider adding their own methods to the iRIC suite of tools.

  18. New public dataset for spotting patterns in medieval document images

    Science.gov (United States)

    En, Sovann; Nicolas, Stéphane; Petitjean, Caroline; Jurie, Frédéric; Heutte, Laurent

    2017-01-01

    With advances in technology, a large part of our cultural heritage is becoming digitally available. In particular, in the field of historical document image analysis, there is now a growing need for indexing and data mining tools, thus allowing us to spot and retrieve the occurrences of an object of interest, called a pattern, in a large database of document images. Patterns may present some variability in terms of color, shape, or context, making the spotting of patterns a challenging task. Pattern spotting is a relatively new field of research, still hampered by the lack of available annotated resources. We present a new publicly available dataset named DocExplore dedicated to spotting patterns in historical document images. The dataset contains 1500 images and 1464 queries, and allows the evaluation of two tasks: image retrieval and pattern localization. A standardized benchmark protocol along with ad hoc metrics is provided for a fair comparison of the submitted approaches. We also provide some first results obtained with our baseline system on this new dataset, which show that there is room for improvement and that should encourage researchers of the document image analysis community to design new systems and submit improved results.

  19. Dancing with the Electrons: Time-Domain and CW In Vivo EPR Imaging

    Directory of Open Access Journals (Sweden)

    Murali C. Krishna

    2008-01-01

    Full Text Available The progress in the development of imaging the distribution of unpaired electrons in living systems and the functional and the potential diagnostic dimensions of such an imaging process, using Electron Paramagnetic Resonance Imaging (EPRI, is traced from its origins with emphasis on our own work. The importance of EPR imaging stems from the fact that many paramagnetic probes show oxygen dependent spectral broadening. Assessment of in vivo oxygen concentration is an important factor in radiation oncology in treatment-planning and monitoring treatment-outcome. The emergence of narrow-line trairylmethyl based, bio-compatible spin probes has enabled the development of radiofrequency time-domain EPRI. Spectral information in time-domain EPRI can be achieved by generating a time sequence of T2* or T2 weighted images. Progress in CW imaging has led to the use of rotating gradients, more recently rapid scan with direct detection, and a combination of all the three. Very low field MRI employing Dynamic Nuclear polarization (Overhauser effect is also employed for monitoring tumor hypoxia, and re-oxygenation in vivo. We have also been working on the co-registration of MRI and time domain EPRI on mouse tumor models at 300 MHz using a specially designed resonator assembly. The mapping of the unpaired electron distribution and unraveling the spectral characteristics by using magnetic resonance in presence of stationary and rotating gradients in indeed ‘dancing with the (unpaired electrons’, metaphorically speaking.

  20. An easily-achieved time-domain beamformer for ultrafast ultrasound imaging based on compressive sensing.

    Science.gov (United States)

    Wang, Congzhi; Peng, Xi; Liang, Dong; Xiao, Yang; Qiu, Weibao; Qian, Ming; Zheng, Hairong

    2015-01-01

    In ultrafast ultrasound imaging technique, how to maintain the high frame rate, and at the same time to improve the image quality as far as possible, has become a significant issue. Several novel beamforming methods based on compressive sensing (CS) theory have been proposed in previous literatures, but all have their own limitations, such as the excessively large memory consumption and the errors caused by the short-time discrete Fourier transform (STDFT). In this study, a novel CS-based time-domain beamformer for plane-wave ultrasound imaging is proposed and its image quality has been verified to be better than the traditional DAS method and even the popular coherent compounding method on several simulated phantoms. Comparing to the existing CS method, the memory consumption of our method is significantly reduced since the encoding matrix can be sparse-expressed. In addition, the time-delay calculations of the echo signals are directly accomplished in time-domain with a dictionary concept, avoiding the errors induced by the short-time Fourier translation calculation in those frequency-domain methods. The proposed method can be easily implemented on some low-cost hardware platforms, and can obtain ultrasound images with both high frame rate and good image quality, which make it has a great potential for clinical application.

  1. Revealing of steganograms with data, which are hidden in transformation domain of digital images

    Directory of Open Access Journals (Sweden)

    D. O. Progonov

    2014-06-01

    Full Text Available Introduction. The paper is devoted to analysis the correlation and fractal properties of bright¬ness fluctuation the steganograms. The case of multistage embedding the modified stegodata in transformation domain of digital images is considered. Data hiding in transformation domain of digital images. The Gunjal method of message hiding in digital images is investigated. The method is based on usage of Arnold transform for mangling the stegodata. Embedding of modified message is carried out by applying of two-dimensional discrete wavelet transform and block two-dimensional discrete cosine transform. Multifractal detrended fluctuation analysis of digital images. The correlation and fractal characteristics of the digital images noise components are consider. It is shown the advanta¬ges of multifractal detrended fluctuation analysis over classic detrended fluctuation analysis – the representation of signal fluctuation as set of monofractal aggregates with corresponding generalized Hurst exponents. Conclusion. Data hiding in transformation domain of digital images leads to smoothing of spectrum the generalized Hurst exponents and narrowing the multifractal spectrum of fluctuations. It is established that ascertained disclosure features do not depend on degree of container filling.

  2. A Domain Specific Language for Performance Evaluation of Medical Imaging Systems

    NARCIS (Netherlands)

    van den Berg, Freek; Remke, Anne Katharina Ingrid; Haverkort, Boudewijn R.H.M.; Turau, Volker; Kwiatkowska, Marta; Mangharam, Rahul; Weyer, Christoph

    2014-01-01

    We propose iDSL, a domain specific language and toolbox for performance evaluation of Medical Imaging Systems. iDSL provides transformations to MoDeST models, which are in turn converted into UPPAAL and discrete-event MODES models. This enables automated performance evaluation by means of model

  3. Fra Angelico’s painting technique revealed by terahertz time-domain imaging (THz-TDI)

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch; Picollo, Marcello; Cucci, Costanza

    2016-01-01

    We have investigated with terahertz time-domain imaging (THz-TDI) the well-known Lamentation over the dead Christ panel painting (San Marco Museum, Florence) painted by Fra Giovanni Angelico within 1436 and 1441. The investigation provided a better understanding of the construction and gilding te...

  4. Wavelet Domain Image Reconstruction by Compactly-Supported Radial Basis Functions

    Science.gov (United States)

    Diago, Luis A.; Kitago, Masaki; Hagiwara, Ichiro

    In this paper we propose the use of wavelets to accelerate the solution of the System of Linear Algebraic Equations that arise from the formulation of the problem of image interpolation from scattered data by means of Compactly-Supported Radial Basis Functions. Examples demonstrate the superiority of the solution in the wavelet domain using preconditioned iterative Krylov methods.

  5. A method for analysis of lipid vesicle domain structure from confocal image data

    DEFF Research Database (Denmark)

    Husen, Peter Rasmussen; Fidorra, Matthias; Hartel, Steffen

    2012-01-01

    Quantitative characterization of the lateral structure of curved membranes based on fluorescence microscopy requires knowledge of the fluorophore distribution on the surface. We present an image analysis approach for extraction of the fluorophore distribution on a spherical lipid vesicle from....... The analysis allows for investigation of the morphology and size distribution of domains on the surface....

  6. Fast resolution of the neutron diffusion equation through public domain Ode codes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, V.M.; Vidal, V.; Garayoa, J. [Universidad Politecnica de Valencia, Departamento de Sistemas Informaticos, Valencia (Spain); Verdu, G. [Universidad Politecnica de Valencia, Departamento de Ingenieria Quimica y Nuclear, Valencia (Spain); Gomez, R. [I.E.S. de Tavernes Blanques, Valencia (Spain)

    2003-07-01

    The time-dependent neutron diffusion equation is a partial differential equation with source terms. The resolution method usually includes discretizing the spatial domain, obtaining a large system of linear, stiff ordinary differential equations (ODEs), whose resolution is computationally very expensive. Some standard techniques use a fixed time step to solve the ODE system. This can result in errors (if the time step is too large) or in long computing times (if the time step is too little). To speed up the resolution method, two well-known public domain codes have been selected: DASPK and FCVODE that are powerful codes for the resolution of large systems of stiff ODEs. These codes can estimate the error after each time step, and, depending on this estimation can decide which is the new time step and, possibly, which is the integration method to be used in the next step. With these mechanisms, it is possible to keep the overall error below the chosen tolerances, and, when the system behaves smoothly, to take large time steps increasing the execution speed. In this paper we address the use of the public domain codes DASPK and FCVODE for the resolution of the time-dependent neutron diffusion equation. The efficiency of these codes depends largely on the preconditioning of the big systems of linear equations that must be solved. Several pre-conditioners have been programmed and tested; it was found that the multigrid method is the best of the pre-conditioners tested. Also, it has been found that DASPK has performed better than FCVODE, being more robust for our problem.We can conclude that the use of specialized codes for solving large systems of ODEs can reduce drastically the computational work needed for the solution; and combining them with appropriate pre-conditioners, the reduction can be still more important. It has other crucial advantages, since it allows the user to specify the allowed error, which cannot be done in fixed step implementations; this, of course

  7. Image Denoising Using Sure-Based Adaptive Thresholding in Directionlet Domain

    Directory of Open Access Journals (Sweden)

    Sethunadh R

    2012-12-01

    Full Text Available The standard separable two dimensional wavelet transform has achieved a great success in image denoising applications due to its sparse representation of images. However it fails to capture efficiently the anisotropic geometric structures like edges and contours in images as they intersect too many wavelet basis functions and lead to a non-sparse representation. In this paper a novel de-noising scheme based on multi directional and anisotropic wavelet transform called directionlet is presented. The image denoising in wavelet domain has been extended to the directionlet domain to make the image features to concentrate on fewer coefficients so that more effective thresholding is possible. The image is first segmented and the dominant direction of each segment is identified to make a directional map. Then according to the directional map, the directionlet transform is taken along the dominant direction of the selected segment. The decomposed images with directional energy are used for scale dependent subband adaptive optimal threshold computation based on SURE risk. This threshold is then applied to the sub-bands except the LLL subband. The threshold corrected sub-bands with the unprocessed first sub-band (LLL are given as input to the inverse directionlet algorithm for getting the de-noised image. Experimental results show that the proposed method outperforms the standard wavelet-based denoising methods in terms of numeric and visual quality.

  8. Spatial and Transform Domain Filtering Method for Image De-noising: A Review

    Directory of Open Access Journals (Sweden)

    Vandana Roy

    2013-09-01

    Full Text Available Present investigation reveals the quantum of work carried in the filtering methods for image de-noising. An image is often gets corrupted by various noises that are visible or invisible while being gathered, coded, acquired and transmitted. Noise influences various process parameters that may cause a quality problem for further image processing. De-noising of natural images is appears to be very simple however when considered under practical situations becomes complex. It has been cited by various author that parameter such as type and quantum of noise, image etc. through single algorithm or approach becomes cumbersome when results are optimized. In order to improve the quality of an image noise must be removed when the image is pre-processed and the important signal features like edge details should be retained as much as possible. The search on efficient image de-noising methods is still a valid challenge at the crossing of functional analysis and statistics. This paper reviews significant de-noising methods (spatial and transform domain method and their salient features and applications. One filter in each category has been taken in consideration to understand the characteristics of both spatial and transform domain filters.

  9. Sub-Nyquist Sampling and Fourier Domain Beamforming in Volumetric Ultrasound Imaging.

    Science.gov (United States)

    Burshtein, Amir; Birk, Michael; Chernyakova, Tanya; Eilam, Alon; Kempinski, Arcady; Eldar, Yonina C

    2016-05-01

    A key step in ultrasound image formation is digital beamforming of signals sampled by several transducer elements placed upon an array. High-resolution digital beamforming introduces the demand for sampling rates significantly higher than the signals' Nyquist rate, which greatly increases the volume of data that must be transmitted from the system's front end. In 3-D ultrasound imaging, 2-D transducer arrays rather than 1-D arrays are used, and more scan lines are needed. This implies that the amount of sampled data is vastly increased with respect to 2-D imaging. In this work, we show that a considerable reduction in data rate can be achieved by applying the ideas of Xampling and frequency domain beamforming (FDBF), leading to a sub-Nyquist sampling rate, which uses only a portion of the bandwidth of the ultrasound signals to reconstruct the image. We extend previous work on FDBF for 2-D ultrasound imaging to accommodate the geometry imposed by volumetric scanning and a 2-D grid of transducer elements. High image quality from low-rate samples is demonstrated by simulation of a phantom image composed of several small reflectors. Our technique is then applied to raw data of a heart ventricle phantom obtained by a commercial 3-D ultrasound system. We show that by performing 3-D beamforming in the frequency domain, sub-Nyquist sampling and low processing rate are achievable, while maintaining adequate image quality.

  10. Imaging of the intact mouse cochlea by spectral domain optical coherence tomography

    Science.gov (United States)

    Gao, Simon S.; Yuan, Tao; Xia, Anping; Raphael, Patrick; Shelton, Ryan L.; Applegate, Brian E.; Oghalai, John S.

    2011-03-01

    Current medical imaging modalities, such as MRI and CT, do not provide high enough resolution to detect many changes within the cochlea that cause hearing loss. We sought to develop the technique of optical coherence tomography (OCT) to image the cochlea noninvasively and within its native environment. We used spectral domain OCT with 950 nm as the center wavelength and a bandwidth of ~100 nm to image freshly excised normal mouse cochlea at different developmental ages. The OCT system has an axial resolution of ~4 μm (in air) and a lateral resolution of ~10 μm. When we imaged normal adult mouse cochleae through the round window membrane, Reissner's membrane, the basilar membrane, the tectorial membrane, the spiral ligament, the spiral limbus, and the modiolus could be clearly identified. When we imaged intact adult cochleae, we were able to image through ~130 μm of bone and tissue to see up to a depth of ~600 μm, and all of the previously identified structures were still visible. Imaging of early postnatal mice during the timeline of cochlear development permitted visualization of the expected structural differences from adult cochleae. Therefore, we conclude that spectral domain OCT is an effective technique for noninvasive imaging of the murine cochlea.

  11. Analytical modelling and x-ray imaging of oscillations of a single magnetic domain wall

    Energy Technology Data Exchange (ETDEWEB)

    Bocklage, Lars; Kruger, Benjamin; Fischer, Peter; Meier, Guido

    2009-07-10

    Domain-wall oscillation in a pinnig potential is described analytically in a one dimensional model for the feld-driven case. For a proper description the pinning potential has to be extended by nonharmonic contributions. Oscillations of a domain wall are observed on its genuine time scale by magnetic X-ray microscopy. It is shown that the nonharmonic terms are present in real samples with a strong restoring potential. In the framework of our model we gain deep insight into the domain-wall motion by looking at different phase spaces. The corrections of the harmonic potential can change the motion of the domain wall significantly. The damping parameter of permalloy is determined via the direct imaging technique.

  12. Reflection terahertz time-domain imaging for analysis of an 18th century neoclassical easel painting

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch; Filtenborg, Troels; Fukunaga, Kaori;

    2015-01-01

    , a real hidden portraiton an easel painting has been imaged by THz-TDI, with an unexpected richness of detail. THz C- andB-scans have been compared with images obtained by x-ray radiography and invasive cross-sectional imaging,leading to a deeper understanding of the strengths and limitations......Terahertz time-domain imaging (THz-TDI) has been applied for imaging a hidden portrait and other subsurfacecomposition layers of an 18th century (18C) easel painting by Nicolai Abildgaard, the most important 18CDanish neoclassical painter of historical and mythological subjects. For the first time...... in practical applications of the technique. Interfaces between layers ofthe painting have been successfully imaged, contributing substantially to the understanding of the structure of the painting....

  13. Real-time dispersion-compensated image reconstruction for compressive sensing spectral domain optical coherence tomography.

    Science.gov (United States)

    Xu, Daguang; Huang, Yong; Kang, Jin U

    2014-09-01

    In this work, we propose a novel dispersion compensation method that enables real-time compressive sensing (CS) spectral domain optical coherence tomography (SD OCT) image reconstruction. We show that dispersion compensation can be incorporated into CS SD OCT by multiplying the dispersion-correcting terms by the undersampled spectral data before CS reconstruction. High-quality SD OCT imaging with dispersion compensation was demonstrated at a speed in excess of 70 frames per s using 40% of the spectral measurements required by the well-known Shannon/Nyquist theory. The data processing and image display were performed on a conventional workstation having three graphics processing units.

  14. Wavelet Transform Modulus Maxima-Based Robust Digital Image Watermarking in Wavelet Domain

    Institute of Scientific and Technical Information of China (English)

    LUO Ting; HONG Fan

    2009-01-01

    A new robust watermarking approach was proposed in 2D continuous wavelet domain (CWT).The watermark is embedded into the large coefficients in the middle band of wavelet transform modulus maxima (WTMM) of the host image.After possible attacks,the watermark is then detected and extracted by correlation analysis.Compared with other wavelet domain watermarking approaches,the WTMM approach can endow the image with both rotation and shift invariant properties.On the other hand,scale invariance is achieved with the geometric normalization during watermark detection.Case studies involve various attacks such as shifting,lossy compression,scaling,rotation and median filtering on the watermarked image,and the result shows that the approach is robust to these attacks.

  15. Are maladaptive schema domains and perfectionism related to body image concerns in eating disorder patients?

    Science.gov (United States)

    Boone, Liesbet; Braet, Caroline; Vandereycken, Walter; Claes, Laurence

    2013-01-01

    Both maladaptive schemas (MS) and perfectionism have been associated with eating pathology. However, previous research has not examined these variables simultaneously and has not studied possible mediating relationships between MS and multidimensional perfectionism for body image concerns in eating disorder (ED) patients. Eighty-eight female ED patients completed the Young Schema Questionnaire, the Frost Multidimensional Perfectionism Scale, and the Body Attitude Test. Body image concerns were found to be positively related to Personal Standards (PS) and Evaluative Concerns (EC) perfectionism and all five schema domains. PS Perfectionism was positively associated with Disconnection, Other-directedness, and Overvigilance. EC Perfectionism was positively related to Disconnection, Impaired Autonomy, Other-directedness, and Overvigilance. Moreover, EC perfectionism was found to be a significant mediator in the relationship between the schema domains Impaired Autonomy and Overvigilance and body image concerns. These findings denote the importance to address both core beliefs and perfectionism in ED treatment.

  16. Spatial Domain based Image Enhancement Techniques for Scanned Electron Microscope-SEM-images

    Directory of Open Access Journals (Sweden)

    Rakhi Chanana

    2011-07-01

    Full Text Available The growing need for efficiently processing and analyzing the information contained in digital images is a continuous challenge in order to apply image processing. Digital images are captured from different imaging media elements like cameras, scanned electron microscopes etc. While going through the imaging process, Images get distorted in various forms resulting in extreme dark or light areas. All these things lead to the loss of information. The goal in each case is to extract useful information. In that case, Image processing extracts useful information by applying various image enhancement and algorithms. In this paper, we have discussed a practical implementation of various enhancement methods for Scanned Electron Microscope (SEM images and their experimental results. SEM images lead to very dark and light areas in an image. While imaging the information in the front scene is not only the source of information but some scenes on the dark side can also have the useful information. Before processing any further we require to enhance such images and one of the enhancement techniques i.e. Histogram Statistics comes out to be an ideal approach.

  17. Domain and range decomposition methods for coded aperture x-ray coherent scatter imaging

    Science.gov (United States)

    Odinaka, Ikenna; Kaganovsky, Yan; O'Sullivan, Joseph A.; Politte, David G.; Holmgren, Andrew D.; Greenberg, Joel A.; Carin, Lawrence; Brady, David J.

    2016-05-01

    Coded aperture X-ray coherent scatter imaging is a novel modality for ascertaining the molecular structure of an object. Measurements from different spatial locations and spectral channels in the object are multiplexed through a radiopaque material (coded aperture) onto the detectors. Iterative algorithms such as penalized expectation maximization (EM) and fully separable spectrally-grouped edge-preserving reconstruction have been proposed to recover the spatially-dependent coherent scatter spectral image from the multiplexed measurements. Such image recovery methods fall into the category of domain decomposition methods since they recover independent pieces of the image at a time. Ordered subsets has also been utilized in conjunction with penalized EM to accelerate its convergence. Ordered subsets is a range decomposition method because it uses parts of the measurements at a time to recover the image. In this paper, we analyze domain and range decomposition methods as they apply to coded aperture X-ray coherent scatter imaging using a spectrally-grouped edge-preserving regularizer and discuss the implications of the increased availability of parallel computational architecture on the choice of decomposition methods. We present results of applying the decomposition methods on experimental coded aperture X-ray coherent scatter measurements. Based on the results, an underlying observation is that updating different parts of the image or using different parts of the measurements in parallel, decreases the rate of convergence, whereas using the parts sequentially can accelerate the rate of convergence.

  18. HIGH RESOLUTION IMAGE PROJECTION IN FREQUENCY DOMAIN FOR CONTINUOUS IMAGE SEQUENCE

    Directory of Open Access Journals (Sweden)

    M. Nagaraju Naik

    2010-09-01

    Full Text Available Unlike most other information technologies, which have enjoyed an exponential growth for the past several decades, display resolution has largely stagnated. Low display resolution has in turn limited the resolution of digital images. Scaling is a non-trivial process that involves a trade-off between efficiency, smoothness and sharpness. As the size of an image is increased, so the pixels, which comprise the image, become increasingly visible, making the image to appear soft. Super scalar representation of image sequence is limited due to image information present in low dimensional image sequence. To project a image frame sequence into high-resolution static or fractional scalingvalue, a scaling approach is developed based on energy spectral interpolation and frequency spectral interpolation techniques. To realize the frequency spectral resolution Cubic-B-Spline method is used.

  19. Contribution of Reflection Terahertz Time Domain-Imaging (THz-TDI) to Imaging Analysis of Artworks

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch; Fukunaga, Kaori; Kohzuma, Y.;

    Different kind s of artefacts (easel painting, panel paintings and Asian lacquerwares) have been scanned by THz - TDI and results have been compared with those obtained by others standard imaging techniques (x-ray radiography, cross sectional imaging, technical photography) ....

  20. Optical color image encryption based on an asymmetric cryptosystem in the Fresnel domain

    Science.gov (United States)

    Chen, Wen; Chen, Xudong

    2011-08-01

    In recent years, optical color image encryption has attracted much attention in the information security field. Some approaches, such as digital holography, have been proposed to encrypt color images, but the previously proposed methods are developed based on optical symmetric cryptographic strategies. In this paper, we apply an optical asymmetric cryptosystem for the color image encryption instead of conventional symmetric cryptosystems. A phase-truncated strategy is applied in the Fresnel domain, and multiple-wavelength and indexed image methods are further employed. The security of optical asymmetric cryptosystem is also analyzed during the decryption. Numerical results are presented to demonstrate the feasibility and effectiveness of the proposed optical asymmetric cryptosystem for color image encryption.

  1. Multivariate compressive sensing for image reconstruction in the wavelet domain: using scale mixture models.

    Science.gov (United States)

    Wu, Jiao; Liu, Fang; Jiao, L C; Wang, Xiaodong; Hou, Biao

    2011-12-01

    Most wavelet-based reconstruction methods of compressive sensing (CS) are developed under the independence assumption of the wavelet coefficients. However, the wavelet coefficients of images have significant statistical dependencies. Lots of multivariate prior models for the wavelet coefficients of images have been proposed and successfully applied to the image estimation problems. In this paper, the statistical structures of the wavelet coefficients are considered for CS reconstruction of images that are sparse or compressive in wavelet domain. A multivariate pursuit algorithm (MPA) based on the multivariate models is developed. Several multivariate scale mixture models are used as the prior distributions of MPA. Our method reconstructs the images by means of modeling the statistical dependencies of the wavelet coefficients in a neighborhood. The proposed algorithm based on these scale mixture models provides superior performance compared with many state-of-the-art compressive sensing reconstruction algorithms.

  2. Adaptive anisotropic diffusion for noise reduction of phase images in Fourier domain Doppler optical coherence tomography.

    Science.gov (United States)

    Xia, Shaoyan; Huang, Yong; Peng, Shizhao; Wu, Yanfeng; Tan, Xiaodi

    2016-08-01

    Phase image in Fourier domain Doppler optical coherence tomography offers additional flow information of investigated samples, which provides valuable evidence towards accurate medical diagnosis. High quality phase images are thus desirable. We propose a noise reduction method for phase images by combining a synthetic noise estimation criteria based on local noise estimator (LNE) and distance median value (DMV) with anisotropic diffusion model. By identifying noise and signal pixels accurately and diffusing them with different coefficients respectively and adaptive iteration steps, we demonstrated the effectiveness of our proposed method in both phantom and mouse artery images. Comparison with other methods such as filtering method (mean, median filtering), wavelet method, probabilistic method and partial differential equation based methods in terms of peak signal-to-noise ratio (PSNR), equivalent number of looks (ENL) and contrast-to-noise ratio (CNR) showed the advantages of our method in reserving image energy and removing noise.

  3. Block-based SVD image watermarking in spatial and transform domains

    Science.gov (United States)

    Ghazy, Rania A.; Abbas, Alaa M.; Al-Zubi, Nayel; Hassan, Emad S.; El-Fishawy, Nawal A.; Hadhoud, Mohiy M.; Dessouky, Moawad I.; El-Rabaie, El-Sayed M.; Alshebeili, Saleh A.; Abd El-Samie, Fathi E.

    2015-07-01

    The idea of this paper is to implement an efficient block-by-block singular value (SV) decomposition digital image watermarking algorithm, which is implemented in both the spatial and transforms domains. The discrete wavelet transform (DWT), the discrete cosine transform and the discrete Fourier transform are exploited for this purpose. The original image or one of its transforms is segmented into non-overlapping blocks, and consequently the image to be inserted as a watermark is embedded in the SVs of these blocks. Embedding the watermark on a block-by-block manner ensures security and robustness to attacks such like Gaussian noise, cropping and compression. The proposed algorithm can also be used for colour image watermarking. A comparison study between the proposed block-based watermarking algorithm and the method of Liu is performed for watermarking in all domains. Simulation results ensure that the proposed algorithm is more effective than the traditional method of Liu, especially when the watermarking is performed in the DWT domain.

  4. Optical cryptosystem of color images using random phase masks in the fractional wavelet transform domain

    Science.gov (United States)

    Singh, Hukum

    2016-05-01

    An optical color image encryption in the Fractional Wavelet Transform (FWT) domain is carried out. The original images are segregated into three colors components: R (red), G (green) and B (blue). After that the components are encrypted separately using double random phase encoding (DRPE) in the FWT domain. Random phase masks (RPMs) are used in the input as well as in Fourier plane. The images to be encrypted are transformed with the discrete wavelet transform (DWT), the resulting coefficients from the DWT are multiplied each one by masks different form RPM. Masks are independent each other and the results are applied an inverse discrete Wavelet Transform (IDWT), obtaining the encrypted images. The input images are recovered from their corresponding encrypted images by using the correct parameters of the FWT, and its digital implementation has been performed using MATLAB 7.6.0 (R2008a). The mother wavelet family and fractional orders associated with the FWT are extra keys that access difficulty an attacker; thereby the scheme is more secure as compared to conventional techniques. The sensitivity of proposed scheme is verified with encryption parameters, occlusions, and noise attacks.

  5. Optical multiple-image encryption based on phase encoding algorithm in the Fresnel transform domain

    Science.gov (United States)

    Huang, Jian-Ji; Hwang, Hone-Ene; Chen, Chun-Yuan; Chen, Ching-Mu

    2012-10-01

    A novel method of the optical multiple-image encryption based on the modified Gerchberg-Saxton algorithm (MGSA) is presented. This proposed method with an architecture of two adjacent phase only functions (POFs) in the Fresnel transform (FrT) domain that can extremely increase capacity of system for completely avoiding the crosstalk between the decrypted images. Each encrypted target image is separately encoded into a POF by using the MGSA which is with constraining the encrypted target image. Each created POF is then added to a prescribed fixed POF composed of a proposed MGSA-based phase encoding algorithm. Not only the wavelength and multiple-position parameters in the FrT domain as keys to increase system security, the created POFs are also served mutually as the encryption keys to decrypt target image based on cascading two POFs scheme. Compared with prior methods [23,24], the main advantages of this proposed encryption system is that it does not need any transformative lenses and that makes it very efficient and easy to implement optically. Simulation results show that this proposed encryption system can successfully achieve the multiple-image encryption with multiple-position keys, which is more advantageous in security than previous work [24] for its decryption process with only two POFs keys to accomplish this task.

  6. Advances in frequency-domain fluorometry, gigahertz instrumentation, time-dependent photomigration, and fluorescence lifetime imaging

    Science.gov (United States)

    Lakowicz, Joseph R.; Gryczynski, Ignacy; Szmacinski, Henryk; Nowaczyk, Kazimierz; Johnson, Michael L.

    1992-02-01

    During the past seven years, there have been remarkable advances in the frequency-domain method for measurement of time-resolved emission or light scattering. In this presentation we describe the recent extension of the frequency range to 10 GHz using a specially designed microchannel plate PMT. Experimental data will be shown for measurement of picosecond rotational diffusion and for sub-picosecond resolution of time delays. The resolution of ps to ns timescale processes is not obtained at the expense of sensitivity or is it shown by measurements on the intrinsic tryptophan emission from hemoglobin. We also describe a time- resolved reflectance imaging experiment on a scattering medium containing an absorbing object. Time-resolved imaging of the back-scattered light is realized by means of a RF-phase- sensitive camera, synchronized to the laser pulses. By processing the stored images, a final image can be created, the contrast of which is based only on time differences of the back- scattered photons. This image reveals the presence and position of the absorber within the scattering medium. And finally, we describe a new methodology, fluorescence lifetime imaging (FLIM), in which the contrast depends on the fluorescence lifetime at each point in a two-dimensional image, and not the local concentration and/or intensity of the fluorophore. We used FLIM to create lifetime images of NADH when free in solution and when bound to malate dehydrogenase. FLIM has numerous potential applications in cell biology and imaging.

  7. Image-domain sampling properties of the Hotelling Observer in CT using filtered back-projection

    Science.gov (United States)

    Sanchez, Adrian A.; Sidky, Emil Y.; Pan, Xiaochuan

    2015-03-01

    The Hotelling Observer (HO),1 along with its channelized variants,2 has been proposed for image quality evaluation in x-ray CT.3,4 In this work, we investigate HO performance for a detection task in parallel-beam FBP as a function of two image-domain sampling parameters, namely pixel size and field-of-view. These two parameters are of central importance in adapting HO methods to use in CT, since the large number of pixels in a single image makes direct computation of HO performance for a full image infeasible in most cases. Reduction of the number of image pixels and/or restriction of the image to a region-of-interest (ROI) has the potential to make direct computation of HO statistics feasible in CT, provided that the signal and noise properties lead to redundant information in some regions of the image. For small signals, we hypothesize that reduction of image pixel size and enlargement of the image field-of-view are approximately equivalent means of gaining additional information relevant to a detection task. The rationale for this hypothesis is that the backprojection operation in FBP introduces long range correlations so that, for small signals, the reconstructed signal outside of a small ROI is not linearly independent of the signal within the ROI. In this work, we perform a preliminary investigation of this hypothesis by sweeping these two sampling parameters and computing HO performance for a signal detection task.

  8. Multifocus image fusion scheme based on the multiscale curvature in nonsubsampled contourlet transform domain

    Science.gov (United States)

    Li, Xiaosong; Li, Huafeng; Yu, Zhengtao; Kong, Yingchun

    2015-07-01

    An efficient multifocus image fusion scheme in nonsubsampled contourlet transform (NSCT) domain is proposed. Based on the property of optical imaging and the theory of defocused image, we present a selection principle for lowpass frequency coefficients and also investigate the connection between a low-frequency image and the defocused image. Generally, the NSCT algorithm decomposes detail image information indwells in different scales and different directions in the bandpass subband coefficient. In order to correctly pick out the prefused bandpass directional coefficients, we introduce multiscale curvature, which not only inherits the advantages of windows with different sizes, but also correctly recognizes the focused pixels from source images, and then develop a new fusion scheme of the bandpass subband coefficients. The fused image can be obtained by inverse NSCT with the different fused coefficients. Several multifocus image fusion methods are compared with the proposed scheme. The experimental results clearly indicate the validity and superiority of the proposed scheme in terms of both the visual qualities and the quantitative evaluation.

  9. THE INFLUENCE OF MARKETING PUBLIC RELATION AND SERVICE QUALITY ON CORPORATE IMAGE THROUGH PUBLIC OPINION: STUDIES AT MANDIRI BANK

    Directory of Open Access Journals (Sweden)

    Vera Suciyati

    2015-09-01

    Full Text Available This research aims to analyze the influence of marketing public relation and service quality at Bank Mandiri on corporate image through public. Convenience sampling method has been selected in order to obtain the data in this study. The analysis method that used was the path analysis. The research result had shown that: marketing public relation and service quality have significant influence simultaneously and partially on public opinion on the first structure equation. The second structure equation shows that: marketing public relation, service quality had significant influence simultaneously on corporate image. The service quality have not partially the quality of service have not influence significant partially on corporate, but variable marketing and public relation have  partially influential public opinion influence significant partially on corporate image.DOI: 10.15408/etk.v12i2.1916

  10. Assessing water availability over peninsular Malaysia using public domain satellite data products

    Science.gov (United States)

    Ali, M. I.; Hashim, M.; Zin, H. S. M.

    2014-02-01

    Water availability monitoring is an essential task for water resource sustainability and security. In this paper, the assessment of satellite remote sensing technique for determining water availability is reported. The water-balance analysis is used to compute the spatio-temporal water availability with main inputs; the precipitation and actual evapotranspiration rate (AET), both fully derived from public-domain satellite products of Tropical Rainfall Measurement Mission (TRMM) and MODIS, respectively. Both these satellite products were first subjected to calibration to suit corresponding selected local precipitation and AET samples. Multi-temporal data sets acquired 2000-2010 were used in this study. The results of study, indicated strong agreement of monthly water availability with the basin flow rate (r2 = 0.5, p < 0.001). Similar agreements were also noted between the estimated annual average water availability with the in-situ measurement. It is therefore concluded that the method devised in this study provide a new alternative for water availability mapping over large area, hence offers the only timely and cost-effective method apart from providing comprehensive spatio-temporal patterns, crucial in water resource planning to ensure water security.

  11. Public domain small-area cancer incidence data for New York State, 2005-2009

    Directory of Open Access Journals (Sweden)

    Francis P. Boscoe

    2016-04-01

    Full Text Available There has long been a demand for cancer incidence data at a fine geographic resolution for use in etiologic hypothesis generation and testing, methodological evaluation and teaching. In this paper we describe a public domain dataset containing data for 23 anatomic sites of cancer diagnosed in New York State, USA between 2005 and 2009 at the census block group level. The dataset includes 524,503 tumours distributed across 13,823 block groups with an average population of about 1400. In addition, the data have been linked with race/ethnicity and with socioeconomic indicators such as income, educational attainment and language proficiency. We demonstrate the application of the dataset by confirming two well-established relationships: that between breast cancer and median household income and that between stomach cancer and Asian race. We foresee that this dataset will serve as the basis for a wide range of spatial analyses and as a benchmark for evaluating spatial methods in the future.

  12. Preserving Madagascar's Natural Heritage: The Importance of Keeping the Island's Vertebrate Fossils in the Public Domain

    Directory of Open Access Journals (Sweden)

    Karen E. Samonds

    2006-12-01

    Full Text Available The origin of Madagascar’s highly endemic vertebrate fauna remains one of the great unsolved mysteries of natural history. From what landmasses did the basal stocks of this unique and imbalanced fauna come? When and how did the ancestral populations arrive on the island? How rapidly did they diversify, and why? The most direct means of addressing these questions, and other enigmas concerning the evolutionary and biogeographic history of Madagascar’s vertebrate fauna, is through discovery of fossils from a sequence of well-dated geological horizons. Many fossils relevant to these queries have been discovered by paleontologists in recent years ... but many more are being lost to commercial enterprises, both foreign and domestic, that have little or no regard for the scientific significance of fossils. The objectives of this essay are to 1 provide an overview of Madagascar’s vertebrate fossil record and its importance, 2 raise awareness concerning the illegal collection, exportation, and sale of vertebrate fossils, and 3 stress the importance of keeping vertebrate fossils from the island in the public domain. In light of these issues, we underscore the necessity for development of adequate repositories and support infrastructure in Madagascar to safeguard and display the country’s vertebrate fossil collections; doing so would ensure the preservation and appreciation of Madagascar’s rich natural heritage for future generations of scientists and Malagasy citizens alike.

  13. Developing a personal computer-based data visualization system using public domain software

    Science.gov (United States)

    Chen, Philip C.

    1999-03-01

    The current research will investigate the possibility of developing a computing-visualization system using a public domain software system built on a personal computer. Visualization Toolkit (VTK) is available on UNIX and PC platforms. VTK uses C++ to build an executable. It has abundant programming classes/objects that are contained in the system library. Users can also develop their own classes/objects in addition to those existing in the class library. Users can develop applications with any of the C++, Tcl/Tk, and JAVA environments. The present research will show how a data visualization system can be developed with VTK running on a personal computer. The topics will include: execution efficiency; visual object quality; availability of the user interface design; and exploring the feasibility of the VTK-based World Wide Web data visualization system. The present research will feature a case study showing how to use VTK to visualize meteorological data with techniques including, iso-surface, volume rendering, vector display, and composite analysis. The study also shows how the VTK outline, axes, and two-dimensional annotation text and title are enhancing the data presentation. The present research will also demonstrate how VTK works in an internet environment while accessing an executable with a JAVA application programing in a webpage.

  14. Multi-stimuli manipulation of antiferromagnetic domains assessed by second-harmonic imaging

    Science.gov (United States)

    Chauleau, J.-Y.; Haltz, E.; Carrétéro, C.; Fusil, S.; Viret, M.

    2017-08-01

    Among the variety of magnetic textures available in nature, antiferromagnetism is one of the most `discrete' because of the exact cancellation of its staggered internal magnetization. It is therefore very challenging to probe. However, its insensitivity to external magnetic perturbations, together with the intrinsic sub-picosecond dynamics, make it very appealing for tomorrow's information technologies. Thus, it is essential to understand the microscopic mechanisms governing antiferromagnetic domains to achieve accurate manipulation and control. Using optical second-harmonic generation, a unique and laboratory-available tool, we succeeded in imaging with sub-micrometre resolution both electric and antiferromagnetic orders in the model multiferroic BiFeO3. We show here that antiferromagnetic domains can be manipulated with low power consumption, using sub-coercive electric fields and sub-picosecond light pulses. Interestingly, we also show that antiferromagnetic and ferroelectric domains can behave independently, thus revealing that magneto-electric coupling can lead to various arrangements of the two orders.

  15. Full waveform inversion using oriented time-domain imaging method for vertical transverse isotropic media

    KAUST Repository

    Zhang, Zhendong

    2017-07-11

    Full waveform inversion for reection events is limited by its linearized update re-quirements given by a process equivalent to migration. Unless the background velocity model is reasonably accurate, the resulting gradient can have an inaccurate update direction leading the inversion to converge what we refer to as local minima of the objective function. In our approach, we consider mild lateral variation in the model, and thus, use a gradient given by the oriented time-domain imaging method. Specifically, we apply the oriented time-domain imaging on the data residual to obtain the geometrical features of the velocity perturbation. After updating the model in the time domain, we convert the perturbation from the time domain to depth using the average velocity. Considering density is constant, we can expand the conventional 1D impedance inversion method to 2D or 3D velocity inversion within the process of full waveform inversion. This method is not only capable of inverting for velocity, but it is also capable of retrieving anisotropic parameters relying on linearized representations of the reection response. To eliminate the cross-talk artifacts between different parameters, we utilize what we consider being an optimal parametrization for this step. To do so, we extend the prestack time-domain migration image in incident angle dimension to incorporate angular dependence needed by the multiparameter inversion. For simple models, this approach provides an efficient and stable way to do full waveform inversion or modified seismic inversion and makes the anisotropic inversion more practicable. The proposed method still needs kinematically accurate initial models since it only recovers the high-wavenumber part as conventional full waveform inversion method does. Results on synthetic data of isotropic and anisotropic cases illustrate the benefits and limitations of this method.

  16. Secret shared multiple-image encryption based on row scanning compressive ghost imaging and phase retrieval in the Fresnel domain

    Science.gov (United States)

    Li, Xianye; Meng, Xiangfeng; Wang, Yurong; Yang, Xiulun; Yin, Yongkai; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

    2017-09-01

    A multiple-image encryption method is proposed that is based on row scanning compressive ghost imaging, (t, n) threshold secret sharing, and phase retrieval in the Fresnel domain. In the encryption process, after wavelet transform and Arnold transform of the target image, the ciphertext matrix can be first detected using a bucket detector. Based on a (t, n) threshold secret sharing algorithm, the measurement key used in the row scanning compressive ghost imaging can be decomposed and shared into two pairs of sub-keys, which are then reconstructed using two phase-only mask (POM) keys with fixed pixel values, placed in the input plane and transform plane 2 of the phase retrieval scheme, respectively; and the other POM key in the transform plane 1 can be generated and updated by the iterative encoding of each plaintext image. In each iteration, the target image acts as the input amplitude constraint in the input plane. During decryption, each plaintext image possessing all the correct keys can be successfully decrypted by measurement key regeneration, compression algorithm reconstruction, inverse wavelet transformation, and Fresnel transformation. Theoretical analysis and numerical simulations both verify the feasibility of the proposed method.

  17. Extracting mining subsidence land from remote sensing images based on domain knowledge

    Institute of Scientific and Technical Information of China (English)

    WANG Xing-feng; WANG Yun-jia; HUANG Tai

    2008-01-01

    Extracting mining subsidence land from RS images is one of important research contents for environment monitoring in mining area. The accuracy of traditional extracting models based on spectral features is low. In order to extract subsidence land from RS images with high accuracy, some domain knowledge should be imported and new models should be proposed. This paper, in terms of the disadvantage of traditional extracting models, imports domain knowledge from practice and experience, converts semantic knowledge into digital information, and proposes a new model for the specific task. By selecting Luan mining area as study area, this new model is tested based on GIS and related knowledge. The result shows that the proposed method is more pre- cise than traditional methods and can satisfy the demands of land subsidence monitoring in mining area.

  18. Multiscale registration of remote sensing image using robust SIFT features in Steerable-Domain

    Directory of Open Access Journals (Sweden)

    Xiangzeng Liu

    2011-12-01

    Full Text Available This paper proposes a multiscale registration technique using robust Scale Invariant Feature Transform (SIFT features in Steerable-Domain, which can deal with the large variations of scale, rotation and illumination between images. First, a new robust SIFT descriptor is presented, which is invariant under affine transformation. Then, an adaptive similarity measure is developed according to the robust SIFT descriptor and the adaptive normalized cross correlation of feature point’s neighborhood. Finally, the corresponding feature points can be determined by the adaptive similarity measure in Steerable-Domain of the two input images, and the final refined transformation parameters determined by using gradual optimization are adopted to achieve the registration results. Quantitative comparisons of our algorithm with the related methods show a significant improvement in the presence of large scale, rotation changes, and illumination contrast. The effectiveness of the proposed method is demonstrated by the experimental results.

  19. In vitro birefringence imaging with spectral domain polarization-sensitive optical coherence tomography

    Institute of Scientific and Technical Information of China (English)

    Qiang Gong; Chuanmao Fan; Fan Zhang; Jianquan Yao

    2008-01-01

    Spectral domain polarization-sensitive optical coherence tomography (SDPS-OCT) is a depth-resolved polarization-sensitive interferometry which integrates polarization optics into spectral domain optical co-herence tomography (SD-OCT). This configuration can obtain birefringence information of samples and improve the imaging speed. In this paper, horizontally polarized light is used to replace natural light of the source. Then, right-rotated circularly polarized light is the incident sample light. To obtain two orthogonal components of the polarized interferogram, the reflected light of the reference arm is set to be 45° linearly polarized light. These two components are acquired by two spectrometers synchronously. The system was employed to achieve 12.8-#m axial resolution and 4.36-#m transverse resolution. We have imaged in vitro chicken tendon and muscle tissues with these system.

  20. Optical image encryption based on compressive sensing and chaos in the fractional Fourier domain

    Science.gov (United States)

    Liu, Xingbin; Mei, Wenbo; Du, Huiqian

    2014-11-01

    We propose a novel image encryption algorithm based on compressive sensing (CS) and chaos in the fractional Fourier domain. The original image is dimensionality reduction measured using CS. The measured values are then encrypted using chaotic-based double-random-phase encoding technique in the fractional Fourier transform domain. The measurement matrix and the random-phase masks used in the encryption process are formed from pseudo-random sequences generated by the chaotic map. In this proposed algorithm, the final result is compressed and encrypted. The proposed cryptosystem decreases the volume of data to be transmitted and simplifies the keys for distribution simultaneously. Numerical experiments verify the validity and security of the proposed algorithm.

  1. A frequency domain radar interferometric imaging (FII) technique based on high-resolution methods

    Science.gov (United States)

    Luce, H.; Yamamoto, M.; Fukao, S.; Helal, D.; Crochet, M.

    2001-01-01

    In the present work, we propose a frequency-domain interferometric imaging (FII) technique for a better knowledge of the vertical distribution of the atmospheric scatterers detected by MST radars. This is an extension of the dual frequency-domain interferometry (FDI) technique to multiple frequencies. Its objective is to reduce the ambiguity (resulting from the use of only two adjacent frequencies), inherent with the FDI technique. Different methods, commonly used in antenna array processing, are first described within the context of application to the FII technique. These methods are the Fourier-based imaging, the Capon's and the singular value decomposition method used with the MUSIC algorithm. Some preliminary simulations and tests performed on data collected with the middle and upper atmosphere (MU) radar (Shigaraki, Japan) are also presented. This work is a first step in the developments of the FII technique which seems to be very promising.

  2. Electro-optical BLM chips enabling dynamic imaging of ordered lipid domains.

    Science.gov (United States)

    Shao, Chenren; Kendall, Eric L; DeVoe, Don L

    2012-09-01

    Studies of lipid rafts, ordered microdomains of sphingolipids and cholesterol within cell membranes, are essential in probing the relationships between membrane organization and cellular function. While in vitro studies of lipid phase separation are commonly performed using spherical vesicles as model membranes, the utility of these models is limited by a number of factors. Here we present a microfluidic device that supports simultaneous electrical measurements and confocal imaging of on-chip bilayer lipid membranes (BLMs), enabling real-time multi-domain imaging of membrane organization. The chips further support closed microfluidic access to both sides of the membrane, allowing the membrane boundary conditions to be rapidly changed and providing a mechanism for dynamically adjusting membrane curvature through application of a transmembrane pressure gradient. Here we demonstrate the platform through the study of dynamic generation and dissolution of ordered lipid domains as membrane components are transported to and from the supporting annulus containing solvated lipids and cholesterol.

  3. Investigation of multilayer domains in large-scale CVD monolayer graphene by optical imaging

    Science.gov (United States)

    Yu, Yuanfang; Li, Zhenzhen; Wang, Wenhui; Guo, Xitao; Jiang, Jie; Nan, Haiyan; Ni, Zhenhua

    2017-03-01

    CVD graphene is a promising candidate for optoelectronic applications due to its high quality and high yield. However, multi-layer domains could inevitably form at the nucleation centers during the growth. Here, we propose an optical imaging technique to precisely identify the multilayer domains and also the ratio of their coverage in large-scale CVD monolayer graphene. We have also shown that the stacking disorder in twisted bilayer graphene as well as the impurities on the graphene surface could be distinguished by optical imaging. Finally, we investigated the effects of bilayer domains on the optical and electrical properties of CVD graphene, and found that the carrier mobility of CVD graphene is seriously limited by scattering from bilayer domains. Our results could be useful for guiding future optoelectronic applications of large-scale CVD graphene. Project supported by the National Natural Science Foundation of China (Nos. 61422503, 61376104), the Open Research Funds of Key Laboratory of MEMS of Ministry of Education (SEU, China), and the Fundamental Research Funds for the Central Universities.

  4. Adaptive Binary Arithmetic Coder-Based Image Feature and Segmentation in the Compressed Domain

    Directory of Open Access Journals (Sweden)

    Hsi-Chin Hsin

    2012-01-01

    Full Text Available Image compression is necessary in various applications, especially for efficient transmission over a band-limited channel. It is thus desirable to be able to segment an image in the compressed domain directly such that the burden of decompressing computation can be avoided. Motivated by the adaptive binary arithmetic coder (MQ coder of JPEG2000, we propose an efficient scheme to segment the feature vectors that are extracted from the code stream of an image. We modify the Compression-based Texture Merging (CTM algorithm to alleviate the influence of overmerging problem by making use of the rate distortion information. Experimental results show that the MQ coder-based image segmentation is preferable in terms of the boundary displacement error (BDE measure. It has the advantage of saving computational cost as the segmentation results even at low rates of bits per pixel (bpp are satisfactory.

  5. Dispersion management for controlling image plane in Fourier-domain spectrally encoded endoscopy.

    Science.gov (United States)

    Merman, Michal; Yelin, Dvir

    2011-02-28

    Spectrally encoded endoscopy (SEE) uses single optical fiber and miniature diffractive optics to allow imaging through a miniature probe. Utilizing Fourier-domain interferometry, SEE was shown capable of video-rate three-dimensional imaging, albeit at limited depth of field due to the limited spectral resolution of the detection spectrometer. We show that by using dispersion management at the reference arm of the interferometer, the tilt and curvature of the field of view could be adjusted without modifying the endoscopic probe itself. By controlling the group velocity dispersion, this technique is demonstrated useful for imaging specimen regions which reside outside the system's depth of field. This approach could be used to improve usability, functionality and image quality of SEE without affecting probe size and flexibility.

  6. Multiple-image encryption based on phase mask multiplexing in fractional Fourier transform domain.

    Science.gov (United States)

    Liansheng, Sui; Meiting, Xin; Ailing, Tian

    2013-06-01

    A multiple-image encryption scheme is proposed based on the phase retrieval process and phase mask multiplexing in the fractional Fourier transform domain. First, each original gray-scale image is encoded into a phase only function by using the proposed phase retrieval process. Second, all the obtained phase functions are modulated into an interim, which is encrypted into the final ciphertext by using the fractional Fourier transform. From a plaintext image, a group of phase masks is generated in the encryption process. The corresponding decrypted image can be recovered from the ciphertext only with the correct phase mask group in the decryption process. Simulation results show that the proposed phase retrieval process has high convergence speed, and the encryption algorithm can avoid cross-talk; in addition, its encrypted capacity is considerably enhanced.

  7. An Adaptive Steganographic Method in Frequency Domain Based on Statistical Metrics of Image

    Directory of Open Access Journals (Sweden)

    Seyyed Amin Seyyedi

    2015-05-01

    Full Text Available Steganography is a branch of information hiding. A tradeoff between the hiding payload and quality of digital image steganographic schemes is major challenge of the steganographic methods. An adaptive steganographic method for embedding secret message into gray scale images is proposed. Before embedding the secret message, the cover image is transformed into frequency domain by integer wavelet. The middle frequency band of cover image is partitioned into 4×4 non overlapping blocks. The blocks by deviation and entropy metrics are classified into three categories: smooth, edge, and texture regions. Number of bits which can be embedded in a block is defined by block features. Moreover, RC4 encryption method is used to increase secrecy protection. Experimental results denote the feasibility of the proposed method. Statistical tests were conducted to collect related data to verify the security of method.

  8. Stacking of large interferometric data sets in the image- and uv-domain -- a comparative study

    OpenAIRE

    Lindroos, Lukas; Knudsen, K. K.; Vlemmings, W.; Conway, J.; Martí-Vidal, I

    2014-01-01

    We present a new algorithm for stacking radio interferometric data in the uv-domain. The performance of uv-stacking is compared to the stacking of fully imaged data using simulated Atacama Large Millimeter/sub-millimeter Array (ALMA) and the Karl G. Jansky Very Large Array (VLA) deep extragalactic surveys. We find that image- and uv-stacking produce similar results, however, uv-stacking is typically the more robust method. An advantage of the uv-stacking algorithm is the availability of uv-da...

  9. A Novel Ship Wake Detection Method of SAR Images Based on Frequency Domain

    Institute of Scientific and Technical Information of China (English)

    Liu Hao; Zhu Minhui

    2003-01-01

    Moving ships produce a set of waves of "V' pattern on the ocean. These waves can often be seen by Synthetic Aperture Radar (SAR). The detection of these wakes can provide important information for surveillance of shipping, such as ship traveling direction and speed. A novel approach to the detection of ship wakes in SAR images based on frequency domain is provided in this letter. Compared with traditional Radon-based approaches, computation is reduced by 20%-40% without losing nearly any of detection performance. The testing results using real data and simulation of synthetic SAR images test the algorithm's feasibility and robustness.

  10. Usage of Clustering Algorithm to Segment Image into Simply Connected Domains

    Directory of Open Access Journals (Sweden)

    S. V. Belim

    2015-01-01

    Full Text Available The article suggests a method of image segmentation into simply connected domains based on color. Pixels from an original image are represented as points in five-dimensional space which includes three color and two spatial coordinates. The points are normalized in order to eliminate distinguished characteristics. The set of points is compared with a weighted complete graph. The points of five-dimensional space are vertexes in the graph. Euclidian distance between the points is used as weights of the edges in the graph. To solve the task of clustering, a minimum spanning tree of the graph is built. For clustering, the tree is separated into sub-trees by removing some edges. Each sub-tree is a simply connected domain on the original image. In order to improve algorithm speed and reduce memory usage a greedy algorithm is used to build this minimum spanning tree for the graph. Edges to be removed are searched on the graph representing the length of an added edge versus a sequence number of its adding to the tree in the greedy algorithm. The desired edges are detected as maximums on the graphic. This search is based on assumption that transition to an adjacent cluster leads to connection of longer edge in comparison with edges within a cluster. Segmentation into clusters is iterative. At each step the bigger clusters are divided into smaller ones. It means that hierarchy of clusters can be built. A computer experiment was carried out using different images.The suggested method has no disadvantages of the most common method of k-means and allows dividing domains with different colors but the same intensity. Therewith there is no need to specify a number of clusters. Instead, it is necessary to choose a segmentation depth then a number of clusters will be automatically defined. The suggested method has no disadvantages of detection of image edges either. It is sufficient to find one point of image edge to separate two domains.A distinctive feature of

  11. Fra Angelico's painting technique revealed by terahertz time-domain imaging (THz-TDI)

    Science.gov (United States)

    Koch Dandolo, Corinna Ludovica; Picollo, Marcello; Cucci, Costanza; Jepsen, Peter Uhd

    2016-10-01

    We have investigated with terahertz time-domain imaging (THz-TDI) the well-known Lamentation over the dead Christ panel painting (San Marco Museum, Florence) painted by Fra Giovanni Angelico within 1436 and 1441. The investigation provided a better understanding of the construction and gilding technique used by the eminent artist, as well as the plastering technique used during the nineteenth-century restoration intervention. The evidence obtained from THz-TDI scans was correlated with the available documentation on the preservation history of the art piece. Erosion and damages documented for the wooden support, especially in the lower margin, found confirmation in the THz-TD images.

  12. Spectral-domain and swept-source OCT imaging of asteroid hyalosis: a case report.

    Science.gov (United States)

    Alasil, Tarek; Adhi, Mehreen; Liu, Jonathan J; Fujimoto, James G; Duker, Jay S; Baumal, Caroline R

    2014-01-01

    A 72-year-old man with diabetes was referred to the retina clinic for diabetic retinopathy. Detailed funduscopic examination of the left eye was limited by prominent asteroid hyalosis. Spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT) were utilized to examine the vitreous, vitreoretinal interface, and the morphology of the retina. Asteroid hyalosis induced artifacts of the OCT images, which resolved when the appropriate imaging protocols were applied. SS-OCT may show superior diagnostic and preoperative capabilities when compared to SD-OCT in the settings of asteroid hyalosis-induced media opacity.

  13. High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography

    Science.gov (United States)

    Olivier, Scot S.; Werner, John S.; Zawadzki, Robert J.; Laut, Sophie P.; Jones, Steven M.

    2010-09-07

    This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

  14. Integrated structural and functional optical imaging combining spectral-domain optical coherence and multiphoton microscopy

    CERN Document Server

    Vinegoni, C; Luo, W; Marks, D L; Ralston, T; Tan, W

    2005-01-01

    An integrated microscope that combines different optical techniques for simultaneous imaging is demonstrated. The microscope enables spectral-domain optical coherence microscopy based on optical backscatter, and multi-photon microscopy for the detection of two-photon fluorescence and second harmonic generation signals. The unique configuration of this integrated microscope allows for the simultaneous acquisition of both anatomical (structural) and functional imaging information with particular emphasis for applications in the fields of tissue engineering and cell biology. In addition, the contemporary analysis of the spectroscopic features can enhance contrast by differentiating among different tissue components.

  15. Feasibility demonstration of frequency domain terahertz imaging in breast cancer margin determination

    Science.gov (United States)

    Yngvesson, Sigfrid K.; St. Peter, Benjamin; Siqueira, Paul; Kelly, Patrick; Glick, Stephen; Karellas, Andrew; Khan, Ashraf

    2012-03-01

    In breast conservation surgery, surgeons attempt to remove malignant tissue along with a surrounding margin of healthy tissue. Subsequent pathological analysis determines if those margins are clear of malignant tissue, a process that typically requires at least one day. Only then can it be determined whether a follow-up surgery is necessary. This possibility of re-excision is undesirable in terms of reducing patient morbidity, emotional stress and healthcare. It has been shown that terahertz (THz) images of breast specimens can accurately differentiate between breast carcinoma, normal fibroglandular tissue, and adipose tissue. That study employed the Time-Domain Spectroscopy (TDS) technique. We are instead developing a new technique, Frequency-Domain Terahertz Imaging (FDTI). In this joint project between UMass/Amherst and UMass Medical School/Worcester (UMMS), we are investigating the feasibility of the FDTI technique for THz reflection imaging of breast cancer margins. Our system, which produces mechanically scanned images of size 2cm x 2cm, uses a THz gas laser. The system is calibrated with mixtures of water and ethanol and reflection coefficients as low as 1% have been measured. Images from phantoms and specimens cut from breast cancer lumpectomies at UMMS will be presented. Finally, there will be a discussion of a possible transition of this FDTI setup to a compact and inexpensive CMOS THz camera for use in the operating room.

  16. A method for estimating spatial resolution of real image in the Fourier domain

    CERN Document Server

    Mizutani, Ryuta; Takekoshi, Susumu; Inomoto, Chie; Nakamura, Naoya; Itokawa, Masanari; Arai, Makoto; Oshima, Kenichi; Takeuchi, Akihisa; Uesugi, Kentaro; Terada, Yasuko; Suzuki, Yoshio

    2016-01-01

    Spatial resolution is a fundamental parameter in structural sciences. In crystallography, the resolution is determined from the detection limit of high-angle diffraction in reciprocal space. In electron microscopy, correlation in the Fourier domain is used for estimating the resolution. In this paper, we report a method for estimating the spatial resolution of real images from a logarithmic intensity plot in the Fourier domain. The logarithmic intensity plots of test images indicated that the full width at half maximum of a Gaussian point-spread function can be estimated from the images. The spatial resolution of imaging X-ray microtomography using Fresnel zone-plate optics was also estimated with this method. A cross section of a test object visualized with the imaging microtomography indicated that square-wave patterns up to 120-nm pitch were resolved. The logarithmic intensity plot was calculated from a tomographic cross section of brain tissue. The full width at half maximum of the point spread function e...

  17. Breaching Biological Barriers: Protein Translocation Domains as Tools for Molecular Imaging and Therapy

    Directory of Open Access Journals (Sweden)

    Benjamin L. Franc

    2003-10-01

    Full Text Available The lipid bilayer of a cell presents a significant barrier for the delivery of many molecular imaging reagents into cells at target sites in the body. Protein translocation domains (PTDs are peptides that breach this barrier. Conjugation of PTDs to imaging agents can be utilized to facilitate the delivery of these agents through the cell wall, and in some cases, into the cell nucleus, and have potential for in vitro and in vivo applications. PTD imaging conjugates have included small molecules, peptides, proteins, DNA, metal chelates, and magnetic nanoparticles. The full potential of the use of PTDs in novel in vivo molecular probes is currently under investigation. Cells have been labeled in culture using magnetic nanoparticles derivatized with a PTD and monitored in vivo to assess trafficking patterns relative to cells expressing a target antigen. In vivo imaging of PTD-mediated gene transfer to cells of the skin has been demonstrated in living animals. Here we review several natural and synthetic PTDs that have evolved in the quest for easier translocation across biological barriers and the application of these peptide domains to in vivo delivery of imaging agents.

  18. Image denoising in bidimensional empirical mode decomposition domain: the role of Student's probability distribution function.

    Science.gov (United States)

    Lahmiri, Salim

    2016-03-01

    Hybridisation of the bi-dimensional empirical mode decomposition (BEMD) with denoising techniques has been proposed in the literature as an effective approach for image denoising. In this Letter, the Student's probability density function is introduced in the computation of the mean envelope of the data during the BEMD sifting process to make it robust to values that are far from the mean. The resulting BEMD is denoted tBEMD. In order to show the effectiveness of the tBEMD, several image denoising techniques in tBEMD domain are employed; namely, fourth order partial differential equation (PDE), linear complex diffusion process (LCDP), non-linear complex diffusion process (NLCDP), and the discrete wavelet transform (DWT). Two biomedical images and a standard digital image were considered for experiments. The original images were corrupted with additive Gaussian noise with three different levels. Based on peak-signal-to-noise ratio, the experimental results show that PDE, LCDP, NLCDP, and DWT all perform better in the tBEMD than in the classical BEMD domain. It is also found that tBEMD is faster than classical BEMD when the noise level is low. When it is high, the computational cost in terms of processing time is similar. The effectiveness of the presented approach makes it promising for clinical applications.

  19. Brain connectivity study of joint attention using frequency-domain optical imaging technique

    Science.gov (United States)

    Chaudhary, Ujwal; Zhu, Banghe; Godavarty, Anuradha

    2010-02-01

    Autism is a socio-communication brain development disorder. It is marked by degeneration in the ability to respond to joint attention skill task, from as early as 12 to 18 months of age. This trait is used to distinguish autistic from nonautistic populations. In this study, diffuse optical imaging is being used to study brain connectivity for the first time in response to joint attention experience in normal adults. The prefrontal region of the brain was non-invasively imaged using a frequency-domain based optical imager. The imaging studies were performed on 11 normal right-handed adults and optical measurements were acquired in response to joint-attention based video clips. While the intensity-based optical data provides information about the hemodynamic response of the underlying neural process, the time-dependent phase-based optical data has the potential to explicate the directional information on the activation of the brain. Thus brain connectivity studies are performed by computing covariance/correlations between spatial units using this frequency-domain based optical measurements. The preliminary results indicate that the extent of synchrony and directional variation in the pattern of activation varies in the left and right frontal cortex. The results have significant implication for research in neural pathways associated with autism that can be mapped using diffuse optical imaging tools in the future.

  20. STEGO TRANSFORMATION OF SPATIAL DOMAIN OF COVER IMAGE ROBUST AGAINST ATTACKS ON EMBEDDED MESSAGE

    Directory of Open Access Journals (Sweden)

    Kobozeva A.

    2014-04-01

    Full Text Available One of the main requirements to steganografic algorithm to be developed is robustness against disturbing influences, that is, to attacks against the embedded message. It was shown that guaranteeing the stego algorithm robustness does not depend on whether the additional information is embedded into the spatial or transformation domain of the cover image. Given the existing advantages of the spatial domain of the cover image in organization of embedding and extracting processes, a sufficient condition for ensuring robustness of such stego transformation was obtained in this work. It was shown that the amount of brightness correction related to the pixels of the cover image block is similar to the amount of correction related to the maximum singular value of the corresponding matrix of the block in case of embedding additional data that ensures robustness against attacks on the embedded message. Recommendations were obtained for selecting the size of the cover image block used in stego transformation as one of the parameters determining the calculation error of stego message. Given the inversely correspondence between the stego capacity of the stego channel being organized and the size of the cover image block, l=8 value was recommended.

  1. The Relationship Between Body Image and Domains of Sexual Functioning Among Heterosexual, Emerging Adult Women.

    Science.gov (United States)

    Quinn-Nilas, Christopher; Benson, Lindsay; Milhausen, Robin R; Buchholz, Andrea C; Goncalves, Melissa

    2016-09-01

    Research suggests that body image affects sexual functioning, but the relationship between specific types of body image (evaluative, affective, and behavioral) and domains of sexual functioning (desire, arousal, and orgasm) has not been investigated. To determine whether, and to what degree, body image concerns (evaluative, affective, and behavioral) influence aspects of women's sexual functioning (desire, arousal, and orgasm). Eighty-eight sexually active women in heterosexual romantic relationships completed surveys assessing evaluative, affective, and behavioral body image and sexual functioning. Body composition data also were collected using dual energy x-ray absorptiometry. Sexual functioning was assessed using the desire, arousal, and orgasm subscales of the Female Sexual Functioning Index. Hierarchical multiple regression analysis indicated that poor evaluative, affective, and behavioral body image were detrimental to women's sexual functioning. Specifically, dissatisfaction with one's body predicted decrements in desire (β = -0.31, P body negatively predicted decrements in desire (β = 0.22, P body during a sexual encounter (body image self-consciousness) predicted decrements in arousal (β = -0.37, P body image and sexual functioning constructs and indicates that interventions to improve body image could have concomitant benefits related to sexual experience. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Fusion of infrared and visible images based on saliency scale-space in frequency domain

    Science.gov (United States)

    Chen, Yanfei; Sang, Nong; Dan, Zhiping

    2015-12-01

    A fusion algorithm of infrared and visible images based on saliency scale-space in the frequency domain was proposed. Focus of human attention is directed towards the salient targets which interpret the most important information in the image. For the given registered infrared and visible images, firstly, visual features are extracted to obtain the input hypercomplex matrix. Secondly, the Hypercomplex Fourier Transform (HFT) is used to obtain the salient regions of the infrared and visible images respectively, the convolution of the input hypercomplex matrix amplitude spectrum with a low-pass Gaussian kernel of an appropriate scale which is equivalent to an image saliency detector are done. The saliency maps are obtained by reconstructing the 2D signal using the original phase and the amplitude spectrum, filtered at a scale selected by minimizing saliency map entropy. Thirdly, the salient regions are fused with the adoptive weighting fusion rules, and the nonsalient regions are fused with the rule based on region energy (RE) and region sharpness (RS), then the fused image is obtained. Experimental results show that the presented algorithm can hold high spectrum information of the visual image, and effectively get the thermal targets information at different scales of the infrared image.

  3. SAR and Infrared Image Fusion in Complex Contourlet Domain Based on Joint Sparse Representation

    Directory of Open Access Journals (Sweden)

    Wu Yiquan

    2017-08-01

    Full Text Available To investigate the problems of the large grayscale difference between infrared and Synthetic Aperture Radar (SAR images and their fusion image not being fit for human visual perception, we propose a fusion method for SAR and infrared images in the complex contourlet domain based on joint sparse representation. First, we perform complex contourlet decomposition of the infrared and SAR images. Then, we employ the KSingular Value Decomposition (K-SVD method to obtain an over-complete dictionary of the low-frequency components of the two source images. Using a joint sparse representation model, we then generate a joint dictionary. We obtain the sparse representation coefficients of the low-frequency components of the source images in the joint dictionary by the Orthogonal Matching Pursuit (OMP method and select them using the selection maximization strategy. We then reconstruct these components to obtain the fused low-frequency components and fuse the high-frequency components using two criteria——the coefficient of visual sensitivity and the degree of energy matching. Finally, we obtain the fusion image by the inverse complex contourlet transform. Compared with the three classical fusion methods and recently presented fusion methods, e.g., that based on the Non-Subsampled Contourlet Transform (NSCT and another based on sparse representation, the method we propose in this paper can effectively highlight the salient features of the two source images and inherit their information to the greatest extent.

  4. A Robust Image Watermarking in the Joint Time-Frequency Domain

    Directory of Open Access Journals (Sweden)

    Çekiç Yalçın

    2010-01-01

    Full Text Available With the rapid development of computers and internet applications, copyright protection of multimedia data has become an important problem. Watermarking techniques are proposed as a solution to copyright protection of digital media files. In this paper, a new, robust, and high-capacity watermarking method that is based on spatiofrequency (SF representation is presented. We use the discrete evolutionary transform (DET calculated by the Gabor expansion to represent an image in the joint SF domain. The watermark is embedded onto selected coefficients in the joint SF domain. Hence, by combining the advantages of spatial and spectral domain watermarking methods, a robust, invisible, secure, and high-capacity watermarking method is presented. A correlation-based detector is also proposed to detect and extract any possible watermarks on an image. The proposed watermarking method was tested on some commonly used test images under different signal processing attacks like additive noise, Wiener and Median filtering, JPEG compression, rotation, and cropping. Simulation results show that our method is robust against all of the attacks.

  5. The public understanding of nanotechnology in the food domain: the hidden role of views on science, technology, and nature.

    Science.gov (United States)

    Vandermoere, Frederic; Blanchemanche, Sandrine; Bieberstein, Andrea; Marette, Stephan; Roosen, Jutta

    2011-03-01

    In spite of great expectations about the potential of nanotechnology, this study shows that people are rather ambiguous and pessimistic about nanotechnology applications in the food domain. Our findings are drawn from a survey of public perceptions about nanotechnology food and nanotechnology food packaging (N = 752). Multinomial logistic regression analyses further reveal that knowledge about food risks and nanotechnology significantly influences people's views about nanotechnology food packaging. However, knowledge variables were unrelated to support for nanofood, suggesting that an increase in people's knowledge might not be sufficient to bridge the gap between the excitement some business leaders in the food sector have and the restraint of the public. Additionally, opposition to nanofood was not related to the use of heuristics but to trust in governmental agencies. Furthermore, the results indicate that public perceptions of nanoscience in the food domain significantly relate to views on science, technology, and nature.

  6. THE INFLUENCE OF MARKETING PUBLIC RELATION AND SERVICE QUALITY ON CORPORATE IMAGE THROUGH PUBLIC OPINION: STUDIES AT MANDIRI BANK

    OpenAIRE

    Vera Suciyati

    2015-01-01

    This research aims to analyze the influence of marketing public relation and service quality at Bank Mandiri on corporate image through public. Convenience sampling method has been selected in order to obtain the data in this study. The analysis method that used was the path analysis. The research result had shown that: marketing public relation and service quality have significant influence simultaneously and partially on public opinion on the first structure equation. The second structure e...

  7. Robust Colour Image Watermarking Scheme Based on Feature Points and Image Normalization in DCT Domain

    Directory of Open Access Journals (Sweden)

    Ibrahim Alsonosi Nasir

    2014-04-01

    Full Text Available Geometric attacks can desynchronize the location of the watermark and hence cause incorrect watermark detection. This paper presents a robust c olour image watermarking scheme based on visually significant feature points and image norma lization technique. The feature points are used as synchronization marks between watermark emb edding and detection. The watermark is embedded into the non overlapped normalized circula r regions in the luminance component or the blue component of a color image. The embedding of the watermark is carried out by modifying the DCT coefficients values in selected b locks. The original unmarked image is not required for watermark extraction Experimental results show that the proposed scheme successfully makes the watermark perceptually invis ible as well as robust to common signal processing and geometric attacks.

  8. Spectral domain optical coherence tomography imaging of spectacular ecdysis in the royal python (Python regius).

    Science.gov (United States)

    Tusler, Charlotte A; Maggs, David J; Kass, Philip H; Paul-Murphy, Joanne R; Schwab, Ivan R; Murphy, Christopher J

    2015-01-01

    To describe using spectral domain optical coherence tomography (SD-OCT), digital slit-lamp biomicroscopy, and external photography, changes in the ophidian cuticle, spectacle, and cornea during ecdysis. Four normal royal pythons (Python regius). Snakes were assessed once daily throughout a complete shed cycle using nasal, axial, and temporal SD-OCT images, digital slit-lamp biomicroscopy, and external photography. Spectral domain optical coherence tomography (SD-OCT) images reliably showed the spectacular cuticle and stroma, subcuticular space (SCS), cornea, anterior chamber, iris, and Schlemm's canal. When visible, the subspectacular space (SSS) was more distended peripherally than axially. Ocular surface changes throughout ecdysis were relatively conserved among snakes at all three regions imaged. From baseline (7 days following completion of a full cycle), the spectacle gradually thickened before separating into superficial cuticular and deep, hyper-reflective stromal components, thereby creating the SCS. During spectacular separation, the stroma regained original reflectivity, and multiple hyper-reflective foci (likely fragments from the cuticular-stromal interface) were noted within the SCS. The cornea was relatively unchanged in character or thickness throughout all stages of ecdysis. Slit-lamp images did not permit observation of these changes. Spectral domain optical coherence tomography (SD-OCT) provided excellent high-resolution images of the snake anterior segment, and especially the cuticle, spectacle, and cornea of manually restrained normal snakes at all stages of ecdysis and warrants investigation in snakes with anterior segment disease. The peripheral spectacle may be the preferred entry point for diagnostic or therapeutic injections into the SSS and for initiating spectacular surgery. © 2014 American College of Veterinary Ophthalmologists.

  9. Computational Complexity Reduction of Synthetic-aperture Focus in Ultrasound Imaging Using Frequency-domain Reconstruction.

    Science.gov (United States)

    Moghimirad, Elahe; Mahloojifar, Ali; Mohammadzadeh Asl, Babak

    2016-05-01

    A new frequency-domain implementation of a synthetic aperture focusing technique is presented in the paper. The concept is based on synthetic aperture radar (SAR) and sonar that is a developed version of the convolution model in the frequency domain. Compared with conventional line-by-line imaging, synthetic aperture imaging has a better resolution and contrast at the cost of more computational load. To overcome this problem, point-by-point reconstruction methods have been replaced by block-processing algorithms in radar and sonar; however, these techniques are relatively unknown in medical imaging. In this paper, we extended one of these methods called wavenumber to medical ultrasound imaging using a simple model of synthetic aperture focus. The model, derived here for monostatic mode, can be generalized to multistatic as well. The method consists of 4 steps: a 2D fast Fourier transform of the data, frequency shift of the data to baseband, interpolation to convert polar coordinates to rectangular ones, and returning the data to the spatial-domain using a 2D inverse Fourier transform. We have also used chirp pulse excitation followed by matched filtering and spotlighting algorithm to compensate the effect of differences in parameters between radar and medical imaging. Computational complexities of the two methods, wavenumber and delay-and-sum (DAS), have been calculated. Field II simulated point data have been used to evaluate the results in terms of resolution and contrast. Evaluations with simulated data show that for typical phantoms, reconstruction by the wavenumber algorithm is almost 20 times faster than classical DAS while retaining the resolution. © The Author(s) 2015.

  10. Myocardial imaging using ultrahigh-resolution spectral domain optical coherence tomography

    Science.gov (United States)

    Yao, Xinwen; Gan, Yu; Marboe, Charles C.; Hendon, Christine P.

    2016-06-01

    We present an ultrahigh-resolution spectral domain optical coherence tomography (OCT) system in 800 nm with a low-noise supercontinuum source (SC) optimized for myocardial imaging. The system was demonstrated to have an axial resolution of 2.72 μm with a large imaging depth of 1.78 mm and a 6-dB falloff range of 0.89 mm. The lateral resolution (5.52 μm) was compromised to enhance the image penetration required for myocardial imaging. The noise of the SC source was analyzed extensively and an imaging protocol was proposed for SC-based OCT imaging with appreciable contrast. Three-dimensional datasets were acquired ex vivo on the endocardium side of tissue specimens from different chambers of fresh human and swine hearts. With the increased resolution and contrast, features such as elastic fibers, Purkinje fibers, and collagen fiber bundles were observed. The correlation between the structural information revealed in the OCT images and tissue pathology was discussed as well.

  11. Frequency and Spatial Domains Adaptive-based Enhancement Technique for Thermal Infrared Images

    Directory of Open Access Journals (Sweden)

    Debasis Chaudhuri

    2014-09-01

    Full Text Available Low contrast and noisy image limits the amount of information conveyed to the user. With the proliferation of digital imagery and computer interface between man-and-machine, it is now viable to consider digital enhancement in the image before presenting it to the user, thus increasing the information throughput. With better contrast, target detection and discrimination can be improved. The paper presents a sequence of filtering operations in frequency and spatial domains to improve the quality of the thermal infrared (IR images. Basically, two filters – homomorphic filter followed by adaptive Gaussian filter are applied to improve the quality of the thermal IR images. We have systematically evaluated the algorithm on a variety of images and carefully compared it with the techniques presented in the literature. We performed an evaluation of three filter banks such as homomorphic, Gaussian 5×5 and the proposed method, and we have seen that the proposed method yields optimal PSNR for all the thermal images. The results demonstrate that the proposed algorithm is efficient for enhancement of thermal IR images.Defence Science Journal, Vol. 64, No. 5, September 2014, pp.451-457, DOI:http://dx.doi.org/10.14429/dsj.64.6873

  12. Making YOHKOH SXT Images Available to the Public: The YOHKOH Public Outreach Project

    Science.gov (United States)

    Larson, M. B.; McKenzie, D.; Slater, T.; Acton, L.; Alexander, D.; Freeland, S.; Lemen, J.; Metcalf, T.

    1999-05-01

    The NASA funded Yohkoh Public Outreach Project (YPOP) provides public access to high quality Yohkoh SXT data via the World Wide Web. The products of this effort are available to the scientific research community, K-12 schools, and informal education centers including planetaria, museums, and libraries. The project utilizes the intrinsic excitement of the SXT data, and in particular the SXT movies, to develop science learning tools and classroom activities. The WWW site at URL: http://solar.physics.montana.edu/YPOP/ uses a movie theater theme to highlight available Yohkoh movies in a format that is entertaining and inviting to non-scientists. The site features informational tours of the Sun as a star, the solar magnetic field, the internal structure and the Sun's general features. The on-line Solar Classroom has proven very popular, showcasing hand-on activities about image filtering, the solar cycle, satellite orbits, image processing, construction of a model Yohkoh satellite, solar rotation, measuring sunspots and building a portable sundial. The YPOP Guestbook has been helpful in evaluating the usefulness of the site with over 300 detailed comments to date.

  13. An Image-Domain Contrast Material Extraction Method for Dual-Energy Computed Tomography.

    Science.gov (United States)

    Lambert, Jack W; Sun, Yuxin; Gould, Robert G; Ohliger, Michael A; Li, Zhixi; Yeh, Benjamin M

    2017-04-01

    Conventional material decomposition techniques for dual-energy computed tomography (CT) assume mass or volume conservation, where the CT number of each voxel is fully assigned to predefined materials. We present an image-domain contrast material extraction process (CMEP) method that preferentially extracts contrast-producing materials while leaving the remaining image intact. Image processing freeware (Fiji) is used to perform consecutive arithmetic operations on a dual-energy ratio map to generate masks, which are then applied to the original images to generate material-specific images. First, a low-energy image is divided by a high-energy image to generate a ratio map. The ratio map is then split into material-specific masks. Ratio intervals known to correspond to particular materials (eg, iodine, calcium) are assigned a multiplier of 1, whereas ratio values in between these intervals are assigned linear gradients from 0 to 1. The masks are then multiplied by an original CT image to produce material-specific images. The method was tested quantitatively at dual-source CT and rapid kVp-switching CT (RSCT) with phantoms using pure and mixed formulations of tungsten, calcium, and iodine. Errors were evaluated by comparing the known material concentrations with those derived from the CMEP material-specific images. Further qualitative evaluation was performed in vivo at RSCT with a rabbit model using identical CMEP parameters to the phantom. Orally administered tungsten, vascularly administered iodine, and skeletal calcium were used as the 3 contrast materials. All 5 material combinations-tungsten, iodine, and calcium, and mixtures of tungsten-calcium and iodine-calcium-showed distinct dual-energy ratios, largely independent of material concentration at both dual-source CT and RSCT. The CMEP was successful in both phantoms and in vivo. For pure contrast materials in the phantom, the maximum error between the known and CMEP-derived material concentrations was 0.9 mg

  14. Anterior segment spectral domain optical coherence tomography imaging of patients with anterior scleritis.

    Science.gov (United States)

    Levison, Ashleigh L; Lowder, Careen Y; Baynes, Kimberly M; Kaiser, Peter K; Srivastava, Sunil K

    2016-08-01

    The purpose of the study was to describe the findings seen on anterior segment spectral domain optical coherence tomography (SD-OCT) in patients with anterior scleritis and determine the feasibility of using SD-OCT to image and grade the degree of scleral inflammation and monitor response to treatment. All patients underwent slit lamp examination by a uveitis specialist, and the degree of scleral inflammation was recorded. Spectral domain OCT imaging was then performed of the conjunctiva and scleral tissue using a standardized acquisition protocol. The scans were graded and compared to clinical findings. Twenty-eight patients with anterior scleritis and ten patients without ocular disease were included in the study. Seventeen of the scleritis patients were followed longitudinally. Common findings on SD-OCT in patients with active scleritis included changes in hyporeflectivity within the sclera, nodules, and visible vessels within the sclera. There was significant variation in findings on SD-OCT within each clinical grade of active scleritis. These changes on SD-OCT improved with treatment and clinical improvement. SD-OCT imaging provided various objective measures that could be used in the future to grade inflammatory activity in patients with anterior scleritis. Longitudinal imaging of patients with active scleritis demonstrated that SD-OCT may have great utility in monitoring response to treatment.

  15. Normal Inverse Gaussian Model-Based Image Denoising in the NSCT Domain

    Directory of Open Access Journals (Sweden)

    Jian Jia

    2015-01-01

    Full Text Available The objective of image denoising is to retain useful details while removing as much noise as possible to recover an original image from its noisy version. This paper proposes a novel normal inverse Gaussian (NIG model-based method that uses a Bayesian estimator to carry out image denoising in the nonsubsampled contourlet transform (NSCT domain. In the proposed method, the NIG model is first used to describe the distributions of the image transform coefficients of each subband in the NSCT domain. Then, the corresponding threshold function is derived from the model using Bayesian maximum a posteriori probability estimation theory. Finally, optimal linear interpolation thresholding algorithm (OLI-Shrink is employed to guarantee a gentler thresholding effect. The results of comparative experiments conducted indicate that the denoising performance of our proposed method in terms of peak signal-to-noise ratio is superior to that of several state-of-the-art methods, including BLS-GSM, K-SVD, BivShrink, and BM3D. Further, the proposed method achieves structural similarity (SSIM index values that are comparable to those of the block-matching 3D transformation (BM3D method.

  16. Robust Digital Image Watermarking Against Cropping Using Sudoku Puzzle in Spatial and Transform Domain

    Directory of Open Access Journals (Sweden)

    shadi saneie

    2016-10-01

    Full Text Available With rapid development of digital technology, protecting information such as copyright, content ownership confirmation has become more important. In image watermarking, information of the image is inserted such that the visual quality of the image is not reduced and the receiver is able to get the required information. Some attacks such as image cropping, destroy the watermark’s information. In this article, a new watermarking scheme is proposed which is robust against tough cropping. In the proposed scheme, classic Sudoku table which is a 9*9 table, has been used. One feature of Sudoku table is that Sudoku's limitations cause uniform scattering of symbols or numbers throughout the table. In the proposed scheme, Sudoku table and both watermarking approaches based on spatial domain and transform domain such as DCT and DWT are used. Lack of using of soduko solution at the stage of extraction and finding correct solution to obtain watermark, is innovation of this scheme. Robustness of watermarking against cropping attack is up to 92%, which shows good and effective performance of the proposed scheme.

  17. Combining double random phase encoding for color image watermarking in quaternion gyrator domain

    Science.gov (United States)

    Shao, Zhuhong; Duan, Yuping; Coatrieux, Gouenou; Wu, Jiasong; Meng, Jinyu; Shu, Huazhong

    2015-05-01

    Quaternion representation of color image has attracted great attention due to its capability to treat holistically the three color channels. In a more general way, it has successfully been used in multi-channel signal processing applications over the past few decades. In this study, a joint encryption/watermarking system with more security based on double random phase encoding (DRPE) in quaternion gyrator transform domain is addressed. In the proposed scheme, an RGB-scale watermark image together with a grayscale watermark image or not is encoded into a quaternion matrix and encrypted through the DRPE, the encrypted data is then fused into the middle coefficients of the quaternion gyrator-transformed host image. In the process of extracting watermarks, it is impossible to retrieve them without authorized keys. Compared with the three channels independently processing approach implemented in fractional Fourier domain, the proposed algorithm achieves lower complexity by reason of avoiding repetitive operations. Experimental results have demonstrated the feasibility of the proposed algorithm and its superior performance in terms of noise robustness.

  18. A NEW APPROACH FOR UNSUPERVISED RESTORING IMAGES BASED ON WAVELET-DOMAIN PROJECTION PURSUIT LEARNING NETWORK

    Institute of Scientific and Technical Information of China (English)

    Lin Wei; Tian Zheng; Wen Xianbin

    2003-01-01

    The Wavelet-Domain Projection Pursuit Learning Network (WDPPLN) is proposedfor restoring degraded image. The new network combines the advantages of both projectionpursuit and wavelet shrinkage. Restoring image is very difficult when little is known about apriori knowledge for multisource degraded factors. WDPPLN successfully resolves this problemby separately processing wavelet coefficients and scale coefficients. Parameters in WDPPLN,which are used to simulate degraded factors, are estimated via WDPPLN training, using scalecoefficients. Also, WDPPLN uses soft-threshold of wavelet shrinkage technique to suppress noisein three high frequency subbands. The new method is compared with the traditional methodsand the Projection Pursuit Learning Network (PPLN) method. Experimental results demonstratethat it is an effective method for unsupervised restoring degraded image.

  19. STUDY ON THE SUBSIDING LAND EXTRACTION FROM LANDSAT TM IMAGE SUPPORTED BY GIS AND DOMAIN KNOWLEDGE

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The subsiding land can be extracted from Remote Sensing image based on its spectral and spatial features. The features of subsiding land caused by mining, especially its RS information features and relative knowledge are proposed. Three methods can be used to extract subsiding land from RS image. The first is to categorize the region into different blocks (or layers) according to their features and apply corresponding strategies for each block, the second is to identify the changeable region based on GIS firstly and then to classify those regions, and the third is to post-process the classified image by traditional methods or ANN(Artificial Neural Network) methods based on domain knowledge and GIS. Two direct extraction methods are introduced also. One is the extraction based on the water accumulating property of subsiding land, and the other is based on the dynamic change of land cover in subsiding land.

  20. Medical Image Watermarking in Sub-block Three-dimensional Discrete Cosine Transform Domain

    Directory of Open Access Journals (Sweden)

    Baoru Han

    2016-03-01

    Full Text Available Digital watermarking can be applied to protection of medical images privacy, hiding of patient's diagnosis information and so on. In order to improve the ability of resisting geometric attacks, a new watermarking algorithm for medical volume data in sub-block three-dimensional discrete cosine transform domain is presented. The original watermarking image is scrambled by a Chebyshev chaotic neural network so as to improve watermarking security. Sub-block three-dimensional discrete cosine transform and perceptual hashing are used to construct zero-watermarking. In this way it does not produce medical image distortion and gives the algorithm the ability to resist geometric attacks. Experimental results show that the algorithm has good security, and it has good robustness to various geometric attacks.

  1. Birefringence imaging of biological tissue by spectral domain polarization sensitive optical coherence tomography

    Science.gov (United States)

    Jing, Zhijun; Fan, Chuanmao; Jiang, Jingying; Gong, Qiang; Ma, Zhenhe; Zhang, Fan; Yao, Jianquan; Wang, R. K.

    2007-02-01

    A spectral domain Polarization sensitive optical coherence tomography (SDPS-OCT) system has been developed to acquire depth images of biological tissues such as porcine tendon, rabbit eye. The Stocks vectors (I, Q, U, and V) of the backscattered light from the biological tissues have been reconstructed. Further, the phase retardation and polarization degree between the two orthogonal polarizing states have been computed. Reconstructed images, i.e. birefringence images, from Stokes parameters, retardation and polarization degree of biological tissues show significant local variations in the polarization state. And the birefringence contrast of biological tissue possibly changes by some outside force. In addition, the local thickness of the birefringence layer determined with our system is significant. The results presented show SDPS-OCT is a potentially powerful technique to investigate tissue structural properties on the basis of the fact that any fibrous structure with biological tissues can influence the polarization state of light.

  2. Fully phase image encryption using double random-structured phase masks in gyrator domain.

    Science.gov (United States)

    Singh, Hukum; Yadav, A K; Vashisth, Sunanda; Singh, Kehar

    2014-10-01

    We propose a method for fully phase image encryption based on double random-structured phase mask encoding in the gyrator transform (GT) domain. The security of the system is strengthened by parameters used in the construction of a structured phase mask (SPM) based on a devil's vortex Fresnel lens (DVFL). The input image is recovered using the correct parameters of the SPMs, transform orders of the GT, and conjugate of the random phase masks. The use of a DVFL-based SPM enhances security by increasing the key space for encryption, and also overcomes the problem of axis alignment associated with an optical setup. The proposed scheme can also be implemented optically. The computed values of mean squared error between the retrieved and the original image show the efficacy of the proposed scheme. We have also investigated the scheme's sensitivity to the encryption parameters, and robustness against occlusion and multiplicative Gaussian noise attacks.

  3. Image encryption using polarized light encoding and amplitude and phase truncation in the Fresnel domain.

    Science.gov (United States)

    Rajput, Sudheesh K; Nishchal, Naveen K

    2013-06-20

    In this paper, an image encryption scheme based on polarized light encoding and a phase-truncation approach in the Fresnel transform domain is proposed. The phase-truncated data obtained by an asymmetric cryptosystem is encrypted and decrypted by using the concept of the Stokes-Mueller formalism. Image encryption based on polarization of light using Stokes-Mueller formalism has the main advantage over Jones vector formalism that it manipulates only intensity information, which is measurable. Thus any intensity information can be encrypted and decrypted using this scheme. The proposed method offers several advantages: (1) a lens-free setup, (2) flexibility in the encryption key design, (3) use of asymmetric keys, and (4) immunity against special attack. We present numerical simulation results for gray-scale and color images in support of the proposed security scheme. The performance measurement parameters relative error and correlation coefficient have been calculated to check the effectiveness of the scheme.

  4. Silhouette-free image encryption using interference in the multiple-parameter fractional Fourier transform domain.

    Science.gov (United States)

    Zhong, Zhi; Qin, Haitao; Liu, Lei; Zhang, Yabin; Shan, Mingguang

    2017-03-20

    A novel approach for silhouette-free image encryption based on interference is proposed using discrete multiple-parameter fractional Fourier transform (DMPFrFT), which generalizes from fractional Fourier transform. An original image is firstly applied by chaotic pixel scrambling (CPS) and then encoded into the real part of a complex signal. Using interference principle, the complex signal generates three phase-only masks in DMPFrFT domain. The silhouette of the original image cannot be extracted using one or two of the three phase-only masks. The parameters of both CPS and DMPFrFT can also serve as encryption keys to extend the key space, which further enhance the level of cryptosystem security. Numerical simulations are demonstrated to show the feasibility and validity of this approach.

  5. Image encryption with chaotic map and Arnold transform in the gyrator transform domains

    Science.gov (United States)

    Sang, Jun; Luo, Hongling; Zhao, Jun; Alam, Mohammad S.; Cai, Bin

    2017-05-01

    An image encryption method combing chaotic map and Arnold transform in the gyrator transform domains was proposed. Firstly, the original secret image is XOR-ed with a random binary sequence generated by a logistic map. Then, the gyrator transform is performed. Finally, the amplitude and phase of the gyrator transform are permutated by Arnold transform. The decryption procedure is the inverse operation of encryption. The secret keys used in the proposed method include the control parameter and the initial value of the logistic map, the rotation angle of the gyrator transform, and the transform number of the Arnold transform. Therefore, the key space is large, while the key data volume is small. The numerical simulation was conducted to demonstrate the effectiveness of the proposed method and the security analysis was performed in terms of the histogram of the encrypted image, the sensitiveness to the secret keys, decryption upon ciphertext loss, and resistance to the chosen-plaintext attack.

  6. Multifractal imaging filtering and decomposition methods in space, Fourier frequency, and eigen domains

    Directory of Open Access Journals (Sweden)

    Qiuming Cheng

    2007-06-01

    Full Text Available The patterns shown on two-dimensional images (fields used in geosciences reflect the end products of geo-processes that occurred on the surface and in the subsurface of the Earth. Anisotropy of these types of patterns can provide information useful for interpretation of geo-processes and identification of features in the mapped area. Quantification of the anisotropy property is therefore essential for image processing and interpretation. This paper introduces several techniques newly developed on the basis of multifractal modeling in space, Fourier frequency, and eigen domains, respectively. A singularity analysis method implemented in the space domain can be used to quantify the intensity and anisotropy of local singularities. The second method, called S-A, characterizes the generalized scale invariance property of a field in the Fourier frequency domain. The third method characterizes the field using a power-law model on the basis of eigenvalues and eigenvectors of the field. The applications of these methods are demonstrated with a case study of Environment Scan Electric Microscope (ESEM microimages for identification of sphalerite (ZnS ore minerals from the Jinding Pb/Zn/Ag mineral deposit in Shangjiang District, Yunnan Province, China.

  7. Blind image quality assessment using statistical independence in the divisive normalization transform domain

    Science.gov (United States)

    Chu, Ying; Mou, Xuanqin; Fu, Hong; Ji, Zhen

    2015-11-01

    We present a general purpose blind image quality assessment (IQA) method using the statistical independence hidden in the joint distributions of divisive normalization transform (DNT) representations for natural images. The DNT simulates the redundancy reduction process of the human visual system and has good statistical independence for natural undistorted images; meanwhile, this statistical independence changes as the images suffer from distortion. Inspired by this, we investigate the changes in statistical independence between neighboring DNT outputs across the space and scale for distorted images and propose an independence uncertainty index as a blind IQA (BIQA) feature to measure the image changes. The extracted features are then fed into a regression model to predict the image quality. The proposed BIQA metric is called statistical independence (STAIND). We evaluated STAIND on five public databases: LIVE, CSIQ, TID2013, IRCCyN/IVC Art IQA, and intentionally blurred background images. The performances are relatively high for both single- and cross-database experiments. When compared with the state-of-the-art BIQA algorithms, as well as representative full-reference IQA metrics, such as SSIM, STAIND shows fairly good performance in terms of quality prediction accuracy, stability, robustness, and computational costs.

  8. White matter correlates of cognitive domains in normal aging with diffusion tensor imaging

    Directory of Open Access Journals (Sweden)

    Efrat eSasson

    2013-03-01

    Full Text Available The ability to perform complex as well as simple cognitive tasks engages a network of brain regions that is mediated by the white matter fiber bundles connecting them. Different cognitive tasks employ distinctive white matter fiber bundles. The temporal lobe and its projections subserve a variety of key functions known to deteriorate during aging. In a cohort of 52 healthy subjects (ages 25-82 years, we performed voxel-wise regression analysis correlating performance in higher-order cognitive domains (executive function, information processing speed, and memory with white matter integrity, as measured by diffusion tensor imaging (DTI fiber tracking in the temporal lobe projections (uncinate fasciculus (UF, fornix, cingulum, inferior longitudinal fasciculus (ILF, and superior longitudinal fasciculus (SLF. The fiber tracts were spatially registered and statistical parametric maps were produced to spatially localize the significant correlations. Results showed that performance in the executive function domain is correlated with DTI parameters in the left SLF and right UF; performance in the information processing speed domain is correlated with fractional anisotropy (FA in the left cingulum, left fornix, right and left ILF and SLF; and the memory domain shows significant correlations with DTI parameters in the right fornix, right cingulum, left ILF, left SLF and right UF. These findings suggest that DTI tractography enables anatomical definition of region of interest for correlation of behavioral parameters with diffusion indices, and functionality can be correlated with white matter integrity.

  9. Application of Fourier Domain OCT Imaging Technology to the Anterior Segment of the Human Eye

    Science.gov (United States)

    Wojtkowski, Maciej; Marcos, Susana; Ortiz, Sergio; Grulkowski, Ireneusz

    The anterior segment is the front part of the human eye, which forms the optical system and hence directly impacts vision. Traumatic or pathological changes in the anterior segment may lead to vision loss and, in some cases, even blindness. Since the eighteenth century, optical instrumentation for measuring and imaging the anterior segment of the human eye has been developing along with modern ophthalmology. The application of OCT to the anterior segment imaging is particularly of interest, since this could potentially provide substantial complementary information regarding the large-scale architecture of the cornea and the crystalline lens, or on small portions of tissue imaged with high spatial resolutions comparable to regular microscopy. Especially an introduction of Fourier domain detection in OCT has opened new frontiers in OCT ophthalmic applications. The resultant substantial speed improvement enables rapid image acquisition, helping to reduce artifacts due to patient motion. Thus, it is currently possible to perform high-speed, in vivo, three-dimensional volumetric imaging over large scales within a reasonable time limit and without reducing system sensitivity. This chapter describes the state-of the art OCT technology dedicated to anterior segment imaging and indicates all important parameters which are required for optimization of the performance of OCT instrument.

  10. Lipid domains in giant unilamellar vesicles and their correspondence with equilibrium thermodynamic phases: A quantitative fluorescence microscopy imaging approach

    DEFF Research Database (Denmark)

    Fidorra, Matthias; Garcia, Alejandra; Ipsen, John Hjort

    2009-01-01

    and reconstruction of 3D domain morphology using active surface models. This method permits the reconstruction of the spherical surface of GUVs and determination of the area fractions of coexisting lipid domains at the level of single vesicles. Obtaining area fractions enables the scrutiny of the lever rule along...... lipid phase diagram's tie lines and to test whether or not the coexistence of lipid domains in GUVs correspond to equilibrium thermodynamic phases. The analysis was applied to DLPC/DPPC GUVs displaying coexistence of lipid domains. Our results confirm the lever rule, demonstrating that the observed......We report a novel analytical procedure to measure the surface areas of coexisting lipid domains in giant unilamellar vesicles (GUVs) based on image processing of 3D fluorescence microscopy data. The procedure involves the segmentation of lipid domains from fluorescent image stacks...

  11. Image reconstruction using wavelet multi-resolution technique for time-domain diffuse optical tomography

    Science.gov (United States)

    Yang, Fang; Gao, Feng; Jiao, Yuting; Zhao, Huijuan

    2010-02-01

    It is generally believed that the inverse problem in diffuse optical tomography (DOT) is highly ill-posed and its solution is always under-determined and sensitive to noise, which is the main problem in the application of DOT. In this paper, we propose a method on image reconstruction for time-domain diffuse optical tomography based on panel detection and Finite-Difference Method, and introduce an approach to reduce the number of unknown parameters in the reconstruction process. We propose a multi-level scheme to reduce the number of unknowns by parameterizing the spatial distribution of optical properties via wavelet transform and then reconstruct the coefficients of this transform. Compared with previous traditional uni-level full spatial domain algorithm, this method can efficiently improve the reconstruction quality. Numerical simulations show that wavelet-based multi-level inversion is superior to the uni-level algebraic reconstruction technique.

  12. Acoustic Imaging Frequency Dynamics of Ferroelectric Domains by Atomic Force Microscopy

    Institute of Scientific and Technical Information of China (English)

    ZHAO Kun-Yu; Shunji Takekawa; Kenji Kitamura; ZENG Hua-Rong; SONG Hong-Zhang; HUI Sen-Xing; LI Guo-Rong; YIN Qing-Rui; Kiyoshi Shimamura; Chinna Venkadasamy Kannan; Encarnacion Antonia Garcia Villora

    2008-01-01

    We report the acoustic imaging frequency dynamics of ferroelectric domains by low-frequency acoustic probe microscopy based on the commercial atomic force microscopy. It is found that ferroelectric domain could be firstly visualized at lower frequency down to 0.h kHz by AFM-based acoustic microscopy. The frequency-dependent acoustic signal revealed a strong acoustic response in the frequency range from 7 kHz to lO kHz, and reached maximum at 8.1 kHz. The acoustic contrast mechanism can be ascribed to the different elastic response of ferroelectric microstructures to local elastic stress fields, which is induced by the acoustic wave transmitting in the sample when the piezoelectric transducer is vibrating and exciting acoustic wave under ac electric fields due to normal piezoelectric effects.

  13. KEYWORD AND IMAGE CONTENT FEATURES FOR IMAGE INDEXING AND RETRIEVAL WITHIN COMPRESSED DOMAIN

    Directory of Open Access Journals (Sweden)

    Irianto .

    2009-01-01

    Full Text Available The central problem of most Content Based Image Retrieval approaches is poor quality in terms of sensitivity (recall and specificity (precision. To overcome this problem, the semantic gap between high-level concepts and low-level features has been acknowledged. In this paper we introduce an approach to reduce the impact of the semantic gap by integrating high-level (semantic and low-level features to improve the quality of Image Retrieval queries. Our experiments have been carried out by applying two hierarchical procedures. The first approach is called keyword-content, and the second content-keyword. Our proposed approaches show better results compared to a single method (keyword or content based in term of recall and precision. The average precision has increased by up to 50%.

  14. MEMS-based handheld fourier domain Doppler optical coherence tomography for intraoperative microvascular anastomosis imaging.

    Directory of Open Access Journals (Sweden)

    Yong Huang

    Full Text Available To demonstrate the feasibility of a miniature handheld optical coherence tomography (OCT imager for real time intraoperative vascular patency evaluation in the setting of super-microsurgical vessel anastomosis.A novel handheld imager Fourier domain Doppler optical coherence tomography based on a 1.3-µm central wavelength swept source for extravascular imaging was developed. The imager was minimized through the adoption of a 2.4-mm diameter microelectromechanical systems (MEMS scanning mirror, additionally a 12.7-mm diameter lens system was designed and combined with the MEMS mirror to achieve a small form factor that optimize functionality as a handheld extravascular OCT imager. To evaluate in-vivo applicability, super-microsurgical vessel anastomosis was performed in a mouse femoral vessel cut and repair model employing conventional interrupted suture technique as well as a novel non-suture cuff technique. Vascular anastomosis patency after clinically successful repair was evaluated using the novel handheld OCT imager.With an adjustable lateral image field of view up to 1.5 mm by 1.5 mm, high-resolution simultaneous structural and flow imaging of the blood vessels were successfully acquired for BALB/C mouse after orthotopic hind limb transplantation using a non-suture cuff technique and BALB/C mouse after femoral artery anastomosis using a suture technique. We experimentally quantify the axial and lateral resolution of the OCT to be 12.6 µm in air and 17.5 µm respectively. The OCT has a sensitivity of 84 dB and sensitivity roll-off of 5.7 dB/mm over an imaging range of 5 mm. Imaging with a frame rate of 36 Hz for an image size of 1000(lateral×512(axial pixels using a 50,000 A-lines per second swept source was achieved. Quantitative vessel lumen patency, lumen narrowing and thrombosis analysis were performed based on acquired structure and Doppler images.A miniature handheld OCT imager that can be used for intraoperative evaluation of

  15. The Wavenumber Algorithm: Fast Fourier-Domain Imaging Using Full Matrix Capture

    Science.gov (United States)

    Hunter, A. J.; Drinkwater, B. W.; Wilcox, P. D.

    2009-03-01

    We develop a Fourier-domain approach to full matrix imaging based on the wavenumber algorithm used in synthetic aperture radar and sonar. The extension to the wavenumber algorithm for full matrix capture is described and the performance of the new algorithm is compared to the total focusing method (TFM), which we use as a representative benchmark for the time-domain algorithms. The wavenumber algorithm provides a mathematically rigorous solution to the inverse problem for the assumed forward wave propagation model, whereas the TFM employs heuristic delay-and-sum beamforming. Consequently, the wavenumber algorithm has an improved point-spread function and provides better imagery. However, the major advantage of the wavenumber algorithm is its superior computational performance. For large arrays and images, the wavenumber algorithm is several orders of magnitude faster than the TFM. On the other hand, the key advantage of the TFM is its flexibility. The wavenumber algorithm requires a regularly sampled linear array, while the TFM can handle arbitrary imaging geometries. The TFM and the wavenumber algorithm are compared using simulated and experimental data.

  16. A Low Power Digital Accumulation Technique for Digital-Domain CMOS TDI Image Sensor

    Science.gov (United States)

    Yu, Changwei; Nie, Kaiming; Xu, Jiangtao; Gao, Jing

    2016-01-01

    In this paper, an accumulation technique suitable for digital domain CMOS time delay integration (TDI) image sensors is proposed to reduce power consumption without degrading the rate of imaging. In terms of the slight variations of quantization codes among different pixel exposures towards the same object, the pixel array is divided into two groups: one is for coarse quantization of high bits only, and the other one is for fine quantization of low bits. Then, the complete quantization codes are composed of both results from the coarse-and-fine quantization. The equivalent operation comparably reduces the total required bit numbers of the quantization. In the 0.18 µm CMOS process, two versions of 16-stage digital domain CMOS TDI image sensor chains based on a 10-bit successive approximate register (SAR) analog-to-digital converter (ADC), with and without the proposed technique, are designed. The simulation results show that the average power consumption of slices of the two versions are 6.47×10-8 J/line and 7.4×10-8 J/line, respectively. Meanwhile, the linearity of the two versions are 99.74% and 99.99%, respectively. PMID:27669256

  17. A Low Power Digital Accumulation Technique for Digital-Domain CMOS TDI Image Sensor.

    Science.gov (United States)

    Yu, Changwei; Nie, Kaiming; Xu, Jiangtao; Gao, Jing

    2016-09-23

    In this paper, an accumulation technique suitable for digital domain CMOS time delay integration (TDI) image sensors is proposed to reduce power consumption without degrading the rate of imaging. In terms of the slight variations of quantization codes among different pixel exposures towards the same object, the pixel array is divided into two groups: one is for coarse quantization of high bits only, and the other one is for fine quantization of low bits. Then, the complete quantization codes are composed of both results from the coarse-and-fine quantization. The equivalent operation comparably reduces the total required bit numbers of the quantization. In the 0.18 µm CMOS process, two versions of 16-stage digital domain CMOS TDI image sensor chains based on a 10-bit successive approximate register (SAR) analog-to-digital converter (ADC), with and without the proposed technique, are designed. The simulation results show that the average power consumption of slices of the two versions are 6 . 47 × 10 - 8 J/line and 7 . 4 × 10 - 8 J/line, respectively. Meanwhile, the linearity of the two versions are 99.74% and 99.99%, respectively.

  18. Developing the Image and Public Reputation of Universities: The Managerial Process.

    Science.gov (United States)

    Davies, John L.; Melchiori, Gerlinda S.

    1982-01-01

    Managerial processes used in developing programs to improve an institution's public image are outlined, drawing on both theory and experience in college administration and public relations. Eight case studies provide illustrations. A five-stage managerial plan is presented. (MSE)

  19. 78 FR 69440 - Certain Electronic Imaging Devices; Notice of Request for Statements on the Public Interest

    Science.gov (United States)

    2013-11-19

    ... COMMISSION Certain Electronic Imaging Devices; Notice of Request for Statements on the Public Interest AGENCY...'') recommended by the ALJ. This notice is soliciting public interest comments from the public only. Parties are to file public interest submissions pursuant to 19 CFR 210.50(a)(4). FOR FURTHER INFORMATION...

  20. Contrast and resolution analysis of angular domain imaging for iterative optical projection tomography reconstruction

    Science.gov (United States)

    Ng, Eldon; Vasefi, Fartash; Kaminska, Bozena; Chapman, Glenn H.; Carson, Jeffrey J. L.

    2010-02-01

    Angular domain imaging (ADI) generates a projection image of an attenuating target within a turbid medium by employing a silicon micro-tunnel array to reject photons that have deviated from the initial propagation direction. In this imaging method, image contrast and resolution are position dependent. The objective of this work was to first characterize the contrast and resolution of the ADI system at a multitude of locations within the imaging plane. The second objective was to compare the reconstructions of different targets using filtered back projection and iterative reconstruction algorithms. The ADI system consisted of a diode laser laser (808nm, CW, ThorLabs) with a beam expander for illumination of the sample cuvette. At the opposite side of the cuvette, an Angular Filter Array (AFA) of 80 μm x 80 μm square-shaped tunnels 1 cm in length was used to reject the transmitted scattered light. Image-forming light exiting the AFA was detected by a linear CCD (16-bit, Mightex). Our approach was to translate two point attenuators (0.5 mm graphite rod, 0.368 mm drill bit) submerged in a 0.6% IntralipidTM dilution using a SCARA robot (Epson E2S351S) to cover a 37x37 and 45x45 matrix of grid points in the imaging plane within the 1 cm path length sample cuvette. At each grid point, a one-dimensional point-spread distribution was collected and system contrast and resolution were measured. Then, the robot was used to rotate the target to collect projection images at several projection angles of various objects, and reconstructed with a filtered back projection and an iterative reconstruction algorithm.

  1. 版权法上的公共领域研究%On public domain in copyright law

    Institute of Scientific and Technical Information of China (English)

    黄汇

    2009-01-01

    Public domain is a core rule of copyright law, under which various creative materials are available for an author to use without charge or liability for infringement, hence ensuring the effective implementation of copyright law.Public domain is characterized by openness, public ownership, irrevocability and formality. Based on the premise that the author's work will not be interfered, public domain ultimately aims at the enlargement of its own universe and prosperity of the culture of human society. Its introduction into copyright law satisfies both historical and logical demands. Without its acknowledgement,copyright cannot be justified. In that sense, public domain and copyright can be deemed as twins. Public domain is not only an existing institution, but also an ideological tendency or a methodology. It has evaluative and inspective values towards copyright. It is an important precondition of copy-rights, and what is more, an important measure for controlling the expansion and realizing the purpose of copyright.%公共领域是版权法的核心,它是保证作者有效运用各种创作素材从而使版权的其余部分得以良好运转的工具.公共领域具有开放性、有主性、不可撤销性和程序性等特征,它以保证作者的创作为前提,却最终以自身的不断扩大和人类社会的文化繁衍为依归.公共领域在版权法上的生成既是历史的,更是逻辑的.没有公共领域的被承认,也就没有版权的正当性可言,因此公共领域和版权实际上一同诞生.公共领域不仅是一种制度存在物,它更是一种思想倾向和方法论,公共领域对版权具有评价和检视功能,它既是版权运行的重要前提,又是控制版权扩张和实现版权目的的重要手段.

  2. Using One hot Residue (OHR in Image Processing: Proposed a Scheme of Filtering in Spatial Domain

    Directory of Open Access Journals (Sweden)

    Davar Kheirandish Taleshmekaeil

    2012-12-01

    Full Text Available In this study, the use of the One Hot Residue (OHR number system for digital image processing and its application for designing fast, high-speed and low area image processors are studied. Since digital image filtering in space domain requires many algebra computations, we're going to propose a system with high computing speed based on OHR. Using proposed system can significantly enhance the speed of the computation operations and hence the system. In the proposed image coding scheme the delay of implementation is equal to delay of a transistor which is a good improvement in compare with the conventional methods such as direct method. Other advantages of using One Hot Residue (OHR number system are its simplicity of implementation and minimum power dissipation. Design of adder and multipliers commonly used for filtering with selected moduli set {2n-1+1, 2n-1, 2n} for one hot coding are presented here. MATLAB was used for simulation studies while VLSI tools have been employed for design analysis. The preliminary results show the capability of the proposed method to speed incensement of operation, decreasing of consumption power, facilitating designed hardware and finally decreasing chip production for image processing.

  3. Cryptosystem for Securing Image Encryption Using Structured Phase Masks in Fresnel Wavelet Transform Domain

    Science.gov (United States)

    Singh, Hukum

    2016-12-01

    A cryptosystem for securing image encryption is considered by using double random phase encoding in Fresnel wavelet transform (FWT) domain. Random phase masks (RPMs) and structured phase masks (SPMs) based on devil's vortex toroidal lens (DVTL) are used in spatial as well as in Fourier planes. The images to be encrypted are first Fresnel transformed and then single-level discrete wavelet transform (DWT) is apply to decompose LL,HL, LH and HH matrices. The resulting matrices from the DWT are multiplied by additional RPMs and the resultants are subjected to inverse DWT for the encrypted images. The scheme is more secure because of many parameters used in the construction of SPM. The original images are recovered by using the correct parameters of FWT and SPM. Phase mask SPM based on DVTL increases security that enlarges the key space for encryption and decryption. The proposed encryption scheme is a lens-less optical system and its digital implementation has been performed using MATLAB 7.6.0 (R2008a). The computed value of mean-squared-error between the retrieved and the input images shows the efficacy of scheme. The sensitivity to encryption parameters, robustness against occlusion, entropy and multiplicative Gaussian noise attacks have been analysed.

  4. Imaging patients with glaucoma using spectral-domain optical coherence tomography and optical microangiography

    Science.gov (United States)

    Auyeung, Kris; Auyeung, Kelsey; Kono, Rei; Chen, Chieh-Li; Zhang, Qinqin; Wang, Ruikang K.

    2015-03-01

    In ophthalmology, a reliable means of diagnosing glaucoma in its early stages is still an open issue. Past efforts, including forays into fluorescent angiography (FA) and early optical coherence tomography (OCT) systems, to develop a potential biomarker for the disease have been explored. However, this development has been hindered by the inability of the current techniques to provide useful depth and microvasculature information of the optic nerve head (ONH), which have been debated as possible hallmarks of glaucoma progression. We reasoned that a system incorporating a spectral-domain OCT (SD-OCT) based Optical Microangiography (OMAG) system, could allow an effective, non-invasive methodology to evaluate effects on microvasculature by glaucoma. SD-OCT follows the principle of light reflection and interference to produce detailed cross-sectional and 3D images of the eye. OMAG produces imaging contrasts via endogenous light scattering from moving particles, allowing for 3D image productions of dynamic blood perfusion at capillary-level resolution. The purpose of this study was to investigate the optic cup perfusion (flow) differences in glaucomatous and normal eyes. Images from three normal and five glaucomatous subjects were analyzed our OCT based OMAG system for blood perfusion and structural images, allowing for comparisons. Preliminary results from blood flow analysis revealed reduced blood perfusion within the whole-depth region encompassing the Lamina Cribrosa in glaucomatous cases as compared to normal ones. We conclude that our OCT-OMAG system may provide promise and viability for glaucoma screening.

  5. Diderot: a Domain-Specific Language for Portable Parallel Scientific Visualization and Image Analysis.

    Science.gov (United States)

    Kindlmann, Gordon; Chiw, Charisee; Seltzer, Nicholas; Samuels, Lamont; Reppy, John

    2016-01-01

    Many algorithms for scientific visualization and image analysis are rooted in the world of continuous scalar, vector, and tensor fields, but are programmed in low-level languages and libraries that obscure their mathematical foundations. Diderot is a parallel domain-specific language that is designed to bridge this semantic gap by providing the programmer with a high-level, mathematical programming notation that allows direct expression of mathematical concepts in code. Furthermore, Diderot provides parallel performance that takes advantage of modern multicore processors and GPUs. The high-level notation allows a concise and natural expression of the algorithms and the parallelism allows efficient execution on real-world datasets.

  6. Image denoising exploiting inter- and intra-scale dependency in complex wavelet domain

    Institute of Scientific and Technical Information of China (English)

    Fengxia Yan; Lizhi Cheng

    2007-01-01

    A new locally adaptive image denoising method, which exploits the intra-scale and inter-scale dependency in the dual-tree complex wavelet domain, is presented. Firstly, a recently emerged bivariate shrinkage rule is extended to a complex coefficient and its neighborhood, the corresponding nonlinear threshold functions are derived from the models using Bayesian estimation theory. Secondly, an adaptive weight, which is able to capture the inter-scale dependency of the complex wavelet coefficients, is combined to the obtained bishrink threshold. The experimental results demonstrate an improved denoising performance over related earlier techniques both in peak signal-to-noise ratio (PSNR) and visual effect.

  7. Optimized cobalt nanowires for domain wall manipulation imaged by in situ Lorentz microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L. A. [Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Universidad de Zaragoza, 50018 Zaragoza (Spain); Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse (France); CEMES-CNRS 29, rue Jeanne Marvig, B.P. 94347 F-31055, Toulouse Cedex (France); Magen, C. [Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Universidad de Zaragoza, 50018 Zaragoza (Spain); Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse (France); Fundacion ARAID, 50004 Zaragoza (Spain); Snoeck, E.; Gatel, C. [Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse (France); CEMES-CNRS 29, rue Jeanne Marvig, B.P. 94347 F-31055, Toulouse Cedex (France); Serrano-Ramon, L. [Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Instituto de Ciencia de Materiales de Aragon (ICMA), Universidad de Zaragoza-CSIC, 50009 Zaragoza (Spain); and others

    2013-01-14

    Direct observation of domain wall (DW) nucleation and propagation in focused electron beam induced deposited Co nanowires as a function of their dimensions was carried out by Lorentz microscopy (LTEM) upon in situ application of magnetic field. Optimal dimensions favoring the unambiguous DW nucleation/propagation required for applications were found in 500-nm-wide and 13-nm-thick Co nanowires, with a maximum nucleation field and the largest gap between nucleation and propagation fields. The internal DW structures were resolved using the transport-of-intensity equation formalism in LTEM images and showed that the optimal nanowire dimensions correspond to the crossover between the nucleation of transverse and vortex walls.

  8. Inspection of Asian Lacquer Substructures by Terahertz Time-Domain Imaging (THz-TDI)

    Science.gov (United States)

    Dandolo, Corinna Ludovica Koch; Fukunaga, Kaori; Kohzuma, Yoshei; Kiriyama, Kyoko; Matsuda, Kazutaka; Jepsen, Peter Uhd

    2017-04-01

    Lacquering is considered one of the most representative Asian artistic techniques. While the decorative part of lacquerwares is the lacquer itself, their substructures serve as the backbone of the object itself. Very little is known about these hidden substructures. Since lacquerwares are mostly composed of organic materials, such as urushi, wood, carbon black, and fabrics which are very X-ray transparent, standard X-ray radiography has some problems in achieving clear X-ray radiographic images. Therefore, we wanted to contribute to the understanding of the lacquer manufacturing technique by inspecting the substructures of Asian lacquerwares by means of THz time-domain imaging (THz-TDI). Three different kinds of Asian lacquerwares were examined by THz-TDI, and the outcomes have been compared with those obtained by standard X-radiography. THz-TDI provides unique information on lacquerwares substructures, aiding in the comprehension of the manufacturing technology yielding to these precious artefacts.

  9. Key rotation multiplexing for multiple-image optical encryption in the Fresnel domain

    Science.gov (United States)

    Yong-Liang, Xiao; Su, Xianyu; Li, Sikun; Liu, Xiaoqing; Zeng, Shuguang

    2011-06-01

    We introduce a key rotation multiplexing method into the double random phase encoding system for multiple-image optical encryption in the Fresnel domain. Each plaintext is encoded into a stationary-white-noise ciphertext by the same only phase mask located at the input plane, and another only phase mask with a certain rotation angle located at the transform plane. All ciphertexts encoded from different plaintexts are added together to produce a final ciphertext, which serves as a single data source for different plaintexts decryption. Thus, the mask located at transform plane can be utilized to decrypt different plaintexts with a certain rotation angle. Also, we perform computer simulations to investigate how the quantization level of decrypted key and CCD, respectively, affect the decrypted quality and the number of images that can be multiplexed.

  10. Performance analysis of digital watermarkingtechniques in the spatial and DCT domain for still images

    Directory of Open Access Journals (Sweden)

    Ajay Goel

    2010-10-01

    Full Text Available Digital watermarking is a process whereby random information is encoded into an image in such a way that the additional payload is indiscernible to the image observer. In this Paper, three typical watermarking techniques are compared and tested extensively, which not only include the private system, the semi-private system but also the public schemes. The comparisons mainly focus on the evaluation of robustness and visual image quality. The results show that the chosen schemes do not have the same behavior and no method has all desirable characteristics. Consequently, we conclude that evaluation of a watermarking algorithm is difficult without first indicating the context in which it is to be applied.

  11. Multiple color-image authentication system using HSI color space and QR decomposition in gyrator domains

    Science.gov (United States)

    Rafiq Abuturab, Muhammad

    2016-06-01

    A new multiple color-image authentication system based on HSI (Hue-Saturation-Intensity) color space and QR decomposition in gyrator domains is proposed. In this scheme, original color images are converted from RGB (Red-Green-Blue) color spaces to HSI color spaces, divided into their H, S, and I components, and then obtained corresponding phase-encoded components. All the phase-encoded H, S, and I components are individually multiplied, and then modulated by random phase functions. The modulated H, S, and I components are convoluted into a single gray image with asymmetric cryptosystem. The resulting image is segregated into Q and R parts by QR decomposition. Finally, they are independently gyrator transformed to get their encoded parts. The encoded Q and R parts should be gathered without missing anyone for decryption. The angles of gyrator transform afford sensitive keys. The protocol based on QR decomposition of encoded matrix and getting back decoded matrix after multiplying matrices Q and R, enhances the security level. The random phase keys, individual phase keys, and asymmetric phase keys provide high robustness to the cryptosystem. Numerical simulation results demonstrate that this scheme is the superior than the existing techniques.

  12. Ultrasonic guided wave based damage imaging by time-reversal method in frequency-wavenumber domain

    Science.gov (United States)

    Xu, C. G.; Xu, B. Q.; Luo, Y.; Xu, G. D.; Lu, L. Z.

    2017-05-01

    More attention has been drawn to ultrasonic guided waves (UGW) based damage detection method for its advantages of wide range inspection of large scale structures. However, complex propagation characteristics of guided waves as well as traditional contact ultrasonic transducers limit its application for the practical damage detection. By combining Scanning Laser Doppler vibrometer (SLDV) technology, Time-Reversal method in frequency-wavenumber domain (f-k RTM) can compensate for the dispersive nature of Lamb waves, localize multiple damage sites and identify their sizes without time consuming numerical calculation. In this work, we adopt f-k RTM for damage detection in plate-like structure. Instead of SLDV in experiment, 3D finite element numerical method is adopted to obtain scattered ultrasonic guided wavefield data with high spatial resolution. The direct path waves were extracted to obtain the incident wavefield while the scattered signals were used to calculate the scattering wave field. Damage imaging can also be achieved by introducing crosscorrelation imaging condition. Imaging results show that the method is very effective for crack localization and boundary shape-recognition. Numerical simulation results and imaging algorithm laid the foundation for the method applied in experiment and practice.

  13. Stimulated Emission Computed Tomography (NSECT) images enhancement using a linear filter in the frequency domain

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Rodrigo S.S.; Tardelli, Tiago C.; Yoriyaz, Helio, E-mail: hyoriyaz@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Jackowski, Marcel P., E-mail: mjack@ime.usp.b [University of Sao Paulo (USP), SP (Brazil). Dept. of Computer Science

    2011-07-01

    In recent years, a new technique for in vivo spectrographic imaging of stable isotopes was presented as Neutron Stimulated Emission Computed Tomography (NSECT). In this technique, a fast neutrons beam stimulates stable nuclei in a sample, which emit characteristic gamma radiation. The photon energy is unique and is used to identify the emitting nuclei. The emitted gamma energy spectra can be used for reconstruction of the target tissue image and for determination of the tissue elemental composition. Due to the stochastic nature of photon emission process by irradiated tissue, one of the most suitable algorithms for tomographic reconstruction is the Expectation-Maximization (E-M) algorithm, once on its formulation are considered simultaneously the probabilities of photons emission and detection. However, a disadvantage of this algorithm is the introduction of noise in the reconstructed image as the number of iterations increases. This increase can be caused either by features of the algorithm itself or by the low sampling rate of projections used for tomographic reconstruction. In this work, a linear filter in the frequency domain was used in order to improve the quality of the reconstructed images. (author)

  14. Source imaging of potential fields through a matrix space-domain algorithm

    Science.gov (United States)

    Baniamerian, Jamaledin; Oskooi, Behrooz; Fedi, Maurizio

    2017-01-01

    Imaging of potential fields yields a fast 3D representation of the source distribution of potential fields. Imaging methods are all based on multiscale methods allowing the source parameters of potential fields to be estimated from a simultaneous analysis of the field at various scales or, in other words, at many altitudes. Accuracy in performing upward continuation and differentiation of the field has therefore a key role for this class of methods. We here describe an accurate method for performing upward continuation and vertical differentiation in the space-domain. We perform a direct discretization of the integral equations for upward continuation and Hilbert transform; from these equations we then define matrix operators performing the transformation, which are symmetric (upward continuation) or anti-symmetric (differentiation), respectively. Thanks to these properties, just the first row of the matrices needs to be computed, so to decrease dramatically the computation cost. Our approach allows a simple procedure, with the advantage of not involving large data extension or tapering, as due instead in case of Fourier domain computation. It also allows level-to-drape upward continuation and a stable differentiation at high frequencies; finally, upward continuation and differentiation kernels may be merged into a single kernel. The accuracy of our approach is shown to be important for multi-scale algorithms, such as the continuous wavelet transform or the DEXP (depth from extreme point method), because border errors, which tend to propagate largely at the largest scales, are radically reduced. The application of our algorithm to synthetic and real-case gravity and magnetic data sets confirms the accuracy of our space domain strategy over FFT algorithms and standard convolution procedures.

  15. 78 FR 18611 - Summit on Color in Medical Imaging; Cosponsored Public Workshop; Request for Comments

    Science.gov (United States)

    2013-03-27

    ... HUMAN SERVICES Food and Drug Administration Summit on Color in Medical Imaging; Cosponsored Public... International Color Consortium (ICC) are announcing the following public workshop entitled ``Summit on Color in... Approaches for Dealing with Color in Medical Images.'' The purpose of the workshop is to bring together...

  16. Domain of the Gods: Do traditional beliefs hinder public acceptance of the human role in climate change?

    Science.gov (United States)

    Donner, S.

    2008-12-01

    Public acceptance of new scientific discoveries like natural selection, plate tectonics, or the human role in climate change naturally lags behind the pace of the discoveries. In the case of climate change, unease or outright rejection of the scientific evidence for the role of human activity in climate change has been a hindrance to mitigation and adaptation efforts. This skepticism is normally attributed to everything from the quality of science education, to disinformation campaigns by representatives of the coal and gas industry, to individual resistance to behavioral change, to the nature of the modern information culture. This skepticism of scientific evidence for climate change, though often inspired by politics, economics and the particular dynamics of climate change, may actually be rooted in ancient beliefs that the climate is beyond the influence of humans. In this presentation, I will outline how the notion that humans control or influence the weather runs contrary to thousands of years of belief in a separation between the earth - the domain of man - and sky - the domain of the gods. Evidence from religious history, traditional villages in the Pacific (Fjij and Kiribati) and from public discourse in North America all indicates that the millennia-old belief in an earth-sky separation hinders people's acceptance that human activity is affecting the climate. The human role in climate change therefore represents a substantial paradigm shift, similar to the role of natural selection in human evolution. These deep roots of climate change skepticism must be factored into public climate change education efforts.

  17. The Maritime Public Domain - concept and implementation in diferent national legal systems.

    Directory of Open Access Journals (Sweden)

    Marco Gameiro Antunes

    2014-05-01

    The paper will also describe how the ownership (public vs. private of coastal and estuarine margins is seen in some legal systems, considering the contribution of MPD to the protection of estuarine water and to the biodiversity resources.

  18. 32 CFR 705.35 - Armed Forces participation in events in the public domain.

    Science.gov (United States)

    2010-07-01

    ... Department of Defense to ensure compliance with public law, to assure equitable distribution of resources to... primary attraction. (4) Armed Forces participation is authorized in a fund-raising event only when the...

  19. Characterisation of historic plastics using terahertz time-domain spectroscopy and pulsed imaging.

    Science.gov (United States)

    Pastorelli, Gianluca; Trafela, Tanja; Taday, Phillip F; Portieri, Alessia; Lowe, David; Fukunaga, Kaori; Strlič, Matija

    2012-05-01

    Terahertz (THz) time-domain spectroscopy and 3D THz pulsed imaging have been explored with regard to polymer materials, both commodity and historic polymers. A systematic spectroscopic study of a wide range of different polymer materials showed significant differences in their spectra. Polyolefins and polystyrenes generally exhibit lower absorption than other examined polymers, various cellulose derivates, poly(vinyl chloride), poly(methyl methacrylate), polyamide, hard rubber and phenol formaldehyde resin, the last of these exhibiting the most intense absorption over the entire range, 0.15-4.2 THz. It was also examined how the presence of plasticisers in poly(vinyl chloride), the presence of fillers in polypropylene, and the degree of branching in polyethylene and polystyrene affect the spectra; inorganic fillers in polypropylene affected the absorption most. With 3D THz pulsed imaging, features in polymer objects were explored, appearing either as integral parts of the material (coatings and pores in foams) or as a consequence of physical deterioration (cracks, delamination). All of these features of various complexities can be successfully imaged in 3D. Terahertz technology is thus shown to have significant potential for both chemical and structural characterisation of polymers, which will be of interest to heritage science, but also to the polymer industry and development of analytical technologies in general.

  20. A comparison between a time domain and continuous wave small animal optical imaging system.

    Science.gov (United States)

    Keren, S; Gheysens, O; Levin, C S; Gambhir, S S

    2008-01-01

    We present a phantom study to evaluate the performance of the eXplore Optix (Advanced Research Technologies-GE Healthcare), the first commercially available time-domain tomography system for small animal fluorescence imaging, and compare its capabilities with the widely used IVIS 200 (Xenogen Corporation-Caliper) continuous wave planar imaging system. The eXplore Optix, based on point-wise illumination and collection scheme, is found to be a log order more sensitive with significantly higher detection depth and spatial resolution as compared with the wide-area illumination IVIS 200 under the conditions tested. A time-resolved detection system allows the eXplore Optix to measure the arrival time distribution of fluorescence photons. This enables fluorescence lifetime measurement, absorption mapping, and estimation of fluorescent inclusion depth, which in turn is used by a reconstruction algorithm to calculate the volumetric distribution of the fluorophore concentration. An increased acquisition time and lack of ability to image multiple animals simultaneously are the main drawbacks of the eXplore Optix as compared with the IVIS 200.

  1. Entropy-constrained vector quantization of images in the transform domain

    Science.gov (United States)

    Lee, Jong Seok; Kim, Rin C.; Lee, Sang Uk

    1994-09-01

    In this paper, two image coding techniques employing an entropy constrained vector quantizer (ECVQ) in the transform domain are presented. In both techniques, the transformed DCT coefficients are rearranged into the Mandala blocks for vector quantization. The first technique is based on the unstructured ECVQ designed separately for each Mandala block, while the second technique employs a structured ECVQ, i.e., an entropy constrained lattice vector quantizer (ECLVQ). In the ECLVQ, unlike the conventional lattice VQ combined with entropy coding, we take into account both the distortion and entropy in the encoding. Moreover, in order to improve the performance further, the ECLVQ parameters are optimized according to the input image statistics. Also we reduce the size of the variable word-length code table, by decomposing the lattice codeword into its magnitude and sign information. The performances of both techniques are evaluated on the real images, and it is found that the proposed techniques provide 1 - 2 dB gain over the DCT-classified VQ at bit rates in the range of 0.3 - 0.5 bits per pixel.

  2. Functional brain imaging with a supercontinuum time-domain NIRS system

    Science.gov (United States)

    Selb, Juliette; Zimmermann, Bernhard B.; Martino, Mark; Ogden, Tyler; Boas, David A.

    2013-03-01

    We have developed the second generation of our time-domain near-infrared spectroscopy (TD-NIRS) system for baseline and functional brain imaging. The instrument uses a pulsed broadband supercontinuum laser emitting a large spectrum between 650 and 1700 nm, and a gated detection based on an intensified CCD camera. The source laser beam is split into two arms, below and above 776 nm. In each arm, a fast motorized filter wheel enables selection of a bandpass filter at the required wavelength. Each filtered laser beam is then launched into one array of source fibers. The multiplexing through the array of fibers is implemented through a very compact home-made design consisting of two galvanometer mirrors followed by an achromatic doublet. Source fibers are then recombined one-by-one from both arms into the source optodes to be positioned on the head. The detection fibers are all imaged in parallel through a relay lens on an intensified CCD camera. By using detection fibers of different lengths, we introduce optical delays that enable simultaneous recording in different delay windows of the temporal point spread functions. We present the instrumentation and show its preliminary functional imaging capabilities. We also introduce a new probe where we use different fiber lengths on the source and the detector sides in order to record simultaneously both wavelengths from one location through different sets of fibers.

  3. Image-based pupil plane characterization via a space-domain basis

    Science.gov (United States)

    Levinson, Zac; Burbine, Andrew; Verduijn, Erik; Wood, Obert; Goldberg, Kenneth A.; Benk, Markus P.; Wojdyla, Antoine; Smith, Bruce W.

    2017-04-01

    Aberration characterization plays a critical role in the development of any optical system. State-of-the-art lithography systems have the tightest aberration tolerances. We present an approach to image-based pupil plane amplitude and phase characterization using models built with a space-domain basis, in which aberration effects are separable. A polynomial model is constructed between the projections of the image intensity for chosen binary mask targets onto this basis and pupil amplitude or phase variation. This method separates model building and pupil characterization into two distinct steps, thus enabling rapid pupil characterization following data collection. The basis is related to both the transmission cross-coefficient function and the principal components of the image intensity. The pupil plane variation of a zone-plate lens from the Semiconductor High-NA Actinic Reticle Review Project (SHARP) at Lawrence Berkeley National Laboratory is examined using this method. Results are compared to pupil plane characterization using a previously proposed methodology where inverse solutions are obtained through an iterative process involving least-squares regression.

  4. Spatial mapping of drug delivery to brain tissue using hyperspectral spatial frequency-domain imaging

    Science.gov (United States)

    Singh-Moon, Rajinder P.; Roblyer, Darren M.; Bigio, Irving J.; Joshi, Shailendra

    2014-09-01

    We present an application of spatial frequency-domain imaging (SFDI) to the wide-field imaging of drug delivery to brain tissue. Measurements were compared with values obtained by a previously validated variation of diffuse reflectance spectroscopy, the method of optical pharmacokinetics (OP). We demonstrate a cross-correlation between the two methods for absorption extraction and drug concentration determination in both experimental tissue phantoms and freshly extracted rodent brain tissue. These methods were first used to assess intra-arterial (IA) delivery of cationic liposomes to brain tissue in Sprague Dawley rats under transient cerebral hypoperfusion. Results were found to be in agreement with previously published experimental data and pharmacokinetic models of IA drug delivery. We then applied the same scheme to evaluate IA mitoxantrone delivery to glioma-bearing rats. Good correlation was seen between OP and SFDI determined concentrations taken from normal and tumor averaged sites. This study shows the feasibility of mapping drug/tracer distributions and encourages the use of SFDI for spatial imaging of tissues for drug/tracer-tagged carrier deposition and pharmacokinetic studies.

  5. Accelerating frequency-domain diffuse optical tomographic image reconstruction using graphics processing units.

    Science.gov (United States)

    Prakash, Jaya; Chandrasekharan, Venkittarayan; Upendra, Vishwajith; Yalavarthy, Phaneendra K

    2010-01-01

    Diffuse optical tomographic image reconstruction uses advanced numerical models that are computationally costly to be implemented in the real time. The graphics processing units (GPUs) offer desktop massive parallelization that can accelerate these computations. An open-source GPU-accelerated linear algebra library package is used to compute the most intensive matrix-matrix calculations and matrix decompositions that are used in solving the system of linear equations. These open-source functions were integrated into the existing frequency-domain diffuse optical image reconstruction algorithms to evaluate the acceleration capability of the GPUs (NVIDIA Tesla C 1060) with increasing reconstruction problem sizes. These studies indicate that single precision computations are sufficient for diffuse optical tomographic image reconstruction. The acceleration per iteration can be up to 40, using GPUs compared to traditional CPUs in case of three-dimensional reconstruction, where the reconstruction problem is more underdetermined, making the GPUs more attractive in the clinical settings. The current limitation of these GPUs in the available onboard memory (4 GB) that restricts the reconstruction of a large set of optical parameters, more than 13,377.

  6. Frequency-domain photoacoustic imaging system%频率域光声成像系统的研究

    Institute of Scientific and Technical Information of China (English)

    杨虹; 黄远辉; 苗少峰; 宫睿; 邵晓鹏; 毕祥丽

    2016-01-01

    Frequency-domain photoacoustic imaging is a new imaging modality, which uses the output amplitude information periodically modulated by a continuous-wave laser as a light source to stimulate biological tissues and to produce photoacoustic signals processed at frequency-domain and used to image the tissues. Firstly, the principles, developments and research status of photoacoustic imaging and frequency-domain photoacoustic imaging were introduced, and then the specific test methods and basic reconstruction algorithms of the frequency-domain photoacoustic imaging filed were described. In order to make up for time domain photoacoustic imaging with high costs, great harmful, poor portability and so on shortcomings, two imaging modalities were proposed and two complete experimental system structure diagrams were exhibited, showing different features and developing directions of photoacoustic imaging with respect to the traditional domain-photoacoustic imaging. At last, the outlook of the frequency-domain photoacoustic imaging was made to provide some references and guidance for our research and development about photoacoustic imaging.%频率域光声成像是指使用连续波激光器输出激光光源,利用该调制后的激光信号辐射组织,在频率域对激励的光声信号进行处理并成像的方式.首先阐述光声成像和频率域光声成像的原理、发展以及研究现状,然后介绍频率域光声成像的具体实验方法和基本重建算法.为了弥补时域光声成像成本高、伤害性大、便携性差等缺点,提出了频率域光声成像的两种成像方式,给出了完整的实验系统结构图,展示其相对于传统时域光声成像不同的研究特点与方向.最后对频率域光声成像进行展望,为光声成像在国内的研究和发展提供一定的借鉴和引导.

  7. Production of radioactive phantoms using a standard inkjet printer and the public domain multi-printing code GENIA.

    Science.gov (United States)

    Scafè, R; Auer, P; Bennati, P; La Porta, L; Pisacane, F; Cinti, M N; Pellegrini, R; De Vincentis, G; Conte, G; Pani, R

    2011-10-01

    The public domain code GENIA, based on multi-printing method for producing surface sources with appropriate radioactivity, is described. The conventional technique, running on standard inkjet printer with radio-marked ink filling, is improved by repeating elementary printing commands in the same band. Well outlined sources with adjustable radioactivity can be obtained without refilling. The intrinsic limitation of printable radioactivity, depending on the value available at nozzles at printing time, was overcome. In addition the method permits the accurate calibration of the amount of activity released onto the paper.

  8. The Courts’ Public Image – The Desired Direction of Change

    Directory of Open Access Journals (Sweden)

    Sylwia Morawska

    2016-10-01

    Full Text Available This paper proposes to scientifically explore notions of court identity, principles of shaping a court system’s image, and best practices in positive court image development relating to the courts in Poland.  It discusses the roles and responsibilities of inter-organizational networks in harmonizing diverse efforts to build a more positive court image.  It presents the results of a pilot project on court image development that considered the level of “maturity of courts” or how much forward progress various courts have made toward achieving an enhanced court image.  The paper uses several methods of scientific exploration including scholarly research to collect information about court image; empirical analysis of such research; personal examinations and observations of courts; and when best practices have been implemented in Polish courts, case studies to determine whether improved court images result from those practices.

  9. 75 FR 8375 - Device Improvements to Reduce Unnecessary Radiation Exposure From Medical Imaging; Public Meeting...

    Science.gov (United States)

    2010-02-24

    ... From Medical Imaging; Public Meeting; Request for Comments AGENCY: Food and Drug Administration, HHS... Medical Imaging.'' The purpose of this meeting is to discuss steps that could be taken by manufacturers of... reduce unnecessary patient exposure to ionizing radiation from these medical imaging modalities. The...

  10. Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

    Science.gov (United States)

    Wu, Jing; Gerendas, Bianca S.; Waldstein, Sebastian M.; Simader, Christian; Schmidt-Erfurth, Ursula

    2014-03-01

    Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high reso- lution, three-dimensional (3D) cross sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD) and glaucoma.1 Disease diagnosis, assessment, and treatment requires a patient to undergo multiple OCT scans, possibly using different scanning devices, to accurately and precisely gauge disease activity, progression and treatment success. However, the use of OCT imaging devices from different vendors, combined with patient movement may result in poor scan spatial correlation, potentially leading to incorrect patient diagnosis or treatment analysis. Image registration can be used to precisely compare disease states by registering differing 3D scans to one another. In order to align 3D scans from different time- points and vendors using registration, landmarks are required, the most obvious being the retinal vasculature. Presented here is a fully automated cross-vendor method to acquire retina vessel locations for OCT registration from fovea centred 3D SD-OCT scans based on vessel shadows. Noise filtered OCT scans are flattened based on vendor retinal layer segmentation, to extract the retinal pigment epithelium (RPE) layer of the retina. Voxel based layer profile analysis and k-means clustering is used to extract candidate vessel shadow regions from the RPE layer. In conjunction, the extracted RPE layers are combined to generate a projection image featuring all candidate vessel shadows. Image processing methods for vessel segmentation of the OCT constructed projection image are then applied to optimize the accuracy of OCT vessel shadow segmentation through the removal of false positive shadow regions such as those caused by exudates and cysts. Validation of segmented vessel shadows uses

  11. Finite-Difference Time-Domain Simulation for Three-dimensional Polarized Light Imaging

    CERN Document Server

    Menzel, Miriam; De Raedt, Hans; Michielsen, Kristel

    2016-01-01

    Three-dimensional Polarized Light Imaging (3D-PLI) is a promising technique to reconstruct the nerve fiber architecture of human post-mortem brains from birefringence measurements of histological brain sections with micrometer resolution. To better understand how the reconstructed fiber orientations are related to the underlying fiber structure, numerical simulations are employed. Here, we present two complementary simulation approaches that reproduce the entire 3D-PLI analysis: First, we give a short review on a simulation approach that uses the Jones matrix calculus to model the birefringent myelin sheaths. Afterwards, we introduce a more sophisticated simulation tool: a 3D Maxwell solver based on a Finite-Difference Time-Domain algorithm that simulates the propagation of the electromagnetic light wave through the brain tissue. We demonstrate that the Maxwell solver is a valuable tool to better understand the interaction of polarized light with brain tissue and to enhance the accuracy of the fiber orientati...

  12. Fresnel domain nonlinear optical image encryption scheme based on Gerchberg-Saxton phase-retrieval algorithm.

    Science.gov (United States)

    Rajput, Sudheesh K; Nishchal, Naveen K

    2014-01-20

    We propose a novel nonlinear image-encryption scheme based on a Gerchberg-Saxton (G-S) phase-retrieval algorithm in the Fresnel transform domain. The decryption process can be performed using conventional double random phase encoding (DRPE) architecture. The encryption is realized by applying G-S phase-retrieval algorithm twice, which generates two asymmetric keys from intermediate phases. The asymmetric keys are generated in such a way that decryption is possible optically with a conventional DRPE method. Due to the asymmetric nature of the keys, the proposed encryption process is nonlinear and offers enhanced security. The cryptanalysis has been carried out, which proves the robustness of proposed scheme against known-plaintext, chosen-plaintext, and special attacks. A simple optical setup for decryption has also been suggested. Results of computer simulation support the idea of the proposed cryptosystem.

  13. Citing National Publications as a metrics for localization of Science: A Study on Scholar Journals of Social Science Domain in Iran from 2002 to 2010

    Directory of Open Access Journals (Sweden)

    Mohammad Tavakolizadeh-Ravari

    2015-02-01

    Conclusion: Based on this metric, the tendency toward the use of national publications in the social science domain is constant despite the number of scientific productions is growing in Iran. This means that the Iranian social science domain not only doesn’t tend to the science localization but its use of foreign science is growing in the span of time as well.

  14. Image-Based Modeling Reveals Dynamic Redistribution of DNA Damageinto Nuclear Sub-Domains

    Energy Technology Data Exchange (ETDEWEB)

    Costes Sylvain V., Ponomarev Artem, Chen James L.; Nguyen, David; Cucinotta, Francis A.; Barcellos-Hoff, Mary Helen

    2007-08-03

    Several proteins involved in the response to DNA doublestrand breaks (DSB) f orm microscopically visible nuclear domains, orfoci, after exposure to ionizing radiation. Radiation-induced foci (RIF)are believed to be located where DNA damage occurs. To test thisassumption, we analyzed the spatial distribution of 53BP1, phosphorylatedATM, and gammaH2AX RIF in cells irradiated with high linear energytransfer (LET) radiation and low LET. Since energy is randomly depositedalong high-LET particle paths, RIF along these paths should also berandomly distributed. The probability to induce DSB can be derived fromDNA fragment data measured experimentally by pulsed-field gelelectrophoresis. We used this probability in Monte Carlo simulations topredict DSB locations in synthetic nuclei geometrically described by acomplete set of human chromosomes, taking into account microscope opticsfrom real experiments. As expected, simulations produced DNA-weightedrandom (Poisson) distributions. In contrast, the distributions of RIFobtained as early as 5 min after exposure to high LET (1 GeV/amu Fe) werenon-random. This deviation from the expected DNA-weighted random patterncan be further characterized by "relative DNA image measurements." Thisnovel imaging approach shows that RIF were located preferentially at theinterface between high and low DNA density regions, and were morefrequent than predicted in regions with lower DNA density. The samepreferential nuclear location was also measured for RIF induced by 1 Gyof low-LET radiation. This deviation from random behavior was evidentonly 5 min after irradiation for phosphorylated ATM RIF, while gammaH2AXand 53BP1 RIF showed pronounced deviations up to 30 min after exposure.These data suggest that DNA damage induced foci are restricted to certainregions of the nucleus of human epithelial cells. It is possible that DNAlesions are collected in these nuclear sub-domains for more efficientrepair.

  15. Extended radar observations with the frequency radar domain interferometric imaging (FII) technique

    Science.gov (United States)

    Luce, H.; Yamamoto, M.; Fukao, S.; Crochet, M.

    2001-07-01

    In this paper, we present high-resolution observations obtained with the Middle and Upper Atmosphere (MU) radar (Shigaraki, Japan, /34.85°N, /136.10°E) using the frequency radar domain interferometric imaging (FII) technique. This technique has recently been introduced for improving the range resolution capabilities of the mesosphere-stratosphere-troposphere (MST) radars which are limited by their minimum pulse length. The Fourier-based imaging, the Capon method have been performed with 5 equally spaced frequencies between 46.25 and 46.75MHz and with an initial range resolution of 300m. These results have been compared firstly to results obtained using the frequency domain interferometry (FDI) technique with Δf=0.5MHz and, secondly, to results from a classical Doppler beam swinging (DBS) mode applied with a range resolution of 150m. Thin echoing structures could be tracked owing to the improved radar range resolution and some complex structures possibly related to Kelvin Helmholtz instabilities have been detected. Indeed, these structures appeared within the core of a wind shear and were associated with intense vertical wind fluctuations. Moreover, a well-defined thin echo layer was found in an altitude range located below the height of the wind shear. The radar observations have not been fully interpreted yet because the radar configuration was not adapted for this kind of study and because of the lack of complementary information provided by other techniques when the interesting echoing phenomena occurred. However, the results confirm the high potentialities of the FII technique for the study of atmospheric dynamics at small scales.

  16. Image-based modeling reveals dynamic redistribution of DNA damage into nuclear sub-domains.

    Directory of Open Access Journals (Sweden)

    Sylvain V Costes

    2007-08-01

    Full Text Available Several proteins involved in the response to DNA double strand breaks (DSB form microscopically visible nuclear domains, or foci, after exposure to ionizing radiation. Radiation-induced foci (RIF are believed to be located where DNA damage occurs. To test this assumption, we analyzed the spatial distribution of 53BP1, phosphorylated ATM, and gammaH2AX RIF in cells irradiated with high linear energy transfer (LET radiation and low LET. Since energy is randomly deposited along high-LET particle paths, RIF along these paths should also be randomly distributed. The probability to induce DSB can be derived from DNA fragment data measured experimentally by pulsed-field gel electrophoresis. We used this probability in Monte Carlo simulations to predict DSB locations in synthetic nuclei geometrically described by a complete set of human chromosomes, taking into account microscope optics from real experiments. As expected, simulations produced DNA-weighted random (Poisson distributions. In contrast, the distributions of RIF obtained as early as 5 min after exposure to high LET (1 GeV/amu Fe were non-random. This deviation from the expected DNA-weighted random pattern can be further characterized by "relative DNA image measurements." This novel imaging approach shows that RIF were located preferentially at the interface between high and low DNA density regions, and were more frequent than predicted in regions with lower DNA density. The same preferential nuclear location was also measured for RIF induced by 1 Gy of low-LET radiation. This deviation from random behavior was evident only 5 min after irradiation for phosphorylated ATM RIF, while gammaH2AX and 53BP1 RIF showed pronounced deviations up to 30 min after exposure. These data suggest that DNA damage-induced foci are restricted to certain regions of the nucleus of human epithelial cells. It is possible that DNA lesions are collected in these nuclear sub-domains for more efficient repair.

  17. Visible and Thermal Imaging of Sea Ice and Open Water from Coast Guard Arctic Domain Awareness Flights

    Science.gov (United States)

    2014-09-30

    seasonal evolution of the ice cover. APPROACH The Coast Guard Arctic Domain Awareness (ADA) flights based out of Kodiak Alaska offer a tremendous...and Thermal Imaging of Sea Ice and Open Water from Coast Guard Arctic Domain Awareness Flights 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...temperature, melt pond temperature, percentage ice coverage, and ice flow and melt pond size 3 distributions. We are also collaborating within APL

  18. Enhancing the Public Image of School Counseling: A Marketing Approach.

    Science.gov (United States)

    Ritchie, Martin H.

    1989-01-01

    Suggests some basic marketing principles that might be applied to assist school counselors in selling their guidance programs to the public. Discusses assessing the needs and demands for guidance services, product development and defining the guidance program, pricing, distribution, and advertising and public relations. (NB)

  19. Changing Perceptions of Homesteading as a Policy of Public Domain Disposal

    Science.gov (United States)

    Edwards, Richard

    2009-01-01

    The inspiring story of homesteaders claiming free land and realizing their dreams became one of the enduring narratives of American history. But scholars who have studied homesteading have often been much more ambivalent, even harshly negative, about how successful it was in practice. While the public often views our history differently from…

  20. Spectral-domain optical coherence tomography staging and autofluorescence imaging in achromatopsia.

    Science.gov (United States)

    Greenberg, Jonathan P; Sherman, Jerome; Zweifel, Sandrine A; Chen, Royce W S; Duncker, Tobias; Kohl, Susanne; Baumann, Britta; Wissinger, Bernd; Yannuzzi, Lawrence A; Tsang, Stephen H

    2014-04-01

    IMPORTANCE Evidence is mounting that achromatopsia is a progressive retinal degeneration, and treatments for this condition are on the horizon. OBJECTIVES To categorize achromatopsia into clinically identifiable stages using spectral-domain optical coherence tomography and to describe fundus autofluorescence imaging in this condition. DESIGN, SETTING, AND PARTICIPANTS A prospective observational study was performed between 2010 and 2012 at the Edward S. Harkness Eye Institute, New York-Presbyterian Hospital. Participants included 17 patients (aged 10-62 years) with full-field electroretinography-confirmed achromatopsia. MAIN OUTCOMES AND MEASURES Spectral-domain optical coherence tomography features and staging system, fundus autofluorescence and near-infrared reflectance features and their correlation to optical coherence tomography, and genetic mutations served as the outcomes and measures. RESULTS Achromatopsia was categorized into 5 stages on spectral-domain optical coherence tomography: stage 1 (2 patients [12%]), intact outer retina; stage 2 (2 patients [12%]), inner segment ellipsoid line disruption; stage 3 (5 patients [29%]), presence of an optically empty space; stage 4 (5 patients [29%]), optically empty space with partial retinal pigment epithelium disruption; and stage 5 (3 patients [18%]), complete retinal pigment epithelium disruption and/or loss of the outer nuclear layer. Stage 1 patients showed isolated hyperreflectivity of the external limiting membrane in the fovea, and the external limiting membrane was hyperreflective above each optically empty space. On near infrared reflectance imaging, the fovea was normal, hyporeflective, or showed both hyporeflective and hyperreflective features. All patients demonstrated autofluorescence abnormalities in the fovea and/or parafovea: 9 participants (53%) had reduced or absent autofluorescence surrounded by increased autofluorescence, 4 individuals (24%) showed only reduced or absent autofluorescence, 3

  1. Lipid domains in giant unilamellar vesicles and their correspondence with equilibrium thermodynamic phases: a quantitative fluorescence microscopy imaging approach.

    Science.gov (United States)

    Fidorra, M; Garcia, A; Ipsen, J H; Härtel, S; Bagatolli, L A

    2009-10-01

    We report a novel analytical procedure to measure the surface areas of coexisting lipid domains in giant unilamellar vesicles (GUVs) based on image processing of 3D fluorescence microscopy data. The procedure involves the segmentation of lipid domains from fluorescent image stacks and reconstruction of 3D domain morphology using active surface models. This method permits the reconstruction of the spherical surface of GUVs and determination of the area fractions of coexisting lipid domains at the level of single vesicles. Obtaining area fractions enables the scrutiny of the lever rule along lipid phase diagram's tie lines and to test whether or not the coexistence of lipid domains in GUVs correspond to equilibrium thermodynamic phases. The analysis was applied to DLPC/DPPC GUVs displaying coexistence of lipid domains. Our results confirm the lever rule, demonstrating that the observed membrane domains correspond to equilibrium thermodynamic phases (i.e., solid ordered and liquid disordered phases). In addition, the fact that the lever rule is validated from 11 to 14 randomly selected GUVs per molar fraction indicates homogeneity in the lipid composition among the explored GUV populations. In conclusion, our study shows that GUVs are reliable model systems to perform equilibrium thermodynamic studies of membranes.

  2. The nursing profession: public image, self-concept and professional identity. A discussion paper.

    Science.gov (United States)

    ten Hoeve, Yvonne; Jansen, Gerard; Roodbol, Petrie

    2014-02-01

    To discuss the actual public image of nurses and other factors that influence the development of nurses' self-concept and professional identity. Nurses have become healthcare professionals in their own right who possess a great deal of knowledge. However, the public does not always value the skills and competences nurses have acquired through education and innovation. Discussion paper. We identified 1216 relevant studies by searching MEDLINE, CINAHL and PsycINFO databases in the period 1997-2010. Finally, 18 studies met our inclusion criteria. The included studies show that the actual public image of nursing is diverse and incongruous. This image is partly self-created by nurses due to their invisibility and their lack of public discourse. Nurses derive their self-concept and professional identity from their public image, work environment, work values, education and traditional social and cultural values. Nurses should work harder to communicate their professionalism to the public. Social media like the Internet and YouTube can be used to show the public what they really do. To improve their public image and to obtain a stronger position in healthcare organizations, nurses need to increase their visibility. This could be realized by ongoing education and a challenging work environment that encourages nurses to stand up for themselves. Furthermore, nurses should make better use of strategic positions, such as case manager, nurse educator or clinical nurse specialist and use their professionalism to show the public what their work really entails. © 2013 John Wiley & Sons Ltd.

  3. Quantitative measurement of laminar material properties and structure using time domain reflection imaging

    Science.gov (United States)

    Zimdars, David; White, Jeffrey; Fichter, G.; Chernovsky, A.; Williamson, S. L.

    2008-04-01

    Time domain terahertz (TD-THz) reflection imaging tomography can be used to investigate the laminar structure of objects. In a monostatic configuration, a sequence of pulses is generated by reflection from each discontinuity in index of refraction. Through analysis of the return pulses, the material absorption and index of refraction properties of each layer can be determined. TD-THz reflection tomography can be used to precisely measure the thickness of coatings such as yttria stabilized zirconia (YSZ) thermal barrier coatings (TBC) on aircraft engine turbine blades; paint on aircraft, ships, and cars; and other thin film measurement applications. In each of these cases, precise determination of the optical delay of the TD-THz pulses is required with as little as sub-10 femtosecond precision for pulses which can be greater than 500 fs in duration. We present a method to accurately measure optical delay between layers where the pulses are fit to a reference template. These are demonstrated to achieve micron scale accuracy in coating thickness. As an example, TD-THz non destructive evaluation (NDE) imaging is used to two-dimensionally map the thickness of YSZ TBCs on aircraft engine turbine blades. Indications of thermal degradation can be seen. The method is non-contact, rapid, and requires no special preparation of the blade.

  4. Agreement between Gonioscopic Examination and Swept Source Fourier Domain Anterior Segment Optical Coherence Tomography Imaging

    Directory of Open Access Journals (Sweden)

    Mohammed Rigi

    2016-01-01

    Full Text Available Purpose. To evaluate interobserver, intervisit, and interinstrument agreements for gonioscopy and Fourier domain anterior segment optical coherence tomography (FD ASOCT for classifying open and narrow angle eyes. Methods. Eighty-six eyes with open or narrow anterior chamber angles were included. The superior angle was classified open or narrow by 2 of 5 glaucoma specialists using gonioscopy and imaged by FD ASOCT in the dark. The superior angle of each FD ASOCT image was graded as open or narrow by 2 masked readers. The same procedures were repeated within 6 months. Kappas for interobserver and intervisit agreements for each instrument and interinstrument agreements were calculated. Results. The mean age was 50.9 (±18.4 years. Interobserver agreements were moderate to good for both gonioscopy (0.57 and 0.69 and FD ASOCT (0.58 and 0.75. Intervisit agreements were moderate to excellent for both gonioscopy (0.53 to 0.86 and FD ASOCT (0.57 and 0.85. Interinstrument agreements were fair to good (0.34 to 0.63, with FD ASOCT classifying more angles as narrow than gonioscopy. Conclusions. Both gonioscopy and FD ASOCT examiners were internally consistent with similar interobserver and intervisit agreements for angle classification. Agreement between instruments was fair to good, with FD ASOCT classifying more angles as narrow than gonioscopy.

  5. Multisensor fusion in gastroenterology domain through video and echo endoscopic image combination: a challenge

    Science.gov (United States)

    Debon, Renaud; Le Guillou, Clara; Cauvin, Jean-Michel; Solaiman, Basel; Roux, Christian

    2001-08-01

    Medical domain makes intensive use of information fusion. In particular, the gastro-enterology is a discipline where physicians have the choice between several imagery modalities that offer complementary advantages. Among all existing systems, videoendoscopy (based on a CCD sensor) and echoendoscopy (based on an ultrasound sensor) are the most efficient. The use of each system corresponds to a given step in the physician diagnostic elaboration. Nowadays, several works aim to achieve automatic interpretation of videoendoscopic sequences. These systems can quantify color and superficial textures of the digestive tube. Unfortunately the relief information, which is important for the diagnostic, is very difficult to retrieve. On the other hand, some studies have proved that 3D information can be easily quantified using echoendoscopy image sequences. That is why the idea to combine these information, acquired from two very different points of view, can be considered as a real challenge for the medical image fusion topic. In this paper, after a review of actual works concerning numerical exploitation of videoendoscopy and echoendoscopy, the following question will be discussed: how can the use of complementary aspects of the different systems ease the automatic exploitation of videoendoscopy ? In a second time, we will evaluate the feasibility of the achievement of a realistic 3D reconstruction based both on information given by echoendoscopy (relief) and videoendoscopy (texture). Enumeration of potential applications of such a fusion system will then follow. Further discussions and perspectives will conclude this first study.

  6. Review of spectral domain enhanced depth imaging optical coherence tomography of tumors of the choroid

    Directory of Open Access Journals (Sweden)

    Carol L Shields

    2015-01-01

    Full Text Available Background: Spectral domain enhanced depth imaging optical coherence tomography (EDI-OCT can provide anatomic localization of intraocular tumors. Aims: The aim was to identify topographical and intrinsic patterns of choroidal tumors on EDI-OCT. Settings and Design: Retrospective review. Materials and Methods: Analysis of published reports and personal observations using office based EDI-OCT. Results: Using EDI-OCT, choroidal nevus displayed a smooth, dome-shaped topography with overlying retinal pigment epithelium alterations, drusen, and occasional subretinal cleft demonstrating photoreceptor loss. Small choroidal melanoma showed smooth, moderately dome-shaped topography, commonly with overlying shallow subretinal fluid that often depicted "shaggy" photoreceptors. Choroidal metastasis showed a minimally "lumpy, bumpy" surface topography and with overlying subretinal fluid and shaggy photoreceptors. Choroidal hemangioma showed a smooth, dome-shaped topography, with expansion of the affected small, medium, and large choroidal vessels. Choroidal lymphoma showed varying topography with increasing tumor thickness as "flat, rippled, or undulating (seasick" surface. Choroidal osteoma displayed a smooth undulating surface with visible intralesional horizontal lines suggestive of bone lamellae and occasional horizontal and vertical tubules with intralesional "spongy" flecks. Choroidal melanocytosis appeared as uniformly thickened choroid with increased stromal density surrounding the normal choroidal vascular structures. Conclusions: Enhanced depth imaging-OCT can depict characteristic patterns that are suggestive of various choroidal tumors.

  7. Solute Dynamics and Imaging in the Tear Film on an Eye-shaped Domain

    Science.gov (United States)

    Braun, R. J.; Li, Longfei; Henshaw, William; Driscoll, Tobin; King-Smith, P. E.

    2015-11-01

    The concentration of ions in the tear film (osmolarity) is a key variable in understanding dry eye symptoms and disease, yet its global distribution is not available; direct measurements are restricted to a region near the temporal canthus. It has been suggested that imaging methods that use solutes such as fluorescein can be used as a proxy for estimating the osmolarity. The concentration of fluorescein is not measured directly either but the intensity as a function of concentration and thickness of the film is well established. We derived a mathematical model that couples multiple solutes and fluid dynamics within the tear film on a 2D eye-shaped domain. The model includes the physical effects of evaporation, surface tension, viscosity, ocular surface wettability, osmolarity, osmosis, fluorescence and tear fluid supply and drainage. We solved the governing system of coupled nonlinear PDEs using the Overture computational framework developed at LLNL, together with a hybrid time stepping scheme (using variable step BDF and RKC). Results of our numerical simulations provide new insight about the osmolarity distribution and its connection with images obtained in vivo over the whole ocular surface and in local regions of tear thinning due to evaporation and other effects. This work was supported in part by NSF grants 1022706 and 1412085, and NIH grant 1R01EY021794.

  8. Two photon fluorescence imaging of lipid membrane domains and potentials using advanced fluorescent probes

    Science.gov (United States)

    Kilin, Vasyl; Darwich, Zeinab; Richert, Ludovic; Didier, Pascal; Klymchenko, Andrey; Mély, Yves

    2013-02-01

    Biomembranes are ordered and dynamic nanoscale structures critical for cell functions. The biological functions of the membranes strongly depend on their physicochemical properties, such as electrostatics, phase state, viscosity, polarity and hydration. These properties are essential for the membrane structure and the proper folding and function of membrane proteins. To monitor these properties, fluorescence techniques and notably, two-photon microscopy appear highly suited due to their exquisite sensitivity and their capability to operate in complex biological systems, such as living cells and tissues. In this context, we have developed multiparametric environment-sensitive fluorescent probes tailored for precise location in the membrane bilayer. We notably developed probes of the 3-hydroxychromone family, characterized by an excited state intramolecular proton transfer reaction, which generates two tautomeric emissive species with well-separated emission bands. As a consequence, the response of these probes to changes in their environment could be monitored through changes in the ratios of the two bands, as well as through changes in the fluorescence lifetimes. Using two-photon ratiometric imaging and FLIM, these probes were used to monitor the surface membrane potential, and were applied to detect apoptotic cells and image membrane domains.

  9. Spectroscopic measurements and terahertz imaging of the cornea using a rapid scanning terahertz time domain spectrometer

    Science.gov (United States)

    Wen-Quan, Liu; Yuan-Fu, Lu; Guo-Hua, Jiao; Xian-Feng, Chen; Zhi-Sheng, Zhou; Rong-Bin, She; Jin-Ying, Li; Si-Hai, Chen; Yu-Ming, Dong; Jian-Cheng, Lv

    2016-06-01

    Spectroscopic measurements and terahertz imaging of the cornea are carried out by using a rapid scanning terahertz time domain spectroscopy (THz-TDS) system. A voice coil motor stage based optical delay line (VCM-ODL) is developed to provide a rather simple and robust structure with both the high scanning speed and the large delay length. The developed system is used for THz spectroscopic measurements and imaging of the corneal tissue with different amounts of water content, and the measurement results show the consistence with the reported results, in which the measurement time using VCM-ODL is a factor of 360 shorter than the traditional motorized optical delay line (MDL). With reducing the water content a monotonic decrease of the complex permittivity of the cornea is observed. The two-term Debye relaxation model is employed to explain our experimental results, revealing that the fast relaxation time of a dehydrated cornea is much larger than that of a hydrated cornea and its dielectric behavior can be affected by the presence of the biological macromolecules. These results demonstrate that our THz spectrometer may be a promising candidate for tissue hydration sensing and practical application of THz technology. Project supported by the National Natural Science Foundation of China (Grant No. 61205101), the Shenzhen Municipal Research Foundation, China (Grant Nos. GJHZ201404171134305 and JCYJ20140417113130693), and the Marie Curie Actions-International Research Staff Exchange Scheme (IRSES) (Grant No. FP7 PIRSES-2013-612267).

  10. In vivo imaging of raptor retina with ultra high resolution spectral domain optical coherence tomography

    Science.gov (United States)

    Ruggeri, Marco; Major, James C., Jr.; McKeown, Craig; Wehbe, Hassan; Jiao, Shuliang; Puliafito, Carmen A.

    2008-02-01

    Among birds, raptors are well known for their exceptional eyesight, which is partly due to the unique structure of their retina. Because the raptor retina is the most advanced of any animal species, in vivo examination of its structure would be remarkable. Furthermore, a noticeable percentage of traumatic ocular injuries are identified in birds of prey presented to rehabilitation facilities. Injuries affecting the posterior segment have been considered as a major impact on raptor vision. Hence, in vivo examination of the structure of the posterior segment of the raptors would be helpful for the diagnosis of traumatized birds. The purpose of this study is to demonstrate the application of ultrahigh-resolution Spectral Domain Optical Coherence Tomography (SD-OCT) for non contact in vivo imaging of the retina of birds of prey, which to the best of our knowledge has never been attempted. For the first time we present high quality OCT images of the retina of two species of bird of prey, one diurnal hawk and one nocturnal owl.

  11. Quantification and imaging of HER2 protein using nanocrystals conjugated with single-domain antibodies

    Science.gov (United States)

    Glukhov, S.; Berestovoy, M.; Chames, P.; Baty, D.; Nabiev, I.; Sukhanova, A.

    2017-01-01

    This study dealt with quantification and imaging of human epidermal growth factor receptor 2 (HER2), an important prognostic marker for cancer diagnosis and treatment, using specific quantum-dot-based conjugates. Fluorescent inorganic nanocrystals or quantum dots (QDs) are extremely highly resistant to photobleaching and have a high emission quantum yield and a continuous range of emission spectra, from the ultraviolet to the infrared regions. Ultrasmall nanoprobes consisting of highly affine anti-HER2 single-domain antibodies (sdAbs or "nanobodies") conjugated with QDs in a strictly oriented manner have been designed. QDs with a fluorescence peak maxima at wavelengths of 562 nm, 569 nm, 570 nm or in the near-infrared region were used. Here, we present our results of ISA quantification of HER2 protein, in situ imaging of HER2 protein on the surface of HER2-positive SK-BR-3 cells in immunohistochemical experiments, and counting of stained with anti-HER2 conjugates HER2-positive SK-BR-3 cells in their mixture with unstained cells of the same culture in flow cytometry experiments. The data demonstrate that the anti-HER2 QD-sdAb conjugates obtained are highly specific and sensitive and could be used in numerous applications for advanced integrated diagnosis.

  12. Study of Effects of Flat Surface Assumption to Synthetic Aperture Radar Time-domain Algorithms Imaging Quality

    Directory of Open Access Journals (Sweden)

    Lin Shi-bin

    2012-08-01

    Full Text Available Time-domain algorithms have great application prospect in Ultra Wide Band Synthetic Aperture Radar (UWB SAR imaging for its advantages such as perfect focusing and perfect motion compensation. We could adopt the flat surface assumption to simplify the imaging geometric model, when undulating terrain is imaged using time-domain algorithms. Nevertheless, the flat surface assumption leads to geometric errors, thereby affecting the imaging results. This paper studies the effects of this assumption on time-domain imaging algorithms, points out that it leads to position offset problem in the case of linear aperture, and it even leads to target defocusing problem in the case of non-linear aperture. The expression of position offset is given in this paper, as well as the restriction of the maximal offset of the non-linear aperture and the maximum elevation of the area in order to focus the targets. The conclusions are validated by simulated data, which is processed by one kind of time-domain algorithms, namely Back Projection (BP algorithm.

  13. 41 CFR 102-75.100 - When an agency holds land withdrawn or reserved from the public domain and determines that it no...

    Science.gov (United States)

    2010-07-01

    ... land withdrawn or reserved from the public domain and determines that it no longer needs this land, what must it do? 102-75.100 Section 102-75.100 Public Contracts and Property Management Federal... it no longer needs this land, what must it do? An agency holding unneeded land withdrawn or...

  14. Public Relations Efforts for the Third World: Images in the News.

    Science.gov (United States)

    Albritton, Robert B.; Manheim, Jarol B.

    1985-01-01

    Found that, after Argentina, Indonesia, Korea, the Philippines, and Turkey hired U. S. public relations consultants, their news image in the "New York Times" improved in positive coverage and portrayal as more cooperative nations. (PD)

  15. The Public Image of Libraries and Librarians as a Potential Barrier to Rural Access.

    Science.gov (United States)

    MacDonald, Brad

    1995-01-01

    Examines stereotypes of the librarian as serious barriers to rural information access, and offers strategies for improving the public image of rural libraries and of the people who keep them functioning. (Author/JKP)

  16. Co-registered Frequency-Domain Photoacoustic Radar and Ultrasound System for Subsurface Imaging in Turbid Media

    Science.gov (United States)

    Dovlo, Edem; Lashkari, Bahman; Mandelis, Andreas

    2016-03-01

    Frequency-domain photoacoustic radar (FD-PAR) imaging of absorbers in turbid media and their comparison and/or validation as well as co-registration with their corresponding ultrasound (US) images are demonstrated in this paper. Also presented are the FD-PAR tomography and the effects of reducing the number of scan lines (or angles) on image quality, resolution, and contrast. The FD-PAR modality uses intensity-modulated (coded) continuous wave laser sources driven by frequency-swept (chirp) waveforms. The spatial cross-correlation function between the PA response and the reference signal used for laser source modulation produces the reconstructed image. Live animal testing is demonstrated, and images of comparable signal-to-noise ratio, contrast, and spatial resolution were obtained. Various image improvement techniques to further reduce absorber spread and artifacts in the images such as normalization, filtering, and amplification were also investigated. The co-registered image produced from the combined US and PA images provides more information than both images independently. The significance of this work lies in the fact that achieving PA imaging functionality on a commercial ultrasound instrument could accelerate its clinical acceptance and use. This work is aimed at functional PA imaging of small animals in vivo.

  17. Frequency analysis of terahertz time-domain (THz-TDI) imaging of a XIX century Chinese lacquered screen

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch; Mogensen, J. Bornemann; Christensen, Mads Chr

    2016-01-01

    Insights about the manufacturing technique and preservation state of a precious Chinese lacquered cabinet were obtained non-invasively by terahertz time-domain imaging (THz-TDI). THz frequency analysis as well as false color rendering (FC) allowed a better discrimination of surface materials by m...

  18. Analysis of a seventeenth-century panel painting by reflection terahertz time-domain imaging (THz-TDI)

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch; Filtenborg, Troels; Skou-Hansen, Jacob

    2015-01-01

    Terahertz time-domain imaging (THz-TDI) has been applied for nondestructive visualization of a hidden painting and other subsurface composition layers of a seventeenth-century panel painting belonging to the National Gallery of Denmark. Plan-type and cross-sectional scans realized by THz have been...

  19. Airship Sparse Array Antenna Radar Real Aperture Imaging Based on Compressed Sensing and Sparsity in Transform Domain

    Directory of Open Access Journals (Sweden)

    Li Liechen

    2016-02-01

    Full Text Available A conformal sparse array based on combined Barker code is designed for airship platform. The performance of the designed array such as signal-to-noise ratio is analyzed. Using the hovering characteristics of the airship, interferometry operation can be applied on the real aperture imaging results of two pulses, which can eliminate the random backscatter phase and make the image sparse in the transform domain. Building the relationship between echo and transform coefficients, the Compressed Sensing (CS theory can be introduced to solve the formula and achieving imaging. The image quality of the proposed method can reach the image formed by the full array imaging. The simulation results show the effectiveness of the proposed method.

  20. Image processing with ImageJ

    NARCIS (Netherlands)

    Abramoff, M.D.; Magalhães, Paulo J.; Ram, Sunanda J.

    2004-01-01

    Wayne Rasband of NIH has created ImageJ, an open source Java-written program that is now at version 1.31 and is used for many imaging applications, including those that that span the gamut from skin analysis to neuroscience. ImageJ is in the public domain and runs on any operating system (OS). Image

  1. Asthma in Urban Children: Epidemiology, Environmental Risk Factors, and the Public Health Domain.

    Science.gov (United States)

    Milligan, Ki Lee; Matsui, Elizabeth; Sharma, Hemant

    2016-04-01

    Asthma is the most commonly reported chronic condition of childhood in developed countries, with 6.5 million children affected in the USA. A disparate burden of childhood asthma is seen among socioeconomically disadvantaged youth, often concentrated in urban areas with high poverty rates. Host factors that predispose a child to asthma include atopy, male gender, parental history of asthma, and also race, ethnicity, and genetic and epigenetic susceptibilities. Environmental factors, such as improved hygiene, ambient air pollution, and early life exposures to microbes and aeroallergens, also influence the development of asthma. With greater than 90% of time spent indoors, home exposures (such as cockroach, rodent, and indoor air pollution) are highly relevant for urban asthma. Morbidity reduction may require focused public health initiatives for environmental intervention in high priority risk groups and the addition of immune modulatory agents in children with poorly controlled disease.

  2. A high-order public domain code for direct numerical simulations of turbulent combustion

    CERN Document Server

    Babkovskaia, N; Brandenburg, A

    2010-01-01

    A high-order scheme for direct numerical simulations of turbulent combustion is discussed. Its implementation in the massively parallel and publicly available Pencil Code is validated with the focus on hydrogen combustion. Ignition delay times (0D) and laminar flame velocities (1D) are calculated and compared with results from the commercially available Chemkin code. The scheme is verified to be fifth order in space. Upon doubling the resolution, a 32-fold increase in the accuracy of the flame front is demonstrated. Finally, also turbulent and spherical flame front velocities are calculated and the implementation of the non-reflecting so-called Navier-Stokes Characteristic Boundary Condition is validated in all three directions.

  3. Change in Drusen Area Over Time Compared Using Spectral-Domain Optical Coherence Tomography and Color Fundus Imaging

    Science.gov (United States)

    Gregori, Giovanni; Yehoshua, Zohar; Garcia Filho, Carlos Alexandre de Amorim; Sadda, SriniVas R.; Portella Nunes, Renata; Feuer, William J.; Rosenfeld, Philip J.

    2014-01-01

    Purpose. To investigate the relationship between drusen areas measured with color fundus images (CFIs) and those with spectral-domain optical coherence tomography (SDOCT). Methods. Forty-two eyes from thirty patients with drusen in the absence of geographic atrophy were recruited to a prospective study. Digital color fundus images and SDOCT images were obtained at baseline and at follow-up visits at 3 and 6 months. Registered, matched circles centered on the fovea with diameters of 3 mm and 5 mm were identified on both CFIs and SDOCT images. Spectral-domain OCT drusen measurements were obtained using a commercially available proprietary algorithm. Drusen boundaries on CFIs were traced manually at the Doheny Eye Institute Image Reading Center. Results. Mean square root drusen area (SQDA) measurements for the 3-mm circles on the SDOCT images were 1.451 mm at baseline and 1.464 mm at week 26, whereas the measurements on CFIs were 1.555 mm at baseline and 1.584 mm at week 26. Mean SQDA measurements from CFIs were larger than those from the SDOCT measurements at all time points (P = 0.004 at baseline, P = 0.003 at 26 weeks). Changes in SQDA over 26 weeks measured with SDOCT were not different from those measured with CFIs (mean difference = 0.014 mm, P = 0.5). Conclusions. Spectral-domain OCT drusen area measurements were smaller than the measurements obtained from CFIs. However, there were no differences in the change in drusen area over time between the two imaging modalities. Spectral-domain OCT measurements were considerably more sensitive in assessing drusen area changes. PMID:25335982

  4. Imaging and Control of Surface Magnetization Domains in a Magnetoelectric Antiferromagnet

    Science.gov (United States)

    Wu, Ning; He, Xi; Wysocki, Aleksander L.; Lanke, Uday; Komesu, Takashi; Belashchenko, Kirill D.; Binek, Christian; Dowben, Peter A.

    2011-02-01

    We report the direct observation of surface magnetization domains of the magnetoelectric Cr2O3 using photoemission electron microscopy with magnetic circular dichroism contrast and magnetic force microscopy. The domain pattern is strongly affected by the applied electric field conditions. Zero-field cooling results in an equal representation of the two domain types, while electric-field cooling selects one dominant domain type. These observations confirm the existence of surface magnetization, required by symmetry in magnetoelectric antiferromagnets.

  5. Adaptive multifocus image fusion using block compressed sensing with smoothed projected Landweber integration in the wavelet domain.

    Science.gov (United States)

    V S, Unni; Mishra, Deepak; Subrahmanyam, G R K S

    2016-12-01

    The need for image fusion in current image processing systems is increasing mainly due to the increased number and variety of image acquisition techniques. Image fusion is the process of combining substantial information from several sensors using mathematical techniques in order to create a single composite image that will be more comprehensive and thus more useful for a human operator or other computer vision tasks. This paper presents a new approach to multifocus image fusion based on sparse signal representation. Block-based compressive sensing integrated with a projection-driven compressive sensing (CS) recovery that encourages sparsity in the wavelet domain is used as a method to get the focused image from a set of out-of-focus images. Compression is achieved during the image acquisition process using a block compressive sensing method. An adaptive thresholding technique within the smoothed projected Landweber recovery process reconstructs high-resolution focused images from low-dimensional CS measurements of out-of-focus images. Discrete wavelet transform and dual-tree complex wavelet transform are used as the sparsifying basis for the proposed fusion. The main finding lies in the fact that sparsification enables a better selection of the fusion coefficients and hence better fusion. A Laplacian mixture model fit is done in the wavelet domain and estimation of the probability density function (pdf) parameters by expectation maximization leads us to the proper selection of the coefficients of the fused image. Using the proposed method compared with the fusion scheme without employing the projected Landweber (PL) scheme and the other existing CS-based fusion approaches, it is observed that with fewer samples itself, the proposed method outperforms other approaches.

  6. Combining Constraint Types From Public Data in Aerial Image Segmentation

    DEFF Research Database (Denmark)

    Jacobsen, Thomas Stig; Jensen, Jacob Jon; Jensen, Daniel Rune

    2013-01-01

    detect the number of clusters using the elongated K-means algorithm instead of using the standard spectral clustering approach of a predefined number of clusters. The results are refined by filtering out noise with a binary morphological operator. Point data is used for semi-supervised labelling......We introduce a method for image segmentation that constraints the clustering with map and point data. The method is showcased by applying the spectral clustering algorithm on aerial images for building detection with constraints built from a height map and address point data. We automatically...

  7. The Influence of Negative Newspaper Publicity on Corporate Image in the Netherlands.

    Science.gov (United States)

    Renkema, Jan; Hoeken, Hans

    1998-01-01

    Contributes to scholarship on the effects of negative publicity. Notes that the Dutch equivalent of the District Attorney's Office actively spreads information about its suspicions of illegal behavior which are published by newspapers. Finds that corporate image was seriously damaged by negative publicity, and the more categorical the accusations…

  8. The nursing profession : public image, self-concept and professional identity. A discussion paper

    NARCIS (Netherlands)

    ten Hoeve, Yvonne; Jansen, Gerard; Roodbol, Petrie

    2014-01-01

    Aim To discuss the actual public image of nurses and other factors that influence the development of nurses' self-concept and professional identity. Background Nurses have become healthcare professionals in their own right who possess a great deal of knowledge. However, the public does not always va

  9. The nursing profession: public image, self-concept and professional identity : a discussion paper

    NARCIS (Netherlands)

    Hoeve, Yvonne ten; Jansen, Gerard; Roodbol, Petrie

    2013-01-01

    Aim. To discuss the actual public image of nurses and other factors that influence the development of nurses’ self-concept and professional identity. Background. Nurses have become healthcare professionals in their own right who possess a great deal of knowledge. However, the public does not always

  10. The nursing profession: public image, self-concept and professional identity

    NARCIS (Netherlands)

    Yvonne ten Hoeve; Prof. Dr. Petrie F. Roodbol; Gerard Jansen

    2013-01-01

    Aim. To discuss the actual public image of nurses and other factors that influence the development of nurses’ self-concept and professional identity. Background. Nurses have become healthcare professionals in their own right who possess a great deal of knowledge. However, the public does not always

  11. The nursing profession : public image, self-concept and professional identity. A discussion paper

    NARCIS (Netherlands)

    ten Hoeve, Yvonne; Jansen, Gerard; Roodbol, Petrie

    Aim To discuss the actual public image of nurses and other factors that influence the development of nurses' self-concept and professional identity. Background Nurses have become healthcare professionals in their own right who possess a great deal of knowledge. However, the public does not always

  12. Development of mooring-anchor program in public domain for coupling with floater program for FOWTs (Floating Offshore Wind Turbines)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, MooHyun [American Bureau of Shipping (ABS), Houston, TX (United States)

    2014-08-01

    This report presents the development of offshore anchor data sets which are intended to be used to develop a database that allows preliminary selection and sizing of anchors for the conceptual design of floating offshore wind turbines (FOWTs). The study is part of a project entitled “Development of Mooring-Anchor Program in Public Domain for Coupling with Floater Program for FOWTs (Floating Offshore Wind Turbines)”, under the direction of Dr. Moo-Hyun Kim at the Texas A&M University and with the sponsorship from the US Department of Energy (Contract No. DE-EE0005479, CFDA # 81.087 for DE-FOA-0000415, Topic Area 1.3: Subsurface Mooring and Anchoring Dynamics Models).

  13. A phase-image watermarking scheme in gyrator domain using devil's vortex Fresnel lens as a phase mask

    Science.gov (United States)

    Yadav, A. K.; Vashisth, Sunanda; Singh, Hukum; Singh, Kehar

    2015-06-01

    We propose a watermarking scheme for phase images, based on the use of devil's vortex Fresnel lens (DVFL) as a phase mask. The DVFL provides much-desired parameter-rich phase masks which contribute to the enhanced security of the scheme in addition to overcoming the problem of axis alignment in the optical setup. The scheme uses gyrator transform (GT) in the input and the frequency domains to encrypt the input phase image before combining it with a host image. The scheme is validated for its efficacy, and analyzed for its sensitivity to various encryption parameters. Finally, it is examined for its robustness against occlusion and noise attacks.

  14. Transmitting Musical Images: Using Music to Teach Public Speaking

    Science.gov (United States)

    Cohen, Steven D.; Wei, Thomas E.

    2010-01-01

    Oral communication courses traditionally help students identify the proper arrangement of words to convey particular images. Although instructors emphasize the importance of speaking powerfully, they often struggle to find effective ways to teach their students "how" to deliver a message that resonates with the audience. Given the clear importance…

  15. Time domain localization technique with sparsity constraint for imaging acoustic sources

    Science.gov (United States)

    Padois, Thomas; Doutres, Olivier; Sgard, Franck; Berry, Alain

    2017-09-01

    This paper addresses source localization technique in time domain for broadband acoustic sources. The objective is to accurately and quickly detect the position and amplitude of noise sources in workplaces in order to propose adequate noise control options and prevent workers hearing loss or safety risk. First, the generalized cross correlation associated with a spherical microphone array is used to generate an initial noise source map. Then a linear inverse problem is defined to improve this initial map. Commonly, the linear inverse problem is solved with an l2 -regularization. In this study, two sparsity constraints are used to solve the inverse problem, the orthogonal matching pursuit and the truncated Newton interior-point method. Synthetic data are used to highlight the performances of the technique. High resolution imaging is achieved for various acoustic sources configurations. Moreover, the amplitudes of the acoustic sources are correctly estimated. A comparison of computation times shows that the technique is compatible with quasi real-time generation of noise source maps. Finally, the technique is tested with real data.

  16. Corporate Imaging: Teaching Communication Strategies for Reaching Internal and External Publics.

    Science.gov (United States)

    Gaulard, Joan Marie

    A corporation's image is a powerful persuasive tool for reaching external publics such as competitors, regulators, and prospective employees. Corporations should avoid disparities between the actual and the desired image, as well as disparities between the external perception and the internal perception of employees. A course was developed at…

  17. Super-resolution reconstruction in frequency, image, and wavelet domains to reduce through-plane partial voluming in MRI

    Energy Technology Data Exchange (ETDEWEB)

    Gholipour, Ali, E-mail: ali.gholipour@childrens.harvard.edu; Afacan, Onur; Scherrer, Benoit; Prabhu, Sanjay P.; Warfield, Simon K. [Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts 02115 and Harvard Medical School, Boston, Massachusetts 02115 (United States); Aganj, Iman [Radiology Department, Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts 02129 and Harvard Medical School, Boston, Massachusetts 02115 (United States); Sahin, Mustafa [Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts 02115 and Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2015-12-15

    Purpose: To compare and evaluate the use of super-resolution reconstruction (SRR), in frequency, image, and wavelet domains, to reduce through-plane partial voluming effects in magnetic resonance imaging. Methods: The reconstruction of an isotropic high-resolution image from multiple thick-slice scans has been investigated through techniques in frequency, image, and wavelet domains. Experiments were carried out with thick-slice T2-weighted fast spin echo sequence on the Academic College of Radiology MRI phantom, where the reconstructed images were compared to a reference high-resolution scan using peak signal-to-noise ratio (PSNR), structural similarity image metric (SSIM), mutual information (MI), and the mean absolute error (MAE) of image intensity profiles. The application of super-resolution reconstruction was then examined in retrospective processing of clinical neuroimages of ten pediatric patients with tuberous sclerosis complex (TSC) to reduce through-plane partial voluming for improved 3D delineation and visualization of thin radial bands of white matter abnormalities. Results: Quantitative evaluation results show improvements in all evaluation metrics through super-resolution reconstruction in the frequency, image, and wavelet domains, with the highest values obtained from SRR in the image domain. The metric values for image-domain SRR versus the original axial, coronal, and sagittal images were PSNR = 32.26 vs 32.22, 32.16, 30.65; SSIM = 0.931 vs 0.922, 0.924, 0.918; MI = 0.871 vs 0.842, 0.844, 0.831; and MAE = 5.38 vs 7.34, 7.06, 6.19. All similarity metrics showed high correlations with expert ranking of image resolution with MI showing the highest correlation at 0.943. Qualitative assessment of the neuroimages of ten TSC patients through in-plane and out-of-plane visualization of structures showed the extent of partial voluming effect in a real clinical scenario and its reduction using SRR. Blinded expert evaluation of image resolution in

  18. Open window: when easily identifiable genomes and traits are in the public domain.

    Directory of Open Access Journals (Sweden)

    Misha Angrist

    Full Text Available "One can't be of an enquiring and experimental nature, and still be very sensible."--Charles Fort. As the costs of personal genetic testing "self-quantification" fall, publicly accessible databases housing people's genotypic and phenotypic information are gradually increasing in number and scope. The latest entrant is openSNP, which allows participants to upload their personal genetic/genomic and self-reported phenotypic data. I believe the emergence of such open repositories of human biological data is a natural reflection of inquisitive and digitally literate people's desires to make genomic and phenotypic information more easily available to a community beyond the research establishment. Such unfettered databases hold the promise of contributing mightily to science, science education and medicine. That said, in an age of increasingly widespread governmental and corporate surveillance, we would do well to be mindful that genomic DNA is uniquely identifying. Participants in open biological databases are engaged in a real-time experiment whose outcome is unknown.

  19. Evolution of Industry Knowledge in the Public Domain: Prior Art Searching for Software Patents

    Directory of Open Access Journals (Sweden)

    Jinseok Park

    2005-03-01

    Full Text Available Searching prior art is a key part of the patent application and examination processes. A comprehensive prior art search gives the inventor ideas as to how he can improve or circumvent existing technology by providing up to date knowledge on the state of the art. It also enables the patent applicant to minimise the likelihood of an objection from the patent office. This article explores the characteristics of prior art associated with software patents, dealing with difficulties in searching prior art due to the lack of resources, and considers public contribution to the formation of prior art databases. It addresses the evolution of electronic prior art in line with technological development, and discusses laws and practices in the EPO, USPTO, and the JPO in relation to the validity of prior art resources on the Internet. This article also investigates the main features of searching sources and tools in the three patent offices as well as non-patent literature databases. Based on the analysis of various searching databases, it provides some strategies of efficient prior art searching that should be considered for software-related inventions.

  20. Efficient Time-Domain Imaging Processing for One-Stationary Bistatic Forward-Looking SAR Including Motion Errors

    Directory of Open Access Journals (Sweden)

    Hongtu Xie

    2016-11-01

    Full Text Available With the rapid development of the one-stationary bistatic forward-looking synthetic aperture radar (OS-BFSAR technology, the huge amount of the remote sensing data presents challenges for real-time imaging processing. In this paper, an efficient time-domain algorithm (ETDA considering the motion errors for the OS-BFSAR imaging processing, is presented. This method can not only precisely handle the large spatial variances, serious range-azimuth coupling and motion errors, but can also greatly improve the imaging efficiency compared with the direct time-domain algorithm (DTDA. Besides, it represents the subimages on polar grids in the ground plane instead of the slant-range plane, and derives the sampling requirements considering motion errors for the polar grids to offer a near-optimum tradeoff between the imaging precision and efficiency. First, OS-BFSAR imaging geometry is built, and the DTDA for the OS-BFSAR imaging is provided. Second, the polar grids of subimages are defined, and the subaperture imaging in the ETDA is derived. The sampling requirements for polar grids are derived from the point of view of the bandwidth. Finally, the implementation and computational load of the proposed ETDA are analyzed. Experimental results based on simulated and measured data validate that the proposed ETDA outperforms the DTDA in terms of the efficiency improvement.

  1. Efficient Time-Domain Imaging Processing for One-Stationary Bistatic Forward-Looking SAR Including Motion Errors.

    Science.gov (United States)

    Xie, Hongtu; Shi, Shaoying; Xiao, Hui; Xie, Chao; Wang, Feng; Fang, Qunle

    2016-11-12

    With the rapid development of the one-stationary bistatic forward-looking synthetic aperture radar (OS-BFSAR) technology, the huge amount of the remote sensing data presents challenges for real-time imaging processing. In this paper, an efficient time-domain algorithm (ETDA) considering the motion errors for the OS-BFSAR imaging processing, is presented. This method can not only precisely handle the large spatial variances, serious range-azimuth coupling and motion errors, but can also greatly improve the imaging efficiency compared with the direct time-domain algorithm (DTDA). Besides, it represents the subimages on polar grids in the ground plane instead of the slant-range plane, and derives the sampling requirements considering motion errors for the polar grids to offer a near-optimum tradeoff between the imaging precision and efficiency. First, OS-BFSAR imaging geometry is built, and the DTDA for the OS-BFSAR imaging is provided. Second, the polar grids of subimages are defined, and the subaperture imaging in the ETDA is derived. The sampling requirements for polar grids are derived from the point of view of the bandwidth. Finally, the implementation and computational load of the proposed ETDA are analyzed. Experimental results based on simulated and measured data validate that the proposed ETDA outperforms the DTDA in terms of the efficiency improvement.

  2. [The professional self and hetero image among public health nurses: a study of social representations].

    Science.gov (United States)

    Gomes, Antonio Marcos Tosoli; Oliveira, Denize Cristina de

    2005-01-01

    The object of this study is the professional image constructed by public health nurses and the objective is to describe and analyze the professional images present in the representations of nurses who deliver direct care to this clientele. The theoretical-methodological reference framework adopted was Social Representations Theory. A qualitative study was developed in Petrópolis-Rio de Janeiro/Brazil, through in-depth interviews with 30 nurses. Alceste 4.5 software was used for the lexical analysis. The results reveal the existence of a professional self-image with three groups of meanings: being a reference for the team, the non-specific image and the image of plaster; and a professional hetero-image with four groups of meanings: administrator, invisible, positive image and superposition. The study of the professional image reflects the construction of the nurse's identity in itself and emphasizes Social Representations Theory as a useful tool for nursing research development.

  3. Double image encryption based on phase-amplitude mixed encoding and multistage phase encoding in gyrator transform domains

    Science.gov (United States)

    Wang, Qu; Guo, Qing; Lei, Liang

    2013-06-01

    We present a novel method for double image encryption that is based on amplitude-phase mixed encoding and multistage random phase encoding in gyrator transform (GT) domains. In the amplitude-phase mixed encoding operation, a random binary distribution matrix is defined to mixed encode two primitive images to a single complex-valued image, which is then encrypted into a stationary white noise distribution by the multistage phase encoding with GTs. Compared with the earlier methods that uses fully phase encoding, the proposed method reduces the difference between two primitive images in key space and sensitivity to the GT orders. The primitive images can be recovered exactly by applying correct keys with initial conditions of chaotic system, the GT orders and the pixel scrambling operation. Numerical simulations demonstrate that the proposed scheme has considerably high security level and certain robustness against data loss and noise disturbance.

  4. Pipeline Processing at the Isaac Newton Group: Using ``Live" Images for Public Understanding of Science

    Science.gov (United States)

    Greimel, Robert; Mendez, Javier; Skillen, Ian; Lennon, D. J.; Walton, Nick A.

    The Isaac Newton Group of Telescopes is currently implementing both optical and near-infrared data reduction pipelines for its imaging cameras. For quality control purposes the quicklook pipelines generate postage stamp and full size images (in jpeg format) of all reduced data frames, which can easily be accessed through a web interface. For spectroscopic instruments only the raw data frames are converted into jpeg images. In this poster we show how these images, combined with automated access to the scheduling information and current weather and observing conditions, can be used as input to form near real time web pages for public relations purposes. To enhance the usefulness of this service, a description of the observing project, accessible to the general public, is requested from the observer. Possible use of such a service for planetariums and museums is discussed. This will provide a valuable means for disseminating the dynamic nature of the observatory to the wider public.

  5. Efficient fully 3D list-mode TOF PET image reconstruction using a factorized system matrix with an image domain resolution model.

    Science.gov (United States)

    Zhou, Jian; Qi, Jinyi

    2014-02-07

    A factorized system matrix utilizing an image domain resolution model is attractive in fully 3D time-of-flight PET image reconstruction using list-mode data. In this paper, we study a factored model based on sparse matrix factorization that is comprised primarily of a simplified geometrical projection matrix and an image blurring matrix. Beside the commonly-used Siddon's ray-tracer, we propose another more simplified geometrical projector based on the Bresenham's ray-tracer which further reduces the computational cost. We discuss in general how to obtain an image blurring matrix associated with a geometrical projector, and provide theoretical analysis that can be used to inspect the efficiency in model factorization. In simulation studies, we investigate the performance of the proposed sparse factorization model in terms of spatial resolution, noise properties and computational cost. The quantitative results reveal that the factorization model can be as efficient as a non-factored model, while its computational cost can be much lower. In addition we conduct Monte Carlo simulations to identify the conditions under which the image resolution model can become more efficient in terms of image contrast recovery. We verify our observations using the provided theoretical analysis. The result offers a general guide to achieve the optimal reconstruction performance based on a sparse factorization model with an image domain resolution model.

  6. Efficient fully 3D list-mode TOF PET image reconstruction using a factorized system matrix with an image domain resolution model

    Science.gov (United States)

    Zhou, Jian; Qi, Jinyi

    2014-01-01

    A factorized system matrix utilizing an image domain resolution model is attractive in fully 3D TOF PET image reconstruction using list-mode data. In this paper, we study a factored model based on sparse matrix factorization that is comprised primarily of a simplified geometrical projection matrix and an image blurring matrix. Beside the commonly-used Siddon's raytracer, we propose another more simplified geometrical projector based on the Bresenham's raytracer which further reduces the computational cost. We discuss in general how to obtain an image blurring matrix associated with a geometrical projector, and provide theoretical analysis that can be used to inspect the efficiency in model factorization. In simulation studies, we investigate the performance of the proposed sparse factorization model in terms of spatial resolution, noise properties and computational cost. The quantitative results reveal that the factorization model can be as efficient as a nonfactored model such as the analytical model while its computational cost can be much lower. In addition we conduct Monte Carlo simulations to identify the conditions under which the image resolution model can become more efficient in terms of image contrast recovery. We verify our observations using the provided theoretical analysis. The result offers a general guide to achieve optimal reconstruction performance based on a sparse factorization model with an only image domain resolution model. PMID:24434568

  7. Nano-domains of high viscosity and stiffness mapped in the cell membrane by thermal noise imaging

    Science.gov (United States)

    Hsu, Yunhsiang; Pralle, Arnd

    2012-02-01

    The cell membrane is thought to contain spatial domains, created by cholesterol-lipid clusters and by interactions with the membrane cytoskeleton. The influence of these domains on membrane protein mobility and cell signaling has clearly been demonstrate. Yet, due to their small size and transient nature, the cholesterol stabilized domains cannot be visualized directly. We show here that thermal noise imaging (TNI) which tracks the diffusion of a colloid labeled membrane protein with microsecond and nanometer precision, can visualize cholesterol stabilized domains, also know as lipid raft, in intact cells. Using TNI to confine a single membrane protein to diffuse for seconds in an area of 300nm x 300nm provides sufficient data for high resolutions maps of the local diffusion, local attraction potentials and membrane stiffness. Using a GPI-anchored GFP molecule to probe the membrane of PtK2 cells we detect domains of increased membrane stiffness, which also show increase viscosity and are the preferred location for the GPI-anchored protein. These domains are further stabilized by addition of ganglioside cross linking toxins and disappear after removal of the cholesterol.

  8. Imaging and control of surface magnetization domains in a magnetoelectric antiferromagnet.

    Science.gov (United States)

    Wu, Ning; He, Xi; Wysocki, Aleksander L; Lanke, Uday; Komesu, Takashi; Belashchenko, Kirill D; Binek, Christian; Dowben, Peter A

    2011-02-25

    We report the direct observation of surface magnetization domains of the magnetoelectric Cr(2)O(3) using photoemission electron microscopy with magnetic circular dichroism contrast and magnetic force microscopy. The domain pattern is strongly affected by the applied electric field conditions. Zero-field cooling results in an equal representation of the two domain types, while electric-field cooling selects one dominant domain type. These observations confirm the existence of surface magnetization, required by symmetry in magnetoelectric antiferromagnets. © 2011 American Physical Society

  9. Angle-domain common-image gathers from anisotropic Gaussian beam migration and its application to anisotropy-induced imaging errors analysis

    Indian Academy of Sciences (India)

    Jianguang Han; Yun Wang; Changqing Yu; Peng Chen

    2017-02-01

    An approach for extracting angle-domain common-image gathers (ADCIGs) from anisotropic Gaussian beam prestack depth migration (GB-PSDM) is presented in this paper. The propagation angle is calculated in the process of migration using the real-value traveltime information of Gaussian beam. Based on the above, we further investigate the effects of anisotropy on GB-PSDM, where the corresponding ADCIGs are extracted to assess the quality of migration images. The test results of the VTI syncline model and the TTI thrust sheet model show that anisotropic parameters ε, δ, and tilt angle θ, have a great influence on the accuracy of the migrated image in anisotropic media, and ignoring any one of them will cause obvious imaging errors. The anisotropic GB-PSDM with the true anisotropic parameters can obtain more accurate seismic images of subsurface structures in anisotropic media.

  10. Angle-domain common-image gathers from anisotropic Gaussian beam migration and its application to anisotropy-induced imaging errors analysis

    Science.gov (United States)

    Han, Jianguang; Wang, Yun; Yu, Changqing; Chen, Peng

    2017-02-01

    An approach for extracting angle-domain common-image gathers (ADCIGs) from anisotropic Gaussian beam prestack depth migration (GB-PSDM) is presented in this paper. The propagation angle is calculated in the process of migration using the real-value traveltime information of Gaussian beam. Based on the above, we further investigate the effects of anisotropy on GB-PSDM, where the corresponding ADCIGs are extracted to assess the quality of migration images. The test results of the VTI syncline model and the TTI thrust sheet model show that anisotropic parameters ɛ, δ, and tilt angle 𝜃, have a great influence on the accuracy of the migrated image in anisotropic media, and ignoring any one of them will cause obvious imaging errors. The anisotropic GB-PSDM with the true anisotropic parameters can obtain more accurate seismic images of subsurface structures in anisotropic media.

  11. What is the public's role in 'space' policymaking? Images of the public by practitioners of 'space' communication in the United Kingdom.

    Science.gov (United States)

    Entradas, Marta

    2016-07-01

    Studies on experts' understanding of the public have mainly focused on the views of scientists. We add to the literature on constructions of the public by analyzing the views of decision-makers, professional science communicators and scientists involved in 'space' communication on the public and public participation in policy. Findings show that contextual situations and roles determine the way the public is conceptualised: the public is sophisticated and knowledgeable to participate in space activities/citizen science, but in matters of policy, a gullible image of the public is brought up. Despite the democratic talk on participation, practitioners delimited public involvement in policy in some way or other to protect their own power and decision-making capabilities. This conception of the public competes with the stated aims of scientific and political institutions for public engagement and the substantive value of public participation, leaving a limited role for the public in space policymaking.

  12. Anatomic vs. acquired image frame discordance in spectral domain optical coherence tomography minimum rim measurements.

    Directory of Open Access Journals (Sweden)

    Lin He

    Full Text Available PURPOSE: To quantify the effects of using the fovea to Bruch's membrane opening (FoBMO axis as the nasal-temporal midline for 30° sectoral (clock-hour spectral domain optical coherence tomography (SDOCT optic nerve head (ONH minimum rim width (MRW and area (MRA calculations. METHODS: The internal limiting membrane and BMO were delineated within 24 radial ONH B-scans in 222 eyes of 222 participants with ocular hypertension and glaucoma. For each eye the fovea was marked within the infrared reflectance image, the FoBMO angle (θ relative to the acquired image frame (AIF horizontal was calculated, the ONH was divided into 30° sectors using a FoBMO or AIF nasal/temporal axis, and SDOCT MRW and MRA were quantified within each FoBMO vs. AIF sector. For each sector, focal rim loss was calculated as the MRW and MRA gradients (i.e. the difference between the value for that sector and the one clockwise to it divided by 30°. Sectoral FoBMO vs. AIF discordance was calculated as the difference between the FoBMO and AIF values for each sector. Generalized estimating equations were used to predict the eyes and sectors of maximum FoBMO vs. AIF discordance. RESULTS: The mean FoBMO angle was -6.6±4.2° (range: -17° to +7°. FoBMO vs. AIF discordance in sectoral mean MRW and MRA was significant for 7 of 12 and 6 of 12 sectors, respectively (p<0.05, Wilcoxon test, Bonferroni correction. Eye-specific, FoBMO vs. AIF sectoral discordance was predicted by sectoral rim gradient (p<0.001 and FoBMO angle (p<0.001 and achieved maximum values of 83% for MRW and 101% for MRA. CONCLUSIONS: Using the FoBMO axis as the nasal-temporal axis to regionalize the ONH rather than a line parallel to the AIF horizontal axis significantly influences clock-hour SDOCT rim values. This effect is greatest in eyes with large FoBMO angles and sectors with focal rim loss.

  13. The image of care delivery by public health nurses as disseminated in Revista da Semana (1929).

    Science.gov (United States)

    de Matos Deslandes, Anna Karina; Aguiar, Simone; Neto, Mercedes; Porto, Fernando Rocha

    2013-02-01

    to analyze the images of Public Health Nurses in care delivery to society, disseminated by the Revista da Semana, in 1929. historical-semiotic study. The documents used were images, to which an analysis matrix was applied, including fashion and body language literature, besides others to address the study object. The data were interpreted in the light of the sociologist Pierre Bourdieu's notions of object representations and body hexis. the distinctive use of uniforms for the Public Health Nurses' activities was a non-verbal communication strategy to gain visibility and credibility during home visits . Public Health Nurses were particularly responsible for patient care and guidance to prevent illnesses, with a view to the qualitative development of Public Health. The intent in this study was to produce knowledge on image records about nurses' care practice at the National Public Health Department's School of Nurses, as well as to strengthen Public Health Nursing History research in Brazil, thus contributing to a better understanding about the construction process of nurses' image.

  14. Terahertz imaging of composite materials in reflection and transmission mode with a time-domain spectroscopy system

    Science.gov (United States)

    Sørgârd, Trygve R.; van Rheenen, Arthur D.; Haakestad, Magnus W.

    2016-02-01

    A fiber-coupled Terahertz time domain spectroscopy (THz-TDS) system based on photoconductive antennas, pumped by a 100-fs fiber laser, has been used to characterize materials in transmission and reflection mode. THz images are acquired by mounting the samples under investigation on an x-y stage, which is stepped through the beam while the transmitted or reflected THz waveform is captured. The samples include a carbon fiber epoxy composite and a sandwich-structured composite panel with an aramid fiber honeycomb core in between two skin layers of fiberglass reinforced plastic. The former has an artificially induced void, and from a comparison of recorded reflected time-domain signals, with and without the void, a simple model for the structure of the composite is proposed that describes the time-domain signals reasonably well.

  15. Body image and personality among British men: associations between the Big Five personality domains, drive for muscularity, and body appreciation.

    Science.gov (United States)

    Benford, Karis; Swami, Viren

    2014-09-01

    The present study examined associations between the Big Five personality domains and measures of men's body image. A total of 509 men from the community in London, UK, completed measures of drive for muscularity, body appreciation, the Big Five domains, and subjective social status, and provided their demographic details. The results of a hierarchical regression showed that, once the effects of participant body mass index (BMI) and subjective social status had been accounted for, men's drive for muscularity was significantly predicted by Neuroticism (β=.29). In addition, taking into account the effects of BMI and subjective social status, men's body appreciation was significantly predicted by Neuroticism (β=-.35) and Extraversion (β=.12). These findings highlight potential avenues for the development of intervention approaches based on the relationship between the Big Five personality traits and body image.

  16. Discrimination and identification of RDX/PETN explosives by chemometrics applied to terahertz time-domain spectral imaging

    Science.gov (United States)

    Bou-Sleiman, J.; Perraud, J.-B.; Bousquet, B.; Guillet, J.-P.; Palka, N.; Mounaix, P.

    2015-10-01

    Detection of explosives has always been a priority for homeland security. Jointly, terahertz spectroscopy and imaging are emerging and promising candidates as contactless and safe systems. In this work, we treated data resulting from hyperspectral imaging obtained by THz-time domain spectroscopy, with chemometric tools. We found efficient identification and sorting of targeted explosives in the case of pure and mixture samples. In this aim, we applied to images Principal Component Analysis (PCA) to discriminate between RDX, PETN and mixtures of the two materials, using the absorbance as the key-parameter. Then we applied Partial Least Squares-Discriminant Analysis (PLS-DA) to each pixel of the hyperspectral images to sort the explosives into different classes. The results clearly show successful identification and categorization of the explosives under study.

  17. A joint watermarking/encryption algorithm for verifying medical image integrity and authenticity in both encrypted and spatial domains.

    Science.gov (United States)

    Bouslimi, D; Coatrieux, G; Roux, Ch

    2011-01-01

    In this paper, we propose a new joint watermarking/encryption algorithm for the purpose of verifying the reliability of medical images in both encrypted and spatial domains. It combines a substitutive watermarking algorithm, the quantization index modulation (QIM), with a block cipher algorithm, the Advanced Encryption Standard (AES), in CBC mode of operation. The proposed solution gives access to the outcomes of the image integrity and of its origins even though the image is stored encrypted. Experimental results achieved on 8 bits encoded Ultrasound images illustrate the overall performances of the proposed scheme. By making use of the AES block cipher in CBC mode, the proposed solution is compliant with or transparent to the DICOM standard.

  18. Image resolution enhancement using edge extraction and sparse representation in wavelet domain for real-time application

    Science.gov (United States)

    Ponomaryov, Volodymyr I.; Chavez-Roman, Herminio; Gonzalez-Huitron, Victor

    2014-05-01

    The paper presents the design and hardware implementation of novel framework for image resolution enhancement employing the wavelet domain. The principal idea of resolution enhancement consists of using edge preservation procedure and mutual interpolation between the input low-resolution (LR) image and the HF sub-band images performed via the Discrete Wavelet Transform (DWT). The LR image is used in the sparse representation for the resolutionenhancement process, employing a 1-D interpolation in set of angle directions; following, the computations of the new samples are found, estimating the missing samples. Finally, pixels are performed via the Lanczos interpolation. To preserve more edge information additional edge extraction in HF sub-bands is performed in the DWT decomposition of input image. The differences between the LL sub-band image and LR input image is used to correct the HF component, generating a significantly sharper reconstructed image. All sub-band images are used to generate the new HR image applying the inverse DWT (IDWT). Additionally, the novel framework employs a denoising procedure by using the Non-Local Means for the input LR image. An efficiency analysis of the designed and other state-of-the-art filters have been performed on the DSP TMS320DM648 by Texas Instruments through MATLAB's Simulink module and on the video card (NVIDIA®Quadro® K2000), showing that novel SR procedure can be used in real-time processing applications. Experimental results have confirmed that implemented framework outperforms existing SR algorithms in terms of objective criteria (PSNR, MAE and SSIM) as well as in subjective perception, justifying better image resolution.

  19. Numerical simulation of partially coherent broadband optical imaging using the finite-difference time-domain method.

    Science.gov (United States)

    Çapoğlu, İlker R; White, Craig A; Rogers, Jeremy D; Subramanian, Hariharan; Taflove, Allen; Backman, Vadim

    2011-05-01

    Rigorous numerical modeling of optical systems has attracted interest in diverse research areas ranging from biophotonics to photolithography. We report the full-vector electromagnetic numerical simulation of a broadband optical imaging system with partially coherent and unpolarized illumination. The scattering of light from the sample is calculated using the finite-difference time-domain (FDTD) numerical method. Geometrical optics principles are applied to the scattered light to obtain the intensity distribution at the image plane. Multilayered object spaces are also supported by our algorithm. For the first time, numerical FDTD calculations are directly compared to and shown to agree well with broadband experimental microscopy results.

  20. Scalable Medical Image Understanding by Fusing Cross-Modal Object Recognition with Formal Domain Semantics

    Science.gov (United States)

    Möller, Manuel; Sintek, Michael; Buitelaar, Paul; Mukherjee, Saikat; Zhou, Xiang Sean; Freund, Jörg

    Recent advances in medical imaging technology have dramatically increased the amount of clinical image data. In contrast, techniques for efficiently exploiting the rich semantic information in medical images have evolved much slower. Despite the research outcomes in image understanding, current image databases are still indexed by manually assigned subjective keywords instead of the semantics of the images. Indeed, most current content-based image search applications index image features that do not generalize well and use inflexible queries. This slow progress is due to the lack of scalable and generic information representation systems which can abstract over the high dimensional nature of medical images as well as semantically model the results of object recognition techniques. We propose a system combining medical imaging information with ontological formalized semantic knowledge that provides a basis for building universal knowledge repositories and gives clinicians fully cross-lingual and cross-modal access to biomedical information.

  1. Extra Domain B Fibronectin as a Target for Near-Infrared Fluorescence Imaging of Rheumatoid Arthritis Affected Joints In Vivo

    Directory of Open Access Journals (Sweden)

    Sonja Vollmer

    2009-11-01

    Full Text Available We investigated a molecular imaging approach for the detection of collagen-induced arthritis in rats by targeting the extra domain B (ED-B of the extracellular matrix protein fibronectin. ED-B is a highly conserved domain (identical in human and rats that is produced by alternative splicing during embryonic development and during vascular remodeling such as angiogenesis. The hallmark of rheumatoid arthritis is synovitis leading to both angiogenesis in the synovium and the promotion of cartilage and bone disruption. For in vivo diagnostics, the ED-B-binding single-chain antibody fragment AP39 was used as a targeting probe. It was covalently linked to the near-infrared dye tetrasulfocyanine (TSC to be visualized by near-infrared fluorescence imaging. The resulting AP39-TSC conjugate was intravenously administered to rats with collagen-induced arthritis and the respective controls. Ovalbumin-TSC was used as control conjugate. Optical imaging over a time period of 24 hours using a planar imaging setup resulted in a clear enhancement of fluorescence intensity in joints with moderate to severe arthritis compared with control joints between 3 and 8 hours postinjection. Given that AP39 is a fully human antibody fragment, this molecular imaging approach for arthritis detection might be translated to humans.

  2. CT and MR Image Fusion Scheme in Nonsubsampled Contourlet Transform Domain

    OpenAIRE

    Ganasala, Padma; Kumar, Vinod

    2014-01-01

    Fusion of CT and MR images allows simultaneous visualization of details of bony anatomy provided by CT image and details of soft tissue anatomy provided by MR image. This helps the radiologist for the precise diagnosis of disease and for more effective interventional treatment procedures. This paper aims at designing an effective CT and MR image fusion method. In the proposed method, first source images are decomposed by using nonsubsampled contourlet transform (NSCT) which is a shift-invaria...

  3. Medical Image Fusion Algorithm based on Local Average Energy-Motivated PCNN in NSCT Domain

    OpenAIRE

    Huda Ahmed; Emad N. Hassan; Amr A. Badr

    2016-01-01

    Medical Image Fusion (MIF) can improve the performance of medical diagnosis, treatment planning and image-guided surgery significantly through providing high-quality and rich-information medical images. Traditional MIF techniques suffer from common drawbacks such as: contrast reduction, edge blurring and image degradation. Pulse-coupled Neural Network (PCNN) based MIF techniques outperform the traditional methods in providing high-quality fused images due to its global coupling and pulse sync...

  4. Functional brain imaging predicts public health campaign success.

    Science.gov (United States)

    Falk, Emily B; O'Donnell, Matthew Brook; Tompson, Steven; Gonzalez, Richard; Dal Cin, Sonya; Strecher, Victor; Cummings, Kenneth Michael; An, Lawrence

    2016-02-01

    Mass media can powerfully affect health decision-making. Pre-testing through focus groups or surveys is a standard, though inconsistent, predictor of effectiveness. Converging evidence demonstrates that activity within brain systems associated with self-related processing can predict individual behavior in response to health messages. Preliminary evidence also suggests that neural activity in small groups can forecast population-level campaign outcomes. Less is known about the psychological processes that link neural activity and population-level outcomes, or how these predictions are affected by message content. We exposed 50 smokers to antismoking messages and used their aggregated neural activity within a 'self-localizer' defined region of medial prefrontal cortex to predict the success of the same campaign messages at the population level (n = 400,000 emails). Results demonstrate that: (i) independently localized neural activity during health message exposure complements existing self-report data in predicting population-level campaign responses (model combined R(2) up to 0.65) and (ii) this relationship depends on message content-self-related neural processing predicts outcomes in response to strong negative arguments against smoking and not in response to compositionally similar neutral images. These data advance understanding of the psychological link between brain and large-scale behavior and may aid the construction of more effective media health campaigns.

  5. Blind Image Deblurring Driven by Nonlinear Processing in the Edge Domain

    Directory of Open Access Journals (Sweden)

    Stefania Colonnese

    2004-12-01

    Full Text Available This work addresses the problem of blind image deblurring, that is, of recovering an original image observed through one or more unknown linear channels and corrupted by additive noise. We resort to an iterative algorithm, belonging to the class of Bussgang algorithms, based on alternating a linear and a nonlinear image estimation stage. In detail, we investigate the design of a novel nonlinear processing acting on the Radon transform of the image edges. This choice is motivated by the fact that the Radon transform of the image edges well describes the structural image features and the effect of blur, thus simplifying the nonlinearity design. The effect of the nonlinear processing is to thin the blurred image edges and to drive the overall blind restoration algorithm to a sharp, focused image. The performance of the algorithm is assessed by experimental results pertaining to restoration of blurred natural images.

  6. A novel image-domain-based cone-beam computed tomography enhancement algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiang; Li Tianfang; Yang Yong; Heron, Dwight E; Huq, M Saiful, E-mail: lix@upmc.edu [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15232 (United States)

    2011-05-07

    Kilo-voltage (kV) cone-beam computed tomography (CBCT) plays an important role in image-guided radiotherapy. However, due to a large cone-beam angle, scatter effects significantly degrade the CBCT image quality and limit its clinical application. The goal of this study is to develop an image enhancement algorithm to reduce the low-frequency CBCT image artifacts, which are also called the bias field. The proposed algorithm is based on the hypothesis that image intensities of different types of materials in CBCT images are approximately globally uniform (in other words, a piecewise property). A maximum a posteriori probability framework was developed to estimate the bias field contribution from a given CBCT image. The performance of the proposed CBCT image enhancement method was tested using phantoms and clinical CBCT images. Compared to the original CBCT images, the corrected images using the proposed method achieved a more uniform intensity distribution within each tissue type and significantly reduced cupping and shading artifacts. In a head and a pelvic case, the proposed method reduced the Hounsfield unit (HU) errors within the region of interest from 300 HU to less than 60 HU. In a chest case, the HU errors were reduced from 460 HU to less than 110 HU. The proposed CBCT image enhancement algorithm demonstrated a promising result by the reduction of the scatter-induced low-frequency image artifacts commonly encountered in kV CBCT imaging.

  7. Seeing Beyond the Painting Surface with Terahertz Time-Domain Imaging (THz-TDI): a signal separation method for extracting images of buried individual layers in paintings

    DEFF Research Database (Denmark)

    Filtenborg, Troels Folke; Skou-Hansen, Jakob; Koch Dandolo, Corinna Ludovica

    2015-01-01

    In this study, the 18C easel painting The Dying Messalina and her Mother, by Nicolai Abildgaard (Statens Museum for Kunst collection, Copenhagen, Denmark), has been investigated by Terahertz Time-Domain Imaging (THz-TDI) in reflection set-up. Despite the validity of traditional deconvolution...... and denoising methods used to resolve temporal features of THz reflected signals, they result impractical if applied to large images analysis. Therefore, we presented a simple, fast and effective method to separate single THz pulses of interest from the entire signal recorded at each spatial coordinate...

  8. Use of media and public-domain Internet sources for detection and assessment of plant health threats

    Directory of Open Access Journals (Sweden)

    David M. Hartley

    2011-09-01

    Full Text Available Event-based biosurveillance is a recognized approach to early warning and situational awareness of emerging health threats. In this study, we build upon previous human and animal health work to develop a new approach to plant pest and pathogen surveillance. We show that monitoring public domain electronic media for indications and warning of epidemics and associated social disruption can provide information about the emergence and progression of plant pest infestation or disease outbreak. The approach is illustrated using a case study, which describes a plant pest and pathogen epidemic in China and Vietnam from February 2006 to December 2007, and the role of ducks in contributing to zoonotic virus spread in birds and humans. This approach could be used as a complementary method to traditional plant pest and pathogen surveillance to aid global and national plant protection officials and political leaders in early detection and timely response to significant biological threats to plant health, economic vitality, and social stability. This study documents the inter-relatedness of health in human, animal, and plant populations and emphasizes the importance of plant health surveillance.

  9. How Large Is the "Public Domain"? A Comparative Analysis of Ringer's 1961 Copyright Renewal Study and HathiTrust CRMS Data

    Science.gov (United States)

    Wilkin, John P.

    2017-01-01

    The 1961 Copyright Office study on renewals, authored by Barbara Ringer, has cast an outsized influence on discussions of the U.S. 1923-1963 public domain. As more concrete data emerge from initiatives such as the large-scale determination process in the Copyright Review Management System (CRMS) project, questions are raised about the reliability…

  10. Ultrahigh-speed imaging of the rat retina using ultrahigh-resolution spectral/Fourier domain OCT

    Science.gov (United States)

    Liu, Jonathan J.; Potsaid, Benjamin; Chen, Yueli; Gorczynska, Iwona; Srinivasan, Vivek J.; Duker, Jay S.; Fujimoto, James G.

    2010-02-01

    We performed OCT imaging of the rat retina at 70,000 axial scans per second with ~3 μm axial resolution. Three-dimensional OCT (3D-OCT) data sets of the rat retina were acquired. The high speed and high density data sets enable improved en face visualization by reducing eye motion artifacts and improve Doppler OCT measurements. Minimal motion artifacts were visible and the OCT fundus images offer more precise registration of individual OCT images to retinal fundus features. Projection OCT fundus images show features such as the nerve fiber layer, retinal capillary networks and choroidal vasculature. Doppler OCT images and quantitative measurements show pulsatility in retinal blood vessels. Doppler OCT provides noninvasive in vivo quantitative measurements of retinal blood flow properties and may benefit studies of diseases such as glaucoma and diabetic retinopathy. Ultrahigh speed imaging using ultrahigh resolution spectral / Fourier domain OCT promises to enable novel protocols for measuring small animal retinal structure and retinal blood flow. This non-invasive imaging technology is a promising tool for monitoring disease progression in rat and mouse models to assess ocular disease pathogenesis and response to treatment.

  11. Multiple-image encryption using polarized light encoding and the optical interference principle in the Fresnel-transform domain.

    Science.gov (United States)

    Wang, Qu; Guo, Qing; Zhou, Jinyun

    2013-12-20

    We propose a multiple-image encryption scheme, based on polarized light encoding and the interference principle of phase-only masks (POMs), in the Fresnel-transform (FrT) domain. In this scheme, each secret image is converted into an intensity image by polarized light encoding, where a random key image and a pixilated polarizer with random angles are employed as keys. The intensity encrypted images produced by different secret images are convolved together and then inverse Fresnel-transformed. Phase and amplitude truncations are used to generate the asymmetric decryption keys. The phase-truncated inverse FrT spectrum is sent into an interference-based encryption (IBE) system to analytically obtain two POMs. To reduce the transmission and storage load on the keys, the chaotic mapping method is employed to generate random distributions of keys for encryption and decryption. One can recover all secret images successfully only if the corresponding decryption keys, the mechanism of FrTs, and correct chaotic conditions are known. The inherent silhouette problem can be thoroughly resolved by polarized light encoding in this proposal, without using any time-consuming iterative methods. The entire encryption and decryption process can be realized digitally, or in combination with optical means. Numerical simulation results are presented to verify the effectiveness and performance of the proposed scheme.

  12. The Relationship Between Body Image and Domains of Sexual Functioning Among Heterosexual, Emerging Adult Women

    Directory of Open Access Journals (Sweden)

    Christopher Quinn-Nilas, MA

    2016-09-01

    Conclusion: Findings from this study suggest important linkages between body image and sexual functioning constructs and indicates that interventions to improve body image could have concomitant benefits related to sexual experience.

  13. Log-Gabor Energy Based Multimodal Medical Image Fusion in NSCT Domain

    OpenAIRE

    Yong Yang; Song Tong; Shuying Huang; Pan Lin

    2014-01-01

    Multimodal medical image fusion is a powerful tool in clinical applications such as noninvasive diagnosis, image-guided radiotherapy, and treatment planning. In this paper, a novel nonsubsampled Contourlet transform (NSCT) based method for multimodal medical image fusion is presented, which is approximately shift invariant and can effectively suppress the pseudo-Gibbs phenomena. The source medical images are initially transformed by NSCT followed by fusing low- and high-frequency components. ...

  14. A joint estimation detection of Glaucoma progression in 3D spectral domain optical coherence tomography optic nerve head images.

    Science.gov (United States)

    Belghith, Akram; Bowd, Christopher; Weinreb, Robert N; Zangwill, Linda M

    2014-03-18

    Glaucoma is an ocular disease characterized by distinctive changes in the optic nerve head (ONH) and visual field. Glaucoma can strike without symptoms and causes blindness if it remains without treatment. Therefore, early disease detection is important so that treatment can be initiated and blindness prevented. In this context, important advances in technology for non-invasive imaging of the eye have been made providing quantitative tools to measure structural changes in ONH topography, an essential element for glaucoma detection and monitoring. 3D spectral domain optical coherence tomography (SD-OCT), an optical imaging technique, has been commonly used to discriminate glaucomatous from healthy subjects. In this paper, we present a new framework for detection of glaucoma progression using 3D SD-OCT images. In contrast to previous works that the retinal nerve fiber layer (RNFL) thickness measurement provided by commercially available spectral-domain optical coherence tomograph, we consider the whole 3D volume for change detection. To integrate a priori knowledge and in particular the spatial voxel dependency in the change detection map, we propose the use of the Markov Random Field to handle a such dependency. To accommodate the presence of false positive detection, the estimated change detection map is then used to classify a 3D SDOCT image into the "non-progressing" and "progressing" glaucoma classes, based on a fuzzy logic classifier. We compared the diagnostic performance of the proposed framework to existing methods of progression detection.

  15. A joint estimation detection of Glaucoma progression in 3D spectral domain optical coherence tomography optic nerve head images

    Science.gov (United States)

    Belghith, Akram; Bowd, Christopher; Weinreb, Robert N.; Zangwill, Linda M.

    2014-03-01

    Glaucoma is an ocular disease characterized by distinctive changes in the optic nerve head (ONH) and visual field. Glaucoma can strike without symptoms and causes blindness if it remains without treatment. Therefore, early disease detection is important so that treatment can be initiated and blindness prevented. In this context, important advances in technology for non-invasive imaging of the eye have been made providing quantitative tools to measure structural changes in ONH topography, an essential element for glaucoma detection and monitoring. 3D spectral domain optical coherence tomography (SD-OCT), an optical imaging technique, has been commonly used to discriminate glaucomatous from healthy subjects. In this paper, we present a new framework for detection of glaucoma progression using 3D SD-OCT images. In contrast to previous works that the retinal nerve fiber layer (RNFL) thickness measurement provided by commercially available spectral-domain optical coherence tomograph, we consider the whole 3D volume for change detection. To integrate a priori knowledge and in particular the spatial voxel dependency in the change detection map, we propose the use of the Markov Random Field to handle a such dependency. To accommodate the presence of false positive detection, the estimated change detection map is then used to classify a 3D SDOCT image into the "non-progressing" and "progressing" glaucoma classes, based on a fuzzy logic classifier. We compared the diagnostic performance of the proposed framework to existing methods of progression detection.

  16. Spatial Domain Watermarking Scheme for Colored Images Based on Log-average Luminance

    CERN Document Server

    Hussein, Jamal A

    2010-01-01

    In this paper a new watermarking scheme is presented based on log-average luminance. A colored-image is divided into blocks after converting the RGB colored image to YCbCr color space. A monochrome image of 1024 bytes is used as the watermark. To embed the watermark, 16 blocks of size 8X8 are selected and used to embed the watermark image into the original image. The selected blocks are chosen spirally (beginning form the center of the image) among the blocks that have log-average luminance higher than or equal the log-average luminance of the entire image. Each byte of the monochrome watermark is added by updating a luminance value of a pixel of the image. If the byte of the watermark image represented white color (255) a value is added to the image pixel luminance value, if it is black (0) the is subtracted from the luminance value. To extract the watermark, the selected blocks are chosen as the above, if the difference between the luminance value of the watermarked image pixel and the original image pixe...

  17. Medical Image Fusion Algorithm based on Local Average Energy-Motivated PCNN in NSCT Domain

    Directory of Open Access Journals (Sweden)

    Huda Ahmed

    2016-10-01

    Full Text Available Medical Image Fusion (MIF can improve the performance of medical diagnosis, treatment planning and image-guided surgery significantly through providing high-quality and rich-information medical images. Traditional MIF techniques suffer from common drawbacks such as: contrast reduction, edge blurring and image degradation. Pulse-coupled Neural Network (PCNN based MIF techniques outperform the traditional methods in providing high-quality fused images due to its global coupling and pulse synchronization property; however, the selection of significant features that motivate the PCNN is still an open problem and plays a major role in measuring the contribution of each source image into the fused image. In this paper, a medical image fusion algorithm is proposed based on the Non-subsampled Contourlet Transform (NSCT and the Pulse-Coupled Neural Network (PCNN to fuse images from different modalities. Local Average Energy is used to motivate the PCNN due to its ability to capture salient features of the image such as edges, contours and textures. The proposed approach produces a high quality fused image with high contrast and improved content in comparison with other image fusion techniques without loss of significant details on both levels: the visual and the quantitative.

  18. Finite-difference time-domain-based optical microscopy simulation of dispersive media facilitates the development of optical imaging techniques

    Science.gov (United States)

    Zhang, Di; Capoglu, Ilker; Li, Yue; Cherkezyan, Lusik; Chandler, John; Spicer, Graham; Subramanian, Hariharan; Taflove, Allen; Backman, Vadim

    2016-06-01

    Combining finite-difference time-domain (FDTD) methods and modeling of optical microscopy modalities, we previously developed an open-source software package called Angora, which is essentially a "microscope in a computer." However, the samples being simulated were limited to nondispersive media. Since media dispersions are common in biological samples (such as cells with staining and metallic biomarkers), we have further developed a module in Angora to simulate samples having complicated dispersion properties, thereby allowing the synthesis of microscope images of most biological samples. We first describe a method to integrate media dispersion into FDTD, and we validate the corresponding Angora dispersion module by applying Mie theory, as well as by experimentally imaging gold microspheres. Then, we demonstrate how Angora can facilitate the development of optical imaging techniques with a case study.

  19. A Sociological Approach to Institutional Communication: The Public Image in Organizational Administration in Education

    Science.gov (United States)

    Serpa, Sandro

    2016-01-01

    Acknowledging that the external context visibly affects any organization, this investigation seeks to constitute a specific contribution to the study of the importance of public image in organizational administration. To that end, a collection and documentary analysis of news stories from the newspaper "O Fayalense on the Asylum for the…

  20. Public Diplomacy Role in Russia Image Formation in the Countries of Asia and Latin America

    Directory of Open Access Journals (Sweden)

    I Y Glinskaya

    2010-06-01

    Full Text Available The article deals with the problem of creating positive image of Russia in the countries of Latin America and also in India and China - leading Asian countries. Alongside with the achievements in economic, political, military spheres the most important for successful reputation of the country is considered to be public diplomacy.

  1. A Secure and Semi-Blind Technique of Embedding Color Watermark in RGB Image Using Curvelet Domain

    Directory of Open Access Journals (Sweden)

    Ranjeeta

    2017-03-01

    Full Text Available A semi-blind and secure watermarking technique for the color image using curvelet domain has been proposed. To make the algorithm secure a Bijection mapping function has been used. The watermark also separated into color planes and each color plane into a bit planes. The most significant bit (MSB planes of each color used as the embedding information and remaining bit planes are used as a key at the time of extraction. The MSB planes of each color of watermark image embedded into the curvelet coefficients of the blue color plane of the processed cover image. For embedding the MSB bit planes of watermark image in the cover image each curvelet coefficient of blue planes of the processed cover image has been compared with the value of its 8 connected coefficients (neighbors. The results of the watermarking scheme have been analyzed by different quality assessment metric such as PSNR, Correlation Coefficient (CC and Mean Structure Similarity Index Measure (MSSIM. The experimental results show that the proposed technique gives the good invisibility of watermark, the quality of extracting watermark and robustness against different attacks.

  2. Enhancement of SAR images using fuzzy shrinkage technique in curvelet domain

    Indian Academy of Sciences (India)

    SHIVAKUMARA SWAMY PURANIK MATH; VANI KALIYAPERUMAL

    2017-09-01

    The synthetic aperture radar (SAR) images are mainly affected by speckle noise. Speckle degrades the features in the image and reduces the ability of a human observer to resolve fine detail, hence despeckling is very much required for SAR images. This paper presents speckle noise reduction in SAR images using a combination of curvelet and fuzzy logic technique to restore speckle-affected images. This method overcomes the limitation of discontinuity in hard threshold and permanent deviation in soft threshold. First, it decomposes noise image into different frequency scales using curvelet transform, and then applies the fuzzy shrinking technique to high-frequency coefficients to restore noise-contaminated coefficients. The proposed method does not use threshold approach only by proper selection of shrinking parameter the speckle in SAR image is suppressed. The experiment is carried out on different resolutions of RISAT-1 SAR images, and results are compared with the existing filtering algorithms in terms of noise mean variance (NMV), mean square difference (MSD), equal number of looks (ENL), noise standard deviation (NSD) and speckle suppression index (SSI). A comparison of the results shows that the proposed technique suppresses noise significantly, preserves the details of the image and improves the visual quality of the image

  3. Anatomical-functional image fusion by information of interest in local Laplacian filtering domain.

    Science.gov (United States)

    Du, Jiao; Li, Weisheng; Xiao, Bin

    2017-08-25

    A novel method for performing anatomical (MRI)-functional (PET or SPECT) image fusion is presented. The method merges specific feature information from input image signals of a single or multiple medical imaging modalities into a single fused image while preserving more information and generating less distortion. The proposed method uses a local Laplacian filtering based technique realized through a novel multi-scale system architecture. Firstly, the input images are generated in a multi-scale image representation and are processed using local Laplacian filtering. Secondly, at each scale, the decomposed images are combined to produce fused approximate images using a local energy maximum scheme and produce the fused residual images using an information of interest-based scheme. Finally, a fused image is obtained using a reconstruction process that is analogous to that of conventional Laplacian pyramid transform. Experimental results computed using individual multi-scale analysis-based decomposition schemes or fusion rules clearly demonstrate the superiority of the proposed method through subjective observation as well as objective metrics. Furthermore, the proposed method can obtain better performance, compared to the state-of-the-art fusion methods.

  4. Imaging lipid domains in cell membranes: the advent of super-resolution fluorescence microscopy

    Directory of Open Access Journals (Sweden)

    Dylan Myers Owen

    2013-12-01

    Full Text Available The lipid bilayer of model membranes, liposomes reconstituted from cell lipids, and plasma membrane vesicles and spheres can separate into two distinct liquid phases to yield lipid domains with liquid-ordered and liquid-disordered properties. These observations are the basis of the lipid raft hypothesis that postulates the existence of cholesterol-enriched ordered-phase lipid domains in cell membranes that could regulate protein mobility, localization and interaction. Here we review the evidence that nano-scaled lipid complexes and meso-scaled lipid domains exist in cell membranes and how new fluorescence microscopy techniques that overcome the diffraction limit provide new insights into lipid organization in cell membranes.

  5. The role of public relations for image creating in health services: a sample patient satisfaction survey.

    Science.gov (United States)

    Kirdar, YalçIn

    2007-01-01

    This study discusses the role of public relations for image creating in health services. Hospitals require public relations activities to distinguish them from competitors, provide bidirectional communication between the society and the hospital, and assist to create of a strong hospital image and culture. A satisfaction survey was conducted on 264 patients who have received health services at Maltepe University Hospital. The research focused on how the Hospital's examination, care, catering and physical services; doctor and nurse politeness towards patients and patient relatives, their attitudes and behaviors; examination, check-in, bedding and discharge operations; public relations activities in and out of the hospital were perceived. Another subject of the study was the degree of recommendation of patients who have been served by the hospital's health services to prospective patients seeking treatment.

  6. Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

    Science.gov (United States)

    Grzybowski, M. J.; Wadley, P.; Edmonds, K. W.; Beardsley, R.; Hills, V.; Campion, R. P.; Gallagher, B. L.; Chauhan, J. S.; Novak, V.; Jungwirth, T.; Maccherozzi, F.; Dhesi, S. S.

    2017-02-01

    The magnetic order in antiferromagnetic materials is hard to control with external magnetic fields. Using x-ray magnetic linear dichroism microscopy, we show that staggered effective fields generated by electrical current can induce modification of the antiferromagnetic domain structure in microdevices fabricated from a tetragonal CuMnAs thin film. A clear correlation between the average domain orientation and the anisotropy of the electrical resistance is demonstrated, with both showing reproducible switching in response to orthogonally applied current pulses. However, the behavior is inhomogeneous at the submicron level, highlighting the complex nature of the switching process in multidomain antiferromagnetic films.

  7. Estimating and modelling bias of the hierarchical partitioning public-domain software: implications in environmental management and conservation.

    Directory of Open Access Journals (Sweden)

    Pedro P Olea

    Full Text Available BACKGROUND: Hierarchical partitioning (HP is an analytical method of multiple regression that identifies the most likely causal factors while alleviating multicollinearity problems. Its use is increasing in ecology and conservation by its usefulness for complementing multiple regression analysis. A public-domain software "hier.part package" has been developed for running HP in R software. Its authors highlight a "minor rounding error" for hierarchies constructed from >9 variables, however potential bias by using this module has not yet been examined. Knowing this bias is pivotal because, for example, the ranking obtained in HP is being used as a criterion for establishing priorities of conservation. METHODOLOGY/PRINCIPAL FINDINGS: Using numerical simulations and two real examples, we assessed the robustness of this HP module in relation to the order the variables have in the analysis. Results indicated a considerable effect of the variable order on the amount of independent variance explained by predictors for models with >9 explanatory variables. For these models the nominal ranking of importance of the predictors changed with variable order, i.e. predictors declared important by its contribution in explaining the response variable frequently changed to be either most or less important with other variable orders. The probability of changing position of a variable was best explained by the difference in independent explanatory power between that variable and the previous one in the nominal ranking of importance. The lesser is this difference, the more likely is the change of position. CONCLUSIONS/SIGNIFICANCE: HP should be applied with caution when more than 9 explanatory variables are used to know ranking of covariate importance. The explained variance is not a useful parameter to use in models with more than 9 independent variables. The inconsistency in the results obtained by HP should be considered in future studies as well as in those

  8. Color image zero-watermarking based on SVD and visual cryptography in DWT domain

    Science.gov (United States)

    Liu, Xilin; Chen, Beijing; Coatrieux, Gouenou; Shu, Huazhong

    2017-02-01

    This paper presents a novel robust color image zero-watermarking scheme based on SVD and visual cryptography. We firstly generate the image feature from the SVD of the image blocks, and then employ the visual secret sharing scheme to construct ownership share from the watermark and the image feature. The low frequency component of one level discrete wavelet transform of the color image is partitioned into blocks. Then we propose to use the feature generated from the first singular value of the blocks to construct the master share. When ownership debate occurs, the ownership share is used to extract the watermark. Experimental results show the better performance of the proposed watermarking system in terms of robustness to various attacks, including noise, filtering, JPEG compression and so on, than other visual cryptography based color image watermarking algorithm.

  9. Domains of quality of life: results of a three-stage Delphi consensus procedure among patients, family of patients, clinicians, scientists and the general public.

    Science.gov (United States)

    Pietersma, Suzanne; de Vries, Marieke; van den Akker-van Marle, M Elske

    2014-06-01

    Our key objective is to identify the core domains of health-related quality of life (QoL). Health-related QoL utility scales are commonly used in economic evaluations to assess the effectiveness of health-care interventions. However, health-care interventions are likely to affect QoL in a broader sense than is quantifiable with traditional scales. Therefore, measures need to go beyond these scales. Unfortunately, there is no consensus in the scientific literature on the essential domains of QoL. We conducted a three-stage online Delphi consensus procedure to identify the key domains of health-related QoL. Five stakeholder groups (i.e., patients, family of patients, clinicians, scientists and general public) were asked, on three consecutive occasions, what they perceive as the most important domains of health-related QoL. An analysis of existing (health-related) QoL and well-being measurements formed the basis of the Delphi-procedure. In total, 42 domains of QoL were judged, covering physical, mental and social aspects. All participants rated 'self-acceptance', 'self-esteem' and 'good social contacts' as essential. Strikingly, mental and social domains are perceived as more essential than physical domains across stakeholders groups. In traditionally used health-related QoL utility measures, physical domains like 'mobility' are prominently present. The Delphi-procedure shows that health-related QoL (utility) scales need to put sufficient emphasis on mental and social domains to capture aspects of QoL that are essential to people.

  10. Imaging of room-temperature ferromagnetic nano-domains at the surface of a non-magnetic oxide

    Science.gov (United States)

    Taniuchi, T.; Motoyui, Y.; Morozumi, K.; Rödel, T. C.; Fortuna, F.; Santander-Syro, A. F.; Shin, S.

    2016-06-01

    Two-dimensional electron gases at oxide surfaces or interfaces show exotic ordered states of matter, like superconductivity, magnetism or spin-polarized states, and are a promising platform for alternative oxide-based electronics. Here we directly image a dense population of randomly distributed ferromagnetic domains of ~40 nm typical sizes at room temperature at the oxygen-deficient surface of SrTiO3, a non-magnetic transparent insulator in the bulk. We use laser-based photoemission electron microscopy, an experimental technique that gives selective spin detection of the surface carriers, even in bulk insulators, with a high spatial resolution of 2.6 nm. We furthermore find that the Curie temperature in this system is as high as 900 K. These findings open perspectives for applications in nano-domain magnetism and spintronics using oxide-based devices, for instance through the nano-engineering of oxygen vacancies at surfaces or interfaces of transition-metal oxides.

  11. CT and MR image fusion scheme in nonsubsampled contourlet transform domain.

    Science.gov (United States)

    Ganasala, Padma; Kumar, Vinod

    2014-06-01

    Fusion of CT and MR images allows simultaneous visualization of details of bony anatomy provided by CT image and details of soft tissue anatomy provided by MR image. This helps the radiologist for the precise diagnosis of disease and for more effective interventional treatment procedures. This paper aims at designing an effective CT and MR image fusion method. In the proposed method, first source images are decomposed by using nonsubsampled contourlet transform (NSCT) which is a shift-invariant, multiresolution and multidirection image decomposition transform. Maximum entropy of square of the coefficients with in a local window is used for low-frequency sub-band coefficient selection. Maximum weighted sum-modified Laplacian is used for high-frequency sub-bands coefficient selection. Finally fused image is obtained through inverse NSCT. CT and MR images of different cases have been used to test the proposed method and results are compared with those of the other conventional image fusion methods. Both visual analysis and quantitative evaluation of experimental results shows the superiority of proposed method as compared to other methods.

  12. Multifocus Image Fusion in Q-Shift DTCWT Domain Using Various Fusion Rules

    Directory of Open Access Journals (Sweden)

    Yingzhong Tian

    2016-01-01

    Full Text Available Multifocus image fusion is a process that integrates partially focused image sequence into a fused image which is focused everywhere, with multiple methods proposed in the past decades. The Dual Tree Complex Wavelet Transform (DTCWT is one of the most precise ones eliminating two main defects caused by the Discrete Wavelet Transform (DWT. Q-shift DTCWT was proposed afterwards to simplify the construction of filters in DTCWT, producing better fusion effects. A different image fusion strategy based on Q-shift DTCWT is presented in this work. According to the strategy, firstly, each image is decomposed into low and high frequency coefficients, which are, respectively, fused by using different rules, and then various fusion rules are innovatively combined in Q-shift DTCWT, such as the Neighborhood Variant Maximum Selectivity (NVMS and the Sum Modified Laplacian (SML. Finally, the fused coefficients could be well extracted from the source images and reconstructed to produce one fully focused image. This strategy is verified visually and quantitatively with several existing fusion methods based on a plenty of experiments and yields good results both on standard images and on microscopic images. Hence, we can draw the conclusion that the rule of NVMS is better than others after Q-shift DTCWT.

  13. An Improved Watermarking Algorithm to Colour Image Based on Wavelet Domain

    Directory of Open Access Journals (Sweden)

    Yinglan Fang

    2013-07-01

    Full Text Available This paper has brought forward an improved non-blind watermarking algorithm based on discrete wavelet transform. Watermarking applies special meaningful color image. Before embedded watermark, the algorithm requires needs the watermarking image and carrier image to separate color and transform discrete wavelet. Then the watermark’s low frequency sub-graph and high low sub-graph are respectively embedded into carrier image using additive watermark embedding rules and iterative mixed method. The experiment results have showed that the algorithm has good concealment and improve the robustness of the algorithm.

  14. A path algorithm for the support vector domain description and its application to medical imaging

    DEFF Research Database (Denmark)

    Sjöstrand, Karl; Hansen, Michael Sass; Larsson, Henrik B. W.

    2007-01-01

    The support vector domain description is a one-class classification method that estimates the distributional support of a data set. A flexible closed boundary function is used to separate trustworthy data on the inside from outliers on the outside. A single regularization parameter determines the...

  15. The analysis of frequency domain characteristics of emotional images in eye-tracking experiment

    Science.gov (United States)

    Fan, Boqiang; Ma, Huimin; Wang, Xiang

    2015-07-01

    Although recently eye-tracking method has been introduced into behavioral experiments based on dot-probe paradigm, some characteristics in eye-tracking data do not draw as much attention as traditional characteristics like reaction time. It is also necessary to associate eye-tracking data to characteristics of images shown in experiments. In this research, new variables, such as fixation length, times of fixation and times of eye movement, in eye-tracking data were extracted from a behavioral experiment based on dot probe paradigm. They were analyzed and compared to traditional reaction time. After the analysis of positive and negative scenery images, parameters such as hue frequency spectrum PAR (Peak to Average Ratio) were extracted and showed difference between negative and positive images. These parameters of emotional images could discriminate scenery images according to their emotions in an SVM classifier well. Besides, it was found that images' hue frequency spectrum PAR is obviously relevant to eye-tracking statistics. When the dot was on the negative side, negative images' hue frequency spectrum PAR and horizontal eye-jumps confirmed to hyperbolic distribution, while that of positive images was linear with horizontal eye-jumps. The result could help to explain the mechanism of human's attention and boost the study in computer vision.

  16. A sub-domain based regularization method with prior information for human thorax imaging using electrical impedance tomography

    Science.gov (United States)

    In Kang, Suk; Khambampati, Anil Kumar; Jeon, Min Ho; Kim, Bong Seok; Kim, Kyung Youn

    2016-02-01

    Electrical impedance tomography (EIT) is a non-invasive imaging technique that can be used as a bed-side monitoring tool for human thorax imaging. EIT has high temporal resolution characteristics but at the same time it suffers from poor spatial resolution due to ill-posedness of the inverse problem. Often regularization methods are used as a penalty term in the cost function to stabilize the sudden changes in resistivity. In human thorax monitoring, with conventional regularization methods employing Tikhonov type regularization, the reconstructed image is smoothed between the heart and the lungs, that is, it makes it difficult to distinguish the exact boundaries of the lungs and the heart. Sometimes, obtaining structural information of the object prior to this can be incorporated into the regularization method to improve the spatial resolution along with helping create clear and distinct boundaries between the objects. However, the boundary of the heart is changed rapidly due to the cardiac cycle hence there is no information concerning the exact boundary of the heart. Therefore, to improve the spatial resolution for human thorax monitoring during the cardiac cycle, in this paper, a sub-domain based regularization method is proposed assuming the lungs and part of background region is known. In the proposed method, the regularization matrix is modified anisotropically to include sub-domains as prior information, and the regularization parameter is assigned with different weights to each sub-domain. Numerical simulations and phantom experiments for 2D human thorax monitoring are performed to evaluate the performance of the proposed regularization method. The results show a better reconstruction performance with the proposed regularization method.

  17. Site-specific labeling of cysteine-tagged camelid single-domain antibody-fragments for use in molecular imaging.

    Science.gov (United States)

    Massa, Sam; Xavier, Catarina; De Vos, Jens; Caveliers, Vicky; Lahoutte, Tony; Muyldermans, Serge; Devoogdt, Nick

    2014-05-21

    Site-specific labeling of molecular imaging probes allows the development of a homogeneous tracer population. The resulting batch-to-batch reproducible pharmacokinetic and pharmacodynamic properties are of great importance for clinical translation. Camelid single-domain antibody-fragments (sdAbs)-the recombinantly produced antigen-binding domains of heavy-chain antibodies, also called Nanobodies-are proficient probes for molecular imaging. To safeguard their intrinsically high binding specificity and affinity and to ensure the tracer's homogeneity, we developed a generic strategy for the site-specific labeling of sdAbs via a thio-ether bond. The unpaired cysteine was introduced at the carboxyl-terminal end of the sdAb to eliminate the risk of antigen binding interference. The spontaneous dimerization and capping of the unpaired cysteine required a reduction step prior to conjugation. This was optimized with the mild reducing agent 2-mercaptoethylamine in order to preserve the domain's stability. As a proof-of-concept the reduced probe was subsequently conjugated to maleimide-DTPA, for labeling with indium-111. A single conjugated tracer was obtained and confirmed via mass spectrometry. The specificity and affinity of the new sdAb-based imaging probe was validated in a mouse xenograft tumor model using a modified clinical lead compound targeting the human epidermal growth factor receptor 2 (HER2) cancer biomarker. These data provide a versatile and standardized strategy for the site-specific labeling of sdAbs. The conjugation to the unpaired cysteine results in the production of a homogeneous group of tracers and is a multimodal alternative to the technetium-99m labeling of sdAbs.

  18. Throughput increase of the covert communication channel organized by the stable steganography algorithm using spatial domain of the image

    Directory of Open Access Journals (Sweden)

    O.V. Kostyrka

    2016-09-01

    Full Text Available At the organization of a covert communication channel a number of requirements are imposed on used steganography algorithms among which one of the main are: resistance to attacks against the built-in message, reliability of perception of formed steganography message, significant throughput of a steganography communication channel. Aim: The aim of this research is to modify the steganography method, developed by the author earlier, which will allow to increase the throughput of the corresponding covert communication channel when saving resistance to attacks against the built-in message and perception reliability of the created steganography message, inherent to developed method. Materials and Methods: Modifications of a steganography method that is steady against attacks against the built-in message which is carrying out the inclusion and decoding of the sent (additional information in spatial domain of the image allowing to increase the throughput of the organized communication channel are offered. Use of spatial domain of the image allows to avoid accumulation of an additional computational error during the inclusion/decoding of additional information due to “transitions” from spatial domain of the image to the area of conversion and back that positively affects the efficiency of decoding. Such methods are considered as attacks against the built-in message: imposing of different noise on a steganography message, filtering, lossy compression of a ste-ganography message where the JPEG and JPEG2000 formats with different quality coefficients for saving of a steganography message are used. Results: It is shown that algorithmic implementations of the offered methods modifications remain steady against the perturbing influences, including considerable, provide reliability of perception of the created steganography message, increase the throughput of the created steganography communication channel in comparison with the algorithm implementing

  19. Images of eyes enhance investments in a real-life public good.

    Directory of Open Access Journals (Sweden)

    Damien Francey

    Full Text Available A key issue in cooperation research is to determine the conditions under which individuals invest in a public good. Here, we tested whether cues of being watched increase investments in an anonymous public good situation in real life. We examined whether individuals would invest more by removing experimentally placed garbage (paper and plastic bottles from bus stop benches in Geneva in the presence of images of eyes compared to controls (images of flowers. We provided separate bins for each of both types of garbage to investigate whether individuals would deposit more items into the appropriate bin in the presence of eyes. The treatment had no effect on the likelihood that individuals present at the bus stop would remove garbage. However, those individuals that engaged in garbage clearing, and were thus likely affected by the treatment, invested more time to do so in the presence of eyes. Images of eyes had a direct effect on behaviour, rather than merely enhancing attention towards a symbolic sign requesting removal of garbage. These findings show that simple images of eyes can trigger reputational effects that significantly enhance on non-monetary investments in anonymous public goods under real life conditions. We discuss our results in the light of previous findings and suggest that human social behaviour may often be shaped by relatively simple and potentially unconscious mechanisms instead of very complex cognitive capacities.

  20. MEO based secured, robust, high capacity and perceptual quality image watermarking in DWT-SVD domain.

    Science.gov (United States)

    Gunjal, Baisa L; Mali, Suresh N

    2015-01-01

    The aim of this paper is to present multiobjective evolutionary optimizer (MEO) based highly secured and strongly robust image watermarking technique using discrete wavelet transform (DWT) and singular value decomposition (SVD). Many researchers have failed to achieve optimization of perceptual quality and robustness with high capacity watermark embedding. Here, we achieved optimized peak signal to noise ratio (PSNR) and normalized correlation (NC) using MEO. Strong security is implemented through eight different security levels including watermark scrambling by Fibonacci-Lucas transformation (FLT). Haar wavelet is selected for DWT decomposition to compare practical performance of wavelets from different wavelet families. The technique is non-blind and tested with cover images of size 512x512 and grey scale watermark of size 256x256. The achieved perceptual quality in terms of PSNR is 79.8611dBs for Lena, 87.8446 dBs for peppers and 93.2853 dBs for lake images by varying scale factor K1 from 1 to 5. All candidate images used for testing namely Lena, peppers and lake images show exact recovery of watermark giving NC equals to 1. The robustness is tested against variety of attacks on watermarked image. The experimental demonstration proved that proposed method gives NC more than 0.96 for majority of attacks under consideration. The performance evaluation of this technique is found superior to all existing hybrid image watermarking techniques under consideration.

  1. Enhancing contrast and quantitation by spatial frequency domain fluorescence molecular imaging

    Science.gov (United States)

    Sun, Jessica; Hathi, Deep; Zhou, Haiying; Shokeen, Monica; Akers, Walter J.

    2016-03-01

    Optical imaging with fluorescent contrast agents is highly sensitive for molecular imaging but is limited in depth to a few centimeters below the skin. Planar fluorescence imaging with full-field, uniform illumination and scientific camera image capture provides a portable and robust configuration for real-time, sensitive fluorescence detection with scalable resolution, but is inherently surface weighted and therefore limited in depth to a few millimeters. At the NIR region (700-1000 nm), tissue absorption and autofluorescence are relatively reduced, increasing depth penetration and reducing background signal, respectively. Optical imaging resolution scales with depth, limiting microscopic resolution with multiphoton microscopy and optical coherence tomography to skin and peri-tumoral tissues are not uniform, varying in thickness and color, complicating subsurface fluorescence measurements. Diffuse optical imaging methods have been developed that better quantify optical signals relative to faster full-field planar reflectance imaging, but require long scan times, complex instrumentation, and reconstruction algorithms. Here we report a novel strategy for rapid measurement of subsurface fluorescence using structured light illumination to improve quantitation of deep-seated fluorescence molecular probe accumulation. This technique, in combination with highly specific, tumor-avid fluorescent molecular probes, will easily integrate noninvasive diagnostics for superficial cancers and fluorescence guided surgery.

  2. Log-Gabor energy based multimodal medical image fusion in NSCT domain.

    Science.gov (United States)

    Yang, Yong; Tong, Song; Huang, Shuying; Lin, Pan

    2014-01-01

    Multimodal medical image fusion is a powerful tool in clinical applications such as noninvasive diagnosis, image-guided radiotherapy, and treatment planning. In this paper, a novel nonsubsampled Contourlet transform (NSCT) based method for multimodal medical image fusion is presented, which is approximately shift invariant and can effectively suppress the pseudo-Gibbs phenomena. The source medical images are initially transformed by NSCT followed by fusing low- and high-frequency components. The phase congruency that can provide a contrast and brightness-invariant representation is applied to fuse low-frequency coefficients, whereas the Log-Gabor energy that can efficiently determine the frequency coefficients from the clear and detail parts is employed to fuse the high-frequency coefficients. The proposed fusion method has been compared with the discrete wavelet transform (DWT), the fast discrete curvelet transform (FDCT), and the dual tree complex wavelet transform (DTCWT) based image fusion methods and other NSCT-based methods. Visually and quantitatively experimental results indicate that the proposed fusion method can obtain more effective and accurate fusion results of multimodal medical images than other algorithms. Further, the applicability of the proposed method has been testified by carrying out a clinical example on a woman affected with recurrent tumor images.

  3. Log-Gabor Energy Based Multimodal Medical Image Fusion in NSCT Domain

    Directory of Open Access Journals (Sweden)

    Yong Yang

    2014-01-01

    Full Text Available Multimodal medical image fusion is a powerful tool in clinical applications such as noninvasive diagnosis, image-guided radiotherapy, and treatment planning. In this paper, a novel nonsubsampled Contourlet transform (NSCT based method for multimodal medical image fusion is presented, which is approximately shift invariant and can effectively suppress the pseudo-Gibbs phenomena. The source medical images are initially transformed by NSCT followed by fusing low- and high-frequency components. The phase congruency that can provide a contrast and brightness-invariant representation is applied to fuse low-frequency coefficients, whereas the Log-Gabor energy that can efficiently determine the frequency coefficients from the clear and detail parts is employed to fuse the high-frequency coefficients. The proposed fusion method has been compared with the discrete wavelet transform (DWT, the fast discrete curvelet transform (FDCT, and the dual tree complex wavelet transform (DTCWT based image fusion methods and other NSCT-based methods. Visually and quantitatively experimental results indicate that the proposed fusion method can obtain more effective and accurate fusion results of multimodal medical images than other algorithms. Further, the applicability of the proposed method has been testified by carrying out a clinical example on a woman affected with recurrent tumor images.

  4. A New Public-key Oblivious Fragile Watermarking for Image Authentication Using Discrete Cosine Transform

    Directory of Open Access Journals (Sweden)

    Chin-Chen Chang

    2009-03-01

    Full Text Available In this paper, a new oblivious fragile watermarking using discrete cosine transform is proposed. It is inspired by Wong's public key watermarking scheme proposed in 1998 and aims to improve its vulnerability towards possible attacks indicated by Barreto and Holliman. Instead of making use of contextual information and making it an inter-block dependent scheme, as suggested by Barreto, we adopt another approach to retain its blockwise independent property. Our scheme can avoid the conditions necessary for such attacks to befeasible. Furthermore, our scheme extracts the inherent image features and embeds them into this image as the watermark. This relieves users from having to maintain a database of watermarks from various sources. Experimental results show that the watermark insertion procedure has little effect on the visual quality of the watermarked image. They also show our scheme can locate the modifications made to the watermarked image, including imagescaling, cropping, geometric distortion, pixel value changes, etc.

  5. New insights into the coronary artery bifurcation hypothesis-generating concepts utilizing 3-dimensional optical frequency domain imaging.

    Science.gov (United States)

    Farooq, Vasim; Serruys, Patrick W; Heo, Jung Ho; Gogas, Bill D; Okamura, Takayuki; Gomez-Lara, Josep; Brugaletta, Salvatore; Garcìa-Garcìa, Hector M; van Geuns, Robert Jan

    2011-08-01

    Coronary artery bifurcations are a common challenging lesion subset accounting for approximately 10% to 20% of all percutaneous coronary interventions. The provisional T-stenting approach is generally recommended as the first-line management of most lesions. Carina shift is suggested to be the predominant mechanism of side-branch pinching during provisional T-stenting and has been indirectly inferred from bench work and other intravascular imaging modalities. Offline 3-dimensional (3D) reconstructions of patients studied in the first-in-man trial of the high-frequency (160 frames/s) Terumo optical frequency domain imaging system were undertaken using volume-rendering software. Through a series of 3D reconstructions, several novel hypothesis-generating concepts are presented.

  6. Domain wall velocity measurement in permalloy nanowires with X-ray magnetic circular dichroism imaging and single shot Kerr microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Moore, T.A., E-mail: t.a.moore@physics.or [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Klaeui, M.; Heyne, L.; Moehrke, P. [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Backes, D.; Rhensius, J. [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Ruediger, U. [Fachbereich Physik, Universitaet Konstanz, Universitaetsstrasse 10, 78457 Konstanz (Germany); Heyderman, L.J. [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Mentes, T.O.; Nino, M.A.; Locatelli, A. [Sincrotrone Trieste, 34012 Basovizza-Trieste (Italy); Potenza, A.; Marchetto, H.; Cavill, S.; Dhesi, S.S. [Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot, Oxfordshire, OX11 0DE (United Kingdom)

    2010-05-15

    Domain walls (DWs) propagated along nanoscale magnetic wires by current or field pulses could potentially be used for data storage or logic applications, but the understanding of the DW dynamics, particularly under the influence of spin-polarized current, is incomplete. Measuring the velocity can give insights into the physics of the DW motion. Here we demonstrate DW velocity measurements in permalloy (Ni{sub 80}Fe{sub 20}) nanowires (1500 nm width and 20 nm thickness) using the techniques of X-ray magnetic circular dichroism photoemission electron microscopy (XMCD-PEEM) to image the magnetic contrast in the nanowires, and single shot Kerr microscopy, which allows for dynamic measurements. The magnetic imaging yields the average velocity as well as information on the DW spin structure, whereas the single shot method highlights the stochastic nature of the DW motion.

  7. Experimental Study of High-Range-Resolution Medical Acoustic Imaging for Multiple Target Detection by Frequency Domain Interferometry

    Science.gov (United States)

    Kimura, Tomoki; Taki, Hirofumi; Sakamoto, Takuya; Sato, Toru

    2009-07-01

    We employed frequency domain interferometry (FDI) for use as a medical acoustic imager to detect multiple targets with high range resolution. The phase of each frequency component of an echo varies with the frequency, and target intervals can be estimated from the phase variance. This processing technique is generally used in radar imaging. When the interference within a range gate is coherent, the cross correlation between the desired signal and the coherent interference signal is nonzero. The Capon method works under the guiding principle that output power minimization cancels the desired signal with a coherent interference signal. Therefore, we utilize frequency averaging to suppress the correlation of the coherent interference. The results of computational simulations using a pseudoecho signal show that the Capon method with adaptive frequency averaging (AFA) provides a higher range resolution than a conventional method. These techniques were experimentally investigated and we confirmed the effectiveness of the proposed method of processing by FDI.

  8. PUBLICITÉ, ICONICITÉ, VERBALISATION DE L’IMAGE / PUBLICITY, ICONICITY, IMAGE VERBALIZATION / PUBLICITATE, ICONICITATE, VERBALIZAREA IMAGINII

    Directory of Open Access Journals (Sweden)

    Maria Ana Oprescu

    2013-11-01

    Full Text Available Structure sémiologique mixte, la publicité écrite se fonde sur un double système, iconique et verbal. Les différents niveaux s’interpénètrent et se confondent. Les signes linguistiques du texte publicitaire sont en étroite relation de dépendance avec les signes iconiques de l’image. Le sens est le résultat d’une amalgamation recherchée des deux niveaux de lecture. Le texte et l’image ne jouent pas le même rôle et n’ont pas le même poids au sein de l’annonce.

  9. Direct Nanoscale Imaging of Evolving Electric Field Domains in Quantum Structures

    Science.gov (United States)

    Dhar, Rudra Sankar; Razavipour, Seyed Ghasem; Dupont, Emmanuel; Xu, Chao; Laframboise, Sylvain; Wasilewski, Zbig; Hu, Qing; Ban, Dayan

    2014-01-01

    The external performance of quantum optoelectronic devices is governed by the spatial profiles of electrons and potentials within the active regions of these devices. For example, in quantum cascade lasers (QCLs), the electric field domain (EFD) hypothesis posits that the potential distribution might be simultaneously spatially nonuniform and temporally unstable. Unfortunately, there exists no prior means of probing the inner potential profile directly. Here we report the nanoscale measured electric potential distribution inside operating QCLs by using scanning voltage microscopy at a cryogenic temperature. We prove that, per the EFD hypothesis, the multi-quantum-well active region is indeed divided into multiple sections having distinctly different electric fields. The electric field across these serially-stacked quantum cascade modules does not continuously increase in proportion to gradual increases in the applied device bias, but rather hops between discrete values that are related to tunneling resonances. We also report the evolution of EFDs, finding that an incremental change in device bias leads to a hopping-style shift in the EFD boundary – the higher electric field domain expands at least one module each step at the expense of the lower field domain within the active region. PMID:25431158

  10. [Images of Ageing in Health Care Magazines of the Public Health System].

    Science.gov (United States)

    Hartmann-Tews, Ilse; Hoppe, Theresa

    2017-05-18

    Objectives Collective images of ageing influence attitudes towards ageing and health- related activities. The aim of this study was to explore images of ageing and old age in magazines published by public health institutions, namely health insurance companies and pharmacies. Design A standardized content analysis was conducted covering age-related articles (n=146) and accompanying photographs (n=218) of public health institutions. The stock of material comprises age-related articles of all magazines published 2012-2013 of 2 public health insurance companies (Allgemeine Ortskrankenkasse: "Bleib gesund", Barmer Ersatzkasse: "Gesundheit konkret"), 2 private health insurance companies (Gothaer Versicherung: "Gothaer magazin", Deutsche Krankenversicherung: "DKV impulse") and 2 consumer magazines of pharmacies ("Apothekenumschau","Senioren Ratgeber"). Results Illness turns out to be the most often focused main theme and key issue of age-related articles. With reference to the central dimensions of somatic culture - health, body-centered performance and appearance - most of the articles focus on deficits of old age, in particular illness and decrease of performance, and thus communicate a negative image of ageing. The visual presentation of elderly people is much more positive. There are various differences in the communication of images of ageing between the 2 types of magazines, with the consumer magazines of the pharmacy covering a broader spectrum of topics, referring more often to a healthy lifestyle and prevention and communicating a more multifaceted image of old age and ageing in comparison to the membership magazines of health insurance companies. Conclusion Institutions of public health have many duties and responsibilities. One of these is to strengthen health competencies and locus of control of the population - in our case - elderly people. As images of ageing influence attitudes towards ageing and health-related activities, it seems to be sensible and of

  11. Combining textual and visual information for image retrieval in the medical domain.

    Science.gov (United States)

    Gkoufas, Yiannis; Morou, Anna; Kalamboukis, Theodore

    2011-01-01

    In this article we have assembled the experience obtained from our participation in the imageCLEF evaluation task over the past two years. Exploitation on the use of linear combinations for image retrieval has been attempted by combining visual and textual sources of images. From our experiments we conclude that a mixed retrieval technique that applies both textual and visual retrieval in an interchangeably repeated manner improves the performance while overcoming the scalability limitations of visual retrieval. In particular, the mean average precision (MAP) has increased from 0.01 to 0.15 and 0.087 for 2009 and 2010 data, respectively, when content-based image retrieval (CBIR) is performed on the top 1000 results from textual retrieval based on natural language processing (NLP).

  12. Blind image watermarking technique based on differential embedding in DWT and DCT domains

    Science.gov (United States)

    Benoraira, Ali; Benmahammed, Khier; Boucenna, Noureddine

    2015-12-01

    This paper presents a new blind and robust image watermarking scheme based on discrete wavelet transform (DWT) and discrete cosine transform (DCT). Two DCT-transformed sub-vectors are used to embed the bits of the watermark sequence in a differential manner. The original sub-vectors are obtained by the sub-sampling of the approximation coefficients of the DWT transform of the host image. During the extraction stage, the simple difference between the corresponding sub-vectors of the watermarked image, gives directly the embedded watermark sequence. Experimental results demonstrate that the proposed technique successfully fulfills the requirement of imperceptibility and provides high robustness against a number of image-processing attacks, such as JPEG compression, noise adding, low-pass filtering, sharpening, and bit-plane removal. Our scheme exhibits also an acceptable to good performance against some geometrical attacks such as resizing and cropping.

  13. Non-Blind Image Watermarking Scheme using DWT-SVD Domain

    OpenAIRE

    M. Devapriya; K. Ramar

    2010-01-01

    Digital watermarking scheme has been well accepted method for hiding the data into a host image. Digital watermarking can applied to a variety of fields like text, image, audio, video and software. Lot of tools has been established in order to duplicate and modify the multimedia data. Therefore security is the most important dispute that requires some mechanism to protect the digital multimedia data. In order to protect those multimedia data on the Internet many techniques are available inclu...

  14. IMAGE STEGANOGRAPHY BASED ON TRANSFORM DOMAIN, BLOWFISH AND AES FOR SECOND LEVEL SECURITY

    Directory of Open Access Journals (Sweden)

    Janki Gajjar

    2015-10-01

    Full Text Available Steganography is technique for secret communication. It hides the existence of the communication between parties. So viewer cannot detect the existence of the message and also not detect the communication channel. So attacker cannot modify and see the secret information. In image steganography, secrecy is accomplished by hide the secret message in cover image using steganography techniques. There are different types of steganography techniques each have their merits and demerits. Using Steganography techniques on cover image we can improve the security and robustness. For improving second level security we are using cryptography. Cryptography is used to convert the secret message in cipher text means unreadable form of message. Cryptography introduces many algorithms. This algorithm converts the secret message in cipher text. In our proposed method we are using Blowfish and AES algorithm for converting the message in cipher text and then hide this cipher text in cover image using DCT steganography technique. Using this combine technique we can get the stego-image. Here using this proposed method we can get the security and robustness in terms of message when we retrieve the message from the stego-image.

  15. Live cell imaging with protein domains capable of recognizing phosphatidylinositol 4,5-bisphosphate; a comparative study

    Directory of Open Access Journals (Sweden)

    Lemmon Mark A

    2009-09-01

    Full Text Available Abstract Background Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5P2] is a critically important regulatory phospholipid found in the plasma membrane of all eukaryotic cells. In addition to being a precursor of important second messengers, PtdIns(4,5P2 also regulates ion channels and transporters and serves the endocytic machinery by recruiting clathrin adaptor proteins. Visualization of the localization and dynamic changes in PtdIns(4,5P2 levels in living cells is critical to understanding the biology of PtdIns(4,5P2. This has been mostly achieved with the use of the pleckstrin homology (PH domain of PLCδ1 fused to GFP. Here we report on a comparative analysis of several recently-described yeast PH domains as well as the mammalian Tubby domain to evaluate their usefulness as PtdIns(4,5P2 imaging tools. Results All of the yeast PH domains that have been previously shown to bind PtdIns(4,5P2 showed plasma membrane localization but only a subset responded to manipulations of plasma membrane PtdIns(4,5P2. None of these domains showed any advantage over the PLCδ1PH-GFP reporter and were compromised either in their expression levels, nuclear localization or by causing peculiar membrane structures. In contrast, the Tubby domain showed high membrane localization consistent with PtdIns(4,5P2 binding and displayed no affinity for the soluble headgroup, Ins(1,4,5P3. Detailed comparison of the Tubby and PLCδ1PH domains showed that the Tubby domain has a higher affinity for membrane PtdIns(4,5P2 and therefore displays a lower sensitivity to report on changes of this lipid during phospholipase C activation. Conclusion These results showed that both the PLCδ1PH-GFP and the GFP-Tubby domain are useful reporters of PtdIns(4,5P2 changes in the plasma membrane, with distinct advantages and disadvantages. While the PLCδ1PH-GFP is a more sensitive reporter, its Ins(1,4,5P3 binding may compromise its accuracy to measure PtdIns(4,5P2changes. The Tubby domain

  16. Nonlinear image encryption using a fully phase nonzero-order joint transform correlator in the Gyrator domain

    Science.gov (United States)

    Vilardy, Juan M.; Millán, María S.; Pérez-Cabré, Elisabet

    2017-02-01

    A novel nonlinear image encryption scheme based on a fully phase nonzero-order joint transform correlator architecture (JTC) in the Gyrator domain (GD) is proposed. In this encryption scheme, the two non-overlapping data distributions of the input plane of the JTC are fully encoded in phase and this input plane is transformed using the Gyrator transform (GT); the intensity distribution captured in the GD represents a new definition of the joint Gyrator power distribution (JGPD). The JGPD is modified by two nonlinear operations with the purpose of retrieving the encrypted image, with enhancement of the decrypted signal quality and improvement of the overall security. There are three keys used in the encryption scheme, two random phase masks and the rotation angle of the GT, which are all necessary for a proper decryption. Decryption is highly sensitivity to changes of the rotation angle of the GT as well as to little changes in other parameters or keys. The proposed encryption scheme in the GD still preserves the shift-invariance properties originated in the JTC-based encryption in the Fourier domain. The proposed encryption scheme is more resistant to brute force attacks, chosen-plaintext attacks, known-plaintext attacks, and ciphertext-only attacks, as they have been introduced in the cryptanalysis of the JTC-based encryption system. Numerical results are presented and discussed in order to verify and analyze the feasibility and validity of the novel encryption-decryption scheme.

  17. History of Mexican Easel Paintings from an Altarpiece Revealed by Non-invasive Terahertz Time-Domain Imaging

    Science.gov (United States)

    Gomez-Sepulveda, A. M.; Hernandez-Serrano, A. I.; Radpour, R.; Koch-Dandolo, C. L.; Rojas-Landeros, S. C.; Ascencio-Rojas, L. F.; Zarate, Alvaro; Hernandez, Gerardo; Gonzalez-Tirado, R. C.; Insaurralde-Caballero, M.; Castro-Camus, E.

    2016-12-01

    Four easel paintings attributed to Hermenegildo Bustos (Purísima del Rincón, Guanajuato, Mexico), one of the most renowned painters of the late nineteenth and early twentieth century Mexican art, have been investigated by means of terahertz time-domain imaging (THz-TDI) and standard imaging techniques, such as near-IR reflectography and X-ray radiography. The archival sources and the recent studies on the paintings suggest that the artworks were created in the eighteenth century and underwent several modifications since then until the intervention of Bustos who authored the currently visible depictions. By combining the records of the paintings obtained by imaging with the different methodologies, aspects of the previous depictions and further details on the paintings' history have been revealed, with THz-TDI playing a key role in attributing a chronological evolution of the images. The paintings of Purísima are the first THz-TDI-scanned paintings belonging to the Mexican cultural heritage.

  18. History of Mexican Easel Paintings from an Altarpiece Revealed by Non-invasive Terahertz Time-Domain Imaging

    Science.gov (United States)

    Gomez-Sepulveda, A. M.; Hernandez-Serrano, A. I.; Radpour, R.; Koch-Dandolo, C. L.; Rojas-Landeros, S. C.; Ascencio-Rojas, L. F.; Zarate, Alvaro; Hernandez, Gerardo; Gonzalez-Tirado, R. C.; Insaurralde-Caballero, M.; Castro-Camus, E.

    2017-04-01

    Four easel paintings attributed to Hermenegildo Bustos ( Purísima del Rincón, Guanajuato, Mexico), one of the most renowned painters of the late nineteenth and early twentieth century Mexican art, have been investigated by means of terahertz time-domain imaging (THz-TDI) and standard imaging techniques, such as near-IR reflectography and X-ray radiography. The archival sources and the recent studies on the paintings suggest that the artworks were created in the eighteenth century and underwent several modifications since then until the intervention of Bustos who authored the currently visible depictions. By combining the records of the paintings obtained by imaging with the different methodologies, aspects of the previous depictions and further details on the paintings' history have been revealed, with THz-TDI playing a key role in attributing a chronological evolution of the images. The paintings of Purísima are the first THz-TDI-scanned paintings belonging to the Mexican cultural heritage.

  19. Danish dentists' career satisfaction in relation to perceived occupational stress and public image

    DEFF Research Database (Denmark)

    Moore, R.

    2000-01-01

    The relationship between Danish dentists' perceptions of satisfaction with their career choice and beliefs about their occupational stress or public image was surveyed. A mailed questionnaire was completed by 216 randomly selected Danish private dentists in and around Århus. Of these, only 19% were...... dissatisfied and would not recommend dentistry as a career to young people, while almost 60% perceived dentistry as more stressful than other professions and 31% felt that dentists' public image was less than good or poor. Odds ratio (OR) analyses indicated that perceived career dissatisfaction was most...... slight improvement only in the association with age. There were no meaningful or significant relationships by gender or practice type, location or size. Considering these statistics and that nearly all the dentists believed that patients evaluated them more by style or behavior than their technical...

  20. Multispectral medical image fusion in Contourlet domain for computer based diagnosis of Alzheimer's disease

    Science.gov (United States)

    Bhateja, Vikrant; Moin, Aisha; Srivastava, Anuja; Bao, Le Nguyen; Lay-Ekuakille, Aimé; Le, Dac-Nhuong

    2016-07-01

    Computer based diagnosis of Alzheimer's disease can be performed by dint of the analysis of the functional and structural changes in the brain. Multispectral image fusion deliberates upon fusion of the complementary information while discarding the surplus information to achieve a solitary image which encloses both spatial and spectral details. This paper presents a Non-Sub-sampled Contourlet Transform (NSCT) based multispectral image fusion model for computer-aided diagnosis of Alzheimer's disease. The proposed fusion methodology involves color transformation of the input multispectral image. The multispectral image in YIQ color space is decomposed using NSCT followed by dimensionality reduction using modified Principal Component Analysis algorithm on the low frequency coefficients. Further, the high frequency coefficients are enhanced using non-linear enhancement function. Two different fusion rules are then applied to the low-pass and high-pass sub-bands: Phase congruency is applied to low frequency coefficients and a combination of directive contrast and normalized Shannon entropy is applied to high frequency coefficients. The superiority of the fusion response is depicted by the comparisons made with the other state-of-the-art fusion approaches (in terms of various fusion metrics).

  1. Blind image quality assessment: a natural scene statistics approach in the DCT domain.

    Science.gov (United States)

    Saad, Michele A; Bovik, Alan C; Charrier, Christophe

    2012-08-01

    We develop an efficient, general-purpose, blind/noreference image quality assessment (NR-IQA) algorithm using a natural scene statistics (NSS) model of discrete cosine transform (DCT) coefficients. The algorithm is computationally appealing, given the availability of platforms optimized for DCT computation. The approach relies on a simple Bayesian inference model to predict image quality scores given certain extracted features. The features are based on an NSS model of the image DCT coefficients. The estimated parameters of the model are utilized to form features that are indicative of perceptual quality. These features are used in a simple Bayesian inference approach to predict quality scores. The resulting algorithm, which we name BLIINDS-II, requires minimal training and adopts a simple probabilistic model for score prediction. Given the extracted features from a test image, the quality score that maximizes the probability of the empirically determined inference model is chosen as the predicted quality score of that image. When tested on the LIVE IQA database, BLIINDS-II is shown to correlate highly with human judgments of quality, at a level that is competitive with the popular SSIM index.

  2. Wide-azimuth angle-domain imaging for anisotropic reverse-time migration

    KAUST Repository

    Sava, Paul C.

    2011-01-01

    Extended common-image-point gathers (CIP) constructed by wide-azimuth TI wave-equation migration contain all the necessary information for angle decomposition as a function of the reflection and azimuth angles at selected locations in the subsurface. The reflection and azimuth angles are derived from the extended images using analytic relations between the space-lag and time-lag extensions. This post-imaging decomposition requires only information which is already available at the time of migration, i.e. the model parameters and the tilt angles of the TI medium. The transformation amounts to a linear Radon transform applied to the CIPs obtained after the application of the extended imaging condition. If information about the reflector dip is available at the CIP locations, then only two components of the space-lag vectors are required, thus reducing computational cost and increasing the affordability of the method. This efficient angle decomposition method is suitable for wide-azimuth imaging in anisotropic media with arbitrary orientation of the symmetry plane. © 2011 Society of Exploration Geophysicists.

  3. Multispectral medical image fusion in Contourlet domain for computer based diagnosis of Alzheimer’s disease

    Energy Technology Data Exchange (ETDEWEB)

    Bhateja, Vikrant, E-mail: bhateja.vikrant@gmail.com, E-mail: nhuongld@hus.edu.vn; Moin, Aisha; Srivastava, Anuja [Shri Ramswaroop Memorial Group of Professional Colleges (SRMGPC), Lucknow, Uttar Pradesh 226028 (India); Bao, Le Nguyen [Duytan University, Danang 550000 (Viet Nam); Lay-Ekuakille, Aimé [Department of Innovation Engineering, University of Salento, Lecce 73100 (Italy); Le, Dac-Nhuong, E-mail: bhateja.vikrant@gmail.com, E-mail: nhuongld@hus.edu.vn [Duytan University, Danang 550000 (Viet Nam); Haiphong University, Haiphong 180000 (Viet Nam)

    2016-07-15

    Computer based diagnosis of Alzheimer’s disease can be performed by dint of the analysis of the functional and structural changes in the brain. Multispectral image fusion deliberates upon fusion of the complementary information while discarding the surplus information to achieve a solitary image which encloses both spatial and spectral details. This paper presents a Non-Sub-sampled Contourlet Transform (NSCT) based multispectral image fusion model for computer-aided diagnosis of Alzheimer’s disease. The proposed fusion methodology involves color transformation of the input multispectral image. The multispectral image in YIQ color space is decomposed using NSCT followed by dimensionality reduction using modified Principal Component Analysis algorithm on the low frequency coefficients. Further, the high frequency coefficients are enhanced using non-linear enhancement function. Two different fusion rules are then applied to the low-pass and high-pass sub-bands: Phase congruency is applied to low frequency coefficients and a combination of directive contrast and normalized Shannon entropy is applied to high frequency coefficients. The superiority of the fusion response is depicted by the comparisons made with the other state-of-the-art fusion approaches (in terms of various fusion metrics).

  4. College Library Public Image Management%高校图书馆公众形象管理

    Institute of Scientific and Technical Information of China (English)

    刘利芳

    2015-01-01

    文章首先阐述了高校图书馆公众形象管理的必要性,然后从形象定位、形象塑造及形象传播三方面阐述了公众形象管理的措施。%The article first discusses the necessity of public university library image management, and from the image orien-tation, image building and image communication three aspects to describe public image management measures.

  5. Precision Near-Field Reconstruction in the Time Domain via Minimum Entropy for Ultra-High Resolution Radar Imaging

    Directory of Open Access Journals (Sweden)

    Jiwoong Yu

    2017-05-01

    Full Text Available Ultra-high resolution (UHR radar imaging is used to analyze the internal structure of objects and to identify and classify their shapes based on ultra-wideband (UWB signals using a vector network analyzer (VNA. However, radar-based imaging is limited by microwave propagation effects, wave scattering, and transmit power, thus the received signals are inevitably weak and noisy. To overcome this problem, the radar may be operated in the near-field. The focusing of UHR radar signals over a close distance requires precise geometry in order to accommodate the spherical waves. In this paper, a geometric estimation and compensation method that is based on the minimum entropy of radar images with sub-centimeter resolution is proposed and implemented. Inverse synthetic aperture radar (ISAR imaging is used because it is applicable to several fields, including medical- and security-related applications, and high quality images of various targets have been produced to verify the proposed method. For ISAR in the near-field, the compensation for the time delay depends on the distance from the center of rotation and the internal RF circuits and cables. Required parameters for the delay compensation algorithm that can be used to minimize the entropy of the radar images are determined so that acceptable results can be achieved. The processing speed can be enhanced by performing the calculations in the time domain without the phase values, which are removed after upsampling. For comparison, the parameters are also estimated by performing random sampling in the data set. Although the reduced data set contained only 5% of the observed angles, the parameter optimization method is shown to operate correctly.

  6. Advancing the country image construct from a public relations perspective: from model to measurement

    OpenAIRE

    Buhmann, Alexander; Ingenhoff, Diana

    2017-01-01

    Purpose – The purpose of this paper is to develop and test a new model for the measurement of the constitution and effects of the country image as a central target construct in international public relations. Design/methodology/approach – The authors combine concepts from reputation management (Eisenegger and Imhof, 2008; Ingenhoff and Sommer, 2007), national identity theory (Smith, 1987), and attitude theory (Ajzen and Fishbein, 1980) to derive a four-dimensional model, conceptualizing count...

  7. The public face of zoos: Images of entertainment, education, and conservation

    OpenAIRE

    Carr, N; Cohen, SA

    2011-01-01

    The contemporary justification for zoos is based on their ability to act as sites of wildlife conservation. Alongside this is the reality that zoos have historically been defined as sites for the entertainment of the general public and continue to be dependent on the revenue raised through visitor receipts. Consequently, zoos are, today, identified as sites of conservation, research, education, and entertainment. In recognition of this, the aim of our research was to assess the image that zoo...

  8. A modified CoSaMP algorithm for electromagnetic imaging of two dimensional domains

    KAUST Repository

    Sandhu, Ali Imran

    2017-05-13

    The compressive sampling matching pursuit (CoSaMP) algorithm is used for solving the electromagnetic inverse scattering problem on two-dimensional sparse domains. Since the scattering matrix, which is computed by sampling the Green function, does not satisfy the restricted isometry property, a damping parameter is added to the diagonal entries of the matrix to make the CoSaMP work. The damping factor can be selected based on the level of noise in the measurements. Numerical experiments, which demonstrate the accuracy and applicability of the proposed algorithm, are presented.

  9. Improvement of range spatial resolution of medical ultrasound imaging by element-domain signal processing

    Science.gov (United States)

    Hasegawa, Hideyuki

    2017-07-01

    The range spatial resolution is an important factor determining the image quality in ultrasonic imaging. The range spatial resolution in ultrasonic imaging depends on the ultrasonic pulse length, which is determined by the mechanical response of the piezoelectric element in an ultrasonic probe. To improve the range spatial resolution without replacing the transducer element, in the present study, methods based on maximum likelihood (ML) estimation and multiple signal classification (MUSIC) were proposed. The proposed methods were applied to echo signals received by individual transducer elements in an ultrasonic probe. The basic experimental results showed that the axial half maximum of the echo from a string phantom was improved from 0.21 mm (conventional method) to 0.086 mm (ML) and 0.094 mm (MUSIC).

  10. A Novel Scrambling Digital Image Watermark Algorithm Based on Double Transform Domains

    Directory of Open Access Journals (Sweden)

    Taiyue Wang

    2015-01-01

    Full Text Available Digital watermark technology is a very good method for protecting copyright. In this paper, in terms of requisition of imperceptibility and robustness of watermarking, the multidirectional, multiscale, and band-pass coefficient features of Curvelet transform are introduced and a novel image watermark scheme based on Curvelet and human visual system is proposed. Digital watermark information is embedded into the first 16 directions with larger energy in the fourth layer. Experimental results indicate that the proposed watermark scheme is feasible and simple. Simultaneously, the embedded watermark images just have tiny difference with the original images and the extracted watermark is accurate. Moreover, it is imperceptible and robust against various methods of signals processing such as cropping, noise adding, and rotating and altering.

  11. Development of a Multiview Time Domain Imaging Algorithm (MTDI) with a Fermat Correction

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, K A; Lehman, S K; Chambers, D H

    2004-09-22

    An imaging algorithm is presented based on the standard assumption that the total scattered field can be separated into an elastic component with monopole like dependence and an inertial component with a dipole like dependence. The resulting inversion generates two separate image maps corresponding to the monopole and dipole terms of the forward model. The complexity of imaging flaws and defects in layered elastic media is further compounded by the existence of high contrast gradients in either sound speed and/or density from layer to layer. To compensate for these gradients, we have incorporated Fermat's method of least time into our forward model to determine the appropriate delays between individual source-receiver pairs. Preliminary numerical and experimental results are in good agreement with each other.

  12. Compression and denoising in magnetic resonance imaging via SVD on the Fourier domain using computer algebra

    Science.gov (United States)

    Díaz, Felipe

    2015-09-01

    Magnetic resonance (MR) data reconstruction can be computationally a challenging task. The signal-to-noise ratio might also present complications, especially with high-resolution images. In this sense, data compression can be useful not only for reducing the complexity and memory requirements, but also to reduce noise, even to allow eliminate spurious components.This article proposes the use of a system based on singular value decomposition of low order for noise reconstruction and reduction in MR imaging system. The proposed method is evaluated using in vivo MRI data. Rebuilt images with less than 20 of the original data and with similar quality in terms of visual inspection are presented. Also a quantitative evaluation of the method is presented.

  13. State-of-the-art soft computing techniques in image steganography domain

    Science.gov (United States)

    Hussain, Hanizan Shaker; Din, Roshidi; Samad, Hafiza Abdul; Yaacub, Mohd Hanafizah; Murad, Roslinda; Rukhiyah, A.; Sabdri, Noor Maizatulshima

    2016-08-01

    This paper reviews major works of soft computing (SC) techniques in image steganography and watermarking in the last ten years, focusing on three main SC techniques, which are neural network, genetic algorithm, and fuzzy logic. The findings suggests that all these works applied SC techniques either during pre-processing, embedding or extracting stages or more than one of these stages. Therefore, the presence of SC techniques with their diverse approaches and strengths can help researchers in future work to attain excellent quality of image information hiding that comprises both imperceptibility and robustness.

  14. Double image encryption by using iterative random binary encoding in gyrator domains.

    Science.gov (United States)

    Liu, Zhengjun; Guo, Qing; Xu, Lie; Ahmad, Muhammad Ashfaq; Liu, Shutian

    2010-05-24

    We propose a double image encryption by using random binary encoding and gyrator transform. Two secret images are first regarded as the real part and imaginary part of complex function. Chaotic map is used for obtaining random binary matrix. The real part and imaginary part of complex function are exchanged under the control of random binary data. An iterative structure composed of the random binary encoding method is designed and employed for enhancing the security of encryption algorithm. The parameters in chaotic map and gyrator transform serve as the keys of this encryption scheme. Some numerical simulations have been made, to demonstrate the performance this algorithm.

  15. A multifocus image fusion in nonsubsampled contourlet domain with variational fusion strategy

    Science.gov (United States)

    Ma, Ning; Luo, Limin; Zhou, Zeming; Liang, Miaoyuan

    2011-11-01

    Based on the variational idea, we propose a new fusion strategy for nonsubsampled contourlet transform (NSCT). For NSCT bandpass subband coefficients of input images, we take the main component of coefficients as the target and then build an extremum problem for energy functional to find the closest to the target one as the fused coefficient. We apply the gradient descent flow to minimize the functional and give the numerical scheme. The experimental results show that the proposed strategy outperforms state-of-the-art image fusion strategies for NSCT in terms of both visual quality and objective evaluation criteria.

  16. Frequency-Domain Tomography for Single-shot, Ultrafast Imaging of Evolving Laser-Plasma Accelerators

    Science.gov (United States)

    Li, Zhengyan; Zgadzaj, Rafal; Wang, Xiaoming; Downer, Michael

    2011-10-01

    Intense laser pulses propagating through plasma create plasma wakefields that often evolve significantly, e.g. by expanding and contracting. However, such dynamics are known in detail only through intensive simulations. Laboratory visualization of evolving plasma wakes in the ``bubble'' regime is important for optimizing and scaling laser-plasma accelerators. Recently snap-shots of quasi-static wakes were recorded using frequency-domain holography (FDH). To visualize the wake's evolution, we have generalized FDH to frequency-domain tomography (FDT), which uses multiple probes propagating at different angles with respect to the pump pulse. Each probe records a phase streak, imprinting a partial record of the evolution of pump-created structures. We then topographically reconstruct the full evolution from all phase streaks. To prove the concept, a prototype experiment visualizing nonlinear index evolution in glass is demonstrated. Four probes propagating at 0, 0.6, 2, 14 degrees to the index ``bubble'' are angularly and temporally multiplexed to a single spectrometer to achieve cost-effective FDT. From these four phase streaks, an FDT algorithm analogous to conventional CT yields a single-shot movie of the pump's self-focusing dynamics.

  17. Image feature extraction in encrypted domain with privacy-preserving SIFT.

    Science.gov (United States)

    Hsu, Chao-Yung; Lu, Chun-Shien; Pei, Soo-Chang

    2012-11-01

    Privacy has received considerable attention but is still largely ignored in the multimedia community. Consider a cloud computing scenario where the server is resource-abundant, and is capable of finishing the designated tasks. It is envisioned that secure media applications with privacy preservation will be treated seriously. In view of the fact that scale-invariant feature transform (SIFT) has been widely adopted in various fields, this paper is the first to target the importance of privacy-preserving SIFT (PPSIFT) and to address the problem of secure SIFT feature extraction and representation in the encrypted domain. As all of the operations in SIFT must be moved to the encrypted domain, we propose a privacy-preserving realization of the SIFT method based on homomorphic encryption. We show through the security analysis based on the discrete logarithm problem and RSA that PPSIFT is secure against ciphertext only attack and known plaintext attack. Experimental results obtained from different case studies demonstrate that the proposed homomorphic encryption-based privacy-preserving SIFT performs comparably to the original SIFT and that our method is useful in SIFT-based privacy-preserving applications.

  18. Guidelines for the use of protein domains in acidic phospholipid imaging

    Science.gov (United States)

    Platre, Matthieu Pierre; Jaillais, Yvon

    2015-01-01

    Acidic phospholipids are minor membrane lipids but critically important for signaling events. The main acidic phospholipids are phosphatidylinositol phosphates (PIPs also known as phosphoinositides), phosphatidylserine (PS) and phosphatidic acid (PA). Acidic phospholipids are precursors of second messengers of key signaling cascades or are second messengers themselves. They regulate the localization and activation of many proteins, and are involved in virtually all membrane trafficking events. As such, it is crucial to understand the subcellular localization and dynamics of each of these lipids within the cell. Over the years, several techniques have emerged in either fixed or live cells to analyze the subcellular localization and dynamics of acidic phospholipids. In this chapter, we review one of them: the use of genetically encoded biosensors that are based on the expression of specific lipid binding domains (LBDs) fused to fluorescent proteins. We discuss how to design such sensors, including the criteria for selecting the lipid binding domains of interest and to validate them. We also emphasize the care that must be taken during data analysis as well as the main limitations and advantages of this approach. PMID:26552684

  19. Utility of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) to non-invasively diagnose burn depth in a porcine model.

    Science.gov (United States)

    Burmeister, David M; Ponticorvo, Adrien; Yang, Bruce; Becerra, Sandra C; Choi, Bernard; Durkin, Anthony J; Christy, Robert J

    2015-09-01

    Surgical intervention of second degree burns is often delayed because of the difficulty in visual diagnosis, which increases the risk of scarring and infection. Non-invasive metrics have shown promise in accurately assessing burn depth. Here, we examine the use of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) for predicting burn depth. Contact burn wounds of increasing severity were created on the dorsum of a Yorkshire pig, and wounds were imaged with SFDI/LSI starting immediately after-burn and then daily for the next 4 days. In addition, on each day the burn wounds were biopsied for histological analysis of burn depth, defined by collagen coagulation, apoptosis, and adnexal/vascular necrosis. Histological results show that collagen coagulation progressed from day 0 to day 1, and then stabilized. Results of burn wound imaging using non-invasive techniques were able to produce metrics that correlate to different predictors of burn depth. Collagen coagulation and apoptosis correlated with SFDI scattering coefficient parameter [Formula: see text] and adnexal/vascular necrosis on the day of burn correlated with blood flow determined by LSI. Therefore, incorporation of SFDI scattering coefficient and blood flow determined by LSI may provide an algorithm for accurate assessment of the severity of burn wounds in real time. Published by Elsevier Ltd.

  20. Utility of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) to non-invasively diagnose burn depth in a porcine model☆

    Science.gov (United States)

    Burmeister, David M.; Ponticorvo, Adrien; Yang, Bruce; Becerra, Sandra C.; Choi, Bernard; Durkin, Anthony J.; Christy, Robert J.

    2015-01-01

    Surgical intervention of second degree burns is often delayed because of the difficulty in visual diagnosis, which increases the risk of scarring and infection. Non-invasive metrics have shown promise in accurately assessing burn depth. Here, we examine the use of spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) for predicting burn depth. Contact burn wounds of increasing severity were created on the dorsum of a Yorkshire pig, and wounds were imaged with SFDI/LSI starting immediately after-burn and then daily for the next 4 days. In addition, on each day the burn wounds were biopsied for histological analysis of burn depth, defined by collagen coagulation, apoptosis, and adnexal/vascular necrosis. Histological results show that collagen coagulation progressed from day 0 to day 1, and then stabilized. Results of burn wound imaging using non-invasive techniques were able to produce metrics that correlate to different predictors of burn depth. Collagen coagulation and apoptosis correlated with SFDI scattering coefficient parameter ( μs′) and adnexal/vascular necrosis on the day of burn correlated with blood flow determined by LSI. Therefore, incorporation of SFDI scattering coefficient and blood flow determined by LSI may provide an algorithm for accurate assessment of the severity of burn wounds in real time. PMID:26138371

  1. Designing an image retrieval interface for abstract concepts within the domain of journalism

    NARCIS (Netherlands)

    Besseling, R.

    2011-01-01

    Research has shown that users have difficulties finding images which illustrate abstract concepts. We carried out a user study that confirms the finding that the selection of search terms is perceived difficult and that users find the subjectivity of abstract concepts problematic. In addition, we fo

  2. Designing an image retrieval interface for abstract concepts within the domain of journalism

    NARCIS (Netherlands)

    R. Besseling (Ron)

    2011-01-01

    htmlabstractResearch has shown that users have difficulties finding images which illustrate abstract concepts. We carried out a user study that confirms the finding that the selection of search terms is perceived difficult and that users find the subjectivity of abstract concepts problematic. In

  3. Fourier domain design of microgrid imaging polarimeters with improved spatial resolution

    Science.gov (United States)

    Hirakawa, Keigo; LeMaster, Daniel A.

    2014-05-01

    Microgrid polarimetric imagers sacrifice spatial resolution for sensitivity to states of linear polarization. We have recently shown that a 2 × 4 microgrid analyzer pattern sacrifices less spatial resolution than the conventional 2× 2 case without compromising polarization sensitivity. In this paper, we discuss the design strategy that uncovered the spatial resolution benefits of the 2 × 4 array.

  4. EXPERIMENTAL STUDY OF FORMING A PROFESSIONAL IMAGE OF THE FUTURE PUBLIC RELATIONS SPECIALIST

    Directory of Open Access Journals (Sweden)

    Lydia Mikhailovna Semenova

    2013-11-01

    Full Text Available The article is devoted to the organization of research work on forming professional image of the future public relations specialist. The purposes of the work were to study components of students’ image, to test the concept of a professional image of the specialist, and also to process and evaluate the results. The author has presented three phases of experimental research: statement, formative and evaluative. As a result, a positive trend of forming a professional image was found. The conceptual model of forming a professional image of the future experts tested in the course of experiment has shown to be highly effective, while new methods of training (training, workshops, panel discussions, action games, etc. have substantially improved the level of development of a professional image. The results can be used in the training and retraining of specialists of higher education and people whose profession related to communications.DOI: http://dx.doi.org/10.12731/2218-7405-2013-7-48

  5. Potential and piezoelectric response imaging of 180^o domain of atomically ordered clean surfaces of BaTiO3 single crystals in UHV

    Science.gov (United States)

    Watanabe, Yukio; Kaku, S.; Matsumoto, D.; Cheong, S. W.

    2009-03-01

    We report the electrostatic and piezoelectric properties of the clean, free surface of BaTiO3 single crystal in ultra high vacuum (UHV) The topographic imaging by AFM confirmed that the surface is atomically wellordered exhibiting clear one-lattice-height atomic steps. The amplitude and the phase image of piezoelectric response microscopy (PFM) identified 180^o domains. The electrostatic potential mapping by Kelvin force microscopy (KFM) of these domains revealed that the shapes of the domains agreed exactly with the PFM images, which confirms the correctness of the standard 180^o domain theory and disagrees with closure domains. However, the potential difference of upward and downward domain is approx. 0.1V, which is 100 times smaller than the value estimated by the standard theory. Similar measurements with changing temperature across Curie temperature show that this result cannot be explained by the compensation of the spontaneous polarization by contamination or oxygen deficiency or ionic conduction). The present results suggest that an intrinsic electrostatic shielding mechanism exists for 180^o domains, which is consistent with the reports of surface electron/hole layers [1]. [4pt] [1] Watanabe et al. PRL86332(2001);Ferroelectr.367, 23(2008) We acknowledge JSPS No.19340084.

  6. Lithospheric imaging from teleseismic data by frequency-domain elastic full-waveform tomography

    Science.gov (United States)

    Pageot, D.; Operto, S.; Vallée, M.; Brossier, R.; Virieux, J.; Seiscope

    2010-12-01

    Teleseismic data recorded by dense multicomponent surveys are potentially amenable to multichannel processing such as full waveform inversion to develop high-resolution lithospheric models. In this study, 2D frequency-domain full waveform tomography (FWT) is tailored to suit teleseismic geometries. Frequency-domain FWT seeks to estimate the elastic properties of the Earth by minimizing a misfit function between recorded and modeled full wavefields. FWT is designed to invert few discrete frequencies by proceeding hierarchically from the low frequencies to the higher ones, following a multiscale approach useful to mitigate the inversion nonlinearity. In teleseismic framework, seismic sources are planar incident wavefields impinging the base of the lithosphere with arbitrary incidence and obliquity angles. The full wavefield is computed using a scattered-field formulation in the frequency domain. First, an analytical wavefield is computed in a homogeneous background model with free surface on the topside for an incident compressional plane wave. Then, a scattering source is formed by the product of the analytical planewave with the difference of the forward problem operators associated with the homogeneous background and lithospheric models. The scattered wavefield is then computed by performing a simulation in the lithospheric model using the scattering source, and, finally, the full wavefield is built by summation of the analytical wavefield and of the scattered wavefield. The 2D P-SV wave modeling is performed with a finite element discontinuous Galerkin method allowing for unstructured triangular meshes. Teleseismic experiments are characterized by a narrow illumination of aperture angles because of the limited number of planewave sources related to the teleseismic earthquake distribution. This narrow aperture bandwith requires the use of finely-sampled frequencies to prevent spatial aliasing in the reconstructed FWT models. Moreover, planewave propagation from

  7. Design and Implementation of a Novel Compatible Encoding Scheme in the Time Domain for Image Sensor Communication

    Directory of Open Access Journals (Sweden)

    Trang Nguyen

    2016-05-01

    Full Text Available This paper presents a modulation scheme in the time domain based on On-Off-Keying and proposes various compatible supports for different types of image sensors. The content of this article is a sub-proposal to the IEEE 802.15.7r1 Task Group (TG7r1 aimed at Optical Wireless Communication (OWC using an image sensor as the receiver. The compatibility support is indispensable for Image Sensor Communications (ISC because the rolling shutter image sensors currently available have different frame rates, shutter speeds, sampling rates, and resolutions. However, focusing on unidirectional communications (i.e., data broadcasting, beacons, an asynchronous communication prototype is also discussed in the paper. Due to the physical limitations associated with typical image sensors (including low and varying frame rates, long exposures, and low shutter speeds, the link speed performance is critically considered. Based on the practical measurement of camera response to modulated light, an operating frequency range is suggested along with the similar system architecture, decoding procedure, and algorithms. A significant feature of our novel data frame structure is that it can support both typical frame rate cameras (in the oversampling mode as well as very low frame rate cameras (in the error detection mode for a camera whose frame rate is lower than the transmission packet rate. A high frame rate camera, i.e., no less than 20 fps, is supported in an oversampling mode in which a majority voting scheme for decoding data is applied. A low frame rate camera, i.e., when the frame rate drops to less than 20 fps at some certain time, is supported by an error detection mode in which any missing data sub-packet is detected in decoding and later corrected by external code. Numerical results and valuable analysis are also included to indicate the capability of the proposed schemes.

  8. Comparison of Scheimpflug imaging and spectral domain anterior segment optical coherence tomography for detection of narrow anterior chamber angles.

    Science.gov (United States)

    Grewal, D S; Brar, G S; Jain, R; Grewal, S P S

    2011-05-01

    To compare the performance of anterior chamber volume (ACV) and anterior chamber depth (ACD) obtained using Scheimpflug imaging with angle opening distance (AOD500) and trabecular-iris space area (TISA500) obtained using spectral domain anterior segment optical coherence tomography (SD-ASOCT) in detecting narrow angles classified using gonioscopy. In this prospective, cross-sectional observational study, 265 eyes of 265 consecutive patients underwent sequential Scheimpflug imaging, SD-ASOCT imaging, and gonioscopy. Correlations between gonioscopy grading, ACV, ACD, AOD500, and TISA500 were evaluated. Area under receiver operating characteristic curve (AUC), sensitivity, specificity, and likelihood ratios (LRs) were calculated to assess the performance of ACV, ACD, AOD500, and TISA500 in detecting narrow angles (defined as Shaffer grade ≤1 in all quadrants). SD-ASOCT images were obtained at the nasal and temporal quadrants only. Twenty-eight eyes (10.6%) were classified as narrow angles on gonioscopy. ACV correlated with gonioscopy grading (PACV correlated with TISA500 for nasal (r=0.135, P=0.029) and temporal (P=0.160, P=0.009) quadrants and also with AOD500 for nasal (r=0.498, PACV (AUC=0.935; 95% confidence interval (CI) =0.898-0.961) performed similar to ACD (AUC=0.88, P=0.06) and significantly better than AOD500 nasal (AUC=0.761, P=0.001), AOD500 temporal (AUC=0.808, PACV had 90% sensitivity and 88% specificity for detecting narrow angles. Positive and negative LRs for ACV were 8.63 (95% CI=7.4-10.0) and 0.11 (95% CI=0.03-0.4), respectively. ACV measurements using Scheimpflug imaging outperformed AOD500 and TISA500 using SD-ASOCT for detecting narrow angles.

  9. Design and Implementation of a Novel Compatible Encoding Scheme in the Time Domain for Image Sensor Communication.

    Science.gov (United States)

    Nguyen, Trang; Hossain, Mohammad Arif; Jang, Yeong Min

    2016-05-20

    This paper presents a modulation scheme in the time domain based on On-Off-Keying and proposes various compatible supports for different types of image sensors. The content of this article is a sub-proposal to the IEEE 802.15.7r1 Task Group (TG7r1) aimed at Optical Wireless Communication (OWC) using an image sensor as the receiver. The compatibility support is indispensable for Image Sensor Communications (ISC) because the rolling shutter image sensors currently available have different frame rates, shutter speeds, sampling rates, and resolutions. However, focusing on unidirectional communications (i.e., data broadcasting, beacons), an asynchronous communication prototype is also discussed in the paper. Due to the physical limitations associated with typical image sensors (including low and varying frame rates, long exposures, and low shutter speeds), the link speed performance is critically considered. Based on the practical measurement of camera response to modulated light, an operating frequency range is suggested along with the similar system architecture, decoding procedure, and algorithms. A significant feature of our novel data frame structure is that it can support both typical frame rate cameras (in the oversampling mode) as well as very low frame rate cameras (in the error detection mode for a camera whose frame rate is lower than the transmission packet rate). A high frame rate camera, i.e., no less than 20 fps, is supported in an oversampling mode in which a majority voting scheme for decoding data is applied. A low frame rate camera, i.e., when the frame rate drops to less than 20 fps at some certain time, is supported by an error detection mode in which any missing data sub-packet is detected in decoding and later corrected by external code. Numerical results and valuable analysis are also included to indicate the capability of the proposed schemes.

  10. A Modified Frequency Domain Imaging Method for One-stationary Bistatic SAR

    Directory of Open Access Journals (Sweden)

    Jin Ri-chu

    2014-04-01

    Full Text Available Bistatic Synthetic Aperture Radar (BiSAR in one-stationary mode has many advantages over the traditional monostatic SAR. Its echo, however, shows serious space variance in both range and azimuth directions due to its complex imaging geometry, making it hard to be processed by the frequency methods used in the monostatic SAR. To solve that problem, a method based on blocks and interpolation has been proposed by Wang Yu et al.. With this method, points can be well focused except for those located on the edge of each block. In this paper, a modified method is put forward, which adopts new block-dividing strategy and new mapping relationship in the interpolation. With the proposed method, points on the edge can also be well focused, making the quality of the final image greatly improved.

  11. A Demonstration of Wavefront Sensing and Mirror Phasing from the Image Domain

    CERN Document Server

    Pope, Benjamin; Cheetham, Anthony; Martinache, Frantz; Norris, Barnaby; Tuthill, Peter

    2014-01-01

    In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the optical path, or by imperfectly phased subapertures in a segmented mirror. Active and adaptive optics (AO), consisting of a wavefront sensor and a deformable mirror, are employed to address this problem. Nevertheless, the non-common-path between the wavefront sensor and the science camera leads to persistent quasi-static speckles that are difficult to calibrate and which impose a floor on the image contrast. In this paper we present the first experimental demonstration of a novel wavefront sensor requiring only a minor asymmetric obscuration of the pupil, using the science camera itself to detect high order wavefront errors from the speckle pattern produced. We apply this to correct errors imposed on a deformable microelectromechanical (MEMS) segmented mirror in a closed l...

  12. Robust Global Image Registration Based on a Hybrid Algorithm Combining Fourier and Spatial Domain Techniques

    Science.gov (United States)

    2012-09-01

    laboratory includes several visible PixeLINK CMOS machine vision cameras and an LWIR microbolometer camera. All results reported in this paper using...of nearly log-spaced positions, resulting in a 101 image sequence; the minimum and maximum calibrated shifts are 0.001 and 49.974 pixels...the four algorithms identified above, and the results are presented in Fig. 10 as a function of true ( calibrated ) shift. Results are shown on the

  13. Retinal Arteriolar Morphometry Based on Full Width at Half Maximum Analysis of Spectral-Domain Optical Coherence Tomography Images.

    Directory of Open Access Journals (Sweden)

    Yu Hua Tong

    Full Text Available In this study, we develop a microdensitometry method using full width at half maximum (FWHM analysis of the retinal vascular structure in a spectral-domain optical coherence tomography (SD-OCT image and present the application of this method in the morphometry of arteriolar changes during hypertension.Two raters using manual and FWHM methods measured retinal vessel outer and lumen diameters in SD-OCT images. Inter-rater reproducibility was measured using coefficients of variation (CV, intraclass correlation coefficient and a Bland-Altman plot. OCT images from forty-three eyes of 43 hypertensive patients and 40 eyes of 40 controls were analyzed using an FWHM approach; wall thickness, wall cross-sectional area (WCSA and wall to lumen ratio (WLR were subsequently calculated.Mean difference in inter-rater agreement ranged from -2.713 to 2.658 μm when using a manual method, and ranged from -0.008 to 0.131 μm when using a FWHM approach. The inter-rater CVs were significantly less for the FWHM approach versus the manual method (P < 0.05. Compared with controls, the wall thickness, WCSA and WLR of retinal arterioles were increased in the hypertensive patients, particular in diabetic hypertensive patients.The microdensitometry method using a FWHM algorithm markedly improved inter-rater reproducibility of arteriolar morphometric analysis, and SD-OCT may represent a promising noninvasive method for in vivo arteriolar morphometry.

  14. Spectral Difference in the Image Domain for Large Neighborhoods, a GEOBIA Pre-Processing Step for High Resolution Imagery

    Directory of Open Access Journals (Sweden)

    Roeland de Kok

    2012-08-01

    Full Text Available Contrast plays an important role in the visual interpretation of imagery. To mimic visual interpretation and using contrast in a Geographic Object Based Image Analysis (GEOBIA environment, it is useful to consider an analysis for single pixel objects. This should be done before applying homogeneity criteria in the aggregation of pixels for the construction of meaningful image objects. The habit or “best practice” to start GEOBIA with pixel aggregation into homogeneous objects should come with the awareness that feature attributes for single pixels are at risk of becoming less accessible for further analysis. Single pixel contrast with image convolution on close neighborhoods is a standard technique, also applied in edge detection. This study elaborates on the analysis of close as well as much larger neighborhoods inside the GEOBIA domain. The applied calculations are limited to the first segmentation step for single pixel objects in order to produce additional feature attributes for objects of interest to be generated in further aggregation processes. The equation presented functions at a level that is considered an intermediary product in the sequential processing of imagery. The procedure requires intensive processor and memory capacity. The resulting feature attributes highlight not only contrasting pixels (edges but also contrasting areas of local pixel groups. The suggested approach can be extended and becomes useful in classifying artificial areas at national scales using high resolution satellite mosaics.

  15. Spectral-domain optical coherence tomography enhanced depth imaging of the normal and glaucomatous nonhuman primate optic nerve head.

    Science.gov (United States)

    Yang, Hongli; Qi, Jingjing; Hardin, Christy; Gardiner, Stuart K; Strouthidis, Nicholas G; Fortune, Brad; Burgoyne, Claude F

    2012-01-25

    To test whether the enhanced depth imaging (EDI) modality improves anterior and posterior lamina cribrosa surface (ALCS and PLCS) visibility compared with conventional spectral-domain optical coherence tomography (SD-OCT). Conventional and EDI SD-OCT scans were obtained 30 minutes after IOP was manometrically lowered to 10 mm Hg in both eyes of 14 nonhuman primates (NHPs) with unilateral experimental glaucoma (EG). Thirteen horizontal and seven vertical radial B-scans of each SD-OCT data set were delineated by one operator masked to image type. Delineated ALCS and PLCS points were projected to 1 of 100 equal-sized subregions of the neural canal opening (NCO) reference plane, and the number of delineated subregions (≥2 points) was counted. Poisson regression was used to analyze the effects of image type, treatment, and quadrant. Two additional delineations were performed for three NHPs to compare reproducibility. EDI increased the number of subregions delineated for both the ALCS (by 28%; P PLCS (by 225%; P PLCS visibility was significant in all four quadrants (P PLCS depth which was deeper in the EDI data sets (P = 0.0002). ALCS and PLCS visibility within control and EG NHP ONHs increased in EDI compared to conventional SD-OCT data sets. Further study of EDI effects on PLCS parameterization is required.

  16. PUBLIC DIPLOMACY AS A TOOL TO CHANGE THE IMAGE OF A COUNTRY IN CRISIS

    Directory of Open Access Journals (Sweden)

    Maria Vaxevanidou

    2016-12-01

    Full Text Available The aim of this study is to explore the means, the methods, and the techniques of public diplomacy that a country in crisis, such as Greece, should use. The paper addresses the very issues of whether a country in crisis can conduct public diplomacy and whether it should be recognized as a legitimate and powerful actor in the field. In a broader sense, it focuses on the processes that a country should follow and how a better understanding and framing of its situation, principles, and policy can be provided. A crucial factor for such countries is the choice of communication channels, which includes traditional tools like press releases, letters to editor, editorials, interviews, or more active tools like social media, events, campaigns, and networking. In this paper, three dimensions of public diplomacy are examined, and appropriate tools to be developed in the short, medium and long-term are proposed. The results of the study are based on case studies, methods, and tools employed by Greece during the last years that the country has faced a huge economic crisis. There is a short presentation on the methods that Greece tries to adopt in order to enhance its image worldwide. Keywords: reactive public diplomacy, proactive public diplomacy, relationship building

  17. Automatic Side-Scan Sonar Image Enhancement in Curvelet Transform Domain

    Directory of Open Access Journals (Sweden)

    Yan Zhou

    2015-01-01

    Full Text Available We propose a novel automatic side-scan sonar image enhancement algorithm based on curvelet transform. The proposed algorithm uses the curvelet transform to construct a multichannel enhancement structure based on human visual system (HVS and adopts a new adaptive nonlinear mapping scheme to modify the curvelet transform coefficients in each channel independently and automatically. Firstly, the noisy and low-contrast sonar image is decomposed into a low frequency channel and a series of high frequency channels by using curvelet transform. Secondly, a new nonlinear mapping scheme, which coincides with the logarithmic nonlinear enhancement characteristic of the HVS perception, is designed without any parameter tuning to adjust the curvelet transform coefficients in each channel. Finally, the enhanced image can be reconstructed with the modified coefficients via inverse curvelet transform. The enhancement is achieved by amplifying subtle features, improving contrast, and eliminating noise simultaneously. Experiment results show that the proposed algorithm produces better enhanced results than state-of-the-art algorithms.

  18. A {sup 99m}Tc-labeled dual-domain cytokine ligand for imaging of inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhonglin, E-mail: zliu@radiology.arizona.edu [Department of Radiology, University of Arizona, Tucson, P.O. Box 245067 Tucson, AZ 85724-5067 (United States); Wyffels, Leonie; Barber, Christy [Department of Radiology, University of Arizona, Tucson, P.O. Box 245067 Tucson, AZ 85724-5067 (United States); Hui, Mizhou M. [AmProtein, Inc. San Gabriel, CA (United States); Woolfenden, James M. [Department of Radiology, University of Arizona, Tucson, P.O. Box 245067 Tucson, AZ 85724-5067 (United States)

    2011-08-15

    Introduction: Interleukin (IL)-1 and IL-18 are potent proinflammatory cytokines in inflammation-related diseases. Their actions are regulated by IL-1 receptor antagonist (IL-1ra) and IL-18 binding protein (IL-18bp). This study was designed to {sup 99m}Tc-radiolabel an IL-1ra and IL-18bp dual-domain cytokine ligand, IL-18bp-Fc-IL-1ra, for specific inflammation targeting. Methods: The {sup 99m}Tc-IL-18bp-Fc-IL-1ra was obtained by direct labeling via 2-iminothiolane reduction. Competitive binding of {sup 99m}Tc-labeled and unlabeled IL-18bp-Fc-IL-1ra to rat polymorphonuclear leukocytes was assessed in vitro. A mouse ear edema model was used to evaluate specific targeting properties of {sup 99m}Tc-IL-18bp-Fc-IL1ra in vivo. The correlation between {sup 99m}Tc-IL-18bp-Fc-IL-1ra uptake and {sup 111}In-labeled polymorphonuclear neutrophil infiltration was studied using ischemic-reperfused rat hearts. Results: Direct {sup 99m}Tc-labeling yielded a stable dual-domain cytokine radioligand with radiochemical purity greater than 95% after gel filtration. Competitive binding studies showed specific targeting of {sup 99m}Tc-IL-18bp-Fc-IL-1ra to inflammatory cells. The {sup 99m}Tc-IL-18bp-Fc-IL-1ra uptake was 1.80{+-}0.17 % injected dose per gram (%ID/g) in the inflamed ear without blocking, whereas uptake in the presence of IL-18bp-Fc-IL-1ra was 1.09{+-}0.08 %ID/g (P<.05). The amounts of IL-1{beta} and IL-18 were significantly increased in the inflamed ears compared to the vehicle controls. A significant correlation of {sup 99m}Tc-IL-18bp-Fc-IL-1ra with {sup 111}In-labeled neutrophil distribution was observed in the ischemic-reperfused hearts (P<.001). Conclusion: Targeting proinflammatory cytokines with {sup 99m}Tc-IL-18bp-Fc-IL-1ra may provide a suitable approach for specific detection of inflammatory sites.

  19. Quantitative long term measurements of burns in a rat model using spatial frequency domain imaging and laser speckle imaging (Conference Presentation)

    Science.gov (United States)

    Ponticorvo, Adrien; Rowland, Rebecca A.; Baldado, Melissa L.; Kennedy, Gordon T.; Saager, Rolf B.; Choi, Bernard; Durkin, Anthony J.

    2016-04-01

    The ability to accurately assess burn wound severity in a timely manner is a critical component of wound management as it dictates the course of treatment. While full thickness and superficial burns can be easily diagnosed through visual inspection, burns that fall in between these categories are difficult to classify. Additionally, the ability to better quantify different stages of wound healing from a burn of any severity would be important for evaluating the efficacy of different treatment options. Here we present a longitudinal (28 day) study that employs spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) as non-invasive technologies to characterize in-vivo burn wounds and healing in a murine model. Burn wounds were created using an established technique of a brass comb heated to a given temperature and applied for a set amount of time. They were imaged immediately after the initial injury and then at 2, 4, 7, 14, 21, and 28 days following the injury. Biopsies were taken on the day of the injury in order to verify the extent of the burn damage as well as at different time points after the injury in order to visualize different stages of inflammation and healing. The results of this study suggest that the reduced scattering coefficient measured using SFDI and blood flow as measured using LSI have the potential to provide useful metrics for quantifying the severity of burn injuries as well as track the different stages associated with wound healing progression.

  20. PKDIP: Efficient Public-Key-Based Data Integrity Protection for Wireless Image Sensors

    Directory of Open Access Journals (Sweden)

    Changsheng Wan

    2015-01-01

    Full Text Available Due to limited energy of “wireless image sensors (WISs,” existing data integrity protection mechanisms typically employ a hash-function-based signing algorithm to generate “message authentication codes (MACs” for long image frames. However, hash-function-based signing algorithm requires the WIS and the “end user (EU” sharing a secret, which leads to a new security issue: Once the EU becomes malicious due to some reasons, it will be able to forge the WIS’s data since it holds the shared secret. Therefore, public-key cryptography is desirable. Unfortunately, public-key cryptographic operations are quite time-consuming for energy-restrained WISs. Facing this dilemma, we present a novel data integrity protection protocol named PKDIP in this paper. Similar to the mechanisms of this field, PKDIP generates MACs for data integrity protection. However, different from other well-known approaches, PKDIP introduces the “Montgomery Modular Multiplication (MontMM” technique to current public-key-based signing algorithms. Since MontMM is much more efficient than hash functions, PKDIP can reduce the signing cost significantly. Experimental results show PKDIP can even be more efficient than hash-function-based schemes.

  1. Micro-magnetic simulation study on the magnetic particle imaging performance of anisotropic mono-domain particles.

    Science.gov (United States)

    Weizenecker, Jürgen; Gleich, Bernhard; Rahmer, Jürgen; Borgert, Jörn

    2012-11-21

    The performance of magnetic mono-domain particles is of crucial importance in magnetic particle imaging (MPI). So far, the behavior of mono-domain particles has been modeled within the framework of Langevin theory. This theory predicts the dependence of the MPI signal on the particle core size, but cannot account for the influence of the shape, i.e. the anisotropy of the particle core. In this study we present the first micro-magnetic ab initio simulation of spectra of anisotropic particles with different core diameters in an oscillating magnetic field at 25 and 100 kHz. We find that the MPI signal strongly depends on the anisotropy of the magnetic core. Thus, a difference of 3 nm between the principal axes of a prolate ellipsoid with the volume of a 30 nm sphere can result in a complete loss of the MPI signal. Smaller anisotropies, however, can increase the MPI performance of the particle. The simulations show that the effect of the anisotropy on the MPI signal depends on the frequency of the oscillating magnetic field. At 100 kHz, the optimal signal is found at smaller anisotropies than at 25 kHz. Furthermore, the simulations show that experimental spectroscopic results for Resovist® can only be explained quantitatively by particles with a magnetic core size of at least 25 nm.

  2. Frequency domain phosphorescence lifetime Imaging measurements and applications by ISS FastFLIM and multi pulse excitation

    Science.gov (United States)

    Coskun, Ulas C.; Lam, Sandra; Sun, Yuansheng; Liao, Shih-Chu Jeff; George, Steven C.; Barbieri, Beniamino

    2017-02-01

    Phosphorescence probes can have significantly long lifetimes, on the order of micro- to milli-seconds or longer. In addition, environmental changes can affect the lifetimes of these phosphorescence probes. Thus, Phosphorescence Lifetime Imaging Microscopy (PLIM) is a very useful tool to localize the phosphorescence probes based on their lifetimes to study the variance in the lifetimes due to the micro environmental changes. Since the probes respond to the biologically relevant parameters like oxygen concentration, they can be used to study various biologically relevant processes like cellular metabolism, protein interaction etc. In this case, we study the effects of oxygen on Oxyphor G4 with PLIM. Since The Oxyphor G4 can be quenched by O2, it is a good example of such a probe and has a lifetime around 250us. Here we present the digital frequency domain PLIM technique and study the lifetime of the Oxyphor G4 as a function of the O2 concentration. The lifetime data are successfully presented in a phasor plot for various O2 concentrations and are consistent with the time domain data. Overall, we can analyze the oxygen consumption of varying cells using this technique.

  3. Robot-assisted motor activation monitored by time-domain optical brain imaging

    Science.gov (United States)

    Steinkellner, O.; Wabnitz, H.; Schmid, S.; Steingräber, R.; Schmidt, H.; Krüger, J.; Macdonald, R.

    2011-07-01

    Robot-assisted motor rehabilitation proved to be an effective supplement to conventional hand-to-hand therapy in stroke patients. In order to analyze and understand motor learning and performance during rehabilitation it is desirable to develop a monitor to provide objective measures of the corresponding brain activity at the rehabilitation progress. We used a portable time-domain near-infrared reflectometer to monitor the hemodynamic brain response to distal upper extremity activities. Four healthy volunteers performed two different robot-assisted wrist/forearm movements, flexion-extension and pronation-supination in comparison with an unassisted squeeze ball exercise. A special headgear with four optical measurement positions to include parts of the pre- and postcentral gyrus provided a good overlap with the expected activation areas. Data analysis based on variance of time-of-flight distributions of photons through tissue was chosen to provide a suitable representation of intracerebral signals. In all subjects several of the four detection channels showed a response. In some cases indications were found of differences in localization of the activated areas for the various tasks.

  4. Dialog-Based 3D-Image Recognition Using a Domain Ontology

    Science.gov (United States)

    Hois, Joana; Wünstel, Michael; Bateman, John A.; Röfer, Thomas

    The combination of vision and speech, together with the resulting necessity for formal representations, builds a central component of an autonomous system. A robot that is supposed to navigate autonomously through space must be able to perceive its environment as automatically as possible. But each recognition system has its own inherent limits. Especially a robot whose task is to navigate through unknown terrain has to deal with unidentified or even unknown objects, thus compounding the recognition problem still further. The system described in this paper takes this into account by trying to identify objects based on their functionality where possible. To handle cases where recognition is insufficient, we examine here two further strategies: on the one hand, the linguistic reference and labeling of the unidentified objects and, on the other hand, ontological deduction. This approach then connects the probabilistic area of object recognition with the logical area of formal reasoning. In order to support formal reasoning, additional relational scene information has to be supplied by the recognition system. Moreover, for a sound ontological basis for these reasoning tasks, it is necessary to define a domain ontology that provides for the representation of real-world objects and their corresponding spatial relations in linguistic and physical respects. Physical spatial relations and objects are measured by the visual system, whereas linguistic spatial relations and objects are required for interactions with a user.

  5. Diffusion in Altered Tonalite Sample Using Time Domain Diffusion Simulations in Tomographic Images Combined with Lab-scale Diffusion Experiments

    Science.gov (United States)

    Voutilainen, M.; Sardini, P.; Togneri, L.; Siitari-Kauppi, M.; Timonen, J.

    2010-12-01

    In this work an effect of rock heterogeneity on diffusion was investigated. Time domain diffusion simulations were used to compare behavior of diffusion in homogeneous and heterogeneous 3D media. Tomographic images were used as heterogeneous rock media. One altered tonalite sample from Sievi, Finland, was chosen as test case for introduced analysis procedure. Effective diffusion coefficient of tonalite sample was determined with lab-scale experiments and the same coefficient was used also for homogeneous media. Somewhat technically complicated mathematical solution for analysis of through diffusion experiment is shortly described. Computed tomography (CT) is already quite widely used in many geological, petrological, and paleontological applications when the three-dimensional (3D) structure of the material is of interest, and is an excellent method for gaining information especially about its heterogeneity, grain size, or porosity. In addition to offering means for quantitative characterization, CT provides a lot of qualitative information [1]. A through -diffusion laboratory experiment using radioactive tracer was fitted using the Time Domain Diffusion (TDD) method. This rapid particle tracking method allows simulation of the heterogeneous diffusion based on pore-scale images and local values of diffusivities [2]. As a result we found out that heterogeneity has only a small effect to diffusion coefficient and in-diffusion profile for used geometry. Also direction dependency was tested and was found to be negligible. Whereas significant difference between generally accepted value and value obtained from simulations for constant m in Archie’s law was found. [1] Voutilainen, M., Siitari-Kauppi, M., Sardini, P., and Timonen, J., (2010). On pore-space characterization of an altered tonalite by X-ray µCT and the 14C-PMMA method (in progress). [2] Sardini, P., Robinet, J., Siitari-Kauppi, M., Delay, F., and Hellmuth, K-H, (2007). On direct simulation of heterogeneous

  6. 基于频域的图像增强技术研究%Study on Image Enhancement Technique Based on Frequency Domain

    Institute of Scientific and Technical Information of China (English)

    关雪梅

    2012-01-01

    Image enhancement is a kind of basic image processing technology,the purpose of which is to process the image,to be applied to specific Visual effects for better,more useful images.Image enhancement technology currently used,according to the different processing space,can be divided into image enhancement method based on frequency domain and spatial domain method for image enhancement.This article is intended primarily for image enhancement method in frequency domain for research,including low-pass,high-pass filtering method and homomorphic filtering method.%图像增强是一类基本的图像处理技术,其目的是对图像进行加工,以得到对具体应用来说视觉效果更好、更有用的图像。目前常用的图像增强技术根据处理空间的不同,可分为基于频域的图像增强方法和基于空域的图像增强方法。文中主要针对频域图像增强方法进行研究,包括低通滤波方法、高通滤波方法和同态滤波方法。

  7. Exudate-based diabetic macular edema detection in fundus images using publicly available datasets

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Meriaudeau, Fabrice [ORNL; Karnowski, Thomas Paul [ORNL; Li, Yaquin [University of Tennessee, Knoxville (UTK); Garg, Seema [University of North Carolina; Tobin Jr, Kenneth William [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK)

    2011-01-01

    Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy. In a large scale screening environment DME can be assessed by detecting exudates (a type of bright lesions) in fundus images. In this work, we introduce a new methodology for diagnosis of DME using a novel set of features based on colour, wavelet decomposition and automatic lesion segmentation. These features are employed to train a classifier able to automatically diagnose DME through the presence of exudation. We present a new publicly available dataset with ground-truth data containing 169 patients from various ethnic groups and levels of DME. This and other two publicly available datasets are employed to evaluate our algorithm. We are able to achieve diagnosis performance comparable to retina experts on the MESSIDOR (an independently labelled dataset with 1200 images) with cross-dataset testing (e.g., the classifier was trained on an independent dataset and tested on MESSIDOR). Our algorithm obtained an AUC between 0.88 and 0.94 depending on the dataset/features used. Additionally, it does not need ground truth at lesion level to reject false positives and is computationally efficient, as it generates a diagnosis on an average of 4.4 s (9.3 s, considering the optic nerve localization) per image on an 2.6 GHz platform with an unoptimized Matlab implementation.

  8. Automatic Diabetic Macular Edema Detection in Fundus Images Using Publicly Available Datasets

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Meriaudeau, Fabrice [ORNL; Karnowski, Thomas Paul [ORNL; Li, Yaquin [University of Tennessee, Knoxville (UTK); Garg, Seema [University of North Carolina; Tobin Jr, Kenneth William [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK)

    2011-01-01

    Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy. In a large scale screening environment DME can be assessed by detecting exudates (a type of bright lesions) in fundus images. In this work, we introduce a new methodology for diagnosis of DME using a novel set of features based on colour, wavelet decomposition and automatic lesion segmentation. These features are employed to train a classifier able to automatically diagnose DME. We present a new publicly available dataset with ground-truth data containing 169 patients from various ethnic groups and levels of DME. This and other two publicly available datasets are employed to evaluate our algorithm. We are able to achieve diagnosis performance comparable to retina experts on the MESSIDOR (an independently labelled dataset with 1200 images) with cross-dataset testing. Our algorithm is robust to segmentation uncertainties, does not need ground truth at lesion level, and is very fast, generating a diagnosis on an average of 4.4 seconds per image on an 2.6 GHz platform with an unoptimised Matlab implementation.

  9. The City Image and the Local Public Administration: a Working Tool in Urban Planning

    Directory of Open Access Journals (Sweden)

    Marius Cristian NEACȘU

    2009-10-01

    Full Text Available  The goal of this study consist of identifyingand testing in operational terms the concept of cityimage in the decision-making processes, both asfar as the urban planning and the future policies oflocal and regional development are concerned or inthe management of public spaces. It is well-knownthe fact that the simple series of statistical dataand the models based upon them do not sketchout a complete image regarding the urban reality,the perception of habitants at a micro-scale levelabout habituation conditions, illustrated by thecity image, presenting itself as a barometer of thedysfunctionalities encountered in the city. Thus, thepractical implications of this concept based on anew vision in the philosophy of the managementof urban spaces are likely to be interestingenough. Using this tool in the policies and in theactivity of public administration, in urbanism etc.,complementarily to statistical analyses, shouldaccompany any type of local development policyin order to enhance life quality and to transmit acertain life style, well appreciated by the residentswhich should bestow the city distinctiveness anda particular status in the regional and nationalhierarchy. The conceptual scheme of this studyis based on three elements: theory (what doesthe city image represent?, method (how could wemap at a micro-scale level?, case study (whichare the results and the tests of the applicability inthe city of Ploieşti.

  10. SOIL SPECTRAL IMAGING: MOVING FROM PROXIMAL SENSING TO SPATIAL QUANTITATIVE DOMAIN

    Directory of Open Access Journals (Sweden)

    E. B. Dor

    2012-07-01

    Full Text Available Imaging spectroscopy (IS is a relatively new technique that has attracted the attention of workers in many fields. In the soil sciences, this technology is not well developed and additional research is required – despite the fact that a large number of soil properties in the soil environment have already been studied from a reflectance perspective with much success (e.g. organic matter, cation exchange capacity, carbonate content and specific surface area. Going from proximal sensing to image spectrometry is not only a journey from the micro to macro scales; it is a lengthy one that is fraught with problems, such as dealing with data having a low signal-to-noise level, contamination of the atmosphere, large data sets, the Bidirectional Reflectance Distribution Function (BRDF effect and more. In this paper, provide a brief history of both near infrared spectroscopy (NIRS and IS approaches and attempt to understand why, despite its promise, IS has not yet been well developed for the soil sciences. We assume that research, education, exposure of the technology to end-users and governmental involvement are the major factors that require attention in this venue. Also provide some personal thoughts on the future of IS in soil and conclude that in 5 to 10 years, this application will have matured into one that is ready to use and well-known among soil scientists, end-users and decision-makers.

  11. Additive white Gaussian noise level estimation in SVD domain for images.

    Science.gov (United States)

    Liu, Wei; Lin, Weisi

    2013-03-01

    Accurate estimation of Gaussian noise level is of fundamental interest in a wide variety of vision and image processing applications as it is critical to the processing techniques that follow. In this paper, a new effective noise level estimation method is proposed on the basis of the study of singular values of noise-corrupted images. Two novel aspects of this paper address the major challenges in noise estimation: 1) the use of the tail of singular values for noise estimation to alleviate the influence of the signal on the data basis for the noise estimation process and 2) the addition of known noise to estimate the content-dependent parameter, so that the proposed scheme is adaptive to visual signals, thereby enabling a wider application scope of the proposed scheme. The analysis and experiment results demonstrate that the proposed algorithm can reliably infer noise levels and show robust behavior over a wide range of visual content and noise conditions, and that is outperforms relevant existing methods.

  12. A demonstration of wavefront sensing and mirror phasing from the image domain

    Science.gov (United States)

    Pope, Benjamin; Cvetojevic, Nick; Cheetham, Anthony; Martinache, Frantz; Norris, Barnaby; Tuthill, Peter

    2014-05-01

    In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high-contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the optical path, or by imperfectly phased subapertures in a segmented mirror. Active and adaptive optics (AO), consisting of a wavefront sensor and a deformable mirror, are employed to address this problem. Nevertheless, the non-common-path between the wavefront sensor and the science camera leads to persistent quasi-static speckles that are difficult to calibrate and which impose a floor on the image contrast. In this paper, we present the first experimental demonstration of a novel wavefront sensor requiring only a minor asymmetric obscuration of the pupil, using the science camera itself to detect high-order wavefront errors from the speckle pattern produced. We apply this to correct errors imposed on a deformable microelectromechanical segmented mirror in a closed loop, restoring a high-quality point spread function and residual wavefront errors of the order of ˜10 nm using 1600 nm light, from a starting point of ˜300 nm in piston and ˜0.3 mrad in tip-tilt. We recommend this as a method for measuring the non-common-path error in AO-equipped ground based telescopes, as well as an approach to phasing difficult segmented mirrors such as on the James Webb Space Telescope primary and as a future direction for extreme AO.

  13. Sensitivity Enhancement of (Hyper-)CEST Image Series by Exploiting Redundancies in the Spectral Domain

    CERN Document Server

    Döpfert, Jörg; Kunth, Martin; Schröder, Leif

    2013-01-01

    CEST has proven to be a valuable technique for the detection of hyperpolarized xenon-based functionalized contrast agents. Additional information can be encoded in the spectral dimension, allowing the simultaneous detection of multiple different biosensors. However, due to the low concentration of dissolved xenon in biological tissue, the signal to noise ratio (SNR) of Hyper-CEST data is still a critical issue. In this work, we present two techniques aiming to increase SNR by exploiting the typically high redundancy in spectral CEST image series: PCA-based post-processing and sub-sampled acquisition with low-rank reconstruction. Each of them yields a significant SNR enhancement, demonstrating the feasibility of the two approaches. While the first method is directly applicable to proton CEST experiments as well, the second one is particularly beneficial when dealing with hyperpolarized nuclei, since it distributes the non-renewable initial polarization more efficiently over the sampling points. The results obt...

  14. Image Watermarking Algorithm Based on Multiobjective Ant Colony Optimization and Singular Value Decomposition in Wavelet Domain

    Directory of Open Access Journals (Sweden)

    Khaled Loukhaoukha

    2013-01-01

    Full Text Available We present a new optimal watermarking scheme based on discrete wavelet transform (DWT and singular value decomposition (SVD using multiobjective ant colony optimization (MOACO. A binary watermark is decomposed using a singular value decomposition. Then, the singular values are embedded in a detailed subband of host image. The trade-off between watermark transparency and robustness is controlled by multiple scaling factors (MSFs instead of a single scaling factor (SSF. Determining the optimal values of the multiple scaling factors (MSFs is a difficult problem. However, a multiobjective ant colony optimization is used to determine these values. Experimental results show much improved performances of the proposed scheme in terms of transparency and robustness compared to other watermarking schemes. Furthermore, it does not suffer from the problem of high probability of false positive detection of the watermarks.

  15. A fast optimization transfer algorithm for image inpainting in wavelet domains.

    Science.gov (United States)

    Chan, Raymond H; Wen, You-Wei; Yip, Andy M

    2009-07-01

    A wavelet inpainting problem refers to the problem of filling in missing wavelet coefficients in an image. A variational approach was used by Chan et al. The resulting functional was minimized by the gradient descent method. In this paper, we use an optimization transfer technique which involves replacing their univariate functional by a bivariate functional by adding an auxiliary variable. Our bivariate functional can be minimized easily by alternating minimization: for the auxiliary variable, the minimum has a closed form solution, and for the original variable, the minimization problem can be formulated as a classical total variation (TV) denoising problem and, hence, can be solved efficiently using a dual formulation. We show that our bivariate functional is equivalent to the original univariate functional. We also show that our alternating minimization is convergent. Numerical results show that the proposed algorithm is very efficient and outperforms that of Chan et al.

  16. Multimodal Medical Image Fusion Framework Based on Simplified PCNN in Nonsubsampled Contourlet Transform Domain

    Directory of Open Access Journals (Sweden)

    Nianyi Wang

    2013-06-01

    Full Text Available In this paper, we present a new medical image fusion algorithm based on nonsubsampled contourlet transform (NSCT and spiking cortical model (SCM. The flexible multi-resolution, anisotropy, and directional expansion characteristics of NSCT are associated with global coupling and pulse synchronization features of SCM. Considering the human visual system characteristics, two different fusion rules are used to fuse the low and high frequency sub-bands respectively. Firstly, maximum selection rule (MSR is used to fuse low frequency coefficients. Secondly, spatial frequency (SF is applied to motivate SCM network rather than using coefficients value directly, and then the time matrix of SCM is set as criteria to select coefficients of high frequency subband. The effectiveness of the proposed algorithm is achieved by the comparison with existing fusion methods.

  17. Monochromatic subdiffusive spatial frequency domain imaging provides in-situ sensitivity to intratumoral morphological heterogeneity in a murine model.

    Science.gov (United States)

    McClatchy, David M; Hoopes, P Jack; Pogue, Brian W; Kanick, Stephen Chad

    2017-02-01

    For the first time, spatially resolved quantitative metrics of light scattering recovered with sub-diffusive spatial frequency domain imaging (sd-SFDI) are shown to be sensitive to changes in intratumoral morphology and viability by direct comparison to histopathological analysis. Two freshly excised subcutaneous murine tumor cross-sections were measured with sd-SFDI, and recovered optical scatter parameter maps were co-registered to whole mount histology. Unique clustering of the optical scatter parameters μs' vs. γ (i.e. diffuse scattering vs. relative backscattering) evaluated at a single wavelength showed complete separation between regions of viable tumor, aggresive tumor with stromal growth, varying levels of necrotic tumor, and also peritumor muscle. The results suggest that with further technical development, sd-SFDI may represent a non-destructive screening tool for analysis of excised tissue or a non-invasive approach to investigate suspicious lesions without the need for exogenous labels or spectrally resolved imaging. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Advances in functional brain imaging technology and developmental neuro-psychology: their applications in the Jungian analytic domain.

    Science.gov (United States)

    Petchkovsky, Leon

    2017-06-01

    Analytical psychology shares with many other psychotherapies the important task of repairing the consequences of developmental trauma. The majority of analytic patients come from compromised early developmental backgrounds: they may have experienced neglect, abuse, or failures of empathic resonance from their carers. Functional brain imagery techniques including Quantitative Electroencephalogram (QEEG), and functional Magnetic Resonance Imagery (fMRI), allow us to track mental processes in ways beyond verbal reportage and introspection. This independent perspective is useful for developing new psychodynamic hypotheses, testing current ones, providing diagnostic markers, and monitoring treatment progress. Jung, with the Word Association Test, grasped these principles 100 years ago. Brain imaging techniques have contributed to powerful recent advances in our understanding of neurodevelopmental processes in the first three years of life. If adequate nurturance is compromised, a range of difficulties may emerge. This has important implications for how we understand and treat our psychotherapy clients. The paper provides an overview of functional brain imaging and advances in developmental neuropsychology, and looks at applications of some of these findings (including neurofeedback) in the Jungian psychotherapy domain. © 2017, The Society of Analytical Psychology.

  19. Magnetic surface domain imaging of uncapped epitaxial FeRh(001) thin films across the temperature-induced metamagnetic transition

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xianzhong; Matthes, Frank; Bürgler, Daniel E., E-mail: d.buergler@fz-juelich.de; Schneider, Claus M. [Peter Grünberg Institut, Electronic Properties (PGI-6) and Jülich-Aachen Research Alliance, Fundamentals of Future Information Technology (JARA-FIT), Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2016-01-15

    The surface magnetic domain structure of uncapped epitaxial FeRh/MgO(001) thin films was imaged by in-situ scanning electron microscopy with polarization analysis (SEMPA) at various temperatures between 122 and 450 K. This temperature range covers the temperature-driven antiferromagnetic-to-ferromagnetic phase transition in the body of the films that was observed in-situ by means of the more depth-sensitive magneto-optical Kerr effect. The SEMPA images confirm that the interfacial ferromagnetism coexisting with the antiferromagnetic phase inside the film is an intrinsic property of the FeRh(001) surface. Furthermore, the SEMPA data display a reduction of the in-plane magnetization occuring well above the phase transition temperature which, thus, is not related to the volume expansion at the phase transition. This observation is interpreted as a spin reorientation of the surface magnetization for which we propose a possible mechanism based on temperature-dependent tetragonal distortion due to different thermal expansion coefficients of MgO and FeRh.

  20. Magnetic surface domain imaging of uncapped epitaxial FeRh(001 thin films across the temperature-induced metamagnetic transition

    Directory of Open Access Journals (Sweden)

    Xianzhong Zhou

    2016-01-01

    Full Text Available The surface magnetic domain structure of uncapped epitaxial FeRh/MgO(001 thin films was imaged by in-situ scanning electron microscopy with polarization analysis (SEMPA at various temperatures between 122 and 450 K. This temperature range covers the temperature-driven antiferromagnetic-to-ferromagnetic phase transition in the body of the films that was observed in-situ by means of the more depth-sensitive magneto-optical Kerr effect. The SEMPA images confirm that the interfacial ferromagnetism coexisting with the antiferromagnetic phase inside the film is an intrinsic property of the FeRh(001 surface. Furthermore, the SEMPA data display a reduction of the in-plane magnetization occuring well above the phase transition temperature which, thus, is not related to the volume expansion at the phase transition. This observation is interpreted as a spin reorientation of the surface magnetization for which we propose a possible mechanism based on temperature-dependent tetragonal distortion due to different thermal expansion coefficients of MgO and FeRh.