WorldWideScience

Sample records for digital holographic imaging

  1. In-line digital holographic imaging in volume holographic microscopy.

    Science.gov (United States)

    Zhai, Xiaomin; Lin, Wei-Tang; Chen, Hsi-Hsun; Wang, Po-Hao; Yeh, Li-Hao; Tsai, Jui-Chang; Singh, Vijay Raj; Luo, Yuan

    2015-12-01

    A dual-plane in-line digital holographic imaging method incorporating volume holographic microscopy (VHM) is presented to reconstruct objects in a single shot while eliminating zero-order and twin-image diffracted waves. The proposed imaging method is configured such that information from different axial planes is acquired simultaneously using multiplexed volume holographic imaging gratings, as used in VHM, and recorded as in-line holograms where the corresponding reference beams are generated in the fashion of Gabor's in-line holography. Unlike conventional VHM, which can take axial intensity information only at focal depths, the proposed method digitally reconstructs objects at any axial position. Further, we demonstrate the proposed imaging technique's ability to effectively eliminate zero-order and twin images for single-shot three-dimensional object reconstruction.

  2. Sonorous images through digital holographic images

    Science.gov (United States)

    Azevedo, Isabel; Sandford-Richardson, Elizabeth

    2017-03-01

    The art of the last fifty years has significantly surrounded the presence of the body, the relationship between human and interactive technologies. Today in interactive art, there are not only representations that speak of the body but actions and behaviours that involve the body. In holography, the image appears and disappears from the observer's vision field; because the holographic image is light, we can see multidimensional spaces, shapes and colours existing on the same time, presence and absence of the image on the holographic plate. And the image can be flowing in front of the plate that sometimes people try touching it with his hands. That means, to the viewer will be interactive events, with no beginning or end that can be perceived in any direction, forward or backward, depending on the relative position and the time the viewer spends in front of the hologram. To explore that feature we are proposing an installation with four holograms, and several sources of different kind of sounds connected with each hologram. When viewers will move in front of each hologram they will activate different sources of sound. The search is not only about the images in the holograms, but also the looking for different types of sounds that this demand will require. The digital holograms were produced using the HoloCam Portable Light System with the 35 mm camera Canon 700D to capture image information, it was then edited on computer using the Motion 5 and Final Cut Pro X programs.

  3. Fourier transform digital holographic adaptive optics imaging system

    Science.gov (United States)

    Liu, Changgeng; Yu, Xiao; Kim, Myung K.

    2013-01-01

    A Fourier transform digital holographic adaptive optics imaging system and its basic principles are proposed. The CCD is put at the exact Fourier transform plane of the pupil of the eye lens. The spherical curvature introduced by the optics except the eye lens itself is eliminated. The CCD is also at image plane of the target. The point-spread function of the system is directly recorded, making it easier to determine the correct guide-star hologram. Also, the light signal will be stronger at the CCD, especially for phase-aberration sensing. Numerical propagation is avoided. The sensor aperture has nothing to do with the resolution and the possibility of using low coherence or incoherent illumination is opened. The system becomes more efficient and flexible. Although it is intended for ophthalmic use, it also shows potential application in microscopy. The robustness and feasibility of this compact system are demonstrated by simulations and experiments using scattering objects. PMID:23262541

  4. Terahertz in-line digital holographic multiplane imaging method

    Science.gov (United States)

    Huang, Haochong; Wang, Dayong; Rong, Lu; Li, Weihua; Wang, Yunxin

    2017-05-01

    Terahertz waves of which frequency spans from 0.1 to 10 THz bridge the gap between the infrared spectrum and microwaves. Owing to the special features of terahertz wave, such as penetrability and non-ionizing, terahertz imaging technique is a very significant and important method for inspections and detections. Digital holography can reconstruct the amplitude and phase distributions of a sample without scanning and it already has many successful applications in the area of visible and infrared light. The terahertz in-line digital holographic multi-plane imaging system which is presented in this paper is the combination of a continuous-wave terahertz source and the in-line scheme of digital holography. In order to observe a three dimensional (3D) shape sample only a portion of which appears in good focus, the autofocusing algorithm is brought to the data process. The synthetic aperture method is also applied to provide the high resolution imaging effect in the terahertz waveband. Both intrinsic twin images and defocused objective images confuse the quality of the image in an individual reconstructed plane. In order to solve this issue, phase retrieval iteration algorithm is used for the reconstruction. In addition, the reconstructed amplitude image in each plane multiplies the mask of which the threshold depends on the values of the autofocusing curve. A sample with simple artificial structure is observed which verifies that the present method is an authentic tool to acquire the multi-plane information of a target in terahertz waves. It can expect a wide application in terahertz defect detecting, terahertz medical inspection and other important areas in the future.

  5. 3D Cell Culture Imaging with Digital Holographic Microscopy

    Science.gov (United States)

    Dimiduk, Thomas; Nyberg, Kendra; Almeda, Dariela; Koshelva, Ekaterina; McGorty, Ryan; Kaz, David; Gardel, Emily; Auguste, Debra; Manoharan, Vinothan

    2011-03-01

    Cells in higher organisms naturally exist in a three dimensional (3D) structure, a fact sometimes ignored by in vitro biological research. Confinement to a two dimensional culture imposes significant deviations from the native 3D state. One of the biggest obstacles to wider use of 3D cultures is the difficulty of 3D imaging. The confocal microscope, the dominant 3D imaging instrument, is expensive, bulky, and light-intensive; live cells can be observed for only a short time before they suffer photodamage. We present an alternative 3D imaging techinque, digital holographic microscopy, which can capture 3D information with axial resolution better than 2 μm in a 100 μm deep volume. Capturing a 3D image requires only a single camera exposure with a sub-millisecond laser pulse, allowing us to image cell cultures using five orders of magnitude less light energy than with confocal. This can be done with hardware costing ~ 1000. We use the instrument to image growth of MCF7 breast cancer cells and p. pastoras yeast. We acknowledge support from NSF GRFP.

  6. Digital Holographic Microscopy: Quantitative Phase Imaging and Applications in Live Cell Analysis

    Science.gov (United States)

    Kemper, Björn; Langehanenberg, Patrik; Kosmeier, Sebastian; Schlichthaber, Frank; Remmersmann, Christian; von Bally, Gert; Rommel, Christina; Dierker, Christian; Schnekenburger, Jürgen

    The analysis of complex processes in living cells creates a high demand for fast and label-free methods for online monitoring. Widely used fluorescence methods require specific labeling and are often restricted to chemically fixated samples. Thus, methods that offer label-free and minimally invasive detection of live cell processes and cell state alterations are of particular interest. In combination with light microscopy, digital holography provides label-free, multi-focus quantitative phase imaging of living cells. In overview, several methods for digital holographic microscopy (DHM) are presented. First, different experimental setups for the recording of digital holograms and the modular integration of DHM into common microscopes are described. Then the numerical processing of digitally captured holograms is explained. This includes the description of spatial and temporal phase shifting techniques, spatial filtering based reconstruction, holographic autofocusing, and the evaluation of self-interference holograms. Furthermore, the usage of partial coherent light and multi-wavelength approaches is discussed. Finally, potentials of digital holographic microscopy for quantitative cell imaging are illustrated by results from selected applications. It is shown that DHM can be used for automated tracking of migrating cells and cell thickness monitoring as well as for refractive index determination of cells and particles. Moreover, the use of DHM for label-free analysis in fluidics and micro-injection monitoring is demonstrated. The results show that DHM is a highly relevant method that allows novel insights in dynamic cell biology, with applications in cancer research and for drugs and toxicity testing.

  7. Holographic particle image velocimetry: a comparison of digital shearing and 3D correlation analysis methods

    Science.gov (United States)

    Yang, Hui; Alcock, Rob D.; Halliwell, Neil A.; Coupland, Jeremy M.

    2003-11-01

    In the past, the use of optical and digital three-dimensional correlation methods have been demonstrated to extract velocity data from the complex amplitude distribution of particle images in holographic particle image velocimetry (HPIV). Recently we have proposed a digital shearing method to extract three-component particle displacement data throughout a complete image field. In contrast to full three-dimensional correlation, it has been shown that all three components of particle image displacement can be retrieved using just four two-dimensional fast Fourier transform (FFT) operations and appropriate coordinate transformations. In this paper we describe three-dimensional correlation and digital shearing methods and compare their performance in terms of computational efficiency and measurement accuracy. The simulated results show that the digital shearing method has comparable accuracy to three-dimensional correlation but is significantly faster.

  8. Micro patterned surfaces: an effective tool for long term digital holographic microscopy cell imaging

    Science.gov (United States)

    Mues, Sarah; Lilge, Inga; Schönherr, Holger; Kemper, Björn; Schnekenburger, Jürgen

    2017-02-01

    The major problem of Digital Holographic Microscopy (DHM) long term live cell imaging is that over time most of the tracked cells move out of the image area and other ones move in. Therefore, most of the cells are lost for the evaluation of individual cellular processes. Here, we present an effective solution for this crucial problem of long-term microscopic live cell analysis. We have generated functionalized slides containing areas of 250 μm per 200 μm. These micropatterned biointerfaces consist of passivating polyaclrylamide brushes (PAAm). Inner areas are backfilled with octadecanthiol (ODT), which allows cell attachment. The fouling properties of these surfaces are highly controllable and therefore the defined areas designed for the size our microscopic image areas were effective in keeping all cells inside the rectangles over the selected imaging period.

  9. Holographic recording using a digital micromirror device

    Science.gov (United States)

    Nesbitt, Ryder S.; Smith, Steven L.; Molnar, Raymond A.; Benton, Stephen A.

    1999-03-01

    We describe the use of a digital micromirror device (Texas Instruments, Inc.'s DMDTM) as a spatial light modulator for holographic applications. Questions of the interferometric effects of the moving mirror structure and the appropriateness of pulse-width modulation for grayscale imaging are addressed. Compensation for the particular attributes of DMD imaging has allowed the creation of full-color holographic stereograms of high image quality.

  10. Evaluation of the metastatic potential of malignant cells by image processing of digital holographic microscopy data.

    Science.gov (United States)

    Calin, Violeta L; Mihailescu, Mona; Scarlat, Eugen I; Baluta, Alexandra V; Calin, Daniel; Kovacs, Eugenia; Savopol, Tudor; Moisescu, Mihaela G

    2017-10-01

    The cell refractive index has been proposed as a putative cancer biomarker of great potential, being correlated with cell content and morphology, cell division rate and membrane permeability. We used digital holographic microscopy to compare the refractive index and dry mass density of two B16 murine melanoma sublines of different metastatic potential. Using statistical methods, the distribution of phase shifts within the reconstructed quantitative phase images was analyzed by the method of bimodality coefficients. The observed correlation of refractive index, dry mass density and bimodality profile with the metastatic potential of the cells was validated by real time impedance-based assay and clonogenic tests. We suggest that the refractive index and bimodality analysis of quantitative phase image histograms could be developed as optical biomarkers useful in label-free detection and quantitative evaluation of cell metastatic potential.

  11. Application of the digital shearing method to extract three-component velocity in holographic particle image velocimetry

    Science.gov (United States)

    Yang, Hui; Halliwell, Neil; Coupland, Jeremy

    2004-04-01

    We have recently proposed a new method to extract the three-dimensional (3D) velocity vector data from double-exposure holographic particle image velocimetry (HPIV), which we call the digital shearing method. In contrast to the full 3D correlation, it has been shown that all three components (3Cs) of particle image displacement can be retrieved using six two-dimensional fast Fourier transform operations and appropriate coordinate transformations. In this paper we demonstrate the capabilities of this approach on actual HPIV data. The holographic recording method described uses an imaging system to record a hologram of high numerical aperture using a conventional 35 mm film. The holograms are digitized and particle images are reconstructed numerically. From particle images reconstructed from separate holograms, we illustrate the analysis process by computing the 3Cs of particle image displacement in a step-by-step manner.

  12. Examining live cell cultures during apoptosis by digital holographic phase imaging and Raman spectroscopy

    Science.gov (United States)

    Khmaladze, Alexander

    2017-11-01

    Cellular apoptosis is a unique, organized series of events, leading to programmed cell death. In this work, we present a combined digital holography/Raman spectroscopy technique to study live cell cultures during apoptosis. Digital holographic microscopy measurements of live cell cultures yield information about cell shape and volume, changes to which are indicative of alterations in cell cycle and initiation of cell death mechanisms. Raman spectroscopic measurements provide complementary information about cells, such as protein, lipid and nucleic acid content, and the spectral signatures associated with structural changes in molecules. Our work indicates that the chemical changes in proteins, which were detected by Raman measurements, preceded morphological changes, which were seen with digital holographic microscopy.

  13. Image plane digital holographic microscope for the inspection of ferroelectric single crystals.

    Czech Academy of Sciences Publication Activity Database

    Psota, Pavel; Mokrý, Pavel; Lédl, Vít; Vojtíšek, Petr

    2016-01-01

    Roč. 55, č. 12 (2016), č. článku 121731. ISSN 0091-3286 R&D Projects: GA ČR(CZ) GA14-32228S Institutional support: RVO:61389021 Keywords : Digital holography * barium titanate * domain pattern * ferroelectric crystals * holographic microscopy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.082, year: 2016 http://dx.doi.org/10.1117/1.OE.55.12.121731

  14. Digital hologram transformations for RGB color holographic display with independent image magnification and translation in 3D.

    Science.gov (United States)

    Makowski, Piotr L; Zaperty, Weronika; Kozacki, Tomasz

    2018-01-01

    A new framework for in-plane transformations of digital holograms (DHs) is proposed, which provides improved control over basic geometrical features of holographic images reconstructed optically in full color. The method is based on a Fourier hologram equivalent of the adaptive affine transformation technique [Opt. Express18, 8806 (2010)OPEXFF1094-408710.1364/OE.18.008806]. The solution includes four elementary geometrical transformations that can be performed independently on a full-color 3D image reconstructed from an RGB hologram: (i) transverse magnification; (ii) axial translation with minimized distortion; (iii) transverse translation; and (iv) viewing angle rotation. The independent character of transformations (i) and (ii) constitutes the main result of the work and plays a double role: (1) it simplifies synchronization of color components of the RGB image in the presence of mismatch between capture and display parameters; (2) provides improved control over position and size of the projected image, particularly the axial position, which opens new possibilities for efficient animation of holographic content. The approximate character of the operations (i) and (ii) is examined both analytically and experimentally using an RGB circular holographic display system. Additionally, a complex animation built from a single wide-aperture RGB Fourier hologram is presented to demonstrate full capabilities of the developed toolset.

  15. Experimental setup combining digital holographic microscopy (DHM) and fluorescence imaging to study gold nanoparticle mediated laser manipulation

    Science.gov (United States)

    Antonopoulos, Georgios C.; Rakoski, Mirko S.; Steltner, Benjamin; Kalies, Stefan; Ripken, Tammo; Meyer, Heiko

    2015-03-01

    Our research combines Digital Holographic Microscopy (DHM) and ˛uorescence microscopy to study the basic mechanisms of gold nanoparticle mediated laser manipulation. Herein we describe the technical aspects of the setup and holographic image reconstruction. Furthermore, results pertaining to cell volume change and calcium response of cells in laser manipulation will be presented and discussed. For the reconstruction of phase images from fringe image data, a phase unwrapping algorithm is presented that shows great potential to cope with the vast amount of data that was captured. This algorithm is a hybrid between a tile unwrapping technique and a path following unwrapper. It combines the robustness of a path following algorithm and a parallelizable tile unwrapping preprocessing step. The experimental setup enables simultaneous acquisition of ˛uorescence and phase images. For cell manipulation, a picosecond laser was coupled into the setup and weakly focused on cells incubated with gold nanoparticles. To study the cell volume change in the ˝rst minute, phase images were captured with a frame rate of 33 fps. Fluorescence images yielded the calcium signal of the cells as well as the dynamics of the F-actin cytoskeleton after irradiation. The setup is suitable to study fast changes in biophysical and morphological para

  16. Digital Holographic Microscopy Principles, Techniques, and Applications

    CERN Document Server

    Kim, Myung K

    2011-01-01

    Digital holography is an emerging field of new paradigm in general imaging applications. By replacing the photochemical procedures with electronic imaging and having a direct numerical access to the complex optical field, a wide range of new imaging capabilities become available, many of them difficult or infeasible in conventional holography. An increasing number of researchers—not only in optical physics and optical engineering, but also in diverse applications areas such as microbiology, medicine, marine science, particle analysis, microelectromechanics, and metrology—are realizing and exploiting the new capabilities of digital holography. Digital Holographic Microscopy: Principles, Techniques, and Applications, by Dr. Myung K. Kim, is intended to provide a brief but consistent introduction to the principles of digital holography as well as to give an organized overview of the large number of techniques and applications being developed. This will also shed some light on the range of possibilities for f...

  17. 3D real holographic image movies are projected into a volumetric display using dynamic digital micromirror device (DMD) holograms.

    Science.gov (United States)

    Huebschman, Michael L.; Hunt, Jeremy; Garner, Harold R.

    2006-04-01

    The Texas Instruments Digital Micromirror Device (DMD) is being used as the recording medium for display of pre-calculated digital holograms. The high intensity throughput of the reflected laser light from DMD holograms enables volumetric display of projected real images as well as virtual images. A single DMD and single laser projector system has been designed to reconstruct projected images in a 6''x 6''x 4.5'' volumetric display. The volumetric display is composed of twenty-four, 6''-square, PSCT liquid crystal plates which are each cycled on and off to reduce unnecessary scatter in the volume. The DMD is an XGA format array, 1024x768, with 13.6 micron pitch mirrors. This holographic projection system has been used in the assessment of hologram image resolution, maximum image size, optical focusing of the real image, image look-around, and physiological depth cues. Dynamic movement images are projected by transferring the appropriately sequenced holograms to the DMD at movie frame rates.

  18. Quantitative phase-digital holographic microscopy: a new imaging modality to identify original cellular biomarkers of diseases

    KAUST Repository

    Marquet, P.

    2016-05-03

    Quantitative phase microscopy (QPM) has recently emerged as a powerful label-free technique in the field of living cell imaging allowing to non-invasively measure with a nanometric axial sensitivity cell structure and dynamics. Since the phase retardation of a light wave when transmitted through the observed cells, namely the quantitative phase signal (QPS), is sensitive to both cellular thickness and intracellular refractive index related to the cellular content, its accurate analysis allows to derive various cell parameters and monitor specific cell processes, which are very likely to identify new cell biomarkers. Specifically, quantitative phase-digital holographic microscopy (QP-DHM), thanks to its numerical flexibility facilitating parallelization and automation processes, represents an appealing imaging modality to both identify original cellular biomarkers of diseases as well to explore the underlying pathophysiological processes.

  19. Holographic fluorescence microscopy with incoherent digital holographic adaptive optics.

    Science.gov (United States)

    Jang, Changwon; Kim, Jonghyun; Clark, David C; Lee, Seungjae; Lee, Byoungho; Kim, Myung K

    2015-01-01

    Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: selfinterference incoherent digital holography (SIDH). The SIDH generates a complex—i.e., amplitude plus phase—hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.

  20. Design and calibration of a digital Fourier holographic microscope for particle sizing via goniometry and optical scatter imaging in transmission.

    Science.gov (United States)

    Rossi, Vincent M; Jacques, Steven L

    2016-06-13

    Goniometry and optical scatter imaging have been used for optical determination of particle size based upon optical scattering. Polystyrene microspheres in suspension serve as a standard for system validation purposes. The design and calibration of a digital Fourier holographic microscope (DFHM) are reported. Of crucial importance is the appropriate scaling of scattering angle space in the conjugate Fourier plane. A detailed description of this calibration process is described. Spatial filtering of the acquired digital hologram to use photons scattered within a restricted angular range produces an image. A pair of images, one using photons narrowly scattered within 8 - 15° (LNA), and one using photons broadly scattered within 8 - 39° (HNA), are produced. An image based on the ratio of these two images, OSIR = HNA/LNA, following Boustany et al. (2002), yields a 2D Optical Scatter Image (OSI) whose contrast is based on the angular dependence of photon scattering and is sensitive to the microsphere size, especially in the 0.5-1.0µm range. Goniometric results are also given for polystyrene microspheres in suspension as additional proof of principle for particle sizing via the DFHM.

  1. Simple and fast spectral domain algorithm for quantitative phase imaging of living cells with digital holographic microscopy

    Science.gov (United States)

    Min, Junwei; Yao, Baoli; Ketelhut, Steffi; Kemper, Björn

    2017-02-01

    The modular combination of optical microscopes with digital holographic microscopy (DHM) has been proven to be a powerful tool for quantitative live cell imaging. The introduction of condenser and different microscope objectives (MO) simplifies the usage of the technique and makes it easier to measure different kinds of specimens with different magnifications. However, the high flexibility of illumination and imaging also causes variable phase aberrations that need to be eliminated for high resolution quantitative phase imaging. The existent phase aberrations compensation methods either require add additional elements into the reference arm or need specimen free reference areas or separate reference holograms to build up suitable digital phase masks. These inherent requirements make them unpractical for usage with highly variable illumination and imaging systems and prevent on-line monitoring of living cells. In this paper, we present a simple numerical method for phase aberration compensation based on the analysis of holograms in spatial frequency domain with capabilities for on-line quantitative phase imaging. From a single shot off-axis hologram, the whole phase aberration can be eliminated automatically without numerical fitting or pre-knowledge of the setup. The capabilities and robustness for quantitative phase imaging of living cancer cells are demonstrated.

  2. Imaging the 3D flow around swimming Chlamydomonas reinhardtii using digital inline holographic microscopy

    Science.gov (United States)

    Welch, Kyle; Kumar, Santosh; Hong, Jiarong; Cheng, Xiang

    2017-11-01

    Understanding the 3D flow induced by microswimmers is paramount to revealing how they interact with each other and their environment. While many studies have measured 2D projections of flow fields around single microorganisms, reliable 3D measurement remains elusive due to the difficulty in imaging fast 3D fluid flows at submicron spatial and millisecond temporal scales. Here, we present a precision measurement of the 3D flow field induced by motile planktonic algae cells, Chlamydomonas reinhardtii. We manually capture and hold stationary a single alga using a micropipette, while still allowing it to beat its flagella in the breastroke pattern characteristic to C. reinhardtii. The 3D flow field around the alga is then tracked by employing fast holographic imaging on 1 um tracer particles, which leads to a spatial resolution of 100 nm along the optical axis and 40 nm in the imaging plane normal to the optical axis. We image the flow around a single alga continuously through thousands of flagellar beat cycles and aggregate that data into a complete 3D flow field. Our study demonstrates the power of holography in imaging fast complex microscopic flow structures and provides crucial information for understanding the detailed locomotion of swimming microorganisms.

  3. Imaging the effect of hemoglobin on properties of RBCs using common-path digital holographic microscope

    Science.gov (United States)

    Joglekar, M.; Shah, H.; Trivedi, V.; Mahajan, S.; Chhaniwal, V.; Leitgeb, R.; Javidi, B.; Anand, A.

    2017-07-01

    Adequate supply of oxygen to the body is the most essential requirement. In vertebrate species this function is performed by Hemoglobin contained in red blood cells. The mass concentration of the Hb determines the oxygen carrying capacity of the blood. Thus it becomes necessary to determine its concentration in the blood, which helps in monitoring the health of a person. If the amount of Hb crosses certain range, then it is considered critical. As the Hb constitutes upto 96% of red blood cells dry content, it would be interesting to examine various physical and mechanical parameters of RBCs which depends upon its concentration. Various diseases bring about significant variation in the amount of hemoglobin which may alter certain parameters of the RBC such as surface area, volume, membrane fluctuation etc. The study of the variations of these parameters may be helpful in determining Hb content which will reflect the state of health of a human body leading to disease diagnosis. Any increase or decrease in the amount of Hb will change the density and hence the optical thickness of the RBCs, which affects the cell membrane and thereby changing its mechanical and physical properties. Here we describe the use of lateral shearing digital holographic microscope for quantifying the cell parameters for studying the change in biophysical properties of cells due to variation in hemoglobin concentration.

  4. Digital holographic microscopy for imaging biophysical changes in cells during migration (Conference Presentation)

    Science.gov (United States)

    Nham, Kien V.; Hur, Dong; Kim, Young-tae; Mohanty, Samarendra K.

    2016-03-01

    It is well known that biochemical changes in cancer cell occur in response to environmental cues and during migration. However, information about changes in the physical properties (e.g., volume, elasticity) of cancer cells during migration and/or in response to physical modulations (confinement and perturbations). We report the use of a near-infrared (NIR) laser microbeam system integrated with a NIR digital holographic microscopy (DHM) to study physical response of cancer cells. The cancer cells were cultured in microfluidic devices and subjected to different physical confinement (controlled by channel geometry), osmolarity changes of extracellular medium and/or laser-induced perturbations. The changes in optical thickness (or phase map) of the cells were monitored with high spatial and temporal resolution during and after the physico-chemical perturbations. A weakly-focused continuous-wave laser microbeam was used to impart radiation pressure on cell membrane and the changes in thickness were monitored using DHM to estimate elasticity. Further, an ultrafast tightly-focused laser microbeam was used to allow extracellular fluid flow into the cell or from the cytoplasm under different osmolarity conditions. Dynamic changes in physical properties of various cells and observed differences in responding to different physical/chemical environment/perturbations will be presented.

  5. Digital shearing method for three-dimensional data extraction in holographic particle image velocimetry

    Science.gov (United States)

    Yang, Hui; Halliwell, Neil; Coupland, Jeremy

    2003-11-01

    We report a new digital shearing method for extracting the three-dimensional displacement vector data from double-exposure holograms. With this method we can manipulate both the phase and the amplitude of the recorded signal, which, like optical correlation analysis, is inherently immune to imaging aberration. However, digital shearing is not a direct digital implementation of optical correlation, and a considerable saving in computation time results. We demonstrate the power of the method by MATLAB simulation and discuss its performance with reference to optical analysis.

  6. A low-cost digital holographic imager for calibration and validation of cloud microphysics remote sensing

    Science.gov (United States)

    Chambers, Thomas E.; Hamilton, Murray W.; Reid, Iain M.

    2016-10-01

    Clouds cover approximately 70% of the Earth's surface and therefore play a crucial rule in governing both the climate system and the hydrological cycle. The microphysical properties of clouds such as the cloud particle size distribution, shape distribution and spatial homogeneity contribute significantly to the net radiative effect of clouds and these properties must therefore be measured and understood to determine the exact contribution of clouds to the climate system. Significant discrepancies are observed between meteorological models and observations, particularly in polar regions that are most sensitive to changes in climate, suggesting a lack of understanding of these complex microphysical processes. Remote sensing techniques such as polarimetric LIDAR and radar allow microphysical cloud measurements with high temporal and spatial resolution however these instruments must be calibrated and validated by direct in situ measurements. To this end a low cost, light weight holographic imaging device has been developed and experimentally tested that is suitable for deployment on a weather balloon or tower structure to significantly increase the availability of in situ microphysics retrievals.

  7. Quantitative measurement of holographic image quality using Adobe Photoshop

    Science.gov (United States)

    Wesly, E.

    2013-02-01

    Measurement of the characteristics of image holograms in regards to diffraction efficiency and signal to noise ratio are demonstrated, using readily available digital cameras and image editing software. Illustrations and case studies, using currently available holographic recording materials, are presented.

  8. Quantitative measurement of holographic image quality using Adobe Photoshop

    International Nuclear Information System (INIS)

    Wesly, E

    2013-01-01

    Measurement of the characteristics of image holograms in regards to diffraction efficiency and signal to noise ratio are demonstrated, using readily available digital cameras and image editing software. Illustrations and case studies, using currently available holographic recording materials, are presented.

  9. Experimental research of digital holographic microscopic measuring

    Science.gov (United States)

    Zhu, Xueliang; Chen, Feifei; Li, Jicheng

    2013-06-01

    Digital holography is a new imaging technique, which is developed on the base of optical holography, Digital processing, and Computer techniques. It is using CCD instead of the conventional silver to record hologram, and then reproducing the 3D contour of the object by the way of computer simulation. Compared with the traditional optical holographic, the whole process is of simple measuring, lower production cost, faster the imaging speed, and with the advantages of non-contact real-time measurement. At present, it can be used in the fields of the morphology detection of tiny objects, micro deformation analysis, and biological cells shape measurement. It is one of the research hot spot at home and abroad. This paper introduced the basic principles and relevant theories about the optical holography and Digital holography, and researched the basic questions which influence the reproduce images in the process of recording and reconstructing of the digital holographic microcopy. In order to get a clear digital hologram, by analyzing the optical system structure, we discussed the recording distance and of the hologram. On the base of the theoretical studies, we established a measurement and analyzed the experimental conditions, then adjusted them to the system. To achieve a precise measurement of tiny object in three-dimension, we measured MEMS micro device for example, and obtained the reproduction three-dimensional contour, realized the three dimensional profile measurement of tiny object. According to the experiment results consider: analysis the reference factors between the zero-order term and a pair of twin-images by the choice of the object light and the reference light and the distance of the recording and reconstructing and the characteristics of reconstruction light on the measurement, the measurement errors were analyzed. The research result shows that the device owns certain reliability.

  10. Optofluidic bioimaging platform for quantitative phase imaging of lab on a chip devices using digital holographic microscopy.

    Science.gov (United States)

    Pandiyan, Vimal Prabhu; John, Renu

    2016-01-20

    We propose a versatile 3D phase-imaging microscope platform for real-time imaging of optomicrofluidic devices based on the principle of digital holographic microscopy (DHM). Lab-on-chip microfluidic devices fabricated on transparent polydimethylsiloxane (PDMS) and glass substrates have attained wide popularity in biological sensing applications. However, monitoring, visualization, and characterization of microfluidic devices, microfluidic flows, and the biochemical kinetics happening in these devices is difficult due to the lack of proper techniques for real-time imaging and analysis. The traditional bright-field microscopic techniques fail in imaging applications, as the microfluidic channels and the fluids carrying biological samples are transparent and not visible in bright light. Phase-based microscopy techniques that can image the phase of the microfluidic channel and changes in refractive indices due to the fluids and biological samples present in the channel are ideal for imaging the fluid flow dynamics in a microfluidic channel at high resolutions. This paper demonstrates three-dimensional imaging of a microfluidic device with nanometric depth precisions and high SNR. We demonstrate imaging of microelectrodes of nanometric thickness patterned on glass substrate and the microfluidic channel. Three-dimensional imaging of a transparent PDMS optomicrofluidic channel, fluid flow, and live yeast cell flow in this channel has been demonstrated using DHM. We also quantify the average velocity of fluid flow through the channel. In comparison to any conventional bright-field microscope, the 3D depth information in the images illustrated in this work carry much information about the biological system under observation. The results demonstrated in this paper prove the high potential of DHM in imaging optofluidic devices; detection of pathogens, cells, and bioanalytes on lab-on-chip devices; and in studying microfluidic dynamics in real time based on phase changes.

  11. Holographic video display using digital micromirrors (Invited Paper)

    Science.gov (United States)

    Huebschman, Michael L.; Munjuluri, Bala; Hunt, Jeremy; Garner, Harold R.

    2005-04-01

    We have established that the digital micromirror device (DMD), a component of the Texas Instrument Digital Light Processing system, can be used as a holographic medium by calculating a computer-generated hologram (CGH) and projecting multiple objects at various distances with a single hologram. Like other spatial light modulators (SLM), the DMD has the dynamic capability to display holograms at video rates. Unlike other SLMs, the high reflectivity of the DMD provides the intensity necessary to project a holographic 3D scene. We have characterized many of the properties for utilizing the DMD for holography, including the grating effect of the mirror arrays, resolution, viewing angle, field of view and the number of gray levels that can be displayed by the DMD. Several techniques and algorithms that were investigated to calculate the CGH for vivid display with a DMD are discussed. Prototypes of a holographic real image projection system and a virtual image viewer are being pursued. Since a good, low cost medium for displaying holographic projections does not yet exist, we are developing a volumetric display system consisting of a series of liquid-crystal layers with sequencing electronics. Analysis of image definition, inverted image overlap, and depth of field associated with the current projection system design are also presented. Potential uses of holographic viewing systems are reviewed along with methods for overcoming the challenges of using the DMD for the next generation holographic projection system.

  12. Exploring neural cell dynamics with digital holographic microscopy

    KAUST Repository

    Marquet, Pierre

    2013-07-11

    In this review, we summarize how the new concept of digital optics applied to the field of holographic microscopy has allowed the development of a reliable and flexible digital holographic quantitative phase microscopy (DH-QPM) technique at the nanoscale particularly suitable for cell imaging. Particular emphasis is placed on the original biological ormation provided by the quantitative phase signal. We present the most relevant DH-QPM applications in the field of cell biology, including automated cell counts, recognition, classification, three-dimensional tracking, discrimination between physiological and pathophysiological states, and the study of cell membrane fluctuations at the nanoscale. In the last part, original results show how DH-QPM can address two important issues in the field of neurobiology, namely, multiple-site optical recording of neuronal activity and noninvasive visualization of dendritic spine dynamics resulting from a full digital holographic microscopy tomographic approach. Copyright © 2013 by Annual Reviews.

  13. Digital holographic Michelson interferometer for nanometrology

    Science.gov (United States)

    Sevrygin, Alexander A.; Korotkov, V. I.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Yu.; Volkov, O. V.

    2014-11-01

    The paper considers the dynamic holographic interferometry schemes with amplification (multiplication) of holographic fringes and with correction for distortions, imposed by the interferometer scheme elements. The use of digital microscope and of the matrix light modulator with direct addressing provides the completely digital closed-loop performance of the overall system for real-time evaluation of nano-scale objects size. Considered schemes were verified in the laboratory experiment, using the Michelson micro-interferometer, equipped by the USB-microscope and digital holography stage, equipped by the Holoeye spatial light modulator.

  14. Cellular Dynamics Revealed by Digital Holographic Microscopy☆

    KAUST Repository

    Marquet, P.

    2016-11-22

    Digital holographic microscopy (DHM) is a new optical method that provides, without the use of any contrast agent, real-time, three-dimensional images of transparent living cells, with an axial sensitivity of a few tens of nanometers. They result from the hologram numerical reconstruction process, which permits a sub wavelength calculation of the phase shift, produced on the transmitted wave front, by the optically probed cells, namely the quantitative phase signal (QPS). Specifically, in addition to measurements of cellular surface morphometry and intracellular refractive index (RI), various biophysical cellular parameters including dry mass, absolute volume, membrane fluctuations at the nanoscale and biomechanical properties, transmembrane water permeability as swell as current, can be derived from the QPS. This article presents how quantitative phase DHM (QP-DHM) can explored cell dynamics at the nanoscale with a special attention to both the study of neuronal dynamics and the optical resolution of local neuronal network.

  15. HOLOGondel: A novel in-situ cloud measurement platform on a cable car with a digital holographic imager

    Science.gov (United States)

    Beck, Alexander; Henneberger, Jan; Kanji, Zamin; Lohmann, Ulrike

    2015-04-01

    Cloud particle properties observed in-situ are commonly conducted from airborne or ground-based measurements. When compared to airborne measurements, the advantages of ground-based measurements are a higher spatial resolution and much less costly to perform. However, ground-based observations allow only single-point measurements within a cloud. To overcome this disadvantage, a novel measurement platform with a digital holographic imager has been developed to allow in-situ cloud observations on the roof of a cable car cabin. With a traveling velocity of a cable car of a few m/s, such a measurement platform yields a spatial resolution comparable to those of ground-based measurements. In addition, it is possible to obtain vertical profiles of the microphysical properties within the cloud, because of the vertical distance covered by the cable car of approximately 800m. The major technical challenges for such a measurement platform are the lack of an external power supply and the additional weight constrain on a cable car cabin. To allow continuous operation for eight hours with a battery and to stay within the weight limit of 25kg at the same time, a compact design with carefully chosen material and components with a low power consumption was necessary. The new measurement platform HOLOGondel is equipped with a HOLographic Imager for Microscopic Objects (HOLIMO 3G). Digital in-line holography offers the advantages of measuring simultaneously an ensemble of cloud particles within a well-defined detection volume over a large range of particle size. The image captured, a hologram, yields information about the three-dimensional position, size and a shadow-graph of each particle within the detection volume. The HOLIMO 3G instrument is equipped with a 30MP camera and a 1.8 times magnifying, both-sided telecentric lens system. At a frame rate of six pictures per second a sample volume rate of about 100 cm3s-1 at a maximum resolution of 7 µm is achieved. This configuration

  16. Digital Holographic Capture and Optoelectronic Reconstruction for 3D Displays

    Directory of Open Access Journals (Sweden)

    Damien P. Kelly

    2010-01-01

    Full Text Available The application of digital holography as a viable solution to 3D capture and display technology is examined. A review of the current state of the field is presented in which some of the major challenges involved in a digital holographic solution are highlighted. These challenges include (i the removal of the DC and conjugate image terms, which are features of the holographic recording process, (ii the reduction of speckle noise, a characteristic of a coherent imaging process, (iii increasing the angular range of perspective of digital holograms (iv and replaying captured and/or processed digital holograms using spatial light modulators. Each of these challenges are examined theoretically and several solutions are put forward. Experimental results are presented that demonstrate the validity of the theoretical solutions.

  17. Human red blood cell recognition enhancement with three-dimensional morphological features obtained by digital holographic imaging

    Science.gov (United States)

    Jaferzadeh, Keyvan; Moon, Inkyu

    2016-12-01

    The classification of erythrocytes plays an important role in the field of hematological diagnosis, specifically blood disorders. Since the biconcave shape of red blood cell (RBC) is altered during the different stages of hematological disorders, we believe that the three-dimensional (3-D) morphological features of erythrocyte provide better classification results than conventional two-dimensional (2-D) features. Therefore, we introduce a set of 3-D features related to the morphological and chemical properties of RBC profile and try to evaluate the discrimination power of these features against 2-D features with a neural network classifier. The 3-D features include erythrocyte surface area, volume, average cell thickness, sphericity index, sphericity coefficient and functionality factor, MCH and MCHSD, and two newly introduced features extracted from the ring section of RBC at the single-cell level. In contrast, the 2-D features are RBC projected surface area, perimeter, radius, elongation, and projected surface area to perimeter ratio. All features are obtained from images visualized by off-axis digital holographic microscopy with a numerical reconstruction algorithm, and four categories of biconcave (doughnut shape), flat-disc, stomatocyte, and echinospherocyte RBCs are interested. Our experimental results demonstrate that the 3-D features can be more useful in RBC classification than the 2-D features. Finally, we choose the best feature set of the 2-D and 3-D features by sequential forward feature selection technique, which yields better discrimination results. We believe that the final feature set evaluated with a neural network classification strategy can improve the RBC classification accuracy.

  18. Digital Double-Pulse Holographic Interferometry for Vibration Analysis

    Directory of Open Access Journals (Sweden)

    H.J. Tiziani

    1996-01-01

    Full Text Available Different arrangements for double-pulsed holographic and speckle interferometry for vibration analysis will be described. Experimental results obtained with films (classical holographic interferometry and CCD cameras (digital holographic interferometry as storage materials are presented. In digital holography, two separate holograms of an object under test are recorded within a few microseconds using a CCD camera and are stored in a frame grabber. The phases of the two reconstructed wave fields are calculated from the complex amplitudes. The deformation is obtained from the phase difference. In the case of electronic speckle pattern interferometry (or image plane hologram, the phase can be calculated by using the sinusoid-fitting method. In the case of digital holographic interferometry, the phase is obtained by digital reconstruction of the complex amplitudes of the wave fronts. Using three directions of illumination and one direction of observation, all the information necessary for the reconstruction of the 3-dimensional deformation vector can be recorded at the same time. Applications of the method for measuring rotating objects are discussed where a derotator needs to be used.

  19. Micro patterned surfaces allow long-term digital holographic microscopy live cell imaging

    Science.gov (United States)

    Mues, Sarah; Lilge, Inga; Schönherr, Holger; Kemper, Björn; Schnekenburger, Jürgen

    2017-07-01

    During long-term imaging, cells move out of the field of view. We have generated functionalized substrates containing rectangular areas, which were capable in keeping cells over the whole observation period.

  20. Review of quantitative phase-digital holographic microscopy: promising novel imaging technique to resolve neuronal network activity and identify cellular biomarkers of psychiatric disorders

    KAUST Repository

    Marquet, Pierre

    2014-09-22

    Quantitative phase microscopy (QPM) has recently emerged as a new powerful quantitative imaging technique well suited to noninvasively explore a transparent specimen with a nanometric axial sensitivity. In this review, we expose the recent developments of quantitative phase-digital holographic microscopy (QP-DHM). Quantitative phase-digital holographic microscopy (QP-DHM) represents an important and efficient quantitative phase method to explore cell structure and dynamics. In a second part, the most relevant QPM applications in the field of cell biology are summarized. A particular emphasis is placed on the original biological information, which can be derived from the quantitative phase signal. In a third part, recent applications obtained, with QP-DHM in the field of cellular neuroscience, namely the possibility to optically resolve neuronal network activity and spine dynamics, are presented. Furthermore, potential applications of QPM related to psychiatry through the identification of new and original cell biomarkers that, when combined with a range of other biomarkers, could significantly contribute to the determination of high risk developmental trajectories for psychiatric disorders, are discussed.

  1. Speckle-free digital holographic recording of a diffusely reflecting object.

    Science.gov (United States)

    Kim, You Seok; Kim, Taegeun; Woo, Sung Soo; Kang, Hoonjong; Poon, Ting-Chung; Zhou, Changhe

    2013-04-08

    We demonstrate holographic recording without speckle noise using the digital holographic technique called optical scanning holography (OSH). First, we record a complex hologram of a diffusely reflecting (DR) object using OSH. The incoherent mode of OSH makes it possible to record the complex hologram without speckle noise. Second, we convert the complex hologram to an off-axis real hologram digitally and finally we reconstruct the real hologram using an amplitude-only spatial light modulator (SLM) without twin-image noise and speckle noise. To the best of our knowledge, this is the first time demonstrating digital holographic recording of a DR object without speckle noise.

  2. Vibration measurements by pulsed digital holographic endoscopy

    Science.gov (United States)

    Schedin, Staffan; Pedrini, Giancarlo; Perez-Lopez, Carlos; Mendoza Santoyo, Fernando

    2005-02-01

    Digital holographic interferometry in combination with a flexible fiber endoscope allows high precision measurements of deformations on hidden objects surfaces, inside cavities and objects with small access apertures. A digital holographic endoscopy system is described with a frequency-doubled, twin oscillator Q-switched pulsed Nd:YAG laser as light source. A sequence of digital hologram pairs are recorded with a maximum repetition rate of 260 ms. Each digital hologram is captured at separate video frames of a CCD-camera. The time separation between the laser pulses from each cavity can be set in the range from 50 to 500 μs. The digital holograms are transferred to a PC via a frame grabber and evaluated quantitatively by the Fourier transform method. The resulting phase fringe pattern has the information needed to evaluate quantitatively the amount of the deformation. Experimental results of vibration measurements of hidden mechanical and biological object surfaces are presented. The quality of the results obtained by mechanical object surfaces is usually higher than for biological surfaces. This can be explained easily by the fact that a biological surface is much more complex than a mechanical surface in the sense that some parts of the surface may reflect the light well whereas other parts may absorb the light. Also, biological surfaces are translucent, which means that part of the light may enter inside the sample where it may be absorbed or reflected.

  3. Holographic interferometry using a digital photo-camera

    International Nuclear Information System (INIS)

    Sekanina, H.; Hledik, S.

    2001-01-01

    The possibilities of running digital holographic interferometry using commonly available compact digital zoom photo-cameras are studied. The recently developed holographic setup, suitable especially for digital photo-cameras equipped with an un detachable object lens, is used. The method described enables a simple and straightforward way of both recording and reconstructing of a digital holographic interferograms. The feasibility of the new method is verified by digital reconstruction of the interferograms acquired, using a numerical code based on the fast Fourier transform. Experimental results obtained are presented and discussed. (authors)

  4. Contrast enhancing techniques in digital holographic microscopy

    International Nuclear Information System (INIS)

    Lobera, J; Coupland, J M

    2008-01-01

    A digital holographic microscope (DHM) can be considered as a microscope with an extended depth of field. From a single DHM recording the propagating component of the scattered field can be reconstructed in three dimensions (3D). As in conventional white light microscopy contrasting enhancing techniques can be applied to highlight characteristics of interest. If these techniques are used to enhance the reconstruction from a DHM, then it is important to understand the characteristics of these techniques in 3D. In this paper the performance of phase contrast, differential interference contrast, Hoffman and spiral phase contrast visualization methods are discussed in 3D

  5. Adaptive nonseparable vector lifting scheme for digital holographic data compression.

    Science.gov (United States)

    Xing, Yafei; Kaaniche, Mounir; Pesquet-Popescu, Béatrice; Dufaux, Frédéric

    2015-01-01

    Holographic data play a crucial role in recent three-dimensional imaging as well as microscopic applications. As a result, huge amounts of storage capacity will be involved for this kind of data. Therefore, it becomes necessary to develop efficient hologram compression schemes for storage and transmission purposes. In this paper, we focus on the shifted distance information, obtained by the phase-shifting algorithm, where two sets of difference data need to be encoded. More precisely, a nonseparable vector lifting scheme is investigated in order to exploit the two-dimensional characteristics of the holographic contents. Simulations performed on different digital holograms have shown the effectiveness of the proposed method in terms of bitrate saving and quality of object reconstruction.

  6. Three-dimensional shift-invariant pattern recognition in digital holographic microscopy

    Science.gov (United States)

    Wu, Ning; Halliwell, Neil A.; Coupland, Jeremy M.

    2006-04-01

    This paper reports a three-dimensional (3D) analysis of shift-invariant pattern recognition applied to holographic images reconstructed digitally from holographic microscopes. It is shown that the sequential application of a 2D filter to plane-by-plane reconstructions of an optical field is exactly equivalent to the application of a more general filter with a 3D impulse response. We show that any 3D filter with arbitrary impulse response can be implemented in this way. The process is illustrated (in 3D) by filtering a holographic image of different sized glass spheres suspended in water.

  7. Clustering of red blood cells using digital holographic microscopy

    Science.gov (United States)

    Jaferzadeh, K.; Ahmadzadeh, E.; Moon, I.; Gholami, S.

    2017-05-01

    Digital holographic microscopy can provide quantitative phase images (QPIs) of 3D profile of red blood cell (RBC) with nanometer accuracy. In this paper we propose applying k-means clustering method to cluster RBCs into two groups of young and old RBCs by using a four-dimensional feature vector. The features are RBC thickness average, surface area-volume ratio, sphericity coefficient and RBC perimeter that can be obtained from QPIs. The proposed features are related to the morphology of RBC. The experimental result shows that by utilizing the proposed method two groups of sphero-echinocytes (old RBCs) and non-spheroechinocytes RBCs can be perfectly clustered.

  8. Digital holographic reconstruction detection of localized corrosion arising from scratches

    Directory of Open Access Journals (Sweden)

    LIANG WANG

    2010-04-01

    Full Text Available In this study, electrochemical methods and the digital holographic reconstruction technique were combined to detect the localized scratch-induced corrosion process of Alloy 690 in 0.50 mol dm-3 H2SO4 containing 0.10 mol dm-3 NaCl. The numerical reconstruction method has been proved to be an effective technique to detect changes of solution concentration. One can obtain direct information from the reconstructed images and capture subtle more revealing changes. It provides a method to detect localized corrosion arising from scratches.

  9. Proton beam writing for producing holographic images

    International Nuclear Information System (INIS)

    Ow, Y.S.; Breese, M.B.H.; Bettiol, A.A.

    2009-01-01

    This work reports on the writing of computer generated hologram diffraction patterns using focused 2 MeV proton beam irradiation. These patterns were designed using a ray tracing algorithm and written directly into a thick polymethylmethacrylate layer. When the developed holographic pattern was illuminated with a 650 nm laser it produced a good reconstructed image. This work provides means of forming high-resolution, high aspect ratio holographic images in polymers for applications in data storage using switchable holography.

  10. Development of an Off-Axis Digital Holographic Microscope for Large Scale Measurement in Fluid Mechanics

    Science.gov (United States)

    Tamrin, K. F.; Rahmatullah, B.; Samuri, S. M.

    Holographic particle image velocimetry is a promising technique to probe and characterize complex flow dynamics since it is a truly three-dimensional (3D) three-component measurement technique. The technique simply records the coherent light scattered by small seeding particles that are assumed to faithfully follow the flow and uses it to reconstruct the event afterward. Reconstruction of the event is usually performed using a digital video microscope mounted on a 3D translation stage. The microscope records the intensity only which consequently results in loss of phase information. The objective of this paper is to develop and apply digital holographic microscopy with the aim to recover the phase information. Digital holographic microscopy has immense potentials in microscale solid and fluid measurements as it offers the possibility of digital wavefront processing by manipulating amplitude and phase of the recorded holograms. In this paper, we have developed an off-axis digital holographic microscope to capture both amplitude and phase of the reconstructed object simultaneously. This inherently solves twin image problem in the recorded digital holograms. The microscope was integrated into the reconstruction system and was successfully used to digitize holographic images of 10 μm polystyrene spheres and 1 μm olive oil droplets. The spatial resolution of the system is 0.63 μm, and the field of view is 1250 × 625 μm2. A 3D holographic reconstruction using a k-space analysis (wave-vector) of the optical field is applied to numerically refocus the images. Another potential application includes digital wavefront processing to compensate for aberration in the images.

  11. Exploring Neural Cell Dynamics with Digital Holographic Microscopy

    KAUST Repository

    Marquet, Pierre

    2013-04-21

    In this talk, I will present how digital holographic microscopy, as a powerful quantitative phase technique, can non-invasively measure cell dynamics and especially resolve local neuronal network activity through simultaneous multiple site optical recording.

  12. The digital holographic interferometry in resonant acoustic spectroscopy

    International Nuclear Information System (INIS)

    GAPONOV, V.E.; AZAMATOV, Z.T.; REDKORECHEV, V.I.; ISAEV, A.M.

    2014-01-01

    The opportunities of application of digital holographic interferometry method for studies of shapes of resonant modes in resonant acoustic spectroscopy are shown. The results of experimental measurements and analytical calculations are submitted. (authors)

  13. Towards 3C-3D digital holographic fluid velocity vector field measurement—tomographic digital holographic PIV (Tomo-HPIV)

    International Nuclear Information System (INIS)

    Soria, J; Atkinson, C

    2008-01-01

    Most unsteady and/or turbulent flows of geophysical and engineering interest have a highly three-dimensional (3D) complex topology and their experimental investigation is in pressing need of quantitative velocity measurement methods that are robust and can provide instantaneous 3C-3D velocity field data over a significant volumetric domain of the flow. This paper introduces and demonstrates a new method that uses multiple digital CCD array cameras to record in-line digital holograms of the same volume of seed particles from multiple orientations. This technique uses the same basic equipment as Tomo-PIV minus the camera lenses, it overcomes the depth-of-field problem of digital in-line holography and does not require the complex optical calibration of Tomo-PIV. The digital sensors can be oriented in an optimal manner to overcome the depth-of-field limitation of in-line holograms recorded using digital CCD or CMOS array cameras, resulting in a 3D reconstruction of the seed particles within the volume of interest, which can subsequently be analysed using 3D cross-correlation PIV analysis to yield a 3C-3D velocity field. A demonstration experiment of Tomo-HPIV using uniform translation with nominally 11 µm diameter seed particles shows that the 3D displacement derived from 3D cross-correlation Tomo-HPIV analysis can be measured within 5% of the imposed uniform translation, where the imposed uniform translation has an estimated standard uncertainty of 4.3%. So this paper proposes a multi-camera digital holographic imaging 3C-3D PIV method, which is identified as tomographic digital holographic PIV or Tomo-HPIV

  14. Particle image identification and correlation analysis in microscopic holographic particle image velocimetry

    International Nuclear Information System (INIS)

    Wormald, S. Andrew; Coupland, Jeremy

    2009-01-01

    This paper discusses the different analysis methods used in holographic particle image velocimetry to measure particle displacement and compares their relative performance. A digital holographic microscope is described and is used to record the light scattered by particles deposited on cover slides that are displaced between exposures. In this way, particle position and displacement are controlled and a numerical data set is generated. Data extraction using nearest neighbor analysis and correlation of either the reconstructed complex amplitude or intensity fields is then investigated.

  15. Particle image identification and correlation analysis in microscopic holographic particle image velocimetry

    Energy Technology Data Exchange (ETDEWEB)

    Wormald, S. Andrew; Coupland, Jeremy

    2009-11-20

    This paper discusses the different analysis methods used in holographic particle image velocimetry to measure particle displacement and compares their relative performance. A digital holographic microscope is described and is used to record the light scattered by particles deposited on cover slides that are displaced between exposures. In this way, particle position and displacement are controlled and a numerical data set is generated. Data extraction using nearest neighbor analysis and correlation of either the reconstructed complex amplitude or intensity fields is then investigated.

  16. High quality digital holographic reconstruction on analog film

    Science.gov (United States)

    Nelsen, B.; Hartmann, P.

    2017-05-01

    High quality real-time digital holographic reconstruction, i.e. at 30 Hz frame rates, has been at the forefront of research and has been hailed as the holy grail of display systems. While these efforts have produced a fascinating array of computer algorithms and technology, many applications of reconstructing high quality digital holograms do not require such high frame rates. In fact, applications such as 3D holographic lithography even require a stationary mask. Typical devices used for digital hologram reconstruction are based on spatial-light-modulator technology and this technology is great for reconstructing arbitrary holograms on the fly; however, it lacks the high spatial resolution achievable by its analog counterpart, holographic film. Analog holographic film is therefore the method of choice for reconstructing highquality static holograms. The challenge lies in taking a static, high-quality digitally calculated hologram and effectively writing it to holographic film. We have developed a theoretical system based on a tunable phase plate, an intensity adjustable high-coherence laser and a slip-stick based piezo rotation stage to effectively produce a digitally calculated hologram on analog film. The configuration reproduces the individual components, both the amplitude and phase, of the hologram in the Fourier domain. These Fourier components are then individually written on the holographic film after interfering with a reference beam. The system is analogous to writing angularly multiplexed plane waves with individual component phase control.

  17. Off-axis self-interference incoherent digital holographic microscopy

    Science.gov (United States)

    Jeon, Philjun; Lee, Heejung; So, Byunghwy; Hwang, Wonsang; Bae, Yoonsung; Kim, Dugyoung

    2017-03-01

    3D imaging is demanding technology required in fluorescence microscopy. Even though holography is a powerful technique, it could not be used easily in fluorescence microscopy because of low coherence of fluorescence light. Lately, several incoherent holographic methods such as scanning holography, Fresnel in coherent correlation holography (FINCH), and self-interference incoherent digital holography (SIDH) have been proposed. However, these methods have many problems to be overcome for practical applications. For example, DC term removal, twin image ambiguity, and phase unwrapping problems need to be resolved. Off-axis holography is a straightforward solution which can solve most of these problems. We built an off-axis SIDH system for fluorescence imaging, and investigated various conditions and requirements for practical holographic fluorescence microscopy. Our system is based on a modified Michelson interferometer with a flat mirror at one arm and a curved mirror at the other arm of the interferometer. We made a phantom 3D fluorescence object made of 2 single-mode fibers coupled to a single red LED source to mimic 2 fluorescence point sources distributed by a few tens of micrometers apart. A cooled EM-CCD was used to take holograms of these fiber ends which emit only around 180 nW power.

  18. Feasibility of automated dropsize distributions from holographic data using digital image processing techniques. [particle diameter measurement technique

    Science.gov (United States)

    Feinstein, S. P.; Girard, M. A.

    1979-01-01

    An automated technique for measuring particle diameters and their spatial coordinates from holographic reconstructions is being developed. Preliminary tests on actual cold-flow holograms of impinging jets indicate that a suitable discriminant algorithm consists of a Fourier-Gaussian noise filter and a contour thresholding technique. This process identifies circular as well as noncircular objects. The desired objects (in this case, circular or possibly ellipsoidal) are then selected automatically from the above set and stored with their parametric representations. From this data, dropsize distributions as a function of spatial coordinates can be generated and combustion effects due to hardware and/or physical variables studied.

  19. Wide field of view common-path lateral-shearing digital holographic interference microscope

    Science.gov (United States)

    Vora, Priyanka; Trivedi, Vismay; Mahajan, Swapnil; Patel, Nimit; Joglekar, Mugdha; Chhaniwal, Vani; Moradi, Ali-Reza; Javidi, Bahram; Anand, Arun

    2017-12-01

    Quantitative three-dimensional (3-D) imaging of living cells provides important information about the cell morphology and its time variation. Off-axis, digital holographic interference microscopy is an ideal tool for 3-D imaging, parameter extraction, and classification of living cells. Two-beam digital holographic microscopes, which are usually employed, provide high-quality 3-D images of micro-objects, albeit with lower temporal stability. Common-path digital holographic geometries, in which the reference beam is derived from the object beam, provide higher temporal stability along with high-quality 3-D images. Self-referencing geometry is the simplest of the common-path techniques, in which a portion of the object beam itself acts as the reference, leading to compact setups using fewer optical elements. However, it has reduced field of view, and the reference may contain object information. Here, we describe the development of a common-path digital holographic microscope, employing a shearing plate and converting one of the beams into a separate reference by employing a pin-hole. The setup is as compact as self-referencing geometry, while providing field of view as wide as that of a two-beam microscope. The microscope is tested by imaging and quantifying the morphology and dynamics of human erythrocytes.

  20. Magnonic holographic imaging of magnetic microstructures

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, D.; Chiang, H.; Bhowmick, T.; Volodchenkov, A.D.; Ranjbar, M.; Liu, G.; Jiang, C.; Warren, C. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khivintsev, Y.; Filimonov, Y. [Kotelnikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, Saratov Branch, Saratov 410019 (Russian Federation); Saratov State University, Saratov 410012 (Russian Federation); Garay, J.; Lake, R.; Balandin, A.A. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khitun, A., E-mail: akhitun@engr.ucr.edu [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States)

    2017-04-15

    We propose and demonstrate a technique for magnetic microstructure imaging via their interaction with propagating spin waves. In this approach, the object of interest is placed on top of a magnetic testbed made of material with low spin wave damping. There are micro-antennas incorporated in the testbed. Two of these antennas are used for spin wave excitation while another one is used for the detecting of inductive voltage produced by the interfering spin waves. The measurements are repeated for different phase differences between the spin wave generating antennas which is equivalent to changing the angle of illumination. The collected data appear as a 3D plot – the holographic image of the object. We present experimental data showing magnonic holographic images of a low-coercivity Si/Co sample, a high-coercivity sample made of SrFe{sub 12}O{sub 19} and a diamagnetic copper sample. We also present images of the three samples consisting of a different amount of SrFe{sub 12}O{sub 19} powder. The imaging was accomplished on a Y{sub 3}Fe{sub 2}(FeO{sub 4}){sub 3} testbed at room temperature. The obtained data reveal the unique magnonic signatures of the objects. Experimental data is complemented by the results of numerical modeling, which qualitatively explain the characteristic features of the images. Potentially, magnonic holographic imaging may complement existing techniques and be utilized for non-destructive in-situ magnetic object characterization. The fundamental physical limits of this approach are also discussed. - Highlights: • A technique for magnetic microstructure imaging via their interaction with propagating spin waves is proposed. • In this technique, magnetic structures appear as 3D objects. • Several holographic images of magnetic microstructures are presented.

  1. Magnonic holographic imaging of magnetic microstructures

    Science.gov (United States)

    Gutierrez, D.; Chiang, H.; Bhowmick, T.; Volodchenkov, A. D.; Ranjbar, M.; Liu, G.; Jiang, C.; Warren, C.; Khivintsev, Y.; Filimonov, Y.; Garay, J.; Lake, R.; Balandin, A. A.; Khitun, A.

    2017-04-01

    We propose and demonstrate a technique for magnetic microstructure imaging via their interaction with propagating spin waves. In this approach, the object of interest is placed on top of a magnetic testbed made of material with low spin wave damping. There are micro-antennas incorporated in the testbed. Two of these antennas are used for spin wave excitation while another one is used for the detecting of inductive voltage produced by the interfering spin waves. The measurements are repeated for different phase differences between the spin wave generating antennas which is equivalent to changing the angle of illumination. The collected data appear as a 3D plot - the holographic image of the object. We present experimental data showing magnonic holographic images of a low-coercivity Si/Co sample, a high-coercivity sample made of SrFe12O19 and a diamagnetic copper sample. We also present images of the three samples consisting of a different amount of SrFe12O19 powder. The imaging was accomplished on a Y3Fe2(FeO4)3 testbed at room temperature. The obtained data reveal the unique magnonic signatures of the objects. Experimental data is complemented by the results of numerical modeling, which qualitatively explain the characteristic features of the images. Potentially, magnonic holographic imaging may complement existing techniques and be utilized for non-destructive in-situ magnetic object characterization. The fundamental physical limits of this approach are also discussed.

  2. Readjusting image sharpness by numerical parametric lenses in Forbes-representation and Halton sampling for selective refocusing in digital holographic microscopy

    Science.gov (United States)

    Stuerwald, S.; Schmitt, R.

    2010-08-01

    Digital holographic microscopy (DHM) is utilized for quantitative phase contrast microscopy in optical testing of reflective or transparent specimens and allows altering the focus numerically by propagating the complex wave. Especially for compensation of deformations or displacements and for long-term investigations of living cells, a reliable region selective numerical readjustment of the focus is of particular interest in digital holographic microscopy. Since this method is time consuming, a Halton point set with low discrepancy has been chosen. By this, the effective axial resolution can be enhanced numerically by post processing of complex wave fronts without narrowing the field of view leading to a loss of information around the focus plane by blurring. The concept of numerical parametric lenses is another key feature in DHM and used to correct aberrations in the reconstructed wave front caused by the setup. To reduce the number of parameters for parametric lenses, the polynomial basis by Forbes is applied for the needs of DHM. Both numerical approaches have been characterized and adapted to the requirements of DHM. The applicability is demonstrated by results of investigations of engineered surfaces and biological cells.

  3. Holographic storage of three-dimensional image and data using photopolymer and polymer dispersed liquid crystal films

    International Nuclear Information System (INIS)

    Gao Hong-Yue; Liu Pan; Zeng Chao; Yao Qiu-Xiang; Zheng Zhiqiang; Liu Jicheng; Zheng Huadong; Yu Ying-Jie; Zeng Zhen-Xiang; Sun Tao

    2016-01-01

    We present holographic storage of three-dimensional (3D) images and data in a photopolymer film without any applied electric field. Its absorption and diffraction efficiency are measured, and reflective analog hologram of real object and image of digital information are recorded in the films. The photopolymer is compared with polymer dispersed liquid crystals as holographic materials. Besides holographic diffraction efficiency of the former is little lower than that of the latter, this work demonstrates that the photopolymer is more suitable for analog hologram and big data permanent storage because of its high definition and no need of high voltage electric field. Therefore, our study proposes a potential holographic storage material to apply in large size static 3D holographic displays, including analog hologram displays, digital hologram prints, and holographic disks. (special topic)

  4. Holographic storage of three-dimensional image and data using photopolymer and polymer dispersed liquid crystal films

    Science.gov (United States)

    Gao, Hong-Yue; Liu, Pan; Zeng, Chao; Yao, Qiu-Xiang; Zheng, Zhiqiang; Liu, Jicheng; Zheng, Huadong; Yu, Ying-Jie; Zeng, Zhen-Xiang; Sun, Tao

    2016-09-01

    We present holographic storage of three-dimensional (3D) images and data in a photopolymer film without any applied electric field. Its absorption and diffraction efficiency are measured, and reflective analog hologram of real object and image of digital information are recorded in the films. The photopolymer is compared with polymer dispersed liquid crystals as holographic materials. Besides holographic diffraction efficiency of the former is little lower than that of the latter, this work demonstrates that the photopolymer is more suitable for analog hologram and big data permanent storage because of its high definition and no need of high voltage electric field. Therefore, our study proposes a potential holographic storage material to apply in large size static 3D holographic displays, including analog hologram displays, digital hologram prints, and holographic disks. Project supported by the National Natural Science Foundation of China (Grant Nos. 11474194, 11004037, and 61101176) and the Natural Science Foundation of Shanghai, China (Grant No. 14ZR1415500).

  5. Multispectral digital lensless holographic microscopy: from femtosecond laser to white light LED

    Science.gov (United States)

    Garcia-Sucerquia, J.

    2015-04-01

    The use of femtosecond laser radiation and super bright white LED in digital lensless holographic microscopy is presented. For the ultrafast laser radiation two different configurations of operation of the microscope are presented and the dissimilar performance of each one analyzed. The microscope operating with a super bright white light LED in combination with optical filters shows very competitive performance as it is compared with more expensive optical sources. The broadband emission of both radiation sources allows the multispectral imaging of biological samples to obtain spectral responses and/or full color images of the microscopic specimens; sections of the head of a Drosophila melanogaster fly are imaged in this contribution. The simple, solid, compact, lightweight, and reliable architecture of digital lensless holographic microscopy operating with broadband light sources to image biological specimens exhibiting micrometer-sized details is evaluated in the present contribution.

  6. A direct-view customer-oriented digital holographic camera

    Science.gov (United States)

    Besaga, Vira R.; Gerhardt, Nils C.; Maksimyak, Peter P.; Hofmann, Martin R.

    2018-01-01

    In this paper, we propose a direct-view digital holographic camera system consisting mostly of customer-oriented components. The camera system is based on standard photographic units such as camera sensor and objective and is adapted to operate under off-axis external white-light illumination. The common-path geometry of the holographic module of the system ensures direct-view operation. The system can operate in both self-reference and self-interference modes. As a proof of system operability, we present reconstructed amplitude and phase information of a test sample.

  7. Volume Holographic Storage of Digital Data Implemented in Photorefractive Media

    Science.gov (United States)

    Heanue, John Frederick

    A holographic data storage system is fundamentally different from conventional storage devices. Information is recorded in a volume, rather than on a two-dimensional surface. Data is transferred in parallel, on a page-by -page basis, rather than serially. These properties, combined with a limited need for mechanical motion, lead to the potential for a storage system with high capacity, fast transfer rate, and short access time. The majority of previous volume holographic storage experiments have involved direct storage and retrieval of pictorial information. Success in the development of a practical holographic storage device requires an understanding of the performance capabilities of a digital system. This thesis presents a number of contributions toward this goal. A description of light diffraction from volume gratings is given. The results are used as the basis for a theoretical and numerical analysis of interpage crosstalk in both angular and wavelength multiplexed holographic storage. An analysis of photorefractive grating formation in photovoltaic media such as lithium niobate is presented along with steady-state expressions for the space-charge field in thermal fixing. Thermal fixing by room temperature recording followed by ion compensation at elevated temperatures is compared to simultaneous recording and compensation at high temperature. In particular, the tradeoff between diffraction efficiency and incomplete Bragg matching is evaluated. An experimental investigation of orthogonal phase code multiplexing is described. Two unique capabilities, the ability to perform arithmetic operations on stored data pages optically, rather than electronically, and encrypted data storage, are demonstrated. A comparison of digital signal representations, or channel codes, is carried out. The codes are compared in terms of bit-error rate performance at constant capacity. A well-known one-dimensional digital detection technique, maximum likelihood sequence estimation, is

  8. Sensor influence in digitalholographic interferometry

    International Nuclear Information System (INIS)

    Desse, J M; Picart, P; Tankam, P

    2011-01-01

    In digital holographic interferometry, the resolution of the reconstructed hologram depends on the pixel size and pixel number of the sensor used for recording. When different wavelengths are simultaneously used as a luminous source for the interferometer, the shape and the overlapping of three filters of a color sensor strongly influence the three reconstructed images. This problem can be directly visualized in 2D Fourier planes on red, green and blue channels. To better understand this problem and to avoid parasitic images generated at the reconstruction, three different sensors have been tested: a CCD sensor equipped with a Bayer filter, a Foveon sensor and a 3CCD sensor. The first one is a Bayer mosaic where one half of the pixels detect the green color and only one-quarter detect the red or blue color. As the missing data are interpolated among color detection positions, offsets and artifacts are generated. The second one is a specific sensor constituted with three stacked photodiode layers. Its technology is different from that of the classical color mosaic sensor because each pixel location detects the three colors simultaneously. So, the three colors are recorded simultaneously with identical spatial resolution, which corresponds to the spatial resolution of the sensor. However, the spectral curve of the sensor is large along each wavelength since the color segmentation is based on the penetration depth of the photons in silicon. Finally, with a 3CCD sensor, each image is recorded on three different sensors with the same resolution. In order to test the sensor influence, we have developed a specific optical bench which allows the near wake flow around a circular cylinder at Mach 0.45 to be characterized. Finally, best results have been obtained with the 3CDD sensor

  9. Innovative re-creation of realities in a holographic digital form

    Science.gov (United States)

    Wang, Shuo; Hebblewhite, Richard; Osanlou, Ardieshir; Excell, Peter; Di Gennaro, Sonia; Shi, Lishen

    2014-02-01

    Only nature can create, whereas humans can only re-create. This article is an exploration of synergies between art and science in digital holography in relation to art practice and the making of holograms as art works. This is achieved through involvement in the re-creation of a real object (a telescope) as a case study. A digital three-dimensional model suitable for holographic hard copy re-creation is produced. To explore special and immersive environment, real geographical landscape background from Google Earth is added to the model. After a brief introduction to visual art within the context of two and three-dimensional imaging in the form photography and holography, the whole process of producing the three-dimensional model and the environment in which it should be presented, ready for holographic printing is explained.

  10. Wavelength-coded volume holographic imaging endoscope for multidepth imaging.

    Science.gov (United States)

    Howlett, Isela D; Han, Wanglei; Rice, Photini; Barton, Jennifer K; Kostuk, Raymond K

    2017-10-01

    A wavelength-coded volume holographic imaging (WC-VHI) endoscope system capable of simultaneous multifocal imaging is presented. The system images light from two depths separated by 100  μm in a tissue sample by using axial chromatic dispersion of a gradient index probe in combination with two light-emitting diode sources and a multiplexed volume hologram to separate the images. This system is different from previous VHI systems in that it uses planar multiplexed gratings and does not require curved holographic gratings. This results in improved lateral imaging resolution from 228.1 to 322.5  lp/mm. This letter describes the design and fabrication of the WC-VHI endoscope and experimental images of hard and soft resolution targets and biological tissue samples to illustrate the performance properties. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  11. Spectral selective fluorescence molecular imaging with volume holographic imaging system

    Directory of Open Access Journals (Sweden)

    Yanlu Lv

    2016-03-01

    Full Text Available A compact volume holographic imaging (VHI method that can detect fluorescence objects located in diffusive medium in spectral selective imaging manner is presented. The enlargement of lateral field of view of the VHI system is realized by using broadband illumination and demagnification optics. Each target spectrum of fluorescence emitting from a diffusive medium is probed by tuning the inclination angle of the transmission volume holographic grating (VHG. With the use of the single transmission VHG, fluorescence images with different spectrum are obtained sequentially and precise three-dimensional (3D information of deep fluorescent objects located in a diffusive medium can be reconstructed from these images. The results of phantom experiments demonstrate that two fluorescent objects with a sub-millimeter distance can be resolved by spectral selective imaging.

  12. Digital Holographic Interferometry for Airborne Particle Characterization

    Science.gov (United States)

    2015-03-19

    Atmospheric and Energy Science, Center d’Energétique et de Thermique de Lyon, Lyon, France (2014). 3. Talk: Particle characterization with digital...Characterization, Journal of Quantitative Spectroscopy & Radiative Transfer (04 2014) Jing Wen, Matthew J. Berg, Matthew Steed. Scattering-based...Particulate-Systems Characterization, Journal of Quantitative Spectroscopy & Radiative Transfer (04 2013) Romain Ceolato, Matthew J. Berg, Nicolas

  13. Digital holographic diagnostics of near-injector region

    Science.gov (United States)

    Lee, Jaiho

    Study of primary breakup of liquid jets is important because it is motivated by the application to gas turbine fuel injectors, diesel fuel injectors, industrial cleaning and washing machine, medical spray, and inkjet printers, among others. When it comes to good injectors, a liquid jet has to be disintegrated into a fine spray near injector region during primary breakup. However the dense spray region near the injectors is optically obscure for Phase Doppler Interferometer like Phase Doppler Particle Analyzers (PDPA). Holography can provide three dimensional image of the dense spray and eliminate the problem of the small depth of focus associated with shadowgraphs. Traditional film-based holographic technique has long been used for three dimensional measurements in particle fields, but it is time consuming, expensive, chemically hazardous. With the development of the CCD sensor, holograms were recorded and reconstructed digitally. Digital microscopic holography (DMH) is similar to digital inline holography (DIH) except that no lens is used to collimate the object beam. The laser beams are expanded with an objective lens and a spatial filter. This eliminates two lenses from the typical optical path used for in-line holography, which results in a much cleaner hologram recording. The DMH was used for drop size and velocity measurements of the breakup of aerated liquid jets because it is unaffected by the non-spherical droplets that are encountered very close to the injector exit, which would cause problems for techniques such as Phase Doppler Particle Analyzer, otherwise. Large field of view was obtained by patching several high resolution holograms. Droplet velocities in three dimensions were measured by tracking their displacements in the streamwise and cross-stream direction and by tracking the change in the plane of focus in the spanwise direction. The uncertainty in spanwise droplet location and velocity measurements using single view DMH was large at least 33

  14. Comprehensive time average digital holographic vibrometry

    Czech Academy of Sciences Publication Activity Database

    Psota, Pavel; Lédl, Vít; Doleček, Roman; Mokrý, P.; Vojtíšek, Petr; Václavík, J.

    2016-01-01

    Roč. 55, č. 12 (2016), č. článku 121726. ISSN 0091-3286 R&D Projects: GA ČR(CZ) GA16-11965S Institutional support: RVO:61389021 Keywords : vibration analysis * digital holography * frequency shifting * phase modulation * acousto-optic modulators Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.082, year: 2016 http://dx. doi . org /10.1117/1.oe.55.12.121726

  15. Nano-level position resolution for particle tracking in digital in-line holographic microscopy.

    Science.gov (United States)

    Lei, H; Hu, X; Zhu, P; Chang, X; Zeng, Y; Hu, C; Li, H; Hu, X

    2015-10-01

    Three-dimensional particle tracking in biological systems is a quickly growing field, many techniques have been developed providing tracking characters. Digital in-line holographic microscopy is a valuable technique for particle tracking. However, the speckle noise, out-of-focus signals and twin image influenced the particle tracking. Here an adaptive noise reduction method based on bidimensional ensemble empirical mode decomposition is introduced into digital in-line holographic microscopy. It can eliminate the speckle noise and background of the hologram adaptively. Combined with the three-dimensional deconvolution approach in the reconstruction, the particle feature would be identified effectively. Tracking the fixed beads on the cover-glass with piezoelectric stage through multiple holographic images demonstrate the tracking resolution, which approaches 2 nm in axial direction and 1 nm in transverse direction. This would facilitate the development and use in the biological area such as living cells and single-molecule approaches. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  16. Simple concept for a wide-field lensless digital holographic microscope using a laser diode

    Directory of Open Access Journals (Sweden)

    Adinda-Ougba A.

    2015-09-01

    Full Text Available Wide-field, lensless digital holographic microscopy is a new microscopic imaging technique for telemedicine and for resource limited setting [1]. In this contribution we propose a very simple wide-field lensless digital holographic microscope using a laser diode. It is based on in-line digital holography which is capable to provide amplitude and phase images of a sample resulting from numerical reconstruction. The numerical reconstruction consists of the angular spectrum propagation method together with a phase retrieval algorithm. Amplitude and phase images of the sample with a resolution of ∽2 µm and with ∽24 mm2 field of view are obtained. We evaluate our setup by imaging first the 1951 USAF resolution test chart to verify the resolution. Second, we record holograms of blood smear and diatoms. The individual specimen can be easily identified after the numerical reconstruction. Our system is a very simple, compact and low-cost possibility of realizing a microscope capable of imaging biological samples. The availability of the phase provide topographic information of the sample extending the application of this system to be not only for biological sample but also for transparent microstructure. It is suitable for fault detection, shape and roughness measurements of these structures.

  17. Three-Dimensional Identification of Microorganisms Using a Digital Holographic Microscope

    Directory of Open Access Journals (Sweden)

    Ning Wu

    2013-01-01

    Full Text Available This paper reports a method for three-dimensional (3D analysis of shift-invariant pattern recognition and applies to holographic images digitally reconstructed from holographic microscopes. It is shown that the sequential application of a 2D filter to the plane-by-plane reconstruction of an optical field is exactly equivalent to the application of a more general filter with a 3D impulse response. We show that any 3D filters with arbitrary impulse response can be implemented in this way. This type of processing is applied to the two-class problem of distinguishing different types of bacteria. It is shown that the proposed technique can be easily implemented using a modified microscope to develop a powerful and cost-effective system with great potential for biological screening.

  18. Three-Dimensional Identification of Microorganisms Using a Digital Holographic Microscope

    Science.gov (United States)

    Wu, Ning; Wu, Xiang; Liang, Tiancai

    2013-01-01

    This paper reports a method for three-dimensional (3D) analysis of shift-invariant pattern recognition and applies to holographic images digitally reconstructed from holographic microscopes. It is shown that the sequential application of a 2D filter to the plane-by-plane reconstruction of an optical field is exactly equivalent to the application of a more general filter with a 3D impulse response. We show that any 3D filters with arbitrary impulse response can be implemented in this way. This type of processing is applied to the two-class problem of distinguishing different types of bacteria. It is shown that the proposed technique can be easily implemented using a modified microscope to develop a powerful and cost-effective system with great potential for biological screening. PMID:23606897

  19. Digital holographic-based cancellable biometric for personal authentication

    International Nuclear Information System (INIS)

    Verma, Gaurav; Sinha, Aloka

    2016-01-01

    In this paper, we propose a new digital holographic-based cancellable biometric scheme for personal authentication and verification. The realization of cancellable biometric is presented by using an optoelectronic experimental approach, in which an optically recorded hologram of the fingerprint of a person is numerically reconstructed. Each reconstructed feature has its own perspective, which is utilized to generate user-specific fingerprint features by using a feature-extraction process. New representations of the user-specific fingerprint features can be obtained from the same hologram, by changing the reconstruction distance (d) by an amount Δd between the recording plane and the reconstruction plane. This parameter is the key to make the cancellable user-specific fingerprint features using a digital holographic technique, which allows us to choose different reconstruction distances when reissuing the user-specific fingerprint features in the event of compromise. We have shown theoretically that each user-specific fingerprint feature has a unique identity with a high discrimination ability, and the chances of a match between them are minimal. In this aspect, a recognition system has also been demonstrated using the fingerprint biometric of the enrolled person at a particular reconstruction distance. For the performance evaluation of a fingerprint recognition system—the false acceptance ratio, the false rejection ratio and the equal error rate are calculated using correlation. The obtained results show good discrimination ability between the genuine and the impostor populations with the highest recognition rate of 98.23%. (paper)

  20. Color correction for chromatic distortion in a multi-wavelength digital holographic system

    International Nuclear Information System (INIS)

    Lin, Li-Chien; Huang, Yi-Lun; Tu, Han-Yen; Lai, Xin-Ji; Cheng, Chau-Jern

    2011-01-01

    A multi-wavelength digital holographic (MWDH) system has been developed to record and reconstruct color images. In comparison to working with digital cameras, however, high-quality color reproduction is difficult to achieve, because of the imperfections from the light sources, optical components, optical recording devices and recording processes. Thus, we face the problem of correcting the colors altered during the digital holographic process. We therefore propose a color correction scheme to correct the chromatic distortion caused by the MWDH system. The scheme consists of two steps: (1) creating a color correction profile and (2) applying it to the correction of the distorted colors. To create the color correction profile, we generate two algorithms: the sequential algorithm and the integrated algorithm. The ColorChecker is used to generate the distorted colors and their desired corrected colors. The relationship between these two color patches is fixed into a specific mathematical model, the parameters of which are estimated, creating the profile. Next, the profile is used to correct the color distortion of images, capturing and preserving the original vibrancy of the reproduced colors for different reconstructed images

  1. On measuring 3D flow within inkjet droplet streams using a digital holographic microscope

    Science.gov (United States)

    Wormald, S. A.; Coupland, J. M.

    2010-05-01

    With a view to measuring the internal and external flow fields in an inkjet droplet stream, this paper discusses the problem of imaging through droplet surfaces and more generally interfaces in two-phase flows. First the propagation of optical fields through interfaces between media of different refractive index is discussed with reference to scalar diffraction theory. Some approximations suitable for droplet imaging are then discussed and the use of a priori information is then explained. The imaging technique is applied to holograms recorded using a digital holographic microscope and is illustrated in the synthesis of a 3D image that is reconstructed through a cylindrical telecommunication fibre. Subsequently we demonstrate for the first time, high resolution imaging throughout an inkjet droplet. The practical implementation and improvement of these imaging methods for the measurement of two-phase flows is then discussed.

  2. Automatic cell identification and visualization using digital holographic microscopy with head mounted augmented reality devices.

    Science.gov (United States)

    O'Connor, Timothy; Rawat, Siddharth; Markman, Adam; Javidi, Bahram

    2018-03-01

    We propose a compact imaging system that integrates an augmented reality head mounted device with digital holographic microscopy for automated cell identification and visualization. A shearing interferometer is used to produce holograms of biological cells, which are recorded using customized smart glasses containing an external camera. After image acquisition, segmentation is performed to isolate regions of interest containing biological cells in the field-of-view, followed by digital reconstruction of the cells, which is used to generate a three-dimensional (3D) pseudocolor optical path length profile. Morphological features are extracted from the cell's optical path length map, including mean optical path length, coefficient of variation, optical volume, projected area, projected area to optical volume ratio, cell skewness, and cell kurtosis. Classification is performed using the random forest classifier, support vector machines, and K-nearest neighbor, and the results are compared. Finally, the augmented reality device displays the cell's pseudocolor 3D rendering of its optical path length profile, extracted features, and the identified cell's type or class. The proposed system could allow a healthcare worker to quickly visualize cells using augmented reality smart glasses and extract the relevant information for rapid diagnosis. To the best of our knowledge, this is the first report on the integration of digital holographic microscopy with augmented reality devices for automated cell identification and visualization.

  3. Movies of cellular and sub-cellular motion by digital holographic microscopy

    Directory of Open Access Journals (Sweden)

    Yu Lingfeng

    2006-03-01

    Full Text Available Abstract Background Many biological specimens, such as living cells and their intracellular components, often exhibit very little amplitude contrast, making it difficult for conventional bright field microscopes to distinguish them from their surroundings. To overcome this problem phase contrast techniques such as Zernike, Normarsky and dark-field microscopies have been developed to improve specimen visibility without chemically or physically altering them by the process of staining. These techniques have proven to be invaluable tools for studying living cells and furthering scientific understanding of fundamental cellular processes such as mitosis. However a drawback of these techniques is that direct quantitative phase imaging is not possible. Quantitative phase imaging is important because it enables determination of either the refractive index or optical thickness variations from the measured optical path length with sub-wavelength accuracy. Digital holography is an emergent phase contrast technique that offers an excellent approach in obtaining both qualitative and quantitative phase information from the hologram. A CCD camera is used to record a hologram onto a computer and numerical methods are subsequently applied to reconstruct the hologram to enable direct access to both phase and amplitude information. Another attractive feature of digital holography is the ability to focus on multiple focal planes from a single hologram, emulating the focusing control of a conventional microscope. Methods A modified Mach-Zender off-axis setup in transmission is used to record and reconstruct a number of holographic amplitude and phase images of cellular and sub-cellular features. Results Both cellular and sub-cellular features are imaged with sub-micron, diffraction-limited resolution. Movies of holographic amplitude and phase images of living microbes and cells are created from a series of holograms and reconstructed with numerically adjustable

  4. Adaptation of reference volumes for correlation-based digital holographic particle tracking

    Science.gov (United States)

    Hesseling, Christina; Peinke, Joachim; Gülker, Gerd

    2018-04-01

    Numerically reconstructed reference volumes tailored to particle images are used for particle position detection by means of three-dimensional correlation. After a first tracking of these positions, the experimentally recorded particle images are retrieved as a posteriori knowledge about the particle images in the system. This knowledge is used for a further refinement of the detected positions. A transparent description of the individual algorithm steps including the results retrieved with experimental data complete the paper. The work employs extraordinarily small particles, smaller than the pixel pitch of the camera sensor. It is the first approach known to the authors that combines numerical knowledge about particle images and particle images retrieved from the experimental system to an iterative particle tracking approach for digital holographic particle tracking velocimetry.

  5. Efficient Phase Unwrapping Architecture for Digital Holographic Microscopy

    Directory of Open Access Journals (Sweden)

    Wen-Jyi Hwang

    2011-09-01

    Full Text Available This paper presents a novel phase unwrapping architecture for accelerating the computational speed of digital holographic microscopy (DHM. A fast Fourier transform (FFT based phase unwrapping algorithm providing a minimum squared error solution is adopted for hardware implementation because of its simplicity and robustness to noise. The proposed architecture is realized in a pipeline fashion to maximize through put of thecomputation. Moreover, the number of hardware multipliers and dividers are minimized to reduce the hardware costs. The proposed architecture is used as a custom user logic in a system on programmable chip (SOPC for physical performance measurement. Experimental results reveal that the proposed architecture is effective for expediting the computational speed while consuming low hardware resources for designing an embedded DHM system.

  6. Analysis of dissected tissues with digital holographic microscopy: quantification of inflammation mediated tissue alteration, influence of sample preparation, and reliability of numerical autofocusing

    Science.gov (United States)

    Kemper, Björn; Lenz, Philipp; Bettenworth, Dominik; Krausewitz, Philipp; Domagk, Dirk; Ketelhut, Steffi

    2015-03-01

    Quantitative phase imaging with digital holographic microscopy (DHM) allows label-free imaging of tissue sections and quantification of the spatial refractive index distribution, which is of interest for applications in digital pathology. We show that DHM allows quantitative imaging of different layers in unstained tissue samples by detection of refractive index changes. In addition, we evaluate the automated refocussing feature of DHM for application on dissected tissues and could achieve highly reproducible holographic autofocusing for unstained and moderately stained samples. Finally, it is demonstrated that in human ulcerative colitis patients the average tissue refractive index is reduced significantly in all parts of the inflamed colonic wall in comparison to patients in remission.

  7. Characterization of the holographic imaging grating of GOMOS UVIS spectrometer

    Science.gov (United States)

    Graeffe, Jussi; Saari, Heikki K.; Astola, Heikki; Rainio, Kari; Mazuray, Lorand; Pierot, Dominique; Craen, Pierre; Gruslin, Michel; Lecat, Jean-Herve; Bonnemason, Francis; Flamand, Jean; Thevenon, Alain

    1996-11-01

    A Finnish-French group has proposed an imaging spectrometer- based instrument for the ENVISAT Earth observation satellite of ESA, which yields a global mapping of the vertical profile of ozone and other related atmospheric gases. The GOMOS instrument works by measuring the UV-visible spectrum of a star that is occulting behind the Earth's atmosphere. The prime contractor of GOMOS is Matra Marconi Space France. The focal plane optics are designed and manufactured by Spacebel Instrumentation S.A. and the holographic grating by Jobin-Yvon. VTT Automation, Measurement Technology has participated in the GOMOS studies since 1989 and is presently responsible for the verification tests of the imaging quality and opto-mechanical interfaces of the holographic imaging grating of GOMOS. The UVIS spectrometer of GOMOS consists of a holographic, aberration corrected grating and of a CCD detector. The alignment of the holographic grating needs as an input very accurate knowledge of the mechanical interfaces. VTT Automation has designed, built and tested a characterization system for the holographic grating. This system combines the accurate optical imaging measurements with the absolute knowledge of the geometrical parameters at the accuracy of plus or minus 10 micrometers which makes the system unique. The developed system has been used for two breadboard gratings and the qualification model grating. The imaging quality results and their analysis together with alignment procedure utilizing of the knowledge of mechanical interfaces is described.

  8. Radial super-resolution in digital holographic microscopy using structured illumination with circular symmetry

    Science.gov (United States)

    Yin, Yujian; Su, Ping; Ma, Jianshe

    2018-01-01

    A method to improve the radial resolution using special structured light is proposed in the field of digital holographic microscopy (DHM). A specimen is illuminated with circular symmetrical structured light that makes the spectrum have radial movement, so that high frequency components of the specimen are moved into the passband of the receiver to overcome the diffraction limit. In the DHM imaging system, Computer Generated Hologram (CGH) technology is used to generate the required structured light grating. Then the grating is loaded into a spatial light modulator (SLM) to obtain specific structured illumination. After recording the hologram, digital reconstruction, for the microstructure of a binary optical element that needs to observe radial distribution, the radial resolution of the specimen is improved experimentally compare it with the result of one-dimensional sinusoidal structured light imaging. And a method of designing structured light is presented.

  9. Analysis of reconstructed interference fields in digital holographic interferometry using the polynomial phase transform

    International Nuclear Information System (INIS)

    Gorthi, Sai Siva; Rastogi, Pramod

    2009-01-01

    A noisy wrapped phase map is the end-output of commonly employed phase estimation methods in digital holographic interferometry. Hence filtering and unwrapping are necessary to obtain continuous phase distributions. This paper introduces a new approach for phase estimation in digital holographic interferometry using the polynomial phase transform. The proposed approach directly provides an accurate estimation of the unwrapped phase distribution from a noisy reconstructed interference field, thereby bypassing cumbersome and error-prone filtering and 2D phase unwrapping procedures

  10. 3D measurements of live cells via digital holographic microscopy and terahertz spectroscopy

    Science.gov (United States)

    Park, Jun Yong; Oser, Dorian; Iapozzuto, Peter; Norbury, Sean; Mahajan, Supriya; Khmaladze, Alexander; Sharikova, Anna

    2016-03-01

    This is a study of the central nervous system (CNS) cells, including brain micro vascular endothelial cells (BMV) that constitute the blood brain barrier, and C6 glial cells that are the predominant cell in the brain. The cells are exposed to various chemicals by non-invasive, label-free methods. Digital holographic microscopy (DHM) is a technique that records an interference pattern between an object and reference waves, so that the computationally reconstructed holographic image contains both amplitude and phase information, and 3D images are obtained. The measurement of cell cultures by digital holographic microscopy yields information about cell death mechanisms, since these processes are correlated with individual cell volume. Our in-house DHM combines a visible (red) laser source with a conventional microscope base, and LabVIEW-run data processing. Terahertz spectral signatures are associated with structural changes in molecules and provide complementary information about cells. Both CNS cells BMV and C6 cells are treated with the drug "Methamphetamine" (METH), which induces apoptosis in neuronal cells and exhibits decrease in cell volume, a characteristic of cells undergoing apoptosis (induced cell death). METH can cause CNS cell death by cross-talk between mitochondria-, endoplasmic reticulum-, and receptor-mediated apoptotic events, all of which results in drug induced changes in neuroplasticity and significant neuropathology. Doxorubicin (DOX), a popular anticancer drug, is used as a control. We observe that METH treatment resulted in more pronounced cell volume shrinkage in both the BMV and C6 cells, as compared to DOX-induced cell apoptosis.

  11. Digital holographic setups for phase object measurements in micro and macro scale

    Directory of Open Access Journals (Sweden)

    Lédl Vít

    2015-01-01

    Full Text Available The measurement of properties of so called phase objects is being solved for more than one Century starting probably with schlieren technique 1. Classical interferometry served as a great measurement tool for several decades and was replaced by holographic interferometry, which disposes with many benefits when compared to classical interferometry. Holographic interferometry undergone an enormous development in last decade when digital holography has been established as a standard technique and most of the drawbacks were solved. The paper deals with scope of the huge applicability of digital holographic interferometry in heat and mass transfer measurement from micro to macro scale and from simple 2D measurement up to complex tomographic techniques. Recently the very complex experimental setups are under development in our labs combining many techniques leading to digital holographic micro tomography methods.

  12. Early cell death detection with digital holographic microscopy.

    Directory of Open Access Journals (Sweden)

    Nicolas Pavillon

    Full Text Available BACKGROUND: Digital holography provides a non-invasive measurement of the quantitative phase shifts induced by cells in culture, which can be related to cell volume changes. It has been shown previously that regulation of cell volume, in particular as it relates to ionic homeostasis, is crucially involved in the activation/inactivation of the cell death processes. We thus present here an application of digital holographic microscopy (DHM dedicated to early and label-free detection of cell death. METHODS AND FINDINGS: We provide quantitative measurements of phase signal obtained on mouse cortical neurons, and caused by early neuronal cell volume regulation triggered by excitotoxic concentrations of L-glutamate. We show that the efficiency of this early regulation of cell volume detected by DHM, is correlated with the occurrence of subsequent neuronal death assessed with the widely accepted trypan blue method for detection of cell viability. CONCLUSIONS: The determination of the phase signal by DHM provides a simple and rapid optical method for the early detection of cell death.

  13. New approaches for the analysis of confluent cell layers with quantitative phase digital holographic microscopy

    Science.gov (United States)

    Pohl, L.; Kaiser, M.; Ketelhut, S.; Pereira, S.; Goycoolea, F.; Kemper, Björn

    2016-03-01

    Digital holographic microscopy (DHM) enables high resolution non-destructive inspection of technical surfaces and minimally-invasive label-free live cell imaging. However, the analysis of confluent cell layers represents a challenge as quantitative DHM phase images in this case do not provide sufficient information for image segmentation, determination of the cellular dry mass or calculation of the cell thickness. We present novel strategies for the analysis of confluent cell layers with quantitative DHM phase contrast utilizing a histogram based-evaluation procedure. The applicability of our approach is illustrated by quantification of drug induced cell morphology changes and it is shown that the method is capable to quantify reliable global morphology changes of confluent cell layers.

  14. Imaging and Measuring Electron Beam Dose Distributions Using Holographic Interferometry

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1975-01-01

    Holographic interferometry was used to image and measure ionizing radiation depth-dose and isodose distributions in transparent liquids. Both broad and narrowly collimated electron beams from accelerators (2–10 MeV) provided short irradiation times of 30 ns to 0.6 s. Holographic images...... and measurements of absorbed dose distributions were achieved in liquids of various densities and thermal properties and in water layers thinner than the electron range and with backings of materials of various densities and atomic numbers. The lowest detectable dose in some liquids was of the order of a few k......Rad. The precision limits of the measurement of dose were found to be ±4%. The procedure was simple and the holographic equipment stable and compact, thus allowing experimentation under routine laboratory conditions and limited space....

  15. Near real-time digital holographic microscope based on GPU parallel computing

    Science.gov (United States)

    Zhu, Gang; Zhao, Zhixiong; Wang, Huarui; Yang, Yan

    2018-01-01

    A transmission near real-time digital holographic microscope with in-line and off-axis light path is presented, in which the parallel computing technology based on compute unified device architecture (CUDA) and digital holographic microscopy are combined. Compared to other holographic microscopes, which have to implement reconstruction in multiple focal planes and are time-consuming the reconstruction speed of the near real-time digital holographic microscope can be greatly improved with the parallel computing technology based on CUDA, so it is especially suitable for measurements of particle field in micrometer and nanometer scale. Simulations and experiments show that the proposed transmission digital holographic microscope can accurately measure and display the velocity of particle field in micrometer scale, and the average velocity error is lower than 10%.With the graphic processing units(GPU), the computing time of the 100 reconstruction planes(512×512 grids) is lower than 120ms, while it is 4.9s using traditional reconstruction method by CPU. The reconstruction speed has been raised by 40 times. In other words, it can handle holograms at 8.3 frames per second and the near real-time measurement and display of particle velocity field are realized. The real-time three-dimensional reconstruction of particle velocity field is expected to achieve by further optimization of software and hardware. Keywords: digital holographic microscope,

  16. Polarization digital holographic microscopy using low-cost liquid crystal polarization rotators

    Science.gov (United States)

    Dovhaliuk, Rostyslav Yu

    2018-02-01

    Polarization imaging methods are actively used to study anisotropic objects. A number of methods and systems, such as imaging polarimeters, were proposed to measure the state of polarization of light that passed through the object. Digital holographic and interferometric approaches can be used to quantitatively measure both amplitude and phase of a wavefront. Using polarization modulation optics, the measurement capabilities of such interference-based systems can be extended to measure polarization-dependent parameters, such as phase retardation. Different kinds of polarization rotators can be used to alternate the polarization of a reference beam. Liquid crystals are used in a rapidly increasing number of different optoelectronic devices. Twisted nematic liquid crystals are widely used as amplitude modulators in electronic displays and light valves or shutter glass. Such devices are of particular interest for polarization imaging, as they can be used as polarization rotators, and due to large-scale manufacturing have relatively low cost. A simple Mach-Zehnder polarized holographic setup that uses modified shutter glass as a polarization rotator is demonstrated. The suggested approach is experimentally validated by measuring retardation of quarter-wave film.

  17. Characterization of the reference wave in a compact digital holographic camera.

    Science.gov (United States)

    Park, I S; Middleton, R J C; Coggrave, C R; Ruiz, P D; Coupland, J M

    2018-01-01

    A hologram is a recording of the interference between an unknown object wave and a coherent reference wave. Providing the object and reference waves are sufficiently separated in some region of space and the reference beam is known, a high-fidelity reconstruction of the object wave is possible. In traditional optical holography, high-quality reconstruction is achieved by careful reillumination of the holographic plate with the exact same reference wave that was used at the recording stage. To reconstruct high-quality digital holograms the exact parameters of the reference wave must be known mathematically. This paper discusses a technique that obtains the mathematical parameters that characterize a strongly divergent reference wave that originates from a fiber source in a new compact digital holographic camera. This is a lensless design that is similar in principle to a Fourier hologram, but because of the large numerical aperture, the usual paraxial approximations cannot be applied and the Fourier relationship is inexact. To characterize the reference wave, recordings of quasi-planar object waves are made at various angles of incidence using a Dammann grating. An optimization process is then used to find the reference wave that reconstructs a stigmatic image of the object wave regardless of the angle of incidence.

  18. Expressions for third-order aberration theory for holographic images

    Indian Academy of Sciences (India)

    Expressions for third-order aberration theory for holographic images. S K TRIPATHY and S ANANDA RAO. Department of Physics, Jagannath Institute for Technology and Management,. Parlakhemundi 761 200, India. Email: sukantatripathy@sify.com. MS received 14 September 2001; revised 5 August 2002. Abstract.

  19. Compensation of phase aberration by using a virtual confocal scheme in digital holographic microscopy.

    Science.gov (United States)

    Chew, Yang-Kun; Shiu, Min-Tzung; Wang, Je-Chung; Chang, Chi-Ching

    2014-09-20

    This work presents cost-effective, simple arbitrary phase-step digital holographic microscopy to suppress both zero-order and twin-image terms. A virtual confocal offset lens under in-line configuration is also used to compensate for the introduced quadratic phase by using a microscope objective lens. In addition to reducing the difficulties of physical confocal configurations, the proposed method significantly increases the magnification power, ultimately achieving the purposes of an optical zoom. An attempt is also made to reduce the noise interference of a high magnification system by developing a long focal lens to reduce light detection size, subsequently gaining an approximately plane wave light source to illuminate the object within the effective depth of focus. Experimental results indicate that the proposed high magnification system can be elevated with low noise interference, and image reconstruction without quadratic phase terms.

  20. Quantitative assessment of cancer cell morphology and motility using telecentric digital holographic microscopy and machine learning.

    Science.gov (United States)

    Lam, Van K; Nguyen, Thanh C; Chung, Byung M; Nehmetallah, George; Raub, Christopher B

    2018-03-01

    The noninvasive, fast acquisition of quantitative phase maps using digital holographic microscopy (DHM) allows tracking of rapid cellular motility on transparent substrates. On two-dimensional surfaces in vitro, MDA-MB-231 cancer cells assume several morphologies related to the mode of migration and substrate stiffness, relevant to mechanisms of cancer invasiveness in vivo. The quantitative phase information from DHM may accurately classify adhesive cancer cell subpopulations with clinical relevance. To test this, cells from the invasive breast cancer MDA-MB-231 cell line were cultured on glass, tissue-culture treated polystyrene, and collagen hydrogels, and imaged with DHM followed by epifluorescence microscopy after staining F-actin and nuclei. Trends in cell phase parameters were tracked on the different substrates, during cell division, and during matrix adhesion, relating them to F-actin features. Support vector machine learning algorithms were trained and tested using parameters from holographic phase reconstructions and cell geometric features from conventional phase images, and used to distinguish between elongated and rounded cell morphologies. DHM was able to distinguish between elongated and rounded morphologies of MDA-MB-231 cells with 94% accuracy, compared to 83% accuracy using cell geometric features from conventional brightfield microscopy. This finding indicates the potential of DHM to detect and monitor cancer cell morphologies relevant to cell cycle phase status, substrate adhesion, and motility. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  1. Digital holographic microscopy for detection of Trypanosoma cruzi parasites in fresh blood mounts

    Science.gov (United States)

    Romero, G. G.; Monaldi, A. C.; Alanís, E. E.

    2012-03-01

    An off-axis holographic microscope, in a transmission mode, calibrated to automatically detect the presence of Trypanosoma cruzi in blood is developed as an alternative diagnosis tool for Chagas disease. Movements of the microorganisms are detected by measuring the phase shift they produce on the transmitted wave front. A thin layer of blood infected by Trypanosoma cruzi parasites is examined in the holographic microscope, the images of the visual field being registered with a CCD camera. Two consecutive holograms of the same visual field are subtracted point by point and a phase contrast image of the resulting hologram is reconstructed by means of the angular spectrum propagation algorithm. This method enables the measurement of phase distributions corresponding to temporal differences between digital holograms in order to detect whether parasites are present or not. Experimental results obtained using this technique show that it is an efficient alternative that can be incorporated successfully as a part of a fully automatic system for detection and counting of this type of microorganisms.

  2. Real-time, auto-focusing digital holographic microscope using graphics processors.

    Science.gov (United States)

    Doğar, Mert; İlhan, Hazar A; Özcan, Meriç

    2013-08-01

    The most significant advantage of holographic imaging is that one does not need to do focusing alignment for the scene or objects while capturing their images. To focus on a particular object recorded in a digital hologram, a post-processing on the recorded image must be performed. This post-processing, so called the reconstruction, is essentially the calculation of wave propagation in free space. If the object's optical distance to the recording plane is not known a priori, focusing methods are used to estimate this distance. However, these operations can be quite time consuming as the hologram sizes increase. When there is a time constraint on these procedures and the image resolution is high, traditional central processing units (CPUs) can no longer satisfy the desired reconstruction speeds. Then, especially for real-time operations, additional hardware accelerators are required for reconstructing high resolution holograms. To this extend, today's commercial graphic cards offer a viable solution, as the holograms can be reconstructed tens of times faster with a graphics processing unit than with the state-of-the-art CPUs. Here we present an auto-focusing megapixel-resolution digital holographic microscope (DHM) that uses a graphics processing unit (GPU) as the calculation engine. The computational power of the GPU allows the DHM to work in real-time such that the reconstruction distance is estimated unsupervised, and the post-processing of the holograms are made completely transparent to the user. We compare DHM with GPU and CPU and present experimental results showing a maximum of 70 focused reconstructions per second (frps) with 1024 × 1024 pixel holograms.

  3. High efficiency and flexible working distance digital in-line holographic microscopy based on Fresnel zone plate

    Science.gov (United States)

    Tian, Peng; Hua, Yilei; Yang, Fan; Li, Fanxing; Hu, Song; Yan, Wei

    2017-05-01

    Traditional digital in-line holography suffers from twin-image noise problems and extremely short working distances between the object and light source. Here, we propose lensless Fourier transform digital in-line holographic microscopy based on a single optical element. A Fresnel zone plate is used to split the incident light into two parts: one is scattered along the original direction, the other is gathered at a focal point and the sample is put behind the focus. The interference fringe pattern, formed by the two beams, is recorded digitally by a CCD camera. A novel reconstruction algorithm is proposed to present the object image. The proof-of-concept experiments demonstrate that the proposed technique can eliminate the twin-image noise problem, improving the image contrast with high efficiency, and increasing the flexibility of the working distance. Furthermore, a wide field of view and no contact make it a promising tool for the study of materials science, biology and microelectronics.

  4. Lensless digital holographic microscopy and its applications in biomedicine and environmental monitoring

    KAUST Repository

    Wu, Yichen

    2017-08-31

    Optical compound microscope has been a major tool in biomedical imaging for centuries. Its performance relies on relatively complicated, bulky and expensive lenses and alignment mechanics. In contrast, the lensless microscope digitally reconstructs microscopic images of specimens without using any lenses, as a result of which it can be made much smaller, lighter and lower-cost. Furthermore, the limited space-bandwidth product of objective lenses in a conventional microscope can be significantly surpassed by a lensless microscope. Such lensless imaging designs have enabled high-resolution and high-throughput imaging of specimens using compact, portable and cost-effective devices to potentially address various point-of-care, global-health and telemedicine related challenges. In this review, we discuss the operation principles and the methods behind lensless digital holographic on-chip microscopy. We also go over various applications that are enabled by cost-effective and compact implementations of lensless microscopy, including some recent work on air quality monitoring, which utilized machine learning for high-throughput and accurate quantification of particulate matter in air. Finally, we conclude with a brief future outlook of this computational imaging technology.

  5. Second-harmonic illumination to enhance multispectral digital lensless holographic microscopy.

    Science.gov (United States)

    Mendoza-Yero, Omel; Carbonell-Leal, Miguel; Lancis, Jesús; Garcia-Sucerquia, Jorge

    2016-03-01

    Multispectral digital lensless holographic microscopy (MDLHM) operating with second-harmonic illumination is shown. Added to the improvement of the spatial resolution of the previously reported MDLHM operating with near-infrared illumination, this second-harmonic MDLHM shows promise as a tool to study the behavior of biological samples under a broad spectral illumination. This illumination is generated by focusing a highly spatially coherent ultrashort pulsed radiation into an uncoated Type 1 β-BaB2O4 (BBO) nonlinear crystal. The second-harmonic MDLHM allows achieving multispectral images of biological samples with enhanced micrometer spatial resolution. The illumination wavelength of the second-harmonic MDLHM can be tuned by displacing a focusing optics with respect to a pinhole; spatially resolved information at different wavelengths of the sample can then be retrieved.

  6. Robust, compact implementation of an off-axis digital holographic microscope.

    Science.gov (United States)

    Wallace, J Kent; Rider, Stephanie; Serabyn, Eugene; Kühn, Jonas; Liewer, Kurt; Deming, Jody; Showalter, Gordon; Lindensmith, Chris; Nadeau, Jay

    2015-06-29

    Recent advances in digital technologies, such as high-speed computers and large-format digital imagers, have led to a burgeoning interest in the science and engineering of digital holographic microscopy (DHM). Here we report on a novel off-axis DHM, based on a twin-beam optical design, which avoids the limitations of prior systems, and provides many advantages, including compactness, intrinsic stability, robustness against misalignment, ease of use, and cost. These advantages are traded for a physically constrained sample volume, as well as a fixed fringe spacing. The first trade is not overly restrictive for most applications, and the latter provides for a pre-set assembly alignment that optimizes the spatial frequency sampling. Moreover, our new design supports use in both routine laboratory settings as well as extreme environments without any sacrifice in performance, enabling ready observation of microbial species in the field. The instrument design is presented in detail here, along with a demonstration of bacterial video imaging at sub-micrometer resolution at temperatures down to -15 °C.

  7. Holographic particle image velocimetry: optical conjugate reconstruction using a simplified transmission geometry

    Science.gov (United States)

    Alcock, Rob D.; Garner, Colin P.; Halliwell, Neil A.; Coupland, Jeremy M.

    2003-11-01

    A new simplified Holographic Particle Image Velocimetry technique to make simultaneous measurements of 3D velocity vector information throughout a complex fluid flow is presented in this paper. The method uses a variation of Optical Conjugate Reconstruction with complex correlation analysis and dispenses with the need to have a Holographic Optical Element to correct for distortions introduced by non-uniform windows. Subsequent analysis to extract a map of particle velocity is performed digitally using ray tracing techniques to model the effect of the windows. Results are presented for measurements made within a thick windowed diesel engine, showing that flow velocity vectors can be measured to an accuracy of 3% using the technique and, illustrating the ray trace mapping procedure.

  8. Automated Fourier space region-recognition filtering for off-axis digital holographic microscopy.

    Science.gov (United States)

    He, Xuefei; Nguyen, Chuong Vinh; Pratap, Mrinalini; Zheng, Yujie; Wang, Yi; Nisbet, David R; Williams, Richard J; Rug, Melanie; Maier, Alexander G; Lee, Woei Ming

    2016-08-01

    Automated label-free quantitative imaging of biological samples can greatly benefit high throughput diseases diagnosis. Digital holographic microscopy (DHM) is a powerful quantitative label-free imaging tool that retrieves structural details of cellular samples non-invasively. In off-axis DHM, a proper spatial filtering window in Fourier space is crucial to the quality of reconstructed phase image. Here we describe a region-recognition approach that combines shape recognition with an iterative thresholding method to extracts the optimal shape of frequency components. The region recognition technique offers fully automated adaptive filtering that can operate with a variety of samples and imaging conditions. When imaging through optically scattering biological hydrogel matrix, the technique surpasses previous histogram thresholding techniques without requiring any manual intervention. Finally, we automate the extraction of the statistical difference of optical height between malaria parasite infected and uninfected red blood cells. The method described here paves way to greater autonomy in automated DHM imaging for imaging live cell in thick cell cultures.

  9. Biophysical monitoring of cell cultures for quality assessment utilizing digital holographic microscopy

    Science.gov (United States)

    Kastl, Lena; Isbach, Michael; Dirksen, Dieter; Schnekenburger, Jürgen; Kemper, Björn

    2017-06-01

    Quality and reproducibility of cell-based assays strongly depend on the quality of the underlying cell culture which is influenced by various parameters like nutrient and growth factor availability, buffer conditions, subculture routines and optimal cell concentrations. Thus, methods for accurate assessment of objective cell parameters that characterize a specific cell line and detect global changes in cell culture are highly desirable. During the past years, quantitative phase imaging has been recognized as a promising tool for quantitative label-free live cell analysis. We demonstrate the utilization of quantitative phase imaging with digital holographic microscopy (DHM) to quantify the impact of cell culture conditions on single cells using a pancreatic tumor cell model. Label-free quantitative phase imaging of detached cells in suspension is performed by Michelson interferometer-based self-interference DHM. The quantitative phase images of the cells are analyzed for refractive index, volume and dry mass. We show that the evaluation of quantitative DHM phase images allows to extract absolute biophysical cellular parameters that are related to cell layer confluence states. In summary, the results of our study demonstrate that DHM is capable for label-free imaging cytometry with novel biophysical data sets that are acquired with minimum sample preparation for sophisticated monitoring of cell morphology alterations that are related to changes of cell culture conditions.

  10. Bacteriorhodopsin as a high-resolution, high-capacity buffer for digital holographic measurements

    Science.gov (United States)

    Barnhart, D. H.; Koek, W. D.; Juchem, T.; Hampp, N.; Coupland, J. M.; Halliwell, N. A.

    2004-04-01

    Recent trends in optical metrology suggest that, in order for holographic measurement to become a widespread tool, it must be based on methods that do not require physical development of the hologram. While digital holography has been successfully demonstrated in recent years, unfortunately the limited information capacity of present electronic sensors, such as CCD arrays, is still many orders of magnitude away from directly competing with the high-resolution silver halide plates used in traditional holography. As a result, present digital holographic methods with current electronic sensors cannot record object sizes larger than several hundred microns at high resolution. In this paper, the authors report on the use of bacteriorhodopsin (BR) for digital holography to overcome these limitations. In particular, BR is a real-time recording medium with an information capacity (5000 line-pairs/mm) that even exceeds high resolution photographic film. As such, a centimetre-square area of BR film has the same information capacity of several hundred state-of-the-art CCD cameras. For digital holography, BR temporarily holds the hologram record so that its information content can be digitized for numeric reconstruction. In addition, this paper examines the use of BR for optical reconstruction without chemical development. When correctly managed, it is found that BR is highly effective, in terms of both quality and process time, for three-dimensional holographic measurements. Consequently, several key holographic applications, based on BR, are proposed in this paper.

  11. Measurement of spatial refractive index distributions of fusion spliced optical fibers by digital holographic microtomography

    Science.gov (United States)

    Pan, Feng; Deng, Yating; Ma, Xichao; Xiao, Wen

    2017-11-01

    Digital holographic microtomography is improved and applied to the measurements of three-dimensional refractive index distributions of fusion spliced optical fibers. Tomographic images are reconstructed from full-angle phase projection images obtained with a setup-rotation approach, in which the laser source, the optical system and the image sensor are arranged on an optical breadboard and synchronously rotated around the fixed object. For retrieving high-quality tomographic images, a numerical method is proposed to compensate the unwanted movements of the object in the lateral, axial and vertical directions during rotation. The compensation is implemented on the two-dimensional phase images instead of the sinogram. The experimental results exhibit distinctly the internal structures of fusion splices between a single-mode fiber and other fibers, including a multi-mode fiber, a panda polarization maintaining fiber, a bow-tie polarization maintaining fiber and a photonic crystal fiber. In particular, the internal structure distortion in the fusion areas can be intuitively observed, such as the expansion of the stress zones of polarization maintaining fibers, the collapse of the air holes of photonic crystal fibers, etc.

  12. Pulsed holographic system for imaging through spatially extended scattering media

    Science.gov (United States)

    Kanaev, A. V.; Judd, K. P.; Lebow, P.; Watnik, A. T.; Novak, K. M.; Lindle, J. R.

    2017-10-01

    Imaging through scattering media is a highly sought capability for military, industrial, and medical applications. Unfortunately, nearly all recent progress was achieved in microscopic light propagation and/or light propagation through thin or weak scatterers which is mostly pertinent to medical research field. Sensing at long ranges through extended scattering media, for example turbid water or dense fog, still represents significant challenge and the best results are demonstrated using conventional approaches of time- or range-gating. The imaging range of such systems is constrained by their ability to distinguish a few ballistic photons that reach the detector from the background, scattered, and ambient photons, as well as from detector noise. Holography can potentially enhance time-gating by taking advantage of extra signal filtering based on coherence properties of the ballistic photons as well as by employing coherent addition of multiple frames. In a holographic imaging scheme ballistic photons of the imaging pulse are reflected from a target and interfered with the reference pulse at the detector creating a hologram. Related approaches were demonstrated previously in one-way imaging through thin biological samples and other microscopic scale scatterers. In this work, we investigate performance of holographic imaging systems under conditions of extreme scattering (less than one signal photon per pixel signal), demonstrate advantages of coherent addition of images recovered from holograms, and discuss image quality dependence on the ratio of the signal and reference beam power.

  13. Study of optical techniques for the Ames unitary wind tunnel: Digital image processing, part 6

    Science.gov (United States)

    Lee, George

    1993-01-01

    A survey of digital image processing techniques and processing systems for aerodynamic images has been conducted. These images covered many types of flows and were generated by many types of flow diagnostics. These include laser vapor screens, infrared cameras, laser holographic interferometry, Schlieren, and luminescent paints. Some general digital image processing systems, imaging networks, optical sensors, and image computing chips were briefly reviewed. Possible digital imaging network systems for the Ames Unitary Wind Tunnel were explored.

  14. Automatic phase aberration compensation for digital holographic microscopy based on deep learning background detection.

    Science.gov (United States)

    Nguyen, Thanh; Bui, Vy; Lam, Van; Raub, Christopher B; Chang, Lin-Ching; Nehmetallah, George

    2017-06-26

    We propose a fully automatic technique to obtain aberration free quantitative phase imaging in digital holographic microscopy (DHM) based on deep learning. The traditional DHM solves the phase aberration compensation problem by manually detecting the background for quantitative measurement. This would be a drawback in real time implementation and for dynamic processes such as cell migration phenomena. A recent automatic aberration compensation approach using principle component analysis (PCA) in DHM avoids human intervention regardless of the cells' motion. However, it corrects spherical/elliptical aberration only and disregards the higher order aberrations. Traditional image segmentation techniques can be employed to spatially detect cell locations. Ideally, automatic image segmentation techniques make real time measurement possible. However, existing automatic unsupervised segmentation techniques have poor performance when applied to DHM phase images because of aberrations and speckle noise. In this paper, we propose a novel method that combines a supervised deep learning technique with convolutional neural network (CNN) and Zernike polynomial fitting (ZPF). The deep learning CNN is implemented to perform automatic background region detection that allows for ZPF to compute the self-conjugated phase to compensate for most aberrations.

  15. Digital cine-imaging

    International Nuclear Information System (INIS)

    Masuda, Kazuhiro

    1992-01-01

    Digitization of fluoroscopic images has been developed for the digital cine imaging system as a result of the computer technology, television technology, and popularization of interventional radiology. Present digital cine imaging system is able to offer images similar to cine film because of the higher operatability and better image quality with the development of interventional radiology. As a result, its higher usefulness for catheter diagnosis examination except for interventional radiology was reported, and the possibility of having filmless cine is close to becoming a reality. However several problems have been pointed out, such as spatial resolution, time resolution, storage and exchangeability of data, disconsolidated viewing functions, etc. Anyhow, digital cine imaging system has some unresolved points and lots the needs to be discussed. The tendency of digitization is the passage of the time and we have to promote a study for more useful digital cine imaging system in team medical treatment which centers on the patients. (author)

  16. Holographic laser Doppler imaging of pulsatile blood flow

    Science.gov (United States)

    Bencteux, Jeffrey; Pagnoux, Pierre; Kostas, Thomas; Bayat, Sam; Atlan, Michael

    2015-06-01

    We report on wide-field imaging of pulsatile motion induced by blood flow using heterodyne holographic interferometry on the thumb of a healthy volunteer, in real time. Optical Doppler images were measured with green laser light by a frequency-shifted Mach-Zehnder interferometer in off-axis configuration. The recorded optical signal was linked to local instantaneous out-of-plane motion of the skin at velocities of a few hundreds of microns per second and compared to blood pulse monitored by plethysmoraphy during an occlusion-reperfusion experiment.

  17. A new ball-on-disk vacuum tribometer with in situ measurement of the wear track by digital holographic microscopy

    Science.gov (United States)

    Meylan, B.; Ciani, D.; Zhang, B.; Cuche, E.; Wasmer, K.

    2017-12-01

    This contribution presents a new ball-on-disk vacuum tribometer with in situ measurement of the wear track by digital holographic microscopy. This new tribometer allows observation of the evolution of the wear track in situ and in real-time. The method combines a high vacuum high temperature ball-on-disk tribometer with a digital holographic microscope (DHM). The machine was tested and validated by taking DHM images during wear tests at room temperature and in vacuum at 2 · 10-6 of polished 100Cr6 steel disks. We demonstrated that the DHM system is well suited to monitor the evolution of the wear track during sliding. We found that, with an acquisition time of 0.1 ms for the DHM, the maximal linear speed is 10 cm s-1 to have reliable images. We proved, via scanning electron microscope (SEM) pictures, that the lines in the sliding direction in all DHM images exist. We also validated the new tribometer by having an excellent correlation between the images and profiles of the wear track taken by the DHM with the ones from a confocal microscope. Finally, the new tribometer combined with the DHM has four advantages. It can test under vacuum and various atmospheric conditions. The evolution of the wear track is measured in situ and in real-time. Hence, the problem of replacing the sample is avoided. Thanks to the DHM technology, the vertical accuracy of the topographical measurement is 4 nm.

  18. Refocus criterion for both phase and amplitude objects in digital holographic microscopy.

    Science.gov (United States)

    Dubois, Frank; El Mallahi, Ahmed; Dohet-Eraly, Jérôme; Yourassowsky, Catherine

    2014-08-01

    For digital holographic microscopy applications, we modify the focus criterion based on the integration of the amplitude modulus to make possible its use regardless of the phase or amplitude nature of the objects under test. When applied on holographic data, the original criterion gives, at the focus plane, a minimum or a maximum, for amplitude or phase objects. The criterion we propose here operates on high-pass filtered complex amplitudes. It is shown that the proposed criterion gives a minimum for both types of objects when the focus plane is reached. Experimental results on real samples and simulations are provided, illustrating the efficiency and the potential of the method.

  19. Improvements on digital inline holographic PTV for 3D wall-bounded turbulent flow measurements

    Science.gov (United States)

    Toloui, Mostafa; Mallery, Kevin; Hong, Jiarong

    2017-04-01

    Three-dimensional (3D) particle image velocimetry (PIV) and particle tracking velocimetry (PTV) provide the most comprehensive flow information for unraveling the physical phenomena in a wide range of fluid problems, from microfluidics to wall-bounded turbulent flows. Compared with other 3D PIV techniques, such as tomographic PIV and defocusing PIV, the digital inline holographic PTV (DIH-PTV) provides 3D flow measurement solution with high spatial resolution, low cost optical setup, and easy alignment and calibration. Despite these advantages, DIH-PTV suffers from major limitations including poor longitudinal resolution, human intervention (i.e. requirement for manually determined tuning parameters during tracer field reconstruction and extraction), limited tracer concentration, small sampling volume and expensive computations, limiting its broad use for 3D flow measurements. In this study, we present our latest developments on minimizing these challenges, which enables high-fidelity DIH-PTV implementation to larger sampling volumes with significantly higher particle seeding densities suitable for wall-bounded turbulent flow measurements. The improvements include: (1) adjustable window thresholding; (2) multi-pass 3D tracking; (3) automatic wall localization; and (4) continuity-based out-of-plane velocity component computation. The accuracy of the proposed DIH-PTV method is validated with conventional 2D PIV and double-view holographic PTV measurements in smooth-wall turbulent channel flow experiments. The capability of the technique in characterization of wall-bounded turbulence is further demonstrated through its application to flow measurements for smooth- and rough-wall turbulent channel flows. In these experiments, 3D velocity fields are measured within sampling volumes of 14.7  ×  50.0  ×  14.4 mm3 (covering the entire depth of the channel) with a velocity resolution of  art 3D whole-field flow measurement techniques.

  20. Holographic images reconstructed from GMR-based fringe pattern

    Directory of Open Access Journals (Sweden)

    Kikuchi Hiroshi

    2013-01-01

    Full Text Available We have developed a magneto-optical spatial light modulator (MOSLM using giant magneto-resistance (GMR structures for realizing a holographic three-dimensional (3D display. For practical applications, reconstructed image of hologram consisting of GMR structures should be investigated in order to study the feasibility of the MOSLM. In this study, we fabricated a hologram with GMR based fringe-pattern and demonstrated a reconstructed image. A fringe-pattern convolving a crossshaped image was calculated by a conventional binary computer generated hologram (CGH technique. The CGH-pattern has 2,048 × 2,048 with 5 μm pixel pitch. The GMR stack consists of a Tb-Fe-Co/CoFe pinned layer, a Ag spacer, a Gd-Fe free layer for light modulation, and a Ru capping layer, was deposited by dc-magnetron sputtering. The GMR hologram was formed using photo-lithography and Krion milling processes, followed by the deposition of a Tb-Fe-Co reference layer with large coercivity and the same Kerr-rotation angle compared to the free layer, and a lift-off process. The reconstructed image of the ON-state was clearly observed and successfully distinguished from the OFF-state by switching the magnetization direction of the free-layer with an external magnetic field. These results indicate the possibility of realizing a holographic 3D display by the MOSLM using the GMR structures.

  1. Human genome sequencing with direct x-ray holographic imaging

    International Nuclear Information System (INIS)

    Rhodes, C.K.

    1993-01-01

    Direct holographic imaging of biological materials is widely applicable to the study of the structure, properties and action of genetic material. This particular application involves the sequencing of the human genome where prospective genomic imaging technology is composed of three subtechnologies, name an x-ray holographic camera, suitable chemistry and enzymology for the preparation of tagged DNA samples, and the illuminator in the form of an x-ray laser. We report appropriate x-ray camera, embodied by the instrument developed by MCR, is available and that suitable chemical and enzymatic procedures exist for the preparation of the necessary tagged DNA strands. Concerning the future development of the x-ray illuminator. We find that a practical small scale x-ray light source is indeed feasible. This outcome requires the use of unconventional physical processes in order to achieve the necessary power-compression in the amplifying medium. The understanding of these new physical mechanisms is developing rapidly. Importantly, although the x-ray source does not currently exist, the understanding of these new physical mechanisms is developing rapidly and the research has established the basic scaling laws that will determine the properties of the x-ray illuminator. When this x-ray source becomes available, an extremely rapid and cost effective instrument for 3-D imaging of biological materials can be applied to a wide range of biological structural assays, including the base-pair sequencing of the human genome and many questions regarding its higher levels of organization

  2. Holographic 3D imaging through diffuse media by compressive sampling of the mutual intensity

    Science.gov (United States)

    Falldorf, Claas; Klein, Thorsten; Agour, Mostafa; Bergmann, Ralf B.

    2017-05-01

    We present a method for holographic imaging through a volume scattering material, which is based on selfreference and light with good spatial but limited temporal coherence. In contrast to existing techniques, we do not require a separate reference wave, thus our approach provides great advantages towards the flexibility of the measurement system. The main applications are remote sensing and investigation of moving objects through gaseous streams, bubbles or foggy water for example. Furthermore, due to the common path nature, the system is also insensitive to mechanical disturbances. The measurement result is a complex amplitude which is comparable to a phase shifted digital hologramm and therefore allows 3D imaging, numerical refocusing and quantitative phase contrast imaging. As an example of application, we present measurements of the quantitative phase contrast of the epidermis of an onion through a volume scattering material.

  3. Holographic Particle Image Velocimetry and its Application in Engine Development

    Energy Technology Data Exchange (ETDEWEB)

    Coupland, J M; Garner, C P; Alcock, R D; Halliwell, N A [Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Ashby Road, Lougborough, Leics. LE11 3TU (United Kingdom)

    2006-07-15

    This paper reviews Holographic Particle Image Velocimetry (HPIV) as a means to make three-component velocity measurements throughout a three-dimensional flow-field of interest. A simplified treatment of three-dimensional scalar wave propagation is outlined and subsequently used to illustrate the principles of complex correlation analysis. It is shown that this type of analysis provides the three-dimensional correlation of the propagating, monochromatic fields recorded by the hologram. A similar approach is used to analyse the Object Conjugate Reconstruction (OCR) technique to resolve directional ambiguity by introducing an artificial image shift to the reconstructed particle images. An example of how these methods are used together to measure the instantaneous flow fields within a motored Diesel engine is then described.

  4. Holographic Particle Image Velocimetry and its Application in Engine Development

    International Nuclear Information System (INIS)

    Coupland, J M; Garner, C P; Alcock, R D; Halliwell, N A

    2006-01-01

    This paper reviews Holographic Particle Image Velocimetry (HPIV) as a means to make three-component velocity measurements throughout a three-dimensional flow-field of interest. A simplified treatment of three-dimensional scalar wave propagation is outlined and subsequently used to illustrate the principles of complex correlation analysis. It is shown that this type of analysis provides the three-dimensional correlation of the propagating, monochromatic fields recorded by the hologram. A similar approach is used to analyse the Object Conjugate Reconstruction (OCR) technique to resolve directional ambiguity by introducing an artificial image shift to the reconstructed particle images. An example of how these methods are used together to measure the instantaneous flow fields within a motored Diesel engine is then described

  5. Holographic Particle Image Velocimetry and its Application in Engine Development

    Science.gov (United States)

    Coupland, J. M.; Garner, C. P.; Alcock, R. D.; Halliwell, N. A.

    2006-07-01

    This paper reviews Holographic Particle Image Velocimetry (HPIV) as a means to make three-component velocity measurements throughout a three-dimensional flow-field of interest. A simplified treatment of three-dimensional scalar wave propagation is outlined and subsequently used to illustrate the principles of complex correlation analysis. It is shown that this type of analysis provides the three-dimensional correlation of the propagating, monochromatic fields recorded by the hologram. A similar approach is used to analyse the Object Conjugate Reconstruction (OCR) technique to resolve directional ambiguity by introducing an artificial image shift to the reconstructed particle images. An example of how these methods are used together to measure the instantaneous flow fields within a motored Diesel engine is then described.

  6. Three-dimensional tracking of objects in holographic imaging

    Science.gov (United States)

    DaneshPanah, Mehdi; Javidi, Bahram

    2007-09-01

    In this paper we overview on a three dimensional imaging and tracking algorithm in order to track biological specimen in sequence of holographic microscopy images. We use a region tracking method based on MAP estimator in a Bayesian framework and we adapt it to 3D holographic data sequences to efficiently track the desired microorganism. In our formulation, the target-background interface is modeled as the isolevel of a level set function which is evolved at each frame via level set update rule. The statistical characteristics of the target microorganism versus the background are exploited to evolve the interface from one frame to another. Using the bivariate Gaussian distribution to model the reconstructed hologram data enables one to take into account the correlation between the amplitude and phase of the reconstructed field to obtain a more accurate solution. Also, the level set surface evolution provides a robust, efficient and numerically stable method which deals automatically with the change in the topology and geometrical deformations that a microorganism may be subject to.

  7. Ferroelectric domain pattern in barium titanate single crystals studied by means of digital holographic microscopy

    Czech Academy of Sciences Publication Activity Database

    Mokrý, Pavel; Psota, Pavel; Steiger, Kateřina; Václavík, Jan; Doleček, Roman; Vápenka, David; Lédl, Vít

    2016-01-01

    Roč. 49, č. 25 (2016), č. článku 255307. ISSN 0022-3727 R&D Projects: GA ČR(CZ) GA14-32228S Institutional support: RVO:61389021 Keywords : ferroelectric domain patterns * electro-optical materials * digital holographic microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.588, year: 2016 http://iopscience.iop.org/article/10.1088/0022-3727/49/25/255307

  8. Digital holographic interferometry applied to the study of tympanic membrane displacements

    Science.gov (United States)

    Hernández-Montes, María del Socorro; Mendoza Santoyo, Fernando; Pérez López, Carlos; Muñoz Solís, Silvino; Esquivel, Jesús

    2011-06-01

    Quantitative studies of the mechanical properties of tympanic membrane (TM) are needed for better understanding of its role in detailed clinical evaluation, its research being of extreme importance because it is one of the most important structures of the middle ear. By finding the membrane's vibration patterns and quantifying the induced displacement it is possible to characterize and determine its physiological status. Digital holographic interferometry (DHI) has proved to be a reliable optical non-invasive and full-field-of-view technique for the investigation of different mechanical parameters of biological tissues, i.e., DHI has demonstrated an ability to detect displacement changes in quasi-real time and without the need to contact the sample's surface under study providing relevant information, such as clinical and mechanical sample properties. In this research fresh tympanic membrane specimens taken from post-mortem cats are subjected to acoustic stimuli in the audible frequency range producing resonant vibration patterns on the membrane, a feature that results in an ideal application for DHI. An important feature of this approach over other techniques previously used to study the tympanic membrane vibrations is that it only requires two images and less hardware to carry out the measurements, making of DHI a simpler and faster technique as compared to other proposed approaches. The results found show a very good agreement between the present and past measurements from previous research work, showing that DHI is a technique that no doubt will help to improve the understanding of the tympanic membrane's working mechanisms.

  9. Compact and field-portable 3D printed shearing digital holographic microscope for automated cell identification.

    Science.gov (United States)

    Rawat, Siddharth; Komatsu, Satoru; Markman, Adam; Anand, Arun; Javidi, Bahram

    2017-03-20

    We propose a low-cost, compact, and field-portable 3D printed holographic microscope for automated cell identification based on a common path shearing interferometer setup. Once a hologram is captured from the portable setup, a 3D reconstructed height profile of the cell is created. We extract several morphological cell features from the reconstructed 3D height profiles, including mean physical cell thickness, coefficient of variation, optical volume (OV) of the cell, projected area of the cell (PA), ratio of PA to OV, cell thickness kurtosis, cell thickness skewness, and the dry mass of the cell for identification using the random forest (RF) classifier. The 3D printed prototype can serve as a low-cost alternative for the developing world, where access to laboratory facilities for disease diagnosis are limited. Additionally, a cell phone sensor is used to capture the digital holograms. This enables the user to send the acquired holograms over the internet to a computational device located remotely for cellular identification and classification (analysis). The 3D printed system presented in this paper can be used as a low-cost, stable, and field-portable digital holographic microscope as well as an automated cell identification system. To the best of our knowledge, this is the first research paper presenting automatic cell identification using a low-cost 3D printed digital holographic microscopy setup based on common path shearing interferometry.

  10. Holographic particle image velocimetry: signal recovery from under-sampled CCD data

    Science.gov (United States)

    Coupland, J. M.

    2004-04-01

    Holographic particle image velocimetry (HPIV) has now been demonstrated by several research groups as a method to make three-component velocity measurements from a three-dimensional fluid flow field. More recently digital HPIV has become a hot topic with the promise of near-real-time measurements without the often cumbersome optics and wet processing associated with traditional holographic methods. It is clear, however, that CCD cameras have a limited number of pixels and are not capable of resolving more than a small fraction of the interference pattern that is recorded by a typical particulate hologram. In this paper, we consider under-sampling of the interference pattern to reduce the information content and to allow recordings to be made on a CCD sensor. We describe the basic concept of model fitting to under-sampled data and demonstrate signal recovery through computer simulation. A three-dimensional analysis shows that in general, periodic sampling strategies can result in multiple particle images in the reconstruction. It is shown, however, that the significance of these peaks is reduced in the case of high numerical aperture (NA) reconstruction and can be virtually eliminated by dithering the position of sampling apertures.

  11. Digital image processing

    National Research Council Canada - National Science Library

    Gonzalez, Rafael C; Woods, Richard E

    2008-01-01

    Completely self-contained-and heavily illustrated-this introduction to basic concepts and methodologies for digital image processing is written at a level that truly is suitable for seniors and first...

  12. Quantitative phase imaging with scanning holographic microscopy: an experimental assesment

    Directory of Open Access Journals (Sweden)

    Tada Yoshitaka

    2006-11-01

    Full Text Available Abstract This paper demonstrates experimentally how quantitative phase information can be obtained in scanning holographic microscopy. Scanning holography can operate in both coherent and incoherent modes, simultaneously if desired, with different detector geometries. A spatially integrating detector provides an incoherent hologram of the object's intensity distribution (absorption and/or fluorescence, for example, while a point detector in a conjugate plane of the pupil provides a coherent hologram of the object's complex amplitude, from which a quantitative measure of its phase distribution can be extracted. The possibility of capturing simultaneously holograms of three-dimensional specimens, leading to three-dimensional reconstructions with absorption contrast, reflectance contrast, fluorescence contrast, as was previously demonstrated, and quantitative phase contrast, as shown here for the first time, opens up new avenues for multimodal imaging in biological studies.

  13. Improvements on digital inline holographic PTV for 3D wall-bounded turbulent flow measurements

    International Nuclear Information System (INIS)

    Toloui, Mostafa; Mallery, Kevin; Hong, Jiarong

    2017-01-01

    Three-dimensional (3D) particle image velocimetry (PIV) and particle tracking velocimetry (PTV) provide the most comprehensive flow information for unraveling the physical phenomena in a wide range of fluid problems, from microfluidics to wall-bounded turbulent flows. Compared with other 3D PIV techniques, such as tomographic PIV and defocusing PIV, the digital inline holographic PTV (DIH-PTV) provides 3D flow measurement solution with high spatial resolution, low cost optical setup, and easy alignment and calibration. Despite these advantages, DIH-PTV suffers from major limitations including poor longitudinal resolution, human intervention (i.e. requirement for manually determined tuning parameters during tracer field reconstruction and extraction), limited tracer concentration, small sampling volume and expensive computations, limiting its broad use for 3D flow measurements. In this study, we present our latest developments on minimizing these challenges, which enables high-fidelity DIH-PTV implementation to larger sampling volumes with significantly higher particle seeding densities suitable for wall-bounded turbulent flow measurements. The improvements include: (1) adjustable window thresholding; (2) multi-pass 3D tracking; (3) automatic wall localization; and (4) continuity-based out-of-plane velocity component computation. The accuracy of the proposed DIH-PTV method is validated with conventional 2D PIV and double-view holographic PTV measurements in smooth-wall turbulent channel flow experiments. The capability of the technique in characterization of wall-bounded turbulence is further demonstrated through its application to flow measurements for smooth- and rough-wall turbulent channel flows. In these experiments, 3D velocity fields are measured within sampling volumes of 14.7  ×  50.0  ×  14.4 mm 3 (covering the entire depth of the channel) with a velocity resolution of  <1.1 mm/vector. Overall, the presented DIH-PTV method and

  14. Digital imaging primer

    CERN Document Server

    Parkin, Alan

    2016-01-01

    Digital Imaging targets everyyone with an interest in digital imaging, be they professional or private, who uses even quite modest equipment such as a PC, digital camera and scanner, a graphics editor such as Paint, and an inkjet printer. Uniquely, it is intended to fill the gap between highly technical texts for academics (with access to expensive equipment) and superficial introductions for amateurs. The four-part treatment spans theory, technology, programs and practice. Theory covers integer arithmetic, additive and subtractive color, greyscales, computational geometry, and a new presentation of discrete Fourier analysis; Technology considers bitmap file structures, scanners, digital cameras, graphic editors, and inkjet printers; Programs develops several processing tools for use in conjunction with a standard Paint graphics editor and supplementary processing tools; Practice discusses 1-bit, greyscale, 4-bit, 8-bit, and 24-bit images for the practice section. Relevant QBASIC code is supplied an accompa...

  15. Volume holographic imaging endoscopic design and construction techniques.

    Science.gov (United States)

    Howlett, Isela D; Han, Wanglei; Gordon, Michael; Rice, Photini; Barton, Jennifer K; Kostuk, Raymond K

    2017-05-01

    A reflectance volume holographic imaging (VHI) endoscope has been designed for simultaneous in vivo imaging of surface and subsurface tissue structures. Prior utilization of VHI systems has been limited to ex vivo tissue imaging. The VHI system presented in this work is designed for laparoscopic use. It consists of a probe section that relays light from the tissue sample to a handheld unit that contains the VHI microscope. The probe section is constructed from gradient index (GRIN) lenses that form a 1:1 relay for image collection. The probe has an outer diameter of 3.8 mm and is capable of achieving 228.1 ?? lp / mm resolution with 660-nm Kohler illumination. The handheld optical section operates with a magnification of 13.9 and a field of view of 390 ?? ? m × 244 ?? ? m . System performance is assessed through imaging of 1951 USAF resolution targets and soft tissue samples. The system has also passed sterilization procedures required for surgical use and has been used in two laparoscopic surgical procedures.

  16. The shifting appearance/disappearance of holographic images and the dynamic ontology of perceptual and cognitive processes

    Science.gov (United States)

    Boissonnet, Philippe

    2013-02-01

    The French philosopher M Merleau-Ponty captured the dynamic of perception with his idea of the intertwining of perceiver and perceived. Light is what links them. In the case of holographic images, not only is spatial and colour perception the pure product of light, but this light information is always in the process of self-construction with our eyes, according to our movements and the point of view adopted. According to the aesthetic reception of a work of art, Holographic images vary greatly from those of cinema, photography and even every kind of digital 3D animation. This particular image's status truly makes perceptually apparent the "co-emergence" of light and our gaze. But holography never misleads us with respect to the precarious nature of our perceptions. We have no illusion as to the limits of our empirical understanding of the perceived reality. Holography, like our knowledge of the visible, thus brings to light the phenomenon of reality's "co-constitution" and contributes to a dynamic ontology of perceptual and cognitive processes. The cognitivist Francico Varela defines this as the paradigm of enaction,i which I will adapt and apply to the appearance/disappearance context of holographic images to bring out their affinities on a metaphorical level.

  17. Digital medical imaging

    International Nuclear Information System (INIS)

    Goeringer, F.; Mun, S.K.; Kerlin, B.D.

    1989-01-01

    In formulating an implementation strategy for digital medical imaging, three interrelated thrusts have emerged for the defense medical establishment. These thrusts: totally filmless medical imaging on the battlefield, teleradiology, and DIN/PACS for peacetime military health care are discussed. They have implications in their fully developed form as resource savers and quality improvers for the unique aspects of military health care

  18. Label-free sensor for automatic identification of erythrocytes using digital in-line holographic microscopy and machine learning.

    Science.gov (United States)

    Go, Taesik; Byeon, Hyeokjun; Lee, Sang Joon

    2018-04-30

    Cell types of erythrocytes should be identified because they are closely related to their functionality and viability. Conventional methods for classifying erythrocytes are time consuming and labor intensive. Therefore, an automatic and accurate erythrocyte classification system is indispensable in healthcare and biomedical fields. In this study, we proposed a new label-free sensor for automatic identification of erythrocyte cell types using a digital in-line holographic microscopy (DIHM) combined with machine learning algorithms. A total of 12 features, including information on intensity distributions, morphological descriptors, and optical focusing characteristics, is quantitatively obtained from numerically reconstructed holographic images. All individual features for discocytes, echinocytes, and spherocytes are statistically different. To improve the performance of cell type identification, we adopted several machine learning algorithms, such as decision tree model, support vector machine, linear discriminant classification, and k-nearest neighbor classification. With the aid of these machine learning algorithms, the extracted features are effectively utilized to distinguish erythrocytes. Among the four tested algorithms, the decision tree model exhibits the best identification performance for the training sets (n = 440, 98.18%) and test sets (n = 190, 97.37%). This proposed methodology, which smartly combined DIHM and machine learning, would be helpful for sensing abnormal erythrocytes and computer-aided diagnosis of hematological diseases in clinic. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Laser-induced fluorescence imaging of subsurface tissue structures with a volume holographic spatial-spectral imaging system.

    Science.gov (United States)

    Luo, Yuan; Gelsinger-Austin, Paul J; Watson, Jonathan M; Barbastathis, George; Barton, Jennifer K; Kostuk, Raymond K

    2008-09-15

    A three-dimensional imaging system incorporating multiplexed holographic gratings to visualize fluorescence tissue structures is presented. Holographic gratings formed in volume recording materials such as a phenanthrenquinone poly(methyl methacrylate) photopolymer have narrowband angular and spectral transmittance filtering properties that enable obtaining spatial-spectral information within an object. We demonstrate this imaging system's ability to obtain multiple depth-resolved fluorescence images simultaneously.

  20. Investigation on cytoskeleton dynamics for no-adherent cells subjected to point-like stimuli by digital holographic microscopy and holographic optical trapping

    Science.gov (United States)

    Miccio, Lisa; Merola, Francesco; Memmolo, Pasquale; Mugnano, Martina; Fusco, Sabato; Netti, Paolo A.; Ferraro, Pietro

    2014-05-01

    Guiding, controlling and studying cellular functions are challenging themes in the biomedical field, as they are fundamental prerequisites for new therapeutic strategies from tissue regeneration to controlled drug delivery. In recent years, multidisciplinary studies in nanotechnology offer new tools to investigate important biophysical phenomena in response to the local physical characteristics of the extracellular environment, some examples are the mechanisms of cell adhesion, migration, communication and differentiation. Indeed for reproducing the features of the extracellular matrix in vitro, it is essential to develop active devices that evoke as much as possible the natural cellular environment. Our investigation is in the framework of studying and clarifying the biophysical mechanisms of the interaction between cells and the microenvironment in which they exist. We implement an optical tweezers setup to investigate cell material interaction and we use Digital Holography as non-invasive imaging technique in microscopy. We exploit Holographic Optical Tweezers arrangement in order to trap and manage functionalized micrometric latex beads to induce mechanical deformation in suspended cells. A lot of papers in literature examine the dynamics of the cytoskeleton when cells adhere on substrates and nowadays well established cell models are based on such research activities. Actually, the natural cell environment is made of a complex extracellular matrix and the single cell behavior is due to intricate interactions with the environment and are strongly correlated to the cell-cell interactions. Our investigation is devoted to understand the inner cell mechanism when it is mechanically stressed by point-like stimulus without the substrate influence.

  1. Model-based magnetization retrieval from holographic phase images

    Energy Technology Data Exchange (ETDEWEB)

    Röder, Falk, E-mail: f.roeder@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Vogel, Karin [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Wolf, Daniel [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Hellwig, Olav [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); AG Magnetische Funktionsmaterialien, Institut für Physik, Technische Universität Chemnitz, D-09126 Chemnitz (Germany); HGST, A Western Digital Company, 3403 Yerba Buena Rd., San Jose, CA 95135 (United States); Wee, Sung Hun [HGST, A Western Digital Company, 3403 Yerba Buena Rd., San Jose, CA 95135 (United States); Wicht, Sebastian; Rellinghaus, Bernd [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany)

    2017-05-15

    The phase shift of the electron wave is a useful measure for the projected magnetic flux density of magnetic objects at the nanometer scale. More important for materials science, however, is the knowledge about the magnetization in a magnetic nano-structure. As demonstrated here, a dominating presence of stray fields prohibits a direct interpretation of the phase in terms of magnetization modulus and direction. We therefore present a model-based approach for retrieving the magnetization by considering the projected shape of the nano-structure and assuming a homogeneous magnetization therein. We apply this method to FePt nano-islands epitaxially grown on a SrTiO{sub 3} substrate, which indicates an inclination of their magnetization direction relative to the structural easy magnetic [001] axis. By means of this real-world example, we discuss prospects and limits of this approach. - Highlights: • Retrieval of the magnetization from holographic phase images. • Magnetostatic model constructed for a magnetic nano-structure. • Decomposition into homogeneously magnetized components. • Discretization of a each component by elementary cuboids. • Analytic solution for the phase of a magnetized cuboid considered. • Fitting a set of magnetization vectors to experimental phase images.

  2. Surface shape measurement by multi-illumination lensless Fourier transform digital holographic interferometry

    Science.gov (United States)

    Dong, Jun; Jia, Shuhai; Jiang, Chao

    2017-11-01

    This paper presents a multi-illumination lensless Fourier transform digital holographic interferometry method for surface shape measurement. In this method, the interference phases with different effective synthetic wavelengths are obtained by tilting the illumination angle several times, and all are wrapped. A Fourier-transform demodulation algorithm employing all these wrapped phases simultaneously is used to determine the object surface shape. No phase unwrapping procedure is required, and the shape information of each point is calculated independently, thereby offering great flexibility for measuring objects with discontinuities surface, such as holes, steps and gaps. Experimental results demonstrate the validity of the principle.

  3. Demodulation of moire fringes in digital holographic interferometry using an extended Kalman filter.

    Science.gov (United States)

    Ramaiah, Jagadesh; Rastogi, Pramod; Rajshekhar, Gannavarpu

    2018-03-10

    This paper presents a method for extracting multiple phases from a single moire fringe pattern in digital holographic interferometry. The method relies on component separation using singular value decomposition and an extended Kalman filter for demodulating the moire fringes. The Kalman filter is applied by modeling the interference field locally as a multi-component polynomial phase signal and extracting the associated multiple polynomial coefficients using the state space approach. In addition to phase, the corresponding multiple phase derivatives can be simultaneously extracted using the proposed method. The applicability of the proposed method is demonstrated using simulation and experimental results.

  4. Phase-shifting digital holographic microscopy by using a multi-camera setup.

    Science.gov (United States)

    Trujillo, Carlos; Garcia-Sucerquia, Jorge

    2017-12-01

    In this Letter, the use of two-coupled Mach-Zehnder interferometers for four π/2-phase shifting interferometry is introduced. A multi-camera arrangement using no more than beam splitters and mirrors is utilized to obtain in a single shot the needed phase-shifted interferograms in the different output channels of the setup. The simplicity of the setup makes it ideal for high-speed interferometry applications. This proposal is validated in digital holographic microscopy to visualize a biological sample of epidermal onion cells.

  5. Digital color imaging

    CERN Document Server

    Fernandez-Maloigne, Christine; Macaire, Ludovic

    2013-01-01

    This collective work identifies the latest developments in the field of the automatic processing and analysis of digital color images.For researchers and students, it represents a critical state of the art on the scientific issues raised by the various steps constituting the chain of color image processing.It covers a wide range of topics related to computational color imaging, including color filtering and segmentation, color texture characterization, color invariant for object recognition, color and motion analysis, as well as color image and video indexing and retrieval. <

  6. Three-dimensional counting of morphologically normal human red blood cells via digital holographic microscopy

    Science.gov (United States)

    Yi, Faliu; Moon, Inkyu; Lee, Yeon H.

    2015-01-01

    Counting morphologically normal cells in human red blood cells (RBCs) is extremely beneficial in the health care field. We propose a three-dimensional (3-D) classification method of automatically determining the morphologically normal RBCs in the phase image of multiple human RBCs that are obtained by off-axis digital holographic microscopy (DHM). The RBC holograms are first recorded by DHM, and then the phase images of multiple RBCs are reconstructed by a computational numerical algorithm. To design the classifier, the three typical RBC shapes, which are stomatocyte, discocyte, and echinocyte, are used for training and testing. Nonmain or abnormal RBC shapes different from the three normal shapes are defined as the fourth category. Ten features, including projected surface area, average phase value, mean corpuscular hemoglobin, perimeter, mean corpuscular hemoglobin surface density, circularity, mean phase of center part, sphericity coefficient, elongation, and pallor, are extracted from each RBC after segmenting the reconstructed phase images by using a watershed transform algorithm. Moreover, four additional properties, such as projected surface area, perimeter, average phase value, and elongation, are measured from the inner part of each cell, which can give significant information beyond the previous 10 features for the separation of the RBC groups; these are verified in the experiment by the statistical method of Hotelling's T-square test. We also apply the principal component analysis algorithm to reduce the dimension number of variables and establish the Gaussian mixture densities using the projected data with the first eight principal components. Consequently, the Gaussian mixtures are used to design the discriminant functions based on Bayesian decision theory. To improve the performance of the Bayes classifier and the accuracy of estimation of its error rate, the leaving-one-out technique is applied. Experimental results show that the proposed method can

  7. Improving image quality of parallel phase-shifting digital holography

    International Nuclear Information System (INIS)

    Awatsuji, Yasuhiro; Tahara, Tatsuki; Kaneko, Atsushi; Koyama, Takamasa; Nishio, Kenzo; Ura, Shogo; Kubota, Toshihiro; Matoba, Osamu

    2008-01-01

    The authors propose parallel two-step phase-shifting digital holography to improve the image quality of parallel phase-shifting digital holography. The proposed technique can increase the effective number of pixels of hologram twice in comparison to the conventional parallel four-step technique. The increase of the number of pixels makes it possible to improve the image quality of the reconstructed image of the parallel phase-shifting digital holography. Numerical simulation and preliminary experiment of the proposed technique were conducted and the effectiveness of the technique was confirmed. The proposed technique is more practical than the conventional parallel phase-shifting digital holography, because the composition of the digital holographic system based on the proposed technique is simpler.

  8. Digital image analysis

    DEFF Research Database (Denmark)

    Riber-Hansen, Rikke; Vainer, Ben; Steiniche, Torben

    2012-01-01

    Digital image analysis (DIA) is increasingly implemented in histopathological research to facilitate truly quantitative measurements, decrease inter-observer variation and reduce hands-on time. Originally, efforts were made to enable DIA to reproduce manually obtained results on histological slides...... reproducibility, application of stereology-based quantitative measurements, time consumption, optimization of histological slides, regions of interest selection and recent developments in staining and imaging techniques....

  9. Digital holographic interferometry with CO2 lasers and diffuse illumination applied to large space reflector metrology [Invited].

    Science.gov (United States)

    Georges, Marc P; Vandenrijt, Jean-François; Thizy, Cédric; Stockman, Yvan; Queeckers, Patrick; Dubois, Frank; Doyle, Dominic

    2013-01-01

    Digital holographic interferometry in the long-wave infrared domain has been developed by combining a CO(2) laser and a microbolometer array. The long wavelength allows large deformation measurements, which are of interest in the case of large space reflectors undergoing thermal changes when in orbit. We review holography at such wavelengths and present some specific aspects related to this spectral range on our measurements. For the design of our digital holographic interferometer, we studied the possibility of illuminating specular objects by a reflective diffuser. We discuss the development of the interferometer and the results obtained on a representative space reflector, first in the laboratory and then during vacuum cryogenic test.

  10. Handling digital images for publication

    Directory of Open Access Journals (Sweden)

    Jun Haeng Lee

    2014-08-01

    Full Text Available Currently, images in medical journals are produced in the form of digital image files. The quality of printed images can be easily recognized. However, what comprises the quality of a digital image file is more complex. Some images appear to have good quality when displayed on a computer monitor but do not have sufficient quality for scholarly publication. In this review, basic concepts of digital images for scholarly publication, such as resolution, raster images, and vector images, will be explained. The advantages and limitations of using PowerPoint for processing digital image files will also be touched on briefly.

  11. Digital stereoscopic imaging

    Science.gov (United States)

    Rao, A. Ravishankar; Jaimes, Alejandro

    1999-05-01

    The convergence of inexpensive digital cameras and cheap hardware for displaying stereoscopic images has created the right conditions for the proliferation of stereoscopic imagin applications. One application, which is of growing importance to museums and cultural institutions, consists of capturing and displaying 3D images of objects at multiple orientations. In this paper, we present our stereoscopic imaging system and methodology for semi-automatically capturing multiple orientation stereo views of objects in a studio setting, and demonstrate the superiority of using a high resolution, high fidelity digital color camera for stereoscopic object photography. We show the superior performance achieved with the IBM TDI-Pro 3000 digital camera developed at IBM Research. We examine various choices related to the camera parameters, image capture geometry, and suggest a range of optimum values that work well in practice. We also examine the effect of scene composition and background selection on the quality of the stereoscopic image display. We will demonstrate our technique with turntable views of objects from the IBM Corporate Archive.

  12. Giga-pixel lensfree holographic microscopy and tomography using color image sensors.

    Directory of Open Access Journals (Sweden)

    Serhan O Isikman

    Full Text Available We report Giga-pixel lensfree holographic microscopy and tomography using color sensor-arrays such as CMOS imagers that exhibit Bayer color filter patterns. Without physically removing these color filters coated on the sensor chip, we synthesize pixel super-resolved lensfree holograms, which are then reconstructed to achieve ~350 nm lateral resolution, corresponding to a numerical aperture of ~0.8, across a field-of-view of ~20.5 mm(2. This constitutes a digital image with ~0.7 Billion effective pixels in both amplitude and phase channels (i.e., ~1.4 Giga-pixels total. Furthermore, by changing the illumination angle (e.g., ± 50° and scanning a partially-coherent light source across two orthogonal axes, super-resolved images of the same specimen from different viewing angles are created, which are then digitally combined to synthesize tomographic images of the object. Using this dual-axis lensfree tomographic imager running on a color sensor-chip, we achieve a 3D spatial resolution of ~0.35 µm × 0.35 µm × ~2 µm, in x, y and z, respectively, creating an effective voxel size of ~0.03 µm(3 across a sample volume of ~5 mm(3, which is equivalent to >150 Billion voxels. We demonstrate the proof-of-concept of this lensfree optical tomographic microscopy platform on a color CMOS image sensor by creating tomograms of micro-particles as well as a wild-type C. elegans nematode.

  13. High-throughput characterization of film thickness in thin film materials libraries by digital holographic microscopy

    Directory of Open Access Journals (Sweden)

    Yiu Wai Lai, Michael Krause, Alan Savan, Sigurd Thienhaus, Nektarios Koukourakis, Martin R Hofmann and Alfred Ludwig

    2011-01-01

    Full Text Available A high-throughput characterization technique based on digital holography for mapping film thickness in thin-film materials libraries was developed. Digital holographic microscopy is used for fully automatic measurements of the thickness of patterned films with nanometer resolution. The method has several significant advantages over conventional stylus profilometry: it is contactless and fast, substrate bending is compensated, and the experimental setup is simple. Patterned films prepared by different combinatorial thin-film approaches were characterized to investigate and demonstrate this method. The results show that this technique is valuable for the quick, reliable and high-throughput determination of the film thickness distribution in combinatorial materials research. Importantly, it can also be applied to thin films that have been structured by shadow masking.

  14. Digital imaging in dentistry.

    Science.gov (United States)

    Essen, S Donovan

    2011-01-01

    Information technology is vital to operations, marketing, accounting, finance and administration. One of the most exciting and quickly evolving technologies in the modern dental office is digital applications. The dentist is often the business manager, information technology officer and strategic planning chief for his small business. The information systems triangle applies directly to this critical manager supported by properly trained ancillary staff and good equipment. With emerging technology driving all medical disciplines and the rapid pace at which it emerges, it is vital for the contemporary practitioner to keep abreast of the newest information technology developments. This article compares the strategic and operational advantages of digital applications, specifically imaging. The focus of this paper will be on digital radiography (DR), 3D computerized tomography, digital photography and digitally-driven CAD/CAM to what are now considered obsolescing modalities and contemplates what may arrive in the future. It is the purpose of this essay to succinctly evaluate the decisions involved in the role, application and implications of employing this tool in the dental environment

  15. REAL TIME MICRODISPLACEMENTS TESTING BY OPTO-DIGITAL HOLOGRAPHIC INTERFEROMETRY TECHNIQUE

    Directory of Open Access Journals (Sweden)

    L BOUAMAMA

    2007-12-01

    Since all the process is controlled numerically, it is possible to follow in real time using the holographic interferometry techniques, double exposure, real time or time average, any changes in the object under study and to start and stop the process at any time by adequate software. This can be done by subtracting a reference image by suitable software directly on the CCD camera. We show also, the ability of the technique to study in real time all evolutional phenomena.

  16. All-dielectric meta-holograms with holographic images transforming longitudinally

    KAUST Repository

    Wang, Qiu

    2017-11-22

    Metasurfaces are unique subwavelength geometries capable of engineering electromagnetic waves at will, delivering new opportunities for holography. Most previous meta-holograms, so-called phase-only meta-holograms, modulate only the amplitude distribution of a virtual object, and require optimizing techniques to improve the image quality. However, the phase distribution of the reconstructed image is usually overlooked in previous studies, leading to inevitable information loss. Here, we demonstrate all-dielectric meta-holograms that allow tailoring of both the phase and amplitude distributions of virtual objects. Several longitudinal manipulations of the holographic images are theoretically and experimentally demonstrated, including shifting, stretching, and rotating, enabling a large depth of focus. Furthermore, a new meta-hologram with a three-dimensional holographic design method is demonstrated with an even enhanced depth of focus. The proposed meta-holograms offer more freedom in holographic design and open new avenues for designing complex three-dimensional holography.

  17. Thermal Characterization of Dynamic Silicon Cantilever Array Sensors by Digital Holographic Microscopy

    Directory of Open Access Journals (Sweden)

    Marjan Zakerin

    2017-05-01

    Full Text Available In this paper, we apply a digital holographic microscope (DHM in conjunction with stroboscopic acquisition synchronization. Here, the temperature-dependent decrease of the first resonance frequency (S1(T and Young’s elastic modulus (E1(T of silicon micromechanical cantilever sensors (MCSs are measured. To perform these measurements, the MCSs are uniformly heated from T0 = 298 K to T = 450 K while being externally actuated with a piezo-actuator in a certain frequency range close to their first resonance frequencies. At each temperature, the DHM records the time-sequence of the 3D topographies for the given frequency range. Such holographic data allow for the extracting of the out-of-plane vibrations at any relevant area of the MCSs. Next, the Bode and Nyquist diagrams are used to determine the resonant frequencies with a precision of 0.1 Hz. Our results show that the decrease of resonance frequency is a direct consequence of the reduction of the silicon elastic modulus upon heating. The measured temperature dependence of the Young’s modulus is in very good accordance with the previously-reported values, validating the reliability and applicability of this method for micromechanical sensing applications.

  18. Twin image removal in digital in-line holography based on iterative inter-projections

    Science.gov (United States)

    Chen, Bing Kuan; Chen, Tai-Yu; Hung, Shau Gang; Huang, Sheng-Lung; Lin, Jiunn-Yuan

    2016-06-01

    A simple and efficient phase retrieval method based on the iterative inter-projections of the recorded Fourier modulus between two effective holographic planes is developed to eliminate the twin image in digital in-line holography. The proposed algorithm converges stably in phase extraction procedures without requiring any prior knowledge or sophisticated support of the object and is applicable to lensless Gabor and Fourier holography as well as holographic microscopy with imaging lenses. Numerical and experimental results suggest that the spatial resolution enhancement on the reconstructed image can be achieved with this technique due to the capability of recovering the diffraction phases of low-intensity signals.

  19. Parallel computing of a digital hologram and particle searching for microdigital-holographic particle-tracking velocimetry

    International Nuclear Information System (INIS)

    Satake, Shin-ichi; Kanamori, Hiroyuki; Kunugi, Tomoaki; Sato, Kazuho; Ito, Tomoyoshi; Yamamoto, Keisuke

    2007-01-01

    We have developed a parallel algorithm for microdigital-holographic particle-tracking velocimetry. The algorithm is used in (1) numerical reconstruction of a particle image computer using a digital hologram, and (2) searching for particles. The numerical reconstruction from the digital hologram makes use of the Fresnel diffraction equation and the FFT (fast Fourier transform),whereas the particle search algorithm looks for local maximum graduation in a reconstruction field represented by a 3D matrix. To achieve high performance computing for both calculations (reconstruction and particle search), two memory partitions are allocated to the 3D matrix. In this matrix, the reconstruction part consists of horizontally placed 2D memory partitions on the x-y plane for the FFT, whereas, the particle search part consists of vertically placed 2D memory partitions set along the z axes.Consequently, the scalability can be obtained for the proportion of processor elements,where the benchmarks are carried out for parallel computation by a SGI Altix machine

  20. Digital imaging in diagnostic radiology

    International Nuclear Information System (INIS)

    Newell, J.D. Jr.; Kelsey, C.A.

    1990-01-01

    This monograph on digital imaging provides a basic overview of this field at the present time. This paper covers clinical application, including subtraction angiography; chest radiology; genitourinary, gastrointestinal, and breast radiology; and teleradiology. The chest section also includes an explanation of multiple beam equalization radiography. The remaining chapters discuss some of the technical aspects of digital radiology. It includes the basic technology of digital radiography, image compression, and reconstruction information on the economics of digital radiography

  1. Precise measurement of three-dimensional positions of transparent ellipsoidal particles using digital holographic microscopy.

    Science.gov (United States)

    Byeon, Hyeok Jun; Seo, Kyung Won; Lee, Sang Joon

    2015-03-10

    The dynamic motions of various particles suspended in microscale flows are essential phenomena in the scientific and engineering fields. These motions can be precisely measured by using 3D quantitative flow visualization techniques. Moreover, most cells and particles in nature possess a nonspherical shape. Digital holographic microscopy (DHM) is employed to measure the 3D positional information of transparent ellipsoidal particles. Both in-plane and out-of-plane positional information are obtained by analyzing the distinctive light scattering from the microsized ellipsoidal particles. The performance of the 3D position measurement method is experimentally verified for ellipsoidal particles seeded in a planar surface and a microtube. This DHM technique exhibits promising potential in the dynamic analysis of ellipsoidal particles and cells suspended in various microscale fluid flows.

  2. Investigation on 3D morphological changes of in vitro cells through digital holographic microscopy

    Science.gov (United States)

    Memmolo, Pasquale; Miccio, Lisa; Merola, Francesco; Netti, Paolo A.; Coppola, Giuseppe; Ferraro, Pietro

    2013-04-01

    We report the investigation of the identification and measurement of region of interest (ROI) in quantitative phase-contrast maps (QPMs) of biological cells by digital holographic microscopy (DHM), with the aim to analyze the 3D positions and 3D morphology together. We consider as test case for our tool the in vitro bull sperm head morphometry analysis. Extraction and measurement of various morphological parameters are performed by using two methods: the anisotropic diffusion filter, that is based on the Gaussian diffusivity function which allows more accuracy of the edge position, and the simple thresholding filter. In particular we consider the calculation of area, ellipticity, perimeter, major axis, minor axis and shape factor as a morphological parameter, instead, for the estimation of 3D position, we compute the centroid, the weighted centroid and the maximum phase values. A statistical analysis on a data set composed by N = 14 holograms relative to bovine spermatozoa and its reference holograms is reported.

  3. Digital holographic otoscope for measurements of the human tympanic membrane in vivo

    Science.gov (United States)

    Dobrev, I.; Harrington, E. J.; Cheng, T.; Furlong, C.; Rosowski, J. J.

    We are developing an advanced computer-controlled digital optoelectronic holographic system (DOEHS) for diagnosing middle-ear conductive disorders and investigating the causes of failure of middle-ear surgical procedures. Our current DOEHS system can provide near real-time quantitative measurements of the sound-induced nano-meter scale motion of the eardrum. The DOEHS have been deployed and is currently being tested in clinical conditions, where it is being optimized for in-vivo measurements of patients. The stability of the measurement system during examination is crucial as the non-ideal clinical environment presents disturbances larger than the measured quantities from several domains - thermal, optical, electrical and mechanical. Examples include disturbances are due to heartbeat breathing, patients head's motion as well as environment induced mechanical disturbances (0.1-60Hz, 0.01-100 μm). In this paper we focus on our current progress in the analysis and implementation of various acquisition strategies and algorithms for minimization of the measurement error due to mechanical disturbances in a clinic. We have also developed and implemented a versatile and modular otoscope head (OH) design providing a variety of capabilities for acoustic and displacement measurements of both post-mortem samples of varying sizes (1-12mm) as well as in-vivo examination of patients. The OH offers hybrid on-axis and off axis digital Furrier holographic setup for high resolution (λ/35) 4 phase step measurements as well as fast (<0.1ms) single frame measurements for improved performance in the clinical environment. We also focus on the development of a mechatronic positioning system (MOP) for aiding in the localization of the TM in patients.

  4. Digital images and globalized conflict

    DEFF Research Database (Denmark)

    Bolette, Blaagaard; Mortensen, Mette; Neumayer, Christina

    2017-01-01

    As the number of digital images of globalized conflicts online grow, critical examination of their impact and consequence is timely. This editorial provides an overview of digital images and globalized conflict as a field of study by discussing regimes of visibility and invisibility, proximity...... of conflict-related images raise issues of knowledge production and research....

  5. Digital imaging in cardiovascular radiology

    International Nuclear Information System (INIS)

    Heintzen, P.H.; Brennecke, R.

    1983-01-01

    The present book contains 27 papers presented at an international symposium on digital imaging in cardiovascular radiology held in Kiel in 1982. The main themes were as follows. Introductory reviews, digital systems for X-ray video imaging, quantitative X-ray image analysis, and clinical applications. (MG)

  6. Influence of sample preparation and reliability of automated numerical refocusing in stain-free analysis of dissected tissues with quantitative phase digital holographic microscopy

    Science.gov (United States)

    Kemper, Björn; Lenz, Philipp; Bettenworth, Dominik; Krausewitz, Philipp; Domagk, Dirk; Ketelhut, Steffi

    2015-05-01

    Digital holographic microscopy (DHM) has been demonstrated to be a versatile tool for high resolution non-destructive quantitative phase imaging of surfaces and multi-modal minimally-invasive monitoring of living cell cultures in-vitro. DHM provides quantitative monitoring of physiological processes through functional imaging and structural analysis which, for example, gives new insight into signalling of cellular water permeability and cell morphology changes due to toxins and infections. Also the analysis of dissected tissues quantitative DHM phase contrast prospects application fields by stain-free imaging and the quantification of tissue density changes. We show that DHM allows imaging of different tissue layers with high contrast in unstained tissue sections. As the investigation of fixed samples represents a very important application field in pathology, we also analyzed the influence of the sample preparation. The retrieved data demonstrate that the quality of quantitative DHM phase images of dissected tissues depends strongly on the fixing method and common staining agents. As in DHM the reconstruction is performed numerically, multi-focus imaging is achieved from a single digital hologram. Thus, we evaluated the automated refocussing feature of DHM for application on different types of dissected tissues and revealed that on moderately stained samples highly reproducible holographic autofocussing can be achieved. Finally, it is demonstrated that alterations of the spatial refractive index distribution in murine and human tissue samples represent a reliable absolute parameter that is related of different degrees of inflammation in experimental colitis and Crohn's disease. This paves the way towards the usage of DHM in digital pathology for automated histological examinations and further studies to elucidate the translational potential of quantitative phase microscopy for the clinical management of patients, e.g., with inflammatory bowel disease.

  7. Holographic and light-field imaging for augmented reality

    Science.gov (United States)

    Lee, Byoungho; Hong, Jong-Young; Jang, Changwon; Jeong, Jinsoo; Lee, Chang-Kun

    2017-02-01

    We discuss on the recent state of the augmented reality (AR) display technology. In order to realize AR, various seethrough three-dimensional (3D) display techniques have been reported. We describe the AR display with 3D functionality such as light-field display and holography. See-through light-field display can be categorized by the optical elements which are used for see-through property: optical elements controlling path of the light-fields and those generating see-through light-field. Holographic display can be also a good candidate for AR display because it can reconstruct wavefront information and provide realistic virtual information. We introduce the see-through holographic display using various optical techniques.

  8. Effect of spatial coherence of LED sources on image resolution in holographic displays

    NARCIS (Netherlands)

    Pourreza Ghoushchi, Vahid; Aas, Mehdi; Ulusoy, Erdem; Ürey, Hakan

    2017-01-01

    Holographic Displays (HDs) provide 3D images with all natural depth cues via computer generated holograms (CGHs) implemented on spatial light modulators (SLMs). HDs are coherent light processing systems based on interference and diffraction, thus they generally use laser light. However, laser

  9. Methods of digital image processing

    International Nuclear Information System (INIS)

    Doeler, W.

    1985-01-01

    Increasing use of computerized methods for diagnostical imaging of radiological problems will open up a wide field of applications for digital image processing. The requirements set by routine diagnostics in medical radiology point to picture data storage and documentation and communication as the main points of interest for application of digital image processing. As to the purely radiological problems, the value of digital image processing is to be sought in the improved interpretability of the image information in those cases where the expert's experience and image interpretation by human visual capacities do not suffice. There are many other domains of imaging in medical physics where digital image processing and evaluation is very useful. The paper reviews the various methods available for a variety of problem solutions, and explains the hardware available for the tasks discussed. (orig.) [de

  10. Ultra wide band radar holographic imaging of buried waste at DOE sites

    International Nuclear Information System (INIS)

    Collins, H.D.; Gribble, R.P.; Hall, T.E.; Lechelt, W.M.

    1995-04-01

    Ultra wideband linear array holography is a unique real-time imaging technique for in-situ inspection of buried waste at various DOE sites. The array can be mounted on various platforms such as crane booms, pickup trucks, ATVs, and scanned generating ''3-D'' subsurface images in real time. Inspection speeds are 0.5 to 2 meters/sec, if the image is viewed in real time, greater for off-line processing. The Ground Penetrating Holographic (GPH) system developed for inspection of DOE sites employs two 32element arrays of tapered-slot antenna operating at 5-GHz and 2.5-GHz center frequencies. The GPH system, which is mounted on a small trailer with a computer image processor, display, and power supply, is capable of imaging a wide swath (1 to 2 meters) with its linear arrays. The lower frequency array will be used at INEL (for greater depth penetration) because of high soil attenuation. Recent holographic ''3-D'' images of buried waste container lids and dielectrics obtained in Hanford sand and INEL soils at various depths graphically illustrate the unique image resolution capabilities of the system. Experimental results using the 5-GHz array will be presented showing the excellent holographic image quality of various subsurface targets in sand and INEL soil

  11. Detection of hidden stationary deformations of vibrating surfaces by use of time-averaged digital holographic interferometry.

    Science.gov (United States)

    Demoli, Nazif; Vukicevic, Dalibor

    2004-10-15

    A method of detecting displacements of a surface from its steady-state position to its equilibrium position while it is vibrating has been developed by use of time-average digital holographic interferometry. This method permits extraction of such a hidden deformation by creating two separated systems of interferogram fringes: one corresponding to a time-varying resonantly oscillating optical phase, the other to the stationary phase modification. A mathematical description of the method and illustrative results of experimental verification are presented.

  12. Multi-illumination Gabor holography recorded in a single camera snap-shot for high-resolution phase retrieval in digital in-line holographic microscopy

    Science.gov (United States)

    Sanz, Martin; Picazo-Bueno, Jose A.; Garcia, Javier; Micó, Vicente

    2015-05-01

    In this contribution we introduce MISHELF microscopy, a new concept and design of a lensless holographic microscope based on wavelength multiplexing, single hologram acquisition and digital image processing. The technique which name comes from Multi-Illumination Single-Holographic-Exposure Lensless Fresnel microscopy, is based on the simultaneous illumination and recording of three diffraction patterns in the Fresnel domain. In combination with a novel and fast iterative phase retrieval algorithm, MISHELF microscopy is capable of high-resolution (micron range) phase-retrieved (twin image elimination) biological imaging of dynamic events (video rate recording speed) since it avoids the time multiplexing needed for the in-line hologram sequence recording when using conventional phase-shifting or phase retrieval algorithms. MISHELF microscopy is validated using two different experimental layouts: one using RGB illumination and detection schemes and another using IRRB as illumination while keeping the RGB color camera as detection device. Preliminary experimental results are provided for both experimental layouts using a synthetic object (USAF resolution test target).

  13. Analog and digital image quality

    International Nuclear Information System (INIS)

    Sardo, A.

    2004-01-01

    Background. Lastly the X-ray facilities are moving to a slow, but continuous process of digitalization. The dry laser printers allow hardcopy images with optimum resolution and contrast for all the modalities. In breast imaging, the delay of digitalization depends to the high cost of digital systems and, at times, to the doubts of the diagnostic accuracy of reading the breast digital images. Conclusions. The Screen-film mammography (SFM) is the most efficient diagnostic modality to detect the breast cancer in early stage and with reasonable cost. The digital mammography (DM) with the independent capturing, displaying, processing, printing and archiving phases, makes possible an optimisation of the image quality for each, single phase, assuring a satisfactory diagnosis. (author)

  14. Introduction to digital image processing

    CERN Document Server

    Pratt, William K

    2013-01-01

    CONTINUOUS IMAGE CHARACTERIZATION Continuous Image Mathematical Characterization Image RepresentationTwo-Dimensional SystemsTwo-Dimensional Fourier TransformImage Stochastic CharacterizationPsychophysical Vision Properties Light PerceptionEye PhysiologyVisual PhenomenaMonochrome Vision ModelColor Vision ModelPhotometry and ColorimetryPhotometryColor MatchingColorimetry ConceptsColor SpacesDIGITAL IMAGE CHARACTERIZATION Image Sampling and Reconstruction Image Sampling and Reconstruction ConceptsMonochrome Image Sampling SystemsMonochrome Image Reconstruction SystemsColor Image Sampling SystemsImage QuantizationScalar QuantizationProcessing Quantized VariablesMonochrome and Color Image QuantizationDISCRETE TWO-DIMENSIONAL LINEAR PROCESSING Discrete Image Mathematical Characterization Vector-Space Image RepresentationGeneralized Two-Dimensional Linear OperatorImage Statistical CharacterizationImage Probability Density ModelsLinear Operator Statistical RepresentationSuperposition and ConvolutionFinite-Area Superp...

  15. Digital Images and Globalized Conflict

    DEFF Research Database (Denmark)

    Blaagaard, Bolette; Mortensen, Mette; Neumayer, Christina

    2017-01-01

    As the number of digital images of globalized conflicts online grow, critical examination of their impact and consequence is timely. This editorial provides an overview of digital images and globalized conflict as a field of study by discussing regimes of visibility and invisibility, proximity...... and distance, and the multiplicity of images. It engages critically with these interlinking themes as they are addressed in the contributing articles to the Special Issue as well as beyond, asking how genres and tropes are reproduced, how power plays a role in access to images, and how the sheer quantity...... of conflict-related images raise issues of knowledge production and research....

  16. Combined Raman Spectroscopy and Digital Holographic Microscopy for Sperm Cell Quality Analysis

    Directory of Open Access Journals (Sweden)

    A. De Angelis

    2017-01-01

    Full Text Available The diagnosis of male infertility is vastly complex. To date, morphology, motility, and concentration have been used as key parameters to establish the sperm normality and achieve pregnancy both in natural and in assisted fecundation. However, spermatozoa from infertile men could present a variety of alterations, such as DNA fragmentation, alterations of chromatin structure, and aneuploidy, which have been demonstrated to decrease reproductive capacity of men. Therefore, the ability to see detailed relationships between morphology and physiology in selected spermatozoa with submicrometric resolution in a nondestructive and noninvasive way and within a functional correlated context could be extremely important for the intracytoplasmic sperm injection procedure. In this review, we describe label-free optical spectroscopy and imaging techniques, based on the combination of Raman spectroscopy/imaging with holographic imaging, which are able to noninvasively measure the (biochemistry and morphology of sperm cells. We discuss the benefits and limitation of the proposed photonic techniques, with particular emphasis on applications in detection/characterization of sperm cell morphological defects and photodamage, and the identification/sorting of X- and Y-bearing bovine spermatozoa.

  17. Carrier for registration of optical images and holographic information

    International Nuclear Information System (INIS)

    Andries, A.; Bivol, V.; Iovu, M.

    2000-01-01

    The invention relates to the field of registration of optical information including the holographic one and may be used in the holography, cinematography, micro- and optical electronics, computer engineering. Summary of the invention consists in, that in the carrier containing a dielectric substrate on which there are placed in sequence the first electrode, photoinjection substrate, registration substrate of the chalcogenide vitreous semiconductor and the second electrode, the photoinjection substrate is fabricated of the monocrystalline germanium of the n-type conductivity and the relation of the registration substrate conductivity, during illumination to the photoinjection substrate conductivity in darkness is 0,001. The technical result consists in increasing the carrier photosensibility and in diffraction effectiveness of the information registered on the carrier

  18. Digital adaptive optics line-scanning confocal imaging system

    Science.gov (United States)

    Liu, Changgeng; Kim, Myung K.

    2015-01-01

    Abstract. A digital adaptive optics line-scanning confocal imaging (DAOLCI) system is proposed by applying digital holographic adaptive optics to a digital form of line-scanning confocal imaging system. In DAOLCI, each line scan is recorded by a digital hologram, which allows access to the complex optical field from one slice of the sample through digital holography. This complex optical field contains both the information of one slice of the sample and the optical aberration of the system, thus allowing us to compensate for the effect of the optical aberration, which can be sensed by a complex guide star hologram. After numerical aberration compensation, the corrected optical fields of a sequence of line scans are stitched into the final corrected confocal image. In DAOLCI, a numerical slit is applied to realize the confocality at the sensor end. The width of this slit can be adjusted to control the image contrast and speckle noise for scattering samples. DAOLCI dispenses with the hardware pieces, such as Shack–Hartmann wavefront sensor and deformable mirror, and the closed-loop feedbacks adopted in the conventional adaptive optics confocal imaging system, thus reducing the optomechanical complexity and cost. Numerical simulations and proof-of-principle experiments are presented that demonstrate the feasibility of this idea. PMID:26140334

  19. Measurements of Concentration differences between Liquid Mixtures using Digital Holographic Interferometry

    Directory of Open Access Journals (Sweden)

    Guerrero-Méndez Carlos

    2017-03-01

    Full Text Available We present an alternative method to detect and measure the concentration changes in liquid solutions. The method uses Digital Holographic Interferometry (DHI and is based on measuring refractive index variations. The first hologram is recorded when a wavefront from light comes across an ordinary cylindrical glass container filled with a liquid solution. The second hologram is recorded after slight changing the liquid’s concentration. Differences in phase obtained from the correlation of the first hologram with the second one provide information about the refractive index variation, which is directly related to the changes in physical properties related to the concentration. The method can be used − with high sensitivity, accuracy, and speed − either to detect adulterations or to measure a slight change of concentration in the order of 0.001 moles which is equivalent to a difference of 0.003 g of sodium chloride in solutions. The method also enables to measure and calculate the phase difference among each pixel of two samples. This makes it possible to generate a global measurement of the phase difference of the entire sensed region.

  20. [Clinical evaluation of digital imaging].

    Science.gov (United States)

    Marada, Gyula; Szabó, Gyula

    2006-02-01

    The rapid progression of digital radiography makes us consider its role in different fields of dentistry. The aim of the present survey was to evaluate the advantages of digital imaging over the use of radiographic films in the diagnosis and therapy of common oral pathologic conditions. The underlying hypothesis was that RadioVisiograph (RVG, Trophy Radiology, Marne-la-Vallée, France)--provided that there is access to this digital network--is easily available. Thus it can provide options for specialists of different dental fields to obtain more detailed information in order to make better decisions. Immediately after the installation of the new system and then, ten months later we analysed the results of digital images and radiographic films in outpatients of different sections at our clinic. The quality of both diagnostic procedures was evaluated using a questionnaire. Digital imaging was used mainly by specialists of endodontics, followed by restorative and prosthetic dentistry in setting up the diagnosis. The application of this new technique in parodontology and paediatric dentistry was negligible. However, it is worth mentioning that the majority of dentists participating in the survey thought that conventional radiographic films gave more detailed imaging than the digital technology. To sum it up, currently, digital imaging systems may represent an efficient device in diagnostic and therapeutic procedures. Nevertheless owing to the technical sensitivity of the above systems, traditional radiographic techniques should also be used as an option due to their advantages.

  1. Optical cryptography of gray-level image information using QPSK modulation and digital holography

    Science.gov (United States)

    Gil, Sang Keun; Jeon, Seok Hee; Jeong, Jong Rae

    2009-02-01

    We propose a novel optical cryptography of gray-level information image using QPSK digital modulation method and digital holographic technique. A gray-level information image is digitized into 8-bits binary information data by ASCII encoding method and these binary information data are expressed by four pair of quadrature phase values in a block having 2×2 pixels by QPSK digital modulation. After encoding and modulation, the size of data to be encrypted expands two times more than the original size of gray-level image. The modified information with corresponded phase values is displayed on a phase-type spatial light modulator and is encrypted with a security key by using optical digital holography. The security key is expressed with random binary phase. Digital hologram in this method is Fourier transform hologram and is recorded on CCD camera with 256 gray-level quantized intensities. These encrypted digital holograms are able to be stored by computer and be transmitted over a communication network. With this encrypted digital hologram, the phase values are reconstructed with the same security key by holographic technique and are decrypted into the original gray-level information image by decoding. Simulation results show that the proposed method can be used for a cipher and security system.

  2. Improvement of image quality of holographic projection on tilted plane using iterative algorithm

    Science.gov (United States)

    Pang, Hui; Cao, Axiu; Wang, Jiazhou; Zhang, Man; Deng, Qiling

    2017-12-01

    Holographic image projection on tilted plane has an important application prospect. In this paper, we propose a method to compute the phase-only hologram that can reconstruct a clear image on tilted plane. By adding a constant phase to the target image of the inclined plane, the corresponding light field distribution on the plane that is parallel to the hologram plane is derived through the titled diffraction calculation. Then the phase distribution of the hologram is obtained by the iterative algorithm with amplitude and phase constrain. Simulation and optical experiment are performed to show the effectiveness of the proposed method.

  3. Digital Data Processing of Images

    African Journals Online (AJOL)

    Digital data processing was investigated to perform image processing. Image smoothing and restoration were explored and promising results obtained. The use of the computer, not only as a data management device, but as an important tool to render quantitative information, was illustrated by lung function determination.

  4. Evaluation of thermal exposure on absorbing objects with digital holographic interferometry method

    Science.gov (United States)

    Bodienkov, P. S.; Manukhin, B. G.; Andreeva, N. V.; Andreeva, O. V.

    2014-05-01

    The digital holographic interferometry methods that are used in this work nowadays is widely applied to research of temporal dynamics of objects transformation in different processes [1, 2]. Authors use developed stand and software that are used for detecting and controlling of phase changes of transparent objects with time resolution not less than 100 ms for a long time. Samples of recording polymer material for volume holography «Difphen», solid solution of organic dye phenanthrenequinone (PQ) in polymethylmethacrylate (PMMA), were used as an object of research. Samples were prepared in the shape of plane-parallel disks, 40 mm in diameter and thickness (2÷4) mm [3]. The using radiation with wavelength λ=473 nm is located in the region of absorption of PQ and presents by itself a beam of radiation of solid state DPSS laser which is (2.5÷3.0) mm in diameter and its power is of about 50 mWt. The part of the sample that was exposed by the radiation, absorbing energy, is bleaching and heating up. The bleaching process takes place just in localized area (exposed area), while increase of temperature from exposed area to unexposed areas of the sample is spread by heat transfer. For observation of the process of transfer of heat in the quality of probe radiation we use radiation with wavelength λ = 532 nm in spectral area of light-insensitivity the sample. The probe area was 20x20 mm, which allowed us to evaluate thermal effects in object's area, located out of reach of laser beam 473nm.

  5. Properties of axially loaded implant-abutment assemblies using digital holographic interferometry analysis.

    Science.gov (United States)

    Brozović, Juraj; Demoli, Nazif; Farkaš, Nina; Sušić, Mato; Alar, Zeljko; Gabrić Pandurić, Dragana

    2014-03-01

    The aim of this study was to (i) obtain the force-related interferometric patterns of loaded dental implant-abutment assemblies differing in diameter and brand using digital holographic interferometry (DHI) and (ii) determine the influence of implant diameter on the extent of load-induced implant deformation by quantifying and comparing the obtained interferometric data. Experiments included five implant brands (Ankylos, Astra Tech, blueSKY, MIS and Straumann), each represented by a narrow and a wide diameter implant connected to a corresponding abutment. A quasi-Fourier setup with a 25mW helium-neon laser was used for interferometric measurements in the cervical 5mm of the implants. Holograms were recorded in two conditions per measurement: a 10N preloaded and a measuring-force loaded assembly, resulting with an interferogram. This procedure was repeated throughout the whole process of incremental axial loading, from 20N to 120N. Each measurement series was repeated three times for each assembly, with complete dismantling of the implant-loading device in between. Additional software analyses calculated deformation data. Deformations were presented as mean values±standard deviations. Statistical analysis was performed using linear mixed effects modeling in R's lme4 package. Implants exhibited linear deformation patterns. The wide diameter group had lower mean deformation values than the narrow diameter group. The diameter significantly affected the deformation throughout loading sessions. This study gained in vitro implant performance data, compared the deformations in implant bodies and numerically stated the biomechanical benefits of wider diameter implants. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Digital imaging - future visions

    International Nuclear Information System (INIS)

    Sanford, L.

    1993-01-01

    The reality of a filmless future in medicine is closer in the UK than in the US. The initiative with digital data processing, however, is not. Despite the glowing promises in the literature of such visionware', there is as yet no filmless system anywhere in the World. This article examines research in this field. (Author)

  7. Principles of digital image synthesis

    CERN Document Server

    Glassner, Andrew S

    1995-01-01

    Image synthesis, or rendering, is a field of transformation: it changesgeometry and physics into meaningful images. Because the most popularalgorithms frequently change, it is increasingly important for researchersand implementors to have a basic understanding of the principles of imagesynthesis. Focusing on theory, Andrew Glassner provides a comprehensiveexplanation of the three core fields of study that come together to formdigital image synthesis: the human visual system, digital signalprocessing, and the interaction of matter and light. Assuming no more thana basic background in calculus,

  8. A scheme for recording a fast process at nanosecond scale by using digital holographic interferometry with continuous wave laser

    Science.gov (United States)

    Wang, Jun; Zhao, Jianlin; Di, Jianglei; Jiang, Biqiang

    2015-04-01

    A scheme for recording fast process at nanosecond scale by using digital holographic interferometry with continuous wave (CW) laser is described and demonstrated experimentally, which employs delayed-time fibers and angular multiplexing technique and can realize the variable temporal resolution at nanosecond scale and different measured depths of object field at certain temporal resolution. The actual delay-time is controlled by two delayed-time fibers with different lengths. The object field information in two different states can be simultaneously recorded in a composite hologram. This scheme is also suitable for recording fast process at picosecond scale, by using an electro-optic modulator.

  9. LCD panel characterization by measuring full Jones matrix of individual pixels using polarization-sensitive digital holographic microscopy.

    Science.gov (United States)

    Park, Jongchan; Yu, Hyeonseung; Park, Jung-Hoon; Park, YongKeun

    2014-10-06

    We present measurements of the full Jones matrix of individual pixels in a liquid-crystal display (LCD) panel. Employing a polarization-sensitive digital holographic microscopy based on Mach-Zehnder interferometry, the complex amplitudes of the light passing through individual LCD pixels are precisely measured with respect to orthogonal bases of polarization states, from which the full Jones matrix components of individual pixels are obtained. We also measure the changes in the Jones matrix of individual LCD pixels with respect to an applied bias. In addition, the complex optical responses of a LCD panel with respect to arbitrary polarization states of incident light were characterized from the measured Jones matrix.

  10. Temperature measurement of wick stabilized micro diffusion flame under the influence of magnetic field using digital holographic interferometry

    Science.gov (United States)

    Agarwal, Shilpi; Kumar, Varun; Shakher, Chandra

    2018-03-01

    This paper presents the effect of magnetic field (upward decreasing, uniform and upward increasing) on wick stabilized micro diffusion flame by using digital holographic interferometry (DHI). The investigations reveal that under the influence of upward decreasing and uniform magnetic field temperature inside the micro flame increases in comparison to temperature inside micro flame without magnetic field. This is in contrary to normal diffusion flame, where uniform magnetic field has a little or no effect on the temperature. DHI is inherently more accurate more precise and is having better spatial resolution. DHI is ideally suited to study micro flame.

  11. Remote Sensing Digital Image Analysis

    Science.gov (United States)

    Richards, John A.; Jia, Xiuping

    Remote Sensing Digital Image Analysis provides the non-specialist with an introduction to quantitative evaluation of satellite and aircraft derived remotely retrieved data. Each chapter covers the pros and cons of digital remotely sensed data, without detailed mathematical treatment of computer based algorithms, but in a manner conductive to an understanding of their capabilities and limitations. Problems conclude each chapter. This fourth edition has been developed to reflect the changes that have occurred in this area over the past several years.

  12. Real-time laser holographic interferometry for aerodynamics

    International Nuclear Information System (INIS)

    Lee, G.

    1987-01-01

    Recent developments in thermoplastic recording holograms and advancements in automated image digitalization and analysis make real-time laser holographic interferometry feasible for two-dimensional flows such as airfoil flows. Typical airfoil measurements would include airfoil pressure distributions, wake and boundary layer profiles, and flow field density contours. This paper addresses some of the problems and requirements of a real-time laser holographic interferometer. 13 references

  13. Phase-conjugate holographic system for high-resolution particle-image velocimetry

    International Nuclear Information System (INIS)

    Barnhart, D.H.; Adrian, R.J.; Papen, G.C.

    1994-01-01

    A novel holographic particle-image velocimeter system has been developed for the study of three-dimensional (3-D) fluid velocity fields. The recording system produces 3-D particle images with a resolution, a signal-to-noise ratio, an accuracy, and derived velocity fields that are comparable to high-quality two-dimensional photographic particle-image velocimetry (PIV). The high image resolution is accomplished through the use of low f-number optics, a fringe-stabilized processing chemistry, and a phase conjugate play-back geometry that compensates for aberrations in the imaging system. In addition, the system employs a reference multiplexed, off-axis geometry for the determination of velocity directions with the cross-correlation technique, and a stereo camera geometry for the determination of the three velocity components. The combination of the imaging and reconstruction subsystems makes the analysis of volumetric PIV domains feasible

  14. Phase-conjugate holographic system for high-resolution particle-image velocimetry.

    Science.gov (United States)

    Barnhart, D H; Adrian, R J; Papen, G C

    1994-10-20

    A novel holographic particle-image velocimeter system has been developed for the study of threedimensional (3-D) fluid velocity fields. The recording system produces 3-D particle images with a resolution, a signal-to-noise ratio, an accuracy, and derived velocity fields that are comparable to high-quality two-dimensional photographic particle-image velocimetry (PIV). The high image resolution is accomplished through the use of low f-number optics, a fringe-stabilized processing chemistry, and a phase conjugate play-back geometry that compensates for aberrations in the imaging system. In addition, the system employs a reference multiplexed, off-axis geometry for the determination of velocity directions with the cross-correlation technique, and a stereo camera geometry for the determination of the three velocity components. The combination of the imaging and reconstruction subsystems makes the analysis of volumetric PIV domains feasible.

  15. HOLIMO II: a digital holographic instrument for ground-based in situ observations of microphysical properties of mixed-phase clouds

    Directory of Open Access Journals (Sweden)

    J. Henneberger

    2013-11-01

    Full Text Available Measurements of the microphysical properties of mixed-phase clouds with high spatial resolution are important to understand the processes inside these clouds. This work describes the design and characterization of the newly developed ground-based field instrument HOLIMO II (HOLographic Imager for Microscopic Objects II. HOLIMO II uses digital in-line holography to in situ image cloud particles in a well-defined sample volume. By an automated algorithm, two-dimensional images of single cloud particles between 6 and 250 μm in diameter are obtained and the size spectrum, the concentration and water content of clouds are calculated. By testing the sizing algorithm with monosized beads a systematic overestimation near the resolution limit was found, which has been used to correct the measurements. Field measurements from the high altitude research station Jungfraujoch, Switzerland, are presented. The measured number size distributions are in good agreement with parallel measurements by a fog monitor (FM-100, DMT, Boulder USA. The field data shows that HOLIMO II is capable of measuring the number size distribution with a high spatial resolution and determines ice crystal shape, thus providing a method of quantifying variations in microphysical properties. A case study over a period of 8 h has been analyzed, exploring the transition from a liquid to a mixed-phase cloud, which is the longest observation of a cloud with a holographic device. During the measurement period, the cloud does not completely glaciate, contradicting earlier assumptions of the dominance of the Wegener–Bergeron–Findeisen (WBF process.

  16. Digital Data Processing of Images

    African Journals Online (AJOL)

    lend themselves to computer storage, this article will only be concerned with the image enhancement of ... digital computer to quantitate organ function after dynamic studies using the gamma camera will also be ..... an on-line computer is necessary for the automatic analysis of data. The facility to view the dynamic process ...

  17. Optimized computational imaging methods for small-target sensing in lens-free holographic microscopy

    Science.gov (United States)

    Xiong, Zhen; Engle, Isaiah; Garan, Jacob; Melzer, Jeffrey E.; McLeod, Euan

    2018-02-01

    Lens-free holographic microscopy is a promising diagnostic approach because it is cost-effective, compact, and suitable for point-of-care applications, while providing high resolution together with an ultra-large field-of-view. It has been applied to biomedical sensing, where larger targets like eukaryotic cells, bacteria, or viruses can be directly imaged without labels, and smaller targets like proteins or DNA strands can be detected via scattering labels like micro- or nano-spheres. Automated image processing routines can count objects and infer target concentrations. In these sensing applications, sensitivity and specificity are critically affected by image resolution and signal-to-noise ratio (SNR). Pixel super-resolution approaches have been shown to boost resolution and SNR by synthesizing a high-resolution image from multiple, partially redundant, low-resolution images. However, there are several computational methods that can be used to synthesize the high-resolution image, and previously, it has been unclear which methods work best for the particular case of small-particle sensing. Here, we quantify the SNR achieved in small-particle sensing using regularized gradient-descent optimization method, where the regularization is based on cardinal-neighbor differences, Bayer-pattern noise reduction, or sparsity in the image. In particular, we find that gradient-descent with sparsity-based regularization works best for small-particle sensing. These computational approaches were evaluated on images acquired using a lens-free microscope that we assembled from an off-the-shelf LED array and color image sensor. Compared to other lens-free imaging systems, our hardware integration, calibration, and sample preparation are particularly simple. We believe our results will help to enable the best performance in lens-free holographic sensing.

  18. Image processing techniques for digital orthophotoquad production

    Science.gov (United States)

    Hood, Joy J.; Ladner, L. J.; Champion, Richard A.

    1989-01-01

    Orthophotographs have long been recognized for their value as supplements or alternatives to standard maps. Recent trends towards digital cartography have resulted in efforts by the US Geological Survey to develop a digital orthophotoquad production system. Digital image files were created by scanning color infrared photographs on a microdensitometer. Rectification techniques were applied to remove tile and relief displacement, thereby creating digital orthophotos. Image mosaicking software was then used to join the rectified images, producing digital orthophotos in quadrangle format.

  19. Digital holographic amplification of interferograms in the Michelson interferometer using the phase-only LCOS modulator

    Science.gov (United States)

    Balbekin, Nikolay; Petrov, Nikolay; Pul'kin, Sergey; Shoev, Vladislav; Sevryugin, Alexander; Tursunov, Ibrohim; Venediktov, Dmitrii; Venediktov, Vladimir

    2017-10-01

    The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific "hooks", whose curvature provides the information about the atomic oscillator force. The holographic amplification "smoothes" the hooks and thus makes their analysis much simpler.

  20. Digital image processing techniques in archaeology

    Digital Repository Service at National Institute of Oceanography (India)

    Santanam, K.; Vaithiyanathan, R.; Tripati, S.

    Digital image processing involves the manipulation and interpretation of digital images with the aid of a computer. This form of remote sensing actually began in the 1960's with a limited number of researchers analysing multispectral scanner data...

  1. Apparatus and method using a holographic optical element for converting a spectral distribution to image points

    Science.gov (United States)

    McGill, Matthew J. (Inventor); Scott, Vibart S. (Inventor); Marzouk, Marzouk (Inventor)

    2001-01-01

    A holographic optical element transforms a spectral distribution of light to image points. The element comprises areas, each of which acts as a separate lens to image the light incident in its area to an image point. Each area contains the recorded hologram of a point source object. The image points can be made to lie in a line in the same focal plane so as to align with a linear array detector. A version of the element has been developed that has concentric equal areas to match the circular fringe pattern of a Fabry-Perot interferometer. The element has high transmission efficiency, and when coupled with high quantum efficiency solid state detectors, provides an efficient photon-collecting detection system. The element may be used as part of the detection system in a direct detection Doppler lidar system or multiple field of view lidar system.

  2. Three-Dimensional Microwave Holographic Imaging Employing Forward-Scattered Waves Only

    Directory of Open Access Journals (Sweden)

    Reza K. Amineh

    2013-01-01

    Full Text Available We propose a three-dimensional microwave holographic imaging method based on the forward-scattered waves only. In the proposed method, one transmitter and multiple receivers perform together a two-dimensional scan on two planar apertures on opposite sides of the inspected domain. The ability to achieve three-dimensional imaging without back-scattered waves enables the imaging of high-loss objects, for example, tissues, where the back-scattered waves may not be available due to low signal-to-noise ratio or nonreciprocal measurement setup. The simulation and experimental results demonstrate the satisfactory performance of the proposed method in providing three-dimensional images. Resolution limits are derived and confirmed with simulation examples.

  3. Enhanced depth-of-field of an integral imaging microscope using a bifocal holographic optical element-micro lens array.

    Science.gov (United States)

    Kwon, Ki-Chul; Lim, Young-Tae; Shin, Chang-Won; Erdenebat, Munkh-Uchral; Hwang, Jae-Moon; Kim, Nam

    2017-08-15

    We propose and implement an integral imaging microscope with extended depth-of-field (DoF) using a bifocal holographic micro lens array (MLA). The properties of the two MLAs are switched via peristrophic multiplexing, where different properties of the MLA are recorded onto the single holographic optical element (HOE). The recorded MLA properties are perpendicular to each other: after the first mode is recorded, the HOE is rotated by 90° clockwise, and the second mode is recorded. The experimental results confirm that the DoF of the integral imaging microscopy system is extended successfully by using the bifocal MLA.

  4. Holographic observation of magnetic resonance image CT of intracranial tumors

    International Nuclear Information System (INIS)

    Iwata, Kinjiro; Watanabe, Saburo; Yuasa, Hiromi; Yamada, Takahisa; Hoshino, Daisaku; Suzuki, Masane; Saito, Takayuki.

    1987-01-01

    In 1975, we developed a new method of 3-dimensional observation of CT pictures using Gabor's holography principle. In this study, we are reporting our experience with the multi-tomogram holography using magnetic resonance image CT in order to reconstruct 3-dimensional viewing of the central nervous system and intracranial lesions. (J.P.N.)

  5. Digital radiology and digitally formatted image management systems

    International Nuclear Information System (INIS)

    Cox, G.G.; Dwyer, S.J. III; Templeton, A.W.

    1987-01-01

    The number of diagnostic examinations performed with digitally formatted imaging equipment is increasing. Digital general-purpose and fluoroscopic radiology systems are being clinically evaluated. Digitizing conventional x-ray films, such as mammograms, frequently improves the diagnostic quality of the images. The digitizing process with laser has also afforded the opportunity to document required spatial resolution for digital imaging and network systems. The use of digitally formatted image instrumentation imposes new requirements on the acquisition, display and manipulation, transmission, hard copy image recording, and archiving of diagnostic data. Networking of digitally formatted image data offers many advantages for managing digital information. This paper identifies and describes digital radiographic systems. Parameters required for designing and implementing a digital image management system are outlined. Spatial and contrast resolution requirements are identified. The key parameters include the amount of image data generated each working day, the retrieval rate of the generated data, the display hardware and software needed for interactive diagnosis display stations, the requirements for analog hard copy generation, and on-line and long-term archiving requirements. These image management systems are often called PACS (Picture Archiving and Communication Systems)

  6. Digital image analyser for autoradiography

    International Nuclear Information System (INIS)

    Muth, R.A.; Plotnick, J.

    1985-01-01

    The most critical parameter in quantitative autoradiography for assay of tissue concentrations of tracers is the ability to obtain precise and accurate measurements of optical density of the images. Existing high precision systems for image analysis, rotating drum densitometers, are expensive, suffer from mechanical problems and are slow. More moderately priced and reliable video camera based systems are available, but their outputs generally do not have the uniformity and stability necessary for high resolution quantitative autoradiography. The authors have designed and constructed an image analyser optimized for quantitative single and multiple tracer autoradiography which the authors refer to as a memory-mapped charged-coupled device scanner (MM-CCD). The input is from a linear array of CCD's which is used to optically scan the autoradiograph. Images are digitized into 512 x 512 picture elements with 256 gray levels and the data is stored in buffer video memory in less than two seconds. Images can then be transferred to RAM memory by direct memory-mapping for further processing. Arterial blood curve data and optical density-calibrated standards data can be entered and the optical density images can be converted automatically to tracer concentration or functional images. In double tracer studies, images produced from both exposures can be stored and processed in RAM to yield ''pure'' individual tracer concentration or functional images. Any processed image can be transmitted back to the buffer memory to be viewed on a monitor and processed for region of interest analysis

  7. Higuchi dimension of digital images.

    Directory of Open Access Journals (Sweden)

    Helmut Ahammer

    Full Text Available There exist several methods for calculating the fractal dimension of objects represented as 2D digital images. For example, Box counting, Minkowski dilation or Fourier analysis can be employed. However, there appear to be some limitations. It is not possible to calculate only the fractal dimension of an irregular region of interest in an image or to perform the calculations in a particular direction along a line on an arbitrary angle through the image. The calculations must be made for the whole image. In this paper, a new method to overcome these limitations is proposed. 2D images are appropriately prepared in order to apply 1D signal analyses, originally developed to investigate nonlinear time series. The Higuchi dimension of these 1D signals is calculated using Higuchi's algorithm, and it is shown that both regions of interests and directional dependencies can be evaluated independently of the whole picture. A thorough validation of the proposed technique and a comparison of the new method to the Fourier dimension, a common two dimensional method for digital images, are given. The main result is that Higuchi's algorithm allows a direction dependent as well as direction independent analysis. Actual values for the fractal dimensions are reliable and an effective treatment of regions of interests is possible. Moreover, the proposed method is not restricted to Higuchi's algorithm, as any 1D method of analysis, can be applied.

  8. Holographic Imaging of Evolving Laser-Plasma Structures

    Energy Technology Data Exchange (ETDEWEB)

    Downer, Michael [Univ. of Texas, Austin, TX (United States); Shvets, G. [Univ. of Texas, Austin, TX (United States)

    2014-07-31

    In the 1870s, English photographer Eadweard Muybridge captured motion pictures within one cycle of a horse’s gallop, which settled a hotly debated question of his time by showing that the horse became temporarily airborne. In the 1940s, Manhattan project photographer Berlin Brixner captured a nuclear blast at a million frames per second, and resolved a dispute about the explosion’s shape and speed. In this project, we developed methods to capture detailed motion pictures of evolving, light-velocity objects created by a laser pulse propagating through matter. These objects include electron density waves used to accelerate charged particles, laser-induced refractive index changes used for micromachining, and ionization tracks used for atmospheric chemical analysis, guide star creation and ranging. Our “movies”, like Muybridge’s and Brixner’s, are obtained in one shot, since the laser-created objects of interest are insufficiently repeatable for accurate stroboscopic imaging. Our high-speed photographs have begun to resolve controversies about how laser-created objects form and evolve, questions that previously could be addressed only by intensive computer simulations based on estimated initial conditions. Resolving such questions helps develop better tabletop particle accelerators, atmospheric ranging devices and many other applications of laser-matter interactions. Our photographic methods all begin by splitting one or more “probe” pulses from the laser pulse that creates the light-speed object. A probe illuminates the object and obtains information about its structure without altering it. We developed three single-shot visualization methods that differ in how the probes interact with the object of interest or are recorded. (1) Frequency-Domain Holography (FDH). In FDH, there are 2 probes, like “object” and “reference” beams in conventional holography. Our “object” probe surrounds the light-speed object, like a fleas swarming around a

  9. Exploiting the speckle-correlation scattering matrix for a compact reference-free holographic image sensor.

    Science.gov (United States)

    Lee, KyeoReh; Park, YongKeun

    2016-10-31

    The word 'holography' means a drawing that contains all of the information for light-both amplitude and wavefront. However, because of the insufficient bandwidth of current electronics, the direct measurement of the wavefront of light has not yet been achieved. Though reference-field-assisted interferometric methods have been utilized in numerous applications, introducing a reference field raises several fundamental and practical issues. Here we demonstrate a reference-free holographic image sensor. To achieve this, we propose a speckle-correlation scattering matrix approach; light-field information passing through a thin disordered layer is recorded and retrieved from a single-shot recording of speckle intensity patterns. Self-interference via diffusive scattering enables access to impinging light-field information, when light transport in the diffusive layer is precisely calibrated. As a proof-of-concept, we demonstrate direct holographic measurements of three-dimensional optical fields using a compact device consisting of a regular image sensor and a diffusor.

  10. Low-cost production and sealing procedure of mechanical parts of a versatile 3D-printed perfusion chamber for digital holographic microscopy of primary neurons in culture

    Science.gov (United States)

    Bélanger, Erik; Lévesque, Sébastien A.; Anctil, Gabriel; Poulin-Girard, Anne-Sophie; Marquet, Pierre

    2017-02-01

    We have developed a prototype of a low-cost and versatile 3D-printed perfusion chamber for digital holographic microscopy (DHM) of primary neurons in culture. The imaging chamber is 3D-printed in biocompatible plastic. It is easily convertible between a closed configuration, for refractive index - cellular thickness decoupling, and an open configuration, for electrophysiology. In the closed arrangement, the imaging volume is small, allowing a rapid laminar flow with a fast turnover for an optimal implementation of the decoupling procedure. This paper highlights especially the challenges faced while designing and prototyping the 3D-printed closed perfusion chamber with a small imaging volume for DHM. As all 3D-printed mechanical parts were initially leaking because of internal porosities, we developed a simple sealing protocol using acetone vapors to smooth surfaces. Using this protocol, almost all mechanical parts were successfully sealed. Therefore, the production process of the actual prototype, i.e. the 3D printing and the sealing method, is satisfactory for our target application in the field of microfluidics.

  11. Separate recording of rationally related vibration frequencies using digital stroboscopic holographic interferometry

    International Nuclear Information System (INIS)

    Alexeenko, Igor; Gusev, Michael; Gurevich, Vadim

    2009-01-01

    A method for separate recording of rationally related vibration frequencies is presented. To record and measure the mode shape of vibrations, a synchronized stroboscopic CCD camera is used. Synchronization and control of the camera acquisition for recording stroboscopic holographic sequence has been realized. The phase for different states of the object vibration is calculated using the Fourier-transform method. Experimental results are presented, and the advantages and disadvantages of the proposed method are discussed.

  12. Imaging spectroscopy with digital micromirrors

    Science.gov (United States)

    Kearney, Kevin J.; Corio, Mark A.; Ninkov, Zoran

    2000-05-01

    The availability of optical MEMS (Micro-Electro-Mechanical Systems) is promising to revolutionize optical instrument design. We are developing a multiobject imaging spectrometer based on a commercially available optical MEMS--the Texas Instrument's Digital Micromirror Device (DMD)TM. The micromirror array is laced at an image plane of an optical system, and is used as a spatial light modulator to redirect portions of the image into the spectrograph. The programmability of the micromirror array allows the creation of arbitrary `slit' patterns as input to the spectrograph. In addition, by controlling the dwell time of each micromirror individually, it is possible to adaptively extend the dynamic range of the spectral imaging system.

  13. Short-coherence in-line phase-shifting infrared digital holographic microscopy for measurement of internal structure in silicon

    Science.gov (United States)

    Xi, Teli; Dou, Jiazhen; Di, Jianglei; Li, Ying; Zhang, Jiwei; Ma, Chaojie; Zhao, Jianlin

    2017-06-01

    Short-coherence in-line phase-shifting digital holographic microscopy based on Michelson interferometer is proposed to measure internal structure in silicon. In the configuration, a short-coherence infrared laser is used as the light source in order to avoid the interference formed by the reference wave and the reflected wave from the front surface of specimen. At the same time, in-line phase-shifting configuration is introduced to overcome the problem of poor resolution and large pixel size of the infrared camera and improve the space bandwidth product of the system. A specimen with staircase structure is measured by using the proposed configuration and the 3D shape distribution are given to verify the effectiveness and accuracy of the method.

  14. Digital image transformation and rectification of spacecraft and radar images

    Science.gov (United States)

    Wu, S. S. C.

    1985-01-01

    The application of digital processing techniques to spacecraft television pictures and radar images is discussed. The use of digital rectification to produce contour maps from spacecraft pictures is described; images with azimuth and elevation angles are converted into point-perspective frame pictures. The digital correction of the slant angle of radar images to ground scale is examined. The development of orthophoto and stereoscopic shaded relief maps from digital terrain and digital image data is analyzed. Digital image transformations and rectifications are utilized on Viking Orbiter and Lander pictures of Mars.

  15. Digital processing of radiographic images

    Science.gov (United States)

    Bond, A. D.; Ramapriyan, H. K.

    1973-01-01

    Some techniques are presented and the software documentation for the digital enhancement of radiographs. Both image handling and image processing operations are considered. The image handling operations dealt with are: (1) conversion of format of data from packed to unpacked and vice versa; (2) automatic extraction of image data arrays; (3) transposition and 90 deg rotations of large data arrays; (4) translation of data arrays for registration; and (5) reduction of the dimensions of data arrays by integral factors. Both the frequency and the spatial domain approaches are presented for the design and implementation of the image processing operation. It is shown that spatial domain recursive implementation of filters is much faster than nonrecursive implementations using fast fourier transforms (FFT) for the cases of interest in this work. The recursive implementation of a class of matched filters for enhancing image signal to noise ratio is described. Test patterns are used to illustrate the filtering operations. The application of the techniques to radiographic images of metallic structures is demonstrated through several examples.

  16. New directions in pediatric digital imaging

    International Nuclear Information System (INIS)

    Fletcher, B.D.; Adams, R.B.; Blackham, W.C.

    1985-01-01

    In this chapter the authors describe several simple experiments performed utilizing digital equipment which apply to clinical situations in pediatrics and which suggest future directions for research in digital imaging. They also discuss experimental systems which they believe will overcome certain limitations of current equipment and might be applicable to pediatric digital imaging in the future

  17. Detecting Copy Move Forgery In Digital Images

    Science.gov (United States)

    Gupta, Ashima; Saxena, Nisheeth; Vasistha, S. K.

    2012-03-01

    In today's world several image manipulation software's are available. Manipulation of digital images has become a serious problem nowadays. There are many areas like medical imaging, digital forensics, journalism, scientific publications, etc, where image forgery can be done very easily. To determine whether a digital image is original or doctored is a big challenge. To find the marks of tampering in a digital image is a challenging task. The detection methods can be very useful in image forensics which can be used as a proof for the authenticity of a digital image. In this paper we propose the method to detect region duplication forgery by dividing the image into overlapping block and then perform searching to find out the duplicated region in the image.

  18. The application of digital image plane holography technology to identify Chinese herbal medicine

    Science.gov (United States)

    Wang, Huaying; Guo, Zhongjia; Liao, Wei; Zhang, Zhihui

    2012-03-01

    In this paper, the imaging technology of digital image plane holography to identify the Chinese herbal medicine is studied. The optical experiment system of digital image plane holography which is the special case of pre-magnification digital holography was built. In the record system, one is an object light by using plane waves which illuminates the object, and the other one is recording hologram by using spherical light wave as reference light. There is a Micro objective lens behind the object. The second phase factor which caus ed by the Micro objective lens can be eliminated by choosing the proper position of the reference point source when digital image plane holography is recorded by spherical light. In this experiment, we use the Lygodium cells and Onion cells as the object. The experiment results with Lygodium cells and Onion cells show that digital image plane holography avoid the process of finding recording distance by using auto-focusing approach, and the phase information of the object can be reconstructed more accurately. The digital image plane holography is applied to the microscopic imaging of cells more effectively, and it is suit to apply for the identify of Chinese Herbal Medicine. And it promotes the application of digital holographic in practice.

  19. Holographic line field en-face OCT with digital adaptive optics in the retinain vivo.

    Science.gov (United States)

    Ginner, Laurin; Schmoll, Tilman; Kumar, Abhishek; Salas, Matthias; Pricoupenko, Nastassia; Wurster, Lara M; Leitgeb, Rainer A

    2018-02-01

    We demonstrate a high-resolution line field en-face time domain optical coherence tomography (OCT) system using an off-axis holography configuration. Line field en-face OCT produces high speed en-face images at rates of up to 100 Hz. The high frame rate favors good phase stability across the lateral field-of-view which is indispensable for digital adaptive optics (DAO). Human retinal structures are acquired in-vivo with a broadband light source at 840 nm, and line rates of 10 kHz to 100 kHz. Structures of different retinal layers, such as photoreceptors, capillaries, and nerve fibers are visualized with high resolution of 2.8 µm and 5.5 µm in lateral directions. Subaperture based DAO is successfully applied to increase the visibility of cone-photoreceptors and nerve fibers. Furthermore, en-face Doppler OCT maps are generated based on calculating the differential phase shifts between recorded lines.

  20. Digital image processing mathematical and computational methods

    CERN Document Server

    Blackledge, J M

    2005-01-01

    This authoritative text (the second part of a complete MSc course) provides mathematical methods required to describe images, image formation and different imaging systems, coupled with the principle techniques used for processing digital images. It is based on a course for postgraduates reading physics, electronic engineering, telecommunications engineering, information technology and computer science. This book relates the methods of processing and interpreting digital images to the 'physics' of imaging systems. Case studies reinforce the methods discussed, with examples of current research

  1. A review on noise suppression and aberration compensation in holographic particle image velocimetry

    Directory of Open Access Journals (Sweden)

    K.F. Tamrin

    2016-12-01

    Full Text Available Understanding three-dimensional (3D fluid flow behaviour is undeniably crucial in improving performance and efficiency in a wide range of applications in engineering and medical fields. Holographic particle image velocimetry (HPIV is a potential tool to probe and characterize complex flow dynamics since it is a truly three-dimensional three-component measurement technique. The technique relies on the coherent light scattered by small seeding particles that are assumed to faithfully follow the flow for subsequent reconstruction of the same the event afterward. However, extraction of useful 3D displacement data from these particle images is usually aggravated by noise and aberration which are inherent within the optical system. Noise and aberration have been considered as major hurdles in HPIV in obtaining accurate particle image identification and its corresponding 3D position. Major contributions to noise include zero-order diffraction, out-of-focus particles, virtual image and emulsion grain scattering. Noise suppression is crucial to ensure that particle image can be distinctly differentiated from background noise while aberration compensation forms particle image with high integrity. This paper reviews a number of HPIV configurations that have been proposed to address these issues, summarizes the key findings and outlines a basis for follow-on research.

  2. Holographic particle-image velocimetry in the first International Microgravity Laboratory aboard the Space Shuttle Discovery.

    Science.gov (United States)

    Trolinger, J D; Lal, R B; McIntosh, D; Witherow, W K

    1996-02-01

    In January 1992 the Space Shuttle Discovery carried the first International Microgravity Laboratory into Earth orbit for eight days. One of the many experiments carried out during the orbit was a combined study of triglycine sulfate crystal growth from solution and fluid-particle-dynamics studies in microgravity. Optical diagnostics included holocameras to provide concentration measurements and three-dimensional particle tracking. More than 1000 holograms that were recorded in space have been analyzed since the flight, providing a wide range of interesting conclusions about microgravity, crystal growth, and particle dynamics. This paper focuses on the results of holographic particle-image velocimetry experiments and provides an excellent example, along with new techniques, for exploiting holography for particle and flow diagnostics.

  3. JPEG 2000-based compression of fringe patterns for digital holographic microscopy

    Science.gov (United States)

    Blinder, David; Bruylants, Tim; Ottevaere, Heidi; Munteanu, Adrian; Schelkens, Peter

    2014-12-01

    With the advent of modern computing and imaging technologies, digital holography is becoming widespread in various scientific disciplines such as microscopy, interferometry, surface shape measurements, vibration analysis, data encoding, and certification. Therefore, designing an efficient data representation technology is of particular importance. Off-axis holograms have very different signal properties with respect to regular imagery, because they represent a recorded interference pattern with its energy biased toward the high-frequency bands. This causes traditional images' coders, which assume an underlying 1/f2 power spectral density distribution, to perform suboptimally for this type of imagery. We propose a JPEG 2000-based codec framework that provides a generic architecture suitable for the compression of many types of off-axis holograms. This framework has a JPEG 2000 codec at its core, extended with (1) fully arbitrary wavelet decomposition styles and (2) directional wavelet transforms. Using this codec, we report significant improvements in coding performance for off-axis holography relative to the conventional JPEG 2000 standard, with Bjøntegaard delta-peak signal-to-noise ratio improvements ranging from 1.3 to 11.6 dB for lossy compression in the 0.125 to 2.00 bpp range and bit-rate reductions of up to 1.6 bpp for lossless compression.

  4. Mars Digital Image Mosaic Globe

    Science.gov (United States)

    2000-01-01

    The photomosaic that forms the base for this globe was created by merging two global digital image models (DIM's) of Mars-a medium-resolution monochrome mosaic processed to emphasize topographic features and a lower resolution color mosaic emphasizing color and albedo variations.The medium-resolution (1/256 or roughly 231 m/pixel) monochromatic image model was constructed from about 6,000 images having resolutions of 150-350 m/pixel and oblique illumination (Sun 20 o -45 o above the horizon). Radiometric processing was intended to suppress or remove the effects of albedo variations through the use of a high-pass divide filter, followed by photometric normalization so that the contrast of a given topographic slope would be approximately the same in all images.The global color mosaic was assembled at 1/64 or roughly 864 m/pixel from about 1,000 red- and green-filter images having 500-1,000 m/pixel resolution. These images were first mosaiced in groups, each taken on a single orbit of the Viking spacecraft. The orbit mosaics were then processed to remove spatially and temporally varying atmospheric haze in the overlap regions. After haze removal, the per-orbit mosaics were photometrically normalized to equalize the contrast of albedo features and mosaiced together with cosmetic seam removal. The medium-resolution DIM was used for geometric control of this color mosaic. A green-filter image was synthesized by weighted averaging of the red- and violet-filter mosaics. Finally, the product seen here was obtained by multiplying each color image by the medium-resolution monochrome image. The color balance selected for images in this map series was designed to be close to natural color for brighter, redder regions, such as Arabia Terra and the Tharsis region, but the data have been stretched so that the relatively dark regions appear darker and less red than they actually are.The images are presented in a projection that portrays the entire surface of Mars in a manner

  5. Digital image analysis of NDT radiographs

    International Nuclear Information System (INIS)

    Graeme, W.A. Jr.; Eizember, A.C.; Douglass, J.

    1989-01-01

    Prior to the introduction of Charge Coupled Device (CCD) detectors the majority of image analysis performed on NDT radiographic images was done visually in the analog domain. While some film digitization was being performed, the process was often unable to capture all the usable information on the radiograph or was too time consuming. CCD technology now provides a method to digitize radiographic film images without losing the useful information captured in the original radiograph in a timely process. Incorporating that technology into a complete digital radiographic workstation allows analog radiographic information to be processed, providing additional information to the radiographer. Once in the digital domain, that data can be stored, and fused with radioscopic and other forms of digital data. The result is more productive analysis and management of radiographic inspection data. The principal function of the NDT Scan IV digital radiography system is the digitization, enhancement and storage of radiographic images

  6. Digital X-ray imager

    International Nuclear Information System (INIS)

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying source voltage and filtering (predicting the required dynamic range for the detector); evaluating CsI:Tl, CdWO4 and scintillating glass as image converters; recommending image enhancement algorithms. The LLNL modeling results guided the design and experimental elements of the project. The Laboratory's unique array of sources and detectors was employed to resolve specific technical questions. Our image processing expertise was applied to the selection of enhancement tools for image display

  7. Holographic Information Storage and Retrieval. Final Report.

    Science.gov (United States)

    Spencer, J. R.

    A four-month investigation was made of holographic information storage and retrieval. After an extensive review of the state of the art of various holographic systems, it was concluded that digital holographic storage techniques hold the greatest promise for commercial development, especially since they are particularly well suited to computer…

  8. CLASSROOM MULTISPECTRAL IMAGING USING INEXPENSIVE DIGITAL CAMERAS

    OpenAIRE

    Fortes, Andrew Dominic

    2015-01-01

    Poster presented at the 2007 Fall Meeting of the American Geophysical Union. Describes various ways in which multispectral imaging methods can be taught/demonstrated using low-cost digital imaging devices and filter.

  9. Digital X-ray Imaging in Dentistry

    International Nuclear Information System (INIS)

    Kim, Eun Kyung

    1999-01-01

    In dentistry, Radio Visio Graphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter, many types of direct digital radiographic systems have been produced in the last decade. They are based either on charge-coupled device (CCD) or on storage phosphor technology. In addition, new types of digital radiographic system using amorphous selenium, image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose, image processing, computer storage, electronic transfer of images and so on. Image processing includes image enhancement, image reconstruction, digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system (IMACS) for dentomaxillofacial radiology was reported in 1992, IMACS in dental hospital has been increasing. Meanwhile, researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible, feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis, have been performed actively in the last decade. Further developments in digital radiographic imaging modalities, image transmission system, imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

  10. Digital X-ray Imaging in Dentistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Yongin (Korea, Republic of)

    1999-08-15

    In dentistry, Radio Visio Graphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter, many types of direct digital radiographic systems have been produced in the last decade. They are based either on charge-coupled device (CCD) or on storage phosphor technology. In addition, new types of digital radiographic system using amorphous selenium, image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose, image processing, computer storage, electronic transfer of images and so on. Image processing includes image enhancement, image reconstruction, digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system (IMACS) for dentomaxillofacial radiology was reported in 1992, IMACS in dental hospital has been increasing. Meanwhile, researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible, feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis, have been performed actively in the last decade. Further developments in digital radiographic imaging modalities, image transmission system, imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

  11. Digital image analysis of X-ray television with an image digitizer

    International Nuclear Information System (INIS)

    Mochizuki, Yasuo; Akaike, Hisahiko; Ogawa, Hitoshi; Kyuma, Yukishige

    1995-01-01

    When video signals of X-ray fluoroscopy were transformed from analog-to-digital ones with an image digitizer, their digital characteristic curves, pre-sampling MTF's and digital Wiener spectral could be measured. This method was advant ageous in that it was able to carry out data sampling because the pixel values inputted could be verified on a CRT. The system of image analysis by this method is inexpensive and effective in evaluating the image quality of digital system. Also, it is expected that this method can be used as a tool for learning the measurement techniques and physical characteristics of digital image quality effectively. (author)

  12. Current urologic applications of digital imaging.

    Science.gov (United States)

    Kuo, R L; Preminger, G M

    2001-02-01

    One of the most significant developments in imaging technology has been the process of digitalization. By incorporating currently available digital imaging equipment into surgical practice, urologists can be assured of obtaining real-time video images with optimal clarity and detail. In addition, one can efficiently capture and store still images that are crisper and sharper than their analog counterparts. These factors greatly improve the diagnostic capabilities and organization of today's endourologist.

  13. Managing digitally formatted diagnostic image data

    International Nuclear Information System (INIS)

    Templeton, A.W.; Dwyer, S.J.

    1985-01-01

    Diagnostic radiologists are very comfortable using analog radiographic film and interpreting its recorded images. To improve patient care, the radiologist has sought the finest quality radiographic film for use with the best radiographic imaging systems. The proper choice and use of x-ray tubes, generators, film-screen combinations, and contrast media has occupied the professional attention of the radiologist since the inception of radiology. Image quality can be significantly improved with digitally formatted diagnostic imaging systems by providing dynamic ranges in excess of those possible with analog x-ray films. In a CT scanner, the digital acquisition and reconstruction system can obtain a dynamic range (contrast resolution) of 10,000 to 1. Digital subtraction angiography systems achieve 10-bit dynamic ranges for each of the acquired television frames. Increases in the dynamic ranges of the various imaging modalities have been coupled with improved spatial resolution. A digitally formatted image is a two-dimensional, numerical array of discrete image elements. Each picture element is called a pixel. Each pixel has a discrete size. Figure 15.1 illustrates a digitally formatted image depicting the spatial resolution, array size, and quantization or numerical range of the pixel values. Currently, 512 x 512 image arrays are standard. Development of 1024 x 1024 digital arrays are underway. Significant improvements have also been achieved in the rates at which digital diagnostic imaging data can be acquired, manipulated, and archived

  14. Digital Imaging: An Adobe Photoshop Course

    Science.gov (United States)

    Cobb, Kristine

    2007-01-01

    This article introduces digital imaging, an Adobe Photoshop course at Shrewsbury High School in Shrewsbury, Massachusetts. Students are able to earn art credits to graduate by successfully completing the course. Digital imaging must cover art criteria as well as technical skills. The course begins with tutorials created by the instructor and other…

  15. Ethical Implications of Digital Imaging in Photojournalism.

    Science.gov (United States)

    Terry, Danal; Lasorsa, Dominic L.

    Arguing that the news media are about to adopt digital imaging systems that will have far-reaching implications for the practice of journalism, this paper discusses how the news media is expected to adopt the new technology and explains why the marriage of journalism and digital imaging will create ethical issues with respect to photo manipulation…

  16. Digital radiography image quality: image processing and display.

    Science.gov (United States)

    Krupinski, Elizabeth A; Williams, Mark B; Andriole, Katherine; Strauss, Keith J; Applegate, Kimberly; Wyatt, Margaret; Bjork, Sandra; Seibert, J Anthony

    2007-06-01

    This article on digital radiography image processing and display is the second of two articles written as part of an intersociety effort to establish image quality standards for digital and computed radiography. The topic of the other paper is digital radiography image acquisition. The articles were developed collaboratively by the ACR, the American Association of Physicists in Medicine, and the Society for Imaging Informatics in Medicine. Increasingly, medical imaging and patient information are being managed using digital data during acquisition, transmission, storage, display, interpretation, and consultation. The management of data during each of these operations may have an impact on the quality of patient care. These articles describe what is known to improve image quality for digital and computed radiography and to make recommendations on optimal acquisition, processing, and display. The practice of digital radiography is a rapidly evolving technology that will require timely revision of any guidelines and standards.

  17. 3D holographic printer: fast printing approach.

    Science.gov (United States)

    Morozov, Alexander V; Putilin, Andrey N; Kopenkin, Sergey S; Borodin, Yuriy P; Druzhin, Vladislav V; Dubynin, Sergey E; Dubinin, German B

    2014-02-10

    This article describes the general operation principles of devices for synthesized holographic images such as holographic printers. Special emphasis is placed on the printing speed. In addition, various methods to increase the printing process are described and compared.

  18. Eliminating "Hotspots" in Digital Image Processing

    Science.gov (United States)

    Salomon, P. M.

    1984-01-01

    Signals from defective picture elements rejected. Image processing program for use with charge-coupled device (CCD) or other mosaic imager augmented with algorithm that compensates for common type of electronic defect. Algorithm prevents false interpretation of "hotspots". Used for robotics, image enhancement, image analysis and digital television.

  19. Standard digital reference images for titanium castings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 The digital reference images provided in the adjunct to this standard illustrate various types and degrees of discontinuities occurring in titanium castings. Use of this standard for the specification or grading of castings requires procurement of the adjunct digital reference images, which illustrate the discontinuity types and severity levels. They are intended to provide the following: 1.1.1 A guide enabling recognition of titanium casting discontinuities and their differentiation both as to type and degree through digital radiographic examination. 1.1.2 Example digital radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications and drawings. 1.2 The digital reference images consist of seventeen digital files each illustrating eight grades of increasing severity. The files illustrate seven common discontinuity types representing casting sections up to 1-in. (25.4-mm). 1.3 The reference radiographs were developed for casting sections up to 1...

  20. High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy

    International Nuclear Information System (INIS)

    Lai, Y. W.; Ludwig, A.; Hamann, S.; Ehmann, M.

    2011-01-01

    We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent.

  1. Experimental Research on Thermocapillary-Buoyancy Migration Interaction of Axisymmetric Two Drops by Using Digital Holographic Interferometry

    Science.gov (United States)

    Zhang, Shuoting; Duan, Li; Kang, Qi

    2017-12-01

    The migration and interaction of axisymmetric two drops in a vertical temperature gradient is investigated experimentally on the ground. A silicon oil is used as the continuous phase, and a water-ethanol mixture is used as the drop phase, respectively. The migration and interaction of two drops, under the combined effects of buoyancy and thermocapillary, is recorded by a digital holographic interferometry measurement in the experiment to analyse the velocities and temperature distribution of the drops. As a result, when two drops migrate together, the drop affects the other drop by perturbing the temperature field around itself. For the leading drop, the velocity is faster than the one of the isolated drop, and the maximum of the interfacial temperature distribution is larger than the one of the isolated drop. For the trailing drop, the velocity is slower than the one of the isolated drop, and the maximum of the interfacial temperature distribution is less than the one of the isolated drop. The influence of the dimensionless initial distance between the drop centres to the drop migration is discussed in detail in this study.

  2. High fidelity digital inline holographic PTV for 3D flow measurements: from microfluidics to wall-bounded turbulence

    Science.gov (United States)

    Hong, Jiarong; Toloui, Mostafa; Mallery, Kevin

    2016-11-01

    Three-dimensional PIV and PTV provides the most comprehensive flow information for unraveling the physical phenomena in a wide range of fluid problems, from microfluidics to wall-bounded turbulent flows. Compared with other commercialized 3D PIV techniques, such as tomographic PIV and defocusing PIV, the digital inline holographic PTV (namely DIH-PTV) provides 3D flow measurement solution with high spatial resolution, low cost optical setup, and easy alignment and calibration. Despite these advantages, DIH-PTV suffers from major limitations including poor longitudinal resolution, human intervention (i.e. requirement for manually determined tuning parameters during tracer field reconstruction and extraction), limited tracer concentration, small sampling volume and expensive computations, limiting its broad use for 3D flow measurements. Here we will report our latest work on improving DIH-PTV method through an integration of deconvolution algorithm, iterative removal method and GPU computation to overcome some of abovementioned limitations. We will also present the application of our DIH-PTV for measurements in the following sample cases: (i) flows in bio-filmed microchannel with 50-60 μm vector spacing within sampling volumes of 1 mm (streamwise) x 1 mm (wall-normal) x 1 mm (spanwise); (ii) turbulent flows over smooth and rough surfaces (1.1 mm vector spacing within 15 mm x 50 mm x 15 mm); (iii) 3D distribution and kinematics of inertial particles in turbulent air duct flow.

  3. Intraoral digital radiography: elements of effective imaging.

    Science.gov (United States)

    Cederberg, Robert

    2012-10-01

    Intraoral digital imaging has evolved from an experimental and sometimes disparaged technique in the mid 1980s to a reliable and ubiquitously used technology today. There are many advantages for use of digital radiographic techniques in dentistry, one of the chief ones being patient dose reduction. However, as important as dose reduction is for safe and effective radiography, practicing dentists would also like to understand the fundamental differences between digital system configurations so they may be able to make an informed choice as to which system best fits their needs. In addition, there has been considerable debate on the following topics: sensor technology; factors associated with image display; optimum techniques for image manipulation; and image storage, retrieval, and archiving. This article provides insight into these and other elements of effective imaging in intraoral digital imaging.

  4. Image rejects in general direct digital radiography

    International Nuclear Information System (INIS)

    Hofmann, Bjørn; Rosanowsky, Tine Blomberg; Jensen, Camilla; Wah, Kenneth Hong Ching

    2015-01-01

    The number of rejected images is an indicator of image quality and unnecessary imaging at a radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. One reason may be a belief that rejects have been eliminated with digitalization. To measure the extension of deleted images in direct digital radiography (DR), in order to assess the rates of rejects and unnecessary imaging and to analyze reasons for deletions, in order to improve the radiological services. All exposed images at two direct digital laboratories at a hospital in Norway were reviewed in January 2014. Type of examination, number of exposed images, and number of deleted images were registered. Each deleted image was analyzed separately and the reason for deleting the image was recorded. Out of 5417 exposed images, 596 were deleted, giving a deletion rate of 11%. A total of 51.3% were deleted due to positioning errors and 31.0% due to error in centering. The examinations with the highest percentage of deleted images were the knee, hip, and ankle, 20.6%, 18.5%, and 13.8% respectively. The reject rate is at least as high as the deletion rate and is comparable with previous film-based imaging systems. The reasons for rejection are quite different in digital systems. This falsifies the hypothesis that digitalization would eliminates rejects. A deleted image does not contribute to diagnostics, and therefore is an unnecessary image. Hence, the high rates of deleted images have implications for management, training, education, as well as for quality

  5. Usage of moving nanoparticles for improved holographic recording

    Science.gov (United States)

    Meiri, Amihai; Gur, Eran; Garcia, Javier; Micó, Vicente; Javidi, Bahram; Zalevsky, Zeev

    2013-05-01

    Metal nanoparticles are used for different applications in holographic configurations. The metal nanoparticles are placed close to an object and encode it by a time varying random mask. A decoding mask is computed and used to obtain super-resolution digital hologram and eliminate the twin image and DC from a digital hologram. The method is also shown to be applicable for other optical methods.

  6. Image processing in digital chest radiography

    International Nuclear Information System (INIS)

    Manninen, H.; Partanen, K.; Lehtovirta, J.; Matsi, P.; Soimakallio, S.

    1992-01-01

    The usefulness of digital image processing of chest radiographs was evaluated in a clinical study. In 54 patients, chest radiographs in the posteroanterior projection were obtained by both 14 inch digital image intensifier equipment and the conventional screen-film technique. The digital radiographs (512x512 image format) viewed on a 625 line monitor were processed in 3 different ways: 1.standard display; 2.digital edge enhancement for the standard display; 3.inverse intensity display. The radiographs were interpreted independently by 3 radiologists. Diagnoses were confirmed by CT, follow-up radiographs and clinical records. Chest abnormalities of the films analyzed included 21 primary lung tumors, 44 pulmonary nodules, 16 cases with mediastinal disease, 17 with pneumonia /atelectasis. Interstitial lung disease, pleural plaques, and pulmonary emphysema were found in 30, 18 and 19 cases respectively. Sensitivity of conventional radiography when averaged overall findings was better than that of digital techniques (P<0.001). Differences in diagnostic accuracy measured by sensitivity and specificity between the 3 digital display modes were small. Standard image display showed better sensitivity for pulmonary nodules (0.74 vs 0.66; P<0.05) but poorer specificity for pulmonary emphysema (0.85 vs 0.93; P<0.05) compared with inverse intensity display. It is concluded that when using 512x512 image format, the routine use of digital edge enhancement and tone reversal at digital chest radiographs is not warranted. (author). 12 refs.; 4 figs.; 2 tabs

  7. Fingerprint biometry applications of digital holography and low-coherence interferography.

    Science.gov (United States)

    Potcoava, Mariana C; Kim, Myung K

    2009-12-01

    We use several holographic and interferographic methods for two- and three-dimensional imaging of fingerprints. Holographic phase microscopy is used to produce images of thin-film patterns left by latent fingerprints. Two or more holographic phase images with different wavelengths are combined for optical phase unwrapping of images of thicker patent prints or a plastic print. Digital interference holography uses scanned wavelengths to synthesize short-coherence interference tomographic images of a plastic print. We also demonstrate light-emitting-diode-based low-coherence interferography for imaging plastic as well as latent prints. These demonstrations point to significant contributions to biometry by the emerging technology of digital holography and interferography.

  8. Dual-channel in-line digital holographic double random phase encryption.

    Science.gov (United States)

    Das, Bhargab; Yelleswarapu, Chandra S; Rao, D V G L N

    2012-10-01

    We present a robust encryption method for the encoding of 2D/3D objects using digital holography and virtual optics. Using our recently developed dual-plane in-line digital holography technique, two in-line digital holograms are recorded at two different planes and are encrypted using two different double random phase encryption configurations, independently. The process of using two mutually exclusive encryption channels makes the system more robust against attacks since both the channels should be decrypted accurately in order to get a recognizable reconstruction. Results show that the reconstructed object is unrecognizable even when the portion of the correct phase keys used during decryption is close to 75%. The system is verified against blind decryptions by evaluating the SNR and MSE. Validation of the proposed method and sensitivities of the associated parameters are quantitatively analyzed and illustrated.

  9. Digital image display system for emergency room

    International Nuclear Information System (INIS)

    Murry, R.C.; Lane, T.J.; Miax, L.S.

    1989-01-01

    This paper reports on a digital image display system for the emergency room (ER) in a major trauma hospital. Its objective is to reduce radiographic image delivery time to a busy ER while simultaneously providing a multimodality capability. Image storage, retrieval, and display will also be facilitated with this system. The system's backbone is a token-ring network of RISC and personal computers. The display terminals are higher- function RISC computers with 1,024 2 color or gray-scale monitors. The PCs serve as administrative terminals. Nuclear medicine, CT, MR, and digitized film images are transferred to the image display system

  10. Three-dimensional information encryption and anticounterfeiting using digital holography.

    Science.gov (United States)

    Shiu, Min-Tzung; Chew, Yang-Kun; Chan, Huang-Tian; Wong, Xin-Yu; Chang, Chi-Ching

    2015-01-01

    In this work, arbitrary micro phase-step digital holography with optical interferometry and digital image processing is utilized to obtain information about an image of a three-dimensional object and encrypting keys. Then, a computer-generated hologram is used for the purpose of holographic encryption. All information about the keys is required to perform the decryption, comprising the amplitude and phase distribution of the encrypting key, the distance of image reconstruction, zero-order term elimination, and twin-image term suppression. In addition to using identifiable information on different image planes and linear superposition processing hidden within the encrypted information, not only can we convey an important message, but we can also achieve anticounterfeiting. This approach retains the strictness of traditional holographic encryption and the convenience of digital holographic processing without image distortion. Therefore, this method provides better solutions to earlier methods for the security of the transmission of holographic information.

  11. Experimental imaging research on continuous-wave terahertz in-line digital holography

    Science.gov (United States)

    Huang, Haochong; Wang, Dayong; Rong, Lu; Wang, Yunxin

    2014-09-01

    The terahertz (THz) imaging is an advanced technique on the basis of the unique characteristics of terahertz radiation. Due to its noncontact, non-invasive and high-resolution capabilities, it has already shown great application prospects in biomedical observation, sample measurement, and quality control. The continuous-wave terahertz in-line digital holography is a combination of terahertz technology and in-line digital holography of which the source is a continuous-wave terahertz laser. Over the past decade, many researchers used different terahertz sources and detectors to undertake experiments. In this paper, the pre-process of the hologram is accomplished after the holograms' recording process because of the negative pixels in the pyroelectric detector and the air vibration caused by the chopper inside the camera. To improve the quality of images, the phase retrieval algorithm is applied to eliminate the twin images. In the experiment, the pin which terahertz wave can't penetrate and the TPX slice carved letters "THz" are chosen for the samples. The amplitude and phase images of samples are obtained and the twin image and noise in the reconstructed images are suppressed. The results validate the feasibility of the terahertz in-line digital holographic imaging technique. This work also shows the terahertz in-line digital holography technique's prospects in materials science and biological samples' detection.

  12. Fractal Image Coding with Digital Watermarks

    Directory of Open Access Journals (Sweden)

    Z. Klenovicova

    2000-12-01

    Full Text Available In this paper are presented some results of implementation of digitalwatermarking methods into image coding based on fractal principles. Thepaper focuses on two possible approaches of embedding digitalwatermarks into fractal code of images - embedding digital watermarksinto parameters for position of similar blocks and coefficients ofblock similarity. Both algorithms were analyzed and verified on grayscale static images.

  13. Better imaging: the advantages of digital radiography

    NARCIS (Netherlands)

    van der Stelt, P.F.

    2008-01-01

    Background. Digital radiography has been available in dentistry for more than 25 years, but it has not replaced conventional film-based radiography completely. This could be because of the costs involved in replacing conventional radiographic equipment with a digital imaging system, or because

  14. Checking Fits With Digital Image Processing

    Science.gov (United States)

    Davis, R. M.; Geaslen, W. D.

    1988-01-01

    Computer-aided video inspection of mechanical and electrical connectors feasible. Report discusses work done on digital image processing for computer-aided interface verification (CAIV). Two kinds of components examined: mechanical mating flange and electrical plug.

  15. Digital image processing in art conservation

    Czech Academy of Sciences Publication Activity Database

    Zitová, Barbara; Flusser, Jan

    č. 53 (2003), s. 44-45 ISSN 0926-4981 Institutional research plan: CEZ:AV0Z1075907 Keywords : art conservation * digital image processing * change detection Subject RIV: JD - Computer Applications, Robotics

  16. Better imaging: the advantages of digital radiography.

    Science.gov (United States)

    van der Stelt, Paul F

    2008-06-01

    Digital radiography has been available in dentistry for more than 25 years, but it has not replaced conventional film-based radiography completely. This could be because of the costs involved in replacing conventional radiographic equipment with a digital imaging system, or because implementing new technology in the dental practice requires a bit of courage. When the practitioner is fully aware of the new possibilities offered by digital radiography, he or she can make a more informed decision about adopting it. This article offers information about digital radiography, not just as a replacement of conventional radiography, but also as a concept offering benefits beyond those of conventional radiography. Digital radiographs are composed of a set of numbers arranged as a grid of rows and columns. The dentist can perform mathematical operations on these numbers to create a new image in which certain characteristics are enhanced, thus making interpretation of the image easier. The dentist also can correct, to some extent, overexposed or underexposed images and can optimize contrast and brightness for specific diagnostic procedures, such as caries detection and bone level assessment. More advanced procedures are available as well, such as digital subtraction radiography and computer-aided recognition of image features. The author presents a selection of the advantages of digital radiography that are not achievable with conventional film-based radiography. Implementing digital radiography in the dental office requires additional training. However, once members of the dental team have gone through this initial phase, they have the benefits of several new diagnostic possibilities. With a digital system, information from radiographic images is collected more easily and in a more objective way, which will improve the performance of the diagnostic process.

  17. Digital image processing for thermal observation system

    Science.gov (United States)

    Yu, Wee K.; Song, In Seob; Yoon, Eon S.; Lee, Y. S.; Moon, M. G.; Hong, Seok-Min; Kim, J. K.

    1995-05-01

    This paper describes the digital image processing techniques of a thermal observation system, which is a serial/parallel scan and standard TV display type using a SPRITE (Signal PRocessing In The Element) detector. The designed digital electronics has two major signal processing stages: a high speed digital scan converter and an autoregressive (AR) filter. The digital scan converter is designed with analog-to-digital converter (ADC) and dual port RAM that can carry out reading and writing simultaneously, thus enabling compact scan conversion. The scan converter reformats the five parallel analog signals generated from the detector elements into serial digital signals compatible with RS-170 video rate. For the improvement of signal-to- noise ratio and compensation for the gamma effect of the monitor, we have implemented a real time 1st order AR filter that adopts frame averaging method. With the look-up-table (LUT) ROM that contains the frame averaging factors and the gamma coefficients, this digital filter performs the noise reduction and the gamma correction at the same time. This digital image processor has been proven to provide excellent image quality and superior detection capability for distant targets at night time.

  18. Applications of Digital Image Processing 11

    Science.gov (United States)

    Cho, Y. -C.

    1988-01-01

    A new technique, digital image velocimetry, is proposed for the measurement of instantaneous velocity fields of time dependent flows. A time sequence of single-exposure images of seed particles are captured with a high-speed camera, and a finite number of the single-exposure images are sampled within a prescribed period in time. The sampled images are then digitized on an image processor, enhanced, and superimposed to construct an image which is equivalent to a multiple exposure image used in both laser speckle velocimetry and particle image velocimetry. The superimposed image and a single-exposure Image are digitally Fourier transformed for extraction of information on the velocity field. A great enhancement of the dynamic range of the velocity measurement is accomplished through the new technique by manipulating the Fourier transform of both the single-exposure image and the superimposed image. Also the direction of the velocity vector is unequivocally determined. With the use of a high-speed video camera, the whole process from image acquisition to velocity determination can be carried out electronically; thus this technique can be developed into a real-time capability.

  19. New quality metrics for digital image resizing

    Science.gov (United States)

    Kim, Hongseok; Kumara, Soundar

    2007-09-01

    Digital image rescaling by interpolation has been intensively researched over past decades, and still getting constant attention from many applications such as medical diagnosis, super-resolution, image blow-up, nano-manufacturing, etc. However, there are no consented metrics to objectively assess and compare the quality of resized images. Some existing measures such as peak-signal-to-noise ratio (PSNR) or mean-squared error (MSE), widely used in image restoration area, do not always coincide with the opinions from viewers. Enlarged digital images generally suffer from two major artifacts: blurring, zigzagging, and those undesirable effects especially around edges significantly degrade the overall perceptual image quality. We propose two new image quality metrics to measure the degree of the two major defects, and compare several existing interpolation methods using the proposed metrics. We also evaluate the validity of image quality metrics by comparing rank correlations.

  20. Three-dimensional facial digitization using advanced digital image correlation.

    Science.gov (United States)

    Nguyen, Hieu; Kieu, Hien; Wang, Zhaoyang; Le, Hanh N D

    2018-03-20

    Presented in this paper is an effective technique to acquire the three-dimensional (3D) digital images of the human face without the use of active lighting and artificial patterns. The technique is based on binocular stereo imaging and digital image correlation, and it includes two key steps: camera calibration and image matching. The camera calibration involves a pinhole model and a bundle-adjustment approach, and the governing equations of the 3D digitization process are described. For reliable pixel-to-pixel image matching, the skin pores and freckles or lentigines on the human face serve as the required pattern features to facilitate the process. It employs feature-matching-based initial guess, multiple subsets, iterative optimization algorithm, and reliability-guided computation path to achieve fast and accurate image matching. Experiments have been conducted to demonstrate the validity of the proposed technique. The simplicity of the approach and the affordable cost of the implementation show its practicability in scientific and engineering applications.

  1. Image display device in digital TV

    Science.gov (United States)

    Choi, Seung Jong [Seoul, KR

    2006-07-18

    Disclosed is an image display device in a digital TV that is capable of carrying out the conversion into various kinds of resolution by using single bit map data in the digital TV. The image display device includes: a data processing part for executing bit map conversion, compression, restoration and format-conversion for text data; a memory for storing the bit map data obtained according to the bit map conversion and compression in the data processing part and image data inputted from an arbitrary receiving part, the receiving part receiving one of digital image data and analog image data; an image outputting part for reading the image data from the memory; and a display processing part for mixing the image data read from the image outputting part and the bit map data converted in format from the a data processing part. Therefore, the image display device according to the present invention can convert text data in such a manner as to correspond with various resolution, carry out the compression for bit map data, thereby reducing the memory space, and support text data of an HTML format, thereby providing the image with the text data of various shapes.

  2. Panoramic images of conventional radiographs: digital panoramic dynamic images

    International Nuclear Information System (INIS)

    Schultze, M.

    2001-01-01

    The benefits of digital technic s to od ontology are evident. Instant images, the possibility to handle them, the reduction of exposition time to radiations, better quality image, better quality information, Stocking them in a compact disc, occupying very little space, allows an easy transport and duplication, as well as the possibility to transfer and save it in an electronica l support.This kind of communication allows the transmission of digital images and every other type of data, instantaneously and no matter distances or geographical borders. Anyway, we should point out that conventional and digital technic s reveal the same information contents

  3. Digital Image Processing in Private Industry.

    Science.gov (United States)

    Moore, Connie

    1986-01-01

    Examines various types of private industry optical disk installations in terms of business requirements for digital image systems in five areas: records management; transaction processing; engineering/manufacturing; information distribution; and office automation. Approaches for implementing image systems are addressed as well as key success…

  4. Image digitizer system for bubble chamber laser

    International Nuclear Information System (INIS)

    Haggerty, H.

    1986-01-01

    An IBM PC-based image digitizer system has been assembled to monitor the laser flash used for holography at the 15 foot bubble chamber. The hardware and the operating software are outlined. For an operational test of the system, an array of LEDs was flashed with a 10 microsecond pulse and the image was grabbed by one of the operating programs and processed

  5. COMPARISON OF DIGITAL IMAGE STEGANOGRAPHY METHODS

    OpenAIRE

    S. A. Seyyedi; R. Kh. Sadykhov

    2013-01-01

    Steganography is a method of hiding information in other information of different format (container). There are many steganography techniques with various types of container. In the Internet, digital images are the most popular and frequently used containers. We consider main image steganography techniques and their advantages and disadvantages. We also identify the requirements of a good steganography algorithm and compare various such algorithms.

  6. Digital holographic measurement of liquid-liquid two-phase flows

    Science.gov (United States)

    Lamadie, Fabrice; Bruel, Laurent; Himbert, Marc

    2012-12-01

    A direct application of digital in-line holography to liquid droplets dispersed in a continuous liquid phase is described. The droplet size imposes a regime of intermediate-field diffraction that has been little explored to date. Acquired diffraction patterns show that the usual opaque disk model is not valid and that good agreement is obtained with a thin lens model. Hologram focusing is nevertheless performed with a dedicated automated method that slightly outperforms Royer criteria. A literature review has been conducted to identify the sharpest autofocus function for our application. Droplet paths are retrieved in three dimensions simultaneously with their velocity and diameter. The developed experimental setup is a first step toward implementation of the method in more complex configurations, including pulsed flows.

  7. Holographic image generation with a thin-film resonance caused by chalcogenide phase-change material

    Science.gov (United States)

    Lee, Seung-Yeol; Kim, Yong-Hae; Cho, Seong-M.; Kim, Gi Heon; Kim, Tae-Youb; Ryu, Hojun; Kim, Han Na; Kang, Han Byeol; Hwang, Chi-Young; Hwang, Chi-Sun

    2017-01-01

    The development of digital holography is anticipated for the viewing of 3D images by reconstructing both the amplitude and phase information of the object. Compared to analog holograms written by a laser interference, digital hologram technology has the potential to realize a moving 3D image using a spatial light modulator. However, to ensure a high-resolution 3D image with a large viewing angle, the hologram panel requires a near-wavelength scale pixel pitch with a sufficient large numbers of pixels. In this manuscript, we demonstrate a digital hologram panel based on a chalcogenide phase-change material (PCM) which has a pixel pitch of 1 μm and a panel size of 1.6 × 1.6 cm2. A thin film of PCM encapsulated by dielectric layers can be used for the hologram panel by means of excimer laser lithography. By tuning the thicknesses of upper and lower dielectric layers, a color-selective diffraction panel is demonstrated since a thin film resonance caused by dielectric can affect to the absorption and diffraction spectrum of the proposed hologram panel. We also show reflection color of a small active region (1 μm × 4 μm) made by ultra-thin PCM layer can be electrically changed.

  8. Existential space understanding through digital image

    Directory of Open Access Journals (Sweden)

    Susana Iñarra Abad

    2013-10-01

    Full Text Available The logical way to learn from the architectural space and then be able to design and represent it is, undoubtedly, that of experiencing it through all the sensitive channels that the space wakes up us.  But since the last 30 years, much of our learning about space comes from images of architecture and not from the space itself. The art of architecture is drifting towards a visual art and moving away from its existential side. In digital images that have flooded the architectural media, digital photographs of existing spaces intermingle with non-existent space renderings (photographs with a virtual camera. The first ones represent existing places but can be altered to change the perception that  the observer of the image will have, the second ones speak to us about places that do not exist yet but they present reality portions through extracts from digital photography (textures, trees, people... that compose the image.

  9. Development of an optoelectronic holographic platform for otolaryngology applications

    Science.gov (United States)

    Harrington, Ellery; Dobrev, Ivo; Bapat, Nikhil; Flores, Jorge Mauricio; Furlong, Cosme; Rosowski, John; Cheng, Jeffery Tao; Scarpino, Chris; Ravicz, Michael

    2010-08-01

    In this paper, we present advances on our development of an optoelectronic holographic computing platform with the ability to quantitatively measure full-field-of-view nanometer-scale movements of the tympanic membrane (TM). These measurements can facilitate otologists' ability to study and diagnose hearing disorders in humans. The holographic platform consists of a laser delivery system and an otoscope. The control software, called LaserView, is written in Visual C++ and handles communication and synchronization between hardware components. It provides a user-friendly interface to allow viewing of holographic images with several tools to automate holography-related tasks and facilitate hardware communication. The software uses a series of concurrent threads to acquire images, control the hardware, and display quantitative holographic data at video rates and in two modes of operation: optoelectronic holography and lensless digital holography. The holographic platform has been used to perform experiments on several live and post-mortem specimens, and is to be deployed in a medical research environment with future developments leading to its eventual clinical use.

  10. Replantation of digits - series (image)

    Science.gov (United States)

    Digital nerves and vessels are repaired with microsurgical instruments. This part of the surgery is most critical to its success. The skin is then closed. A bulky dressing is applied. Young children may have a cast applied to protect the area from injury.

  11. Computer assisted visualization of digital mammography images

    International Nuclear Information System (INIS)

    Funke, M.; Breiter, N.; Grabbe, E.; Netsch, T.; Biehl, M.; Peitgen, H.O.

    1999-01-01

    Purpose: In a clinical study, the feasibility of using a mammography workstation for the display and interpretation of digital mammography images was evaluated and the results were compared with the corresponding laser film hard copies. Materials and Methods: Digital phosphorous plate radiographs of the entire breast were obtained in 30 patients using a direct magnification mammography system. The images were displayed for interpretation on the computer monitor of a dedicated mammography workstation and also presented as laser film hard copies on a film view box for comparison. The images were evaluted with respect to the image handling, the image quality and the visualization of relevant structures by 3 readers. Results: Handling and contrast of the monitor displayed images were found to be superior compared with the film hard copies. Image noise was found in some cases but did not compromise the interpretation of the monitor images. The visualization of relevant structures was equal with both modalities. Altogether, image interpretation with the mammography workstation was considered to be easy, quick and confident. Conclusions: Computer-assisted visualization and interpretation of digital mammography images using a dedicated workstation can be performed with sufficiently high diagnostic accuracy. (orig.) [de

  12. Image quality analysis of digital mammographic equipments

    International Nuclear Information System (INIS)

    Mayo, P.; Pascual, A.; Verdu, G.; Rodenas, F.; Campayo, J.M.; Villaescusa, J.I.

    2006-01-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  13. Image quality analysis of digital mammographic equipments

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, P.; Pascual, A.; Verdu, G. [Valencia Univ. Politecnica, Chemical and Nuclear Engineering Dept. (Spain); Rodenas, F. [Valencia Univ. Politecnica, Applied Mathematical Dept. (Spain); Campayo, J.M. [Valencia Univ. Hospital Clinico, Servicio de Radiofisica y Proteccion Radiologica (Spain); Villaescusa, J.I. [Hospital Clinico La Fe, Servicio de Proteccion Radiologica, Valencia (Spain)

    2006-07-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  14. Extended wavelet transformation to digital holographic reconstruction: application to the elliptical, astigmatic Gaussian beams.

    Science.gov (United States)

    Remacha, Clément; Coëtmellec, Sébastien; Brunel, Marc; Lebrun, Denis

    2013-02-01

    Wavelet analysis provides an efficient tool in numerous signal processing problems and has been implemented in optical processing techniques, such as in-line holography. This paper proposes an improvement of this tool for the case of an elliptical, astigmatic Gaussian (AEG) beam. We show that this mathematical operator allows reconstructing an image of a spherical particle without compression of the reconstructed image, which increases the accuracy of the 3D location of particles and of their size measurement. To validate the performance of this operator we have studied the diffraction pattern produced by a particle illuminated by an AEG beam. This study used mutual intensity propagation, and the particle is defined as a chirped Gaussian sum. The proposed technique was applied and the experimental results are presented.

  15. Holographic memories

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Berg, R.H.; Hvilsted, Søren

    1999-01-01

    A Two-dimensional holographic memory for archival storage is described. Assuming a coherent transfer function, an A4 page can be stored at high resolution in an area of 1 mm(2). Recently developed side-chain liquid crystalline azobenzene polyesters are found to be suitable media for holographic s...

  16. Orthogonal Double View Digital Holographic Diagnostics for Random Motion of Micro Polymer Jet by Electrospinning

    Science.gov (United States)

    Lee, Jaiho; Sallam, Khaled

    2008-11-01

    An experimental investigation of three-dimensional random behavior of polymer micro jet generated by electrospinning is described. Two frequency doubled Nd:YAG lasers were used as the light source and a commercial grade CCD sensor (Nikon D-70) was used for holograms recording. The two lasers could be fired with a pulse separation as small as 100 ns, and the two laser beams were aligned with three polarized beam splitter cubes. Orthogonal double-view and double-pulses were recorded on the same camera frame. The camera frame was split into two, and both of the halves of the frame were used for each view. Two objective lenses (M 5x) and two spatial filters (Pinhole ˜ 5μm) were used to generate expanding laser beams in the digital microscopic holography (DMH) optical setup. As the electric field (˜20 kV) was intensified, the polymer solution formed a charged filament (or multiple filaments) from the tip of the Taylor cone. As the filament was accelerated toward the collector, its diameter was shrunk and axisymmetric disturbances grew further away from the exit. The polymer was randomly deposited on the collector as non woven microfiber.

  17. Perceptual digital imaging methods and applications

    CERN Document Server

    Lukac, Rastislav

    2012-01-01

    Visual perception is a complex process requiring interaction between the receptors in the eye that sense the stimulus and the neural system and the brain that are responsible for communicating and interpreting the sensed visual information. This process involves several physical, neural, and cognitive phenomena whose understanding is essential to design effective and computationally efficient imaging solutions. Building on advances in computer vision, image and video processing, neuroscience, and information engineering, perceptual digital imaging greatly enhances the capabilities of tradition

  18. Digital image authentication from thumbnails

    Science.gov (United States)

    Kee, Eric; Farid, Hany

    2010-01-01

    We describe how to exploit the formation and storage of an embedded image thumbnail for image authentication. The creation of a thumbnail is modeled with a series of filtering operations, contrast adjustment, and compression. We automatically estimate these model parameters and show that these parameters differ significantly between camera manufacturers and photo-editing software. We also describe how this signature can be combined with encoding information from the underlying full resolution image to further refine the signature's distinctiveness.

  19. Automatic testing with digital image processing

    International Nuclear Information System (INIS)

    Daum, W.; Rose, P.; Preuss, M.; Builtjes, J.H.

    1987-01-01

    Only a small part of the various applications of use of image processing in nondestructive materials testing could be presented. Digital image processing is an aid in the evaluation of conventional testing methods as well as in the development of new testing methods. By image improvement, it increases the expressiveness of visual evaluations and makes time consuming evaluation processes easier, especially by means of quantitative image analysis. Image processing contributes a lot to automation by the possibility of interpreting picture information with the help of the computer. (orig./DG) [de

  20. Digital fluoroscopy: a new development in medical imaging

    International Nuclear Information System (INIS)

    Maher, K.P.; Malone, J.F.; Dublin Inst. of Technology

    1986-01-01

    Medical fluoroscopy is briefly reviewed and video-image digitization is described. Image processing requirements and image processors available for digital fluoroscopy are discussed in detail. Specific reference is made to an application of digital fluoroscopy in the imaging of blood-vessels. This application involves an image substraction technique which is referred to as digital subtraction angiography (DSA). A number of DSA images of relevance to the discussion are included. (author)

  1. Image processing in the digital tomosynthesis for pulmonary imaging

    International Nuclear Information System (INIS)

    Sone, S.; Kasuga, T.; Sakai, F.; Kawai, T.; Oguchi, K.; Hirano, H.; Li, F.; Kubo, K.; Honda, T.; Haniuda, M.; Takemura, K.; Hosoba, M.

    1995-01-01

    Digital tomosynthesis makes it possible to reconstruct multiple tomographs from digital data obtained during a single tomographic motion and permits digital processing, which adds a number of special advantages to the well-known advantages of conventional tomography. We performed digital tomosynthesis with a fluororadiographic TV unit with tomographic function which was capable of producing pulsed low- and high-energy X-rays alternately, and we studied digital image processing to improve the image clarity of the reconstructed tomographs. To identify the optimal parameters for processing image data by means of spatial frequency filtration we evaluated the spatial frequency distribution of image data in linear tomographs of the lung, and on the basis of the results of this study we developed several types of digital image processing to reduce tomographic blur and system noise, to improve visualisation of faint opacities, to reduce resistant tomographic blur as well as overall blur, and to generate low-noise bone images based on dual-energy subtraction tomosynthesis. (orig.)

  2. An Archive of Digital Images.

    Science.gov (United States)

    Fantini, M.; And Others

    1990-01-01

    Describes the architecture of the prototype of an image management system that has been used to develop an application concerning images of frescoes in the Sistina Chapel in the Vatican. Hardware and software design are described, the use of local area networks (LANs) is discussed, and data organization is explained. (15 references) (LRW)

  3. Digital memory for TV image information

    International Nuclear Information System (INIS)

    Paretti, C.

    1975-01-01

    A system employing closed circuit TV camera and MOS memory is presented to take image information and store it. The apparatus is made in two sections: analog filters and digital memory. Filters have been used to select low amplitude signals from high frequency and low frequency noise components. The memory is arranged to make nondestroying overlap of digit array: this facility is useful for microscope image prejection to overcome depth of field limits, as in automatic nuclear emulsion scanners for personnel radiation monitoring. (author)

  4. Digital networks for the image management

    International Nuclear Information System (INIS)

    Gomez del Campo L, A.

    1999-01-01

    The digital networks designed specifically for the X-ray departments in the hospitals already were found in open development at beginning the 80's decade. Actually the digital network will be present include the image generation without the necessity to use film in direct form and in its case to print it through a laser ray printers network, an electronic image file, the possibility to integrate the hospitable information system to the electronic expedient which will allow communicate radiograph electronic files and consult by satellite via the problem cases. (Author)

  5. The infrared imaging spectrograph (IRIS) for TMT: volume phase holographic grating performance testing and discussion

    Science.gov (United States)

    Chen, Shaojie; Meyer, Elliot; Wright, Shelley A.; Moore, Anna M.; Larkin, James E.; Maire, Jerome; Mieda, Etsuko; Simard, Luc

    2014-07-01

    Maximizing the grating efficiency is a key goal for the first light instrument IRIS (Infrared Imaging Spectrograph) currently being designed to sample the diffraction limit of the TMT (Thirty Meter Telescope). Volume Phase Holographic (VPH) gratings have been shown to offer extremely high efficiencies that approach 100% for high line frequencies (i.e., 600 to 6000l/mm), which has been applicable for astronomical optical spectrographs. However, VPH gratings have been less exploited in the near-infrared, particularly for gratings that have lower line frequencies. Given their potential to offer high throughputs and low scattered light, VPH gratings are being explored for IRIS as a potential dispersing element in the spectrograph. Our team has procured near-infrared gratings from two separate vendors. We have two gratings with the specifications needed for IRIS current design: 1.51-1.82μm (H-band) to produce a spectral resolution of 4000 and 1.19-1.37μm (J-band) to produce a spectral resolution of 8000. The center wavelengths for each grating are 1.629μm and 1.27μm, and the groove densities are 177l/mm and 440l/mm for H-band R=4000 and J-band R=8000, respectively. We directly measure the efficiencies in the lab and find that the peak efficiencies of these two types of gratings are quite good with a peak efficiency of ~88% at the Bragg angle in both TM and TE modes at H-band, and 90.23% in TM mode, 79.91% in TE mode at J-band for the best vendor. We determine the drop in efficiency off the Bragg angle, with a 20-23% decrease in efficiency at H-band when 2.5° deviation from the Bragg angle, and 25%-28% decrease at J-band when 5° deviation from the Bragg angle.

  6. Fundamental Concepts of Digital Image Processing

    Science.gov (United States)

    Twogood, R. E.

    1983-03-01

    The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the patient is still under observation rather than days later.

  7. Fundamental concepts of digital image processing

    Energy Technology Data Exchange (ETDEWEB)

    Twogood, R.E.

    1983-03-01

    The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the patient is still under observation rather than days later.

  8. Digital X-ray imager

    CERN Document Server

    LLNL &MedOptics Corporation

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying so...

  9. Lossless Compression of Digital Images

    DEFF Research Database (Denmark)

    Martins, Bo

    are constructed by this principle. A multi-pass free tree coding scheme produces excellent compression results for all test images. A multi-pass fast free template coding scheme produces much better results than JBIG for difficult images, such as halftonings. Rissanen's algorithm `Context' is presented in a new...... version that is substantially faster than its precursorsand brings it close to the multi-pass coders in compression performance.Handprinted characters are of unequal complexity; recent work by Singer and Tishby demonstrates that utilizing the physiological process of writing one can synthesize cursive...

  10. COMPARISON OF DIGITAL IMAGE STEGANOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    S. A. Seyyedi

    2013-01-01

    Full Text Available Steganography is a method of hiding information in other information of different format (container. There are many steganography techniques with various types of container. In the Internet, digital images are the most popular and frequently used containers. We consider main image steganography techniques and their advantages and disadvantages. We also identify the requirements of a good steganography algorithm and compare various such algorithms.

  11. Cherenkov ring imaging using a television digitizer

    International Nuclear Information System (INIS)

    Charpak, G.; Peisert, A.; Sauli, F.; Cavestro, A.; Vascon, M.; Zanella, G.

    1981-01-01

    A Cherenkov ring imaging device using as photon detector a multistep spark chamber coupled to a television digitizer is described. Results of a test run using triethylamine as photo-ionizing vapour are presented, as well as preliminary results obtained with a new vapour having an extremely low ionization potential. (orig.)

  12. Bone age assessment by digital images

    International Nuclear Information System (INIS)

    Silva, Ana Maria Marques da

    1996-01-01

    An algorithm which allows bone age assessment by digital radiological images was developed. For geometric parameters extraction, the phalangeal and metacarpal regions of interest are enhanced and segmented, through spatial and morphological filtering. This study is based on perimeter, length and area, from distal to proximal portions. The quantification of these parameters make possible comparison between chronological and skeletal age, using growth standard tables

  13. Advantages of digital imaging for radiological diagnostic

    International Nuclear Information System (INIS)

    Trapero, M. A.; Gonzalez, S.; Albillos, J. C.; Martel, J.; Rebollo, M.

    2006-01-01

    The advantages and limitations of radiological digital images in comparison with analogic ones are analyzed. We discuss three main topics: acquisition, post-procedure manipulation, and visualization, archive and communication. Digital acquisition with computed radiology systems present a global sensitivity very close to conventional film for diagnostic purposes. However, flat panel digital systems seems to achieve some advantages in particular clinical situations. A critical issue is the radiation dose-reduction that can be accomplished without reducing image quality nor diagnostic exactitude. The post-procedure manipulation allows, particularly in multiplanar modalities like CT or MR, to extract all implicit diagnostic information in the images: Main procedures are multiplanar and three-dimensional reformations, dynamic acquisitions, functional studies and image fusion. The use of PACS for visualization, archive and communication of images, improves the effectiveness and the efficiency of the workflow, allows a more comfortable diagnosis for the radiologist and gives way to improvements in the communication of images, allowing tele consulting and the tele radiology. (Author) 6 refs

  14. Heterodyned holographic spectroscopy

    NARCIS (Netherlands)

    Douglas, NG

    In holographic spectroscopy an image of an interference pattern is projected onto a detector and transformed back to the input spectrum. The general characteristics are similar to those of Fourier transform spectroscopy, but the spectrum is obtained without scanning. In the heterodyned arrangement

  15. High resolution imaging of particle interactions in a large bubble chamber using holographic techniques

    International Nuclear Information System (INIS)

    Akbari, Homaira.

    1988-01-01

    Particle interactions were recorded holographically in a large volume of the 15-foot Bubble Chamber at Fermilab. This cryogenic bubble chamber was filled with a heavy Neon-Hydrogen mixture and was exposed to a wideband neutrino beam with mean energy of 150 GeV. The use of holography in combination with conventional photography provides a powerful tool for direct detection of short-lived particles. Holography gives a high resolution over a large depth of field which can not be achieved with conventional photography. A high-power pulsed ruby laser was used as the holographic light source. Since short pulses of some 50 ns duration at the required energy were found to give rise to boiling during the chamber's expansion, a reduction of the instantaneous power at a given energy was required to suppress this unwanted after-effect. This was achieved by developing a unique technique for stretching the pulses using an electro-optic feedback loop. One hundred thousand holograms were produced during a wide-band neutrino experiment (E-632, 1985) using a dark-field holographic system. Analysis of a sample of holograms shows a resolution of 150 μm was achieved in an ovoidal shape fiducial volume of 0.48 m 3 % of the 14 m 3 total fiducial volume of the chamber

  16. Digital radiographic imaging: is the dental practice ready?

    Science.gov (United States)

    Parks, Edwin T

    2008-04-01

    Digital radiographic imaging is slowly, but surely, replacing film-based imaging. It has many advantages over traditional imaging, but the technology also has some drawbacks. The author presents an overview of the types of digital image receptors available, image enhancement software and the range of costs for the new technology. PRACTICE IMPLICATIONS. The expenses associated with converting to digital radiographic imaging are considerable. The purpose of this article is to provide the clinician with an overview of digital radiographic imaging technology so that he or she can be an informed consumer when evaluating the numerous digital systems in the marketplace.

  17. Multichannel deblurring of digital images

    Czech Academy of Sciences Publication Activity Database

    Šorel, Michal; Šroubek, Filip; Flusser, Jan

    2011-01-01

    Roč. 47, č. 3 (2011), s. 439-454 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : image restoration * blind deconvolution * deblurring Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/ZOI/sorel-0360217.pdf

  18. Digital Imaging and Communications in Medicine

    Science.gov (United States)

    Onken, Michael; Eichelberg, Marco; Riesmeier, Jörg; Jensch, Peter

    Over the past 15 years Digital Imaging and Communications in Medicine (DICOM) has established itself as the international standard for medical image communication. Most medical imaging equipment uses DICOM network and media services to export image data, thus making this standard highly relevant for medical image processing. The first section of this chapter provides a basic introduction into DICOM with its more than 3,600 pages of technical documentation, followed by a section covering selected advanced topics of special interest for medical image processing. The introductory text familiarizes the reader with the standard's main concepts such as information objects and DICOM media and network services. The rendering pipeline for image display and the concept of DICOM conformance are also discussed. Specialized DICOM services such as advanced image display services that provide means for storing how an image was viewed ("Softcopy Presentation States") and how multiple images should be aligned on an output device ("Structured Display" and "Hanging Protocols") are described. We further describe DICOM's sophisticated approach ("Structured Reporting") for storing structured documents such as CAD information, which is then covered in more detail. Finally, the last section provides an insight into a newly developed DICOM service called "Application Hosting", which introduces a standardized plug-in architecture for image processing, thus permitting users to utilize cross-vendor image processing plug-ins in DICOM applications.

  19. Crack Length Detection by Digital Image Processing

    DEFF Research Database (Denmark)

    Lyngbye, Janus; Brincker, Rune

    1990-01-01

    It is described how digital image processing is used for measuring the length of fatigue cracks. The system is installed in a Personal Computer equipped with image processing hardware and performs automated measuring on plane metal specimens used in fatigue testing. Normally one can not achieve...... a resolution better then that of the image processing equipment. To overcome this problem an extrapolation technique is used resulting in a better resolution. The system was tested on a specimen loaded with different loads. The error σa was less than 0.031 mm, which is of the same size as human measuring...

  20. Crack Detection by Digital Image Processing

    DEFF Research Database (Denmark)

    Lyngbye, Janus; Brincker, Rune

    It is described how digital image processing is used for measuring the length of fatigue cracks. The system is installed in a Personal, Computer equipped with image processing hardware and performs automated measuring on plane metal specimens used in fatigue testing. Normally one can not achieve...... a resolution better than that of the image processing equipment. To overcome this problem an extrapolation technique is used resulting in a better resolution. The system was tested on a specimen loaded with different loads. The error σa was less than 0.031 mm, which is of the same size as human measuring...

  1. Digital Image Watermarking in Transform Domains

    International Nuclear Information System (INIS)

    EL-Shazly, E.H.M.

    2012-01-01

    Fast development of internet and availability of huge digital content make it easy to create, modify and copy digital media such as audio, video and images. This causes a problem for owners of that content and hence a need to copy right protection tool was essential. First, encryption was proposed but it ensures protection during transmission only and once decryption occurred any one can modify the data. at that point watermarking was introduced as a solution to such problem. Watermarking is a process of inserting a low energy signal in to a high energy one so that it doesn't affect the main signal features. A good digital image watermarking technique should satisfy four requirements: 1) Embedding of a watermark should not degrade the host image visual quality (imperceptibility). 2) The embedded watermark should stick to the host image so that it couldn’t be removed by common image processing operation and could be extracted from the attacked watermarked image (robustness). 3) Knowing the embedding and extraction procedures is sufficient but not enough to extract the watermark; extra keys should be needed (security). 4) The watermarking technique should allow embedding and extraction of more than one watermark each independent of the other (capacity). This thesis presents a watermarking scheme that full fill the mentioned four requirements by jointing transform domains with Fractional Fourier Transform Domain (FracFT). More work on cascaded Discrete Wavelet Transform DWT with FracFT was done to develop a joint transform simply called Fractional Wavelet Transform (FWT). The proposed schemes were tested with different image processing attacks to verify its robustness. Finally, the watermarked image is transmitted over simulated MC CDMA channel to prove robustness in real transmission conditions case.

  2. Digital Image Enhancement of Indic Historical Manuscripts

    Science.gov (United States)

    Shi, Zhixin; Setlur, Srirangaraj; Govindaraju, Venu

    Historical documents in Indic scripts can be found on a wide range of media such as paper, palm leaves, and parchment. Palm leaves are believed to be one of the earliest forms of writing media and their use as writing material has been recorded in various parts of the world including India. Ancient palm leaf manuscripts relating to religion, science, medicine, astronomy are still available for reference today due to many ongoing efforts for preservation of ancient documents by libraries and universities around the world. These manuscripts typically last a few centuries but with time the leaves degrade and the writing becomes illegible. Image processing techniques can help enhance the images of these manuscripts so as to enable readability of the written text. In this chapter, we propose methods for enhancing digital images of palm leaf and other historical manuscripts. We approximate the background of a gray-scale image using piece-wise linear and nonlinear models. Normalization algorithms are used on the color channels of the palm leaf image to obtain an enhanced gray-scale image. Experimental results show significant improvement in readability. An adaptive local connectivity map is used to try to segment lines of text from the enhanced images with the objective of facilitating techniques such as keyword spotting or partial OCR and thereby making it possible to index these documents for retrieval from a digital library.

  3. CT image processing using digital networks

    International Nuclear Information System (INIS)

    Rhodes, M.L.

    1985-01-01

    Several digital image transmission networks have been proposed, studied, and measured for local-area medical applications. The image processing service described here uses a commercial digital network to connect the computers of CT scanners. The network service shares image processing tasks with remote sites during the times that the scanners are otherwise idle. The network is nationwide, emphasizes resource sharing, uses moderate-bandwidth (4800 or 9600 baud, i.e., 480 or 960 characters/sec) dedicated leased telephone lines, and is restricted at this time to only a few types of CT scanner. Furthermore, because it offers services that are not interactive, it is able to optimize computer resources without routine interruption from users. Discussion begins by a brief overview of classic computer network topologies, with an emphasis on their application to CT, magnetic resonance imaging (MRI), and other medical imaging modalities. This somewhat technical introduction to networks demonstrates the unique characteristics of medical image communication as opposed to the more common applications of computer communication in the banking, retail, and management information industries. In the sections that follow, a more selective focus is made on the topology, hardware, image-processing, and operational characteristics of a network that is now composed of over 50 CT scanner systems throughout the United States. The chapter concludes by summarizing the network performance during its first 35 months of operation

  4. ASTM reference radiologic digital image standards

    International Nuclear Information System (INIS)

    Wysnewski, R.; Wysnewski, D.

    1996-01-01

    ASTM Reference Radiographs have been essential in defining industry's material defect grade levels for many years. ASTM Reference Radiographs are used extensively as even the American Society for Metals Nondestructive Inspection and Quality Control Metals Handbook, Volume 11, eighth edition refers to ASTM Standard Reference Radiographs. The recently published E 1648 Standard Reference Radiographs for Examination of Aluminum Fusion Welds is a prime example of the on-going need for these references. To date, 14 Standard Reference Radiographs have been published to characterize material defects. Standard Reference Radiographs do not adequately address film-less radiologic methods. There are differences in mediums to content with. On a computer CRT defect indications appear differently when compared to indications viewed in a radiograph on a view box. Industry that uses non-film radiologic methods of inspection can be burdened with additional time and money developing internal standard reference radiologic images. These references may be deemed necessary for grading levels of product defects. Because there are no ASTM Standard Reference Radiologic data files for addressing this need in the industry, the authors of this paper suggested implementing a method for their creation under ASTM supervision. ASTM can assure continuity to those users making the transition from analog radiographic images to digital image data by swiftly addressing the requirements for reference digital image standards. The current status and possible future activities regarding a method to create digital data files is presented in this paper summary

  5. High-precision topography measurement through accurate in-focus plane detection with hybrid digital holographic microscope and white light interferometer module.

    Science.gov (United States)

    Liżewski, Kamil; Tomczewski, Sławomir; Kozacki, Tomasz; Kostencka, Julianna

    2014-04-10

    High-precision topography measurement of micro-objects using interferometric and holographic techniques can be realized provided that the in-focus plane of an imaging system is very accurately determined. Therefore, in this paper we propose an accurate technique for in-focus plane determination, which is based on coherent and incoherent light. The proposed method consists of two major steps. First, a calibration of the imaging system with an amplitude object is performed with a common autofocusing method using coherent illumination, which allows for accurate localization of the in-focus plane position. In the second step, the position of the detected in-focus plane with respect to the imaging system is measured with white light interferometry. The obtained distance is used to accurately adjust a sample with the precision required for the measurement. The experimental validation of the proposed method is given for measurement of high-numerical-aperture microlenses with subwavelength accuracy.

  6. [Digital thoracic radiology: devices, image processing, limits].

    Science.gov (United States)

    Frija, J; de Géry, S; Lallouet, F; Guermazi, A; Zagdanski, A M; De Kerviler, E

    2001-09-01

    In a first part, the different techniques of digital thoracic radiography are described. Since computed radiography with phosphore plates are the most commercialized it is more emphasized. But the other detectors are also described, as the drum coated with selenium and the direct digital radiography with selenium detectors. The other detectors are also studied in particular indirect flat panels detectors and the system with four high resolution CCD cameras. In a second step the most important image processing are discussed: the gradation curves, the unsharp mask processing, the system MUSICA, the dynamic range compression or reduction, the soustraction with dual energy. In the last part the advantages and the drawbacks of computed thoracic radiography are emphasized. The most important are the almost constant good quality of the pictures and the possibilities of image processing.

  7. Speckle pattern processing by digital image correlation

    Directory of Open Access Journals (Sweden)

    Gubarev Fedor

    2016-01-01

    Full Text Available Testing the method of speckle pattern processing based on the digital image correlation is carried out in the current work. Three the most widely used formulas of the correlation coefficient are tested. To determine the accuracy of the speckle pattern processing, test speckle patterns with known displacement are used. The optimal size of a speckle pattern template used for determination of correlation and corresponding the speckle pattern displacement is also considered in the work.

  8. Digital image intensifier radiography: first experiences with the DSI (Digital Spot Imaging)

    International Nuclear Information System (INIS)

    Rueckforth, J.; Wein, B.; Stargardt, A.; Guenther, R.W.

    1995-01-01

    We performed a comparative study of digitally and conventionally acquired images in gastrointestinal examinations. Radiation dose and spatial resolution were determined in a water phantom. In 676 examinations with either conventional or digital imaging (system: Diagnost 76, DSI) the number of images and the duration of the fluoroscopy time were compared. 101 examinations with digital as well as conventional documentation were evaluated by using 5 criteria describing the diagnostic performance. The entrance dose of the DSI is 12% to 36% of the film/screen system and the spatial resolution of the DSI may be better than that of a film/screen system with a speed of 200. The fluoroscopy time shows no significant difference between DSI and the film/screen technique. In 2 of 4 examination modes significantly more images were produced by the DSI. With exception of the criterion of edge sharpness, DSI yields a significantly inferior assessment compared with the film/screen technique. (orig./MG) [de

  9. Digital image sequence processing, compression, and analysis

    CERN Document Server

    Reed, Todd R

    2004-01-01

    IntroductionTodd R. ReedCONTENT-BASED IMAGE SEQUENCE REPRESENTATIONPedro M. Q. Aguiar, Radu S. Jasinschi, José M. F. Moura, andCharnchai PluempitiwiriyawejTHE COMPUTATION OF MOTIONChristoph Stiller, Sören Kammel, Jan Horn, and Thao DangMOTION ANALYSIS AND DISPLACEMENT ESTIMATION IN THE FREQUENCY DOMAINLuca Lucchese and Guido Maria CortelazzoQUALITY OF SERVICE ASSESSMENT IN NEW GENERATION WIRELESS VIDEO COMMUNICATIONSGaetano GiuntaERROR CONCEALMENT IN DIGITAL VIDEOFrancesco G.B. De NataleIMAGE SEQUENCE RESTORATION: A WIDER PERSPECTIVEAnil KokaramVIDEO SUMMARIZATIONCuneyt M. Taskiran and Edward

  10. [Digital imaging and robotics in endoscopic surgery].

    Science.gov (United States)

    Go, P M

    1998-05-23

    The introduction of endoscopical surgery has among other things influenced technical developments in surgery. Owing to digitalisation, major progress will be made in imaging and in the sophisticated technology sometimes called robotics. Digital storage makes the results of imaging diagnostics (e.g. the results of radiological examination) suitable for transmission via video conference systems for telediagnostic purposes. The availability of digital video technique renders possible the processing, storage and retrieval of moving images as well. During endoscopical operations use may be made of a robot arm which replaces the camera man. The arm does not grow tired and provides a stable image. The surgeon himself can operate or address the arm and it can remember fixed image positions to which it can return if ordered to do so. The next step is to carry out surgical manipulations via a robot arm. This may make operations more patient-friendly. A robot arm can also have remote control: telerobotics. At the Internet site of this journal a number of supplements to this article can be found, for instance three-dimensional (3D) illustrations (which is the purpose of the 3D spectacles enclosed with this issue) and a quiz (http:@appendix.niwi. knaw.nl).

  11. Digital image processing in neutron radiography

    International Nuclear Information System (INIS)

    Koerner, S.

    2000-11-01

    Neutron radiography is a method for the visualization of the macroscopic inner-structure and material distributions of various materials. The basic experimental arrangement consists of a neutron source, a collimator functioning as beam formatting assembly and of a plane position sensitive integrating detector. The object is placed between the collimator exit and the detector, which records a two dimensional image. This image contains information about the composition and structure of the sample-interior, as a result of the interaction of neutrons by penetrating matter. Due to rapid developments of detector and computer technology as well as deployments in the field of digital image processing, new technologies are nowadays available which have the potential to improve the performance of neutron radiographic investigations enormously. Therefore, the aim of this work was to develop a state-of-the art digital imaging device, suitable for the two neutron radiography stations located at the 250 kW TRIGA Mark II reactor at the Atominstitut der Oesterreichischen Universitaeten and furthermore, to identify and develop two and three dimensional digital image processing methods suitable for neutron radiographic and tomographic applications, and to implement and optimize them within data processing strategies. The first step was the development of a new imaging device fulfilling the requirements of a high reproducibility, easy handling, high spatial resolution, a large dynamic range, high efficiency and a good linearity. The detector output should be inherently digitized. The key components of the detector system selected on the basis of these requirements consist of a neutron sensitive scintillator screen, a CCD-camera and a mirror to reflect the light emitted by the scintillator to the CCD-camera. This detector design enables to place the camera out of the direct neutron beam. The whole assembly is placed in a light shielded aluminum box. The camera is controlled by a

  12. Digital image processing in neutron radiography

    International Nuclear Information System (INIS)

    Koerner, S.

    2000-11-01

    Neutron radiography is a method for the visualization of the macroscopic inner-structure and material distributions of various samples. The basic experimental arrangement consists of a neutron source, a collimator functioning as beam formatting assembly and of a plane position sensitive integrating detector. The object is placed between the collimator exit and the detector, which records a two dimensional image. This image contains information about the composition and structure of the sample-interior, as a result of the interaction of neutrons by penetrating matter. Due to rapid developments of detector and computer technology as well as deployments in the field of digital image processing, new technologies are nowadays available which have the potential to improve the performance of neutron radiographic investigations enormously. Therefore, the aim of this work was to develop a state-of-the art digital imaging device, suitable for the two neutron radiography stations located at the 250 kW TRIGA Mark II reactor at the Atominstitut der Oesterreichischen Universitaeten and furthermore, to identify and develop two and three dimensional digital image processing methods suitable for neutron radiographic and tomographic applications, and to implement and optimize them within data processing strategies. The first step was the development of a new imaging device fulfilling the requirements of a high reproducibility, easy handling, high spatial resolution, a large dynamic range, high efficiency and a good linearity. The detector output should be inherently digitized. The key components of the detector system selected on the basis of these requirements consist of a neutron sensitive scintillator screen, a CCD-camera and a mirror to reflect the light emitted by the scintillator to the CCD-camera. This detector design enables to place the camera out of the direct neutron beam. The whole assembly is placed in a light shielded aluminum box. The camera is controlled by a

  13. Speckle noise suppression using part of pixels in a single-exposure digital hologram

    Science.gov (United States)

    Leng, Junmin; Zhou, Zhehai; Li, Fubing; Zheng, Qingyu; Liu, Gang

    2017-05-01

    A method is proposed to suppress speckle noise using only part of the pixels in a single-exposure digital hologram. Different holographic patterns are first generated from a single-exposure digital hologram using specially designed binary masks; then, these holographic patterns are reconstructed according to the Fresnel transform. The reconstructed images are superposed and averaged on the intensity to achieve the suppression of speckle noise. The entire denoising process does not need any additional digital holograms or specific requirements for recording a hologram. Theoretical simulation and experiment verification were carried out and confirm that the proposed method is a very convenient and effective way to suppress speckle noise in digital holography. The proposed method has wide applications in holographic imaging, holographic storage, and art display.

  14. Imaging sunlight using a digital spectroheliograph

    CERN Document Server

    Harrison, Ken M

    2016-01-01

    Ken M. Harrison's latest book is a complete guide for amateur astronomers who want to obtain detailed narrowband images of the Sun using a digital spectroheliograph (SHG). The SHG allows the safe imaging of the Sun without the expense of commercial ‘etalon’ solar filters. As the supporting software continues to be refined, the use of the digital spectroheliograph will become more and more mainstream and has the potential to replace the expensive solar filters currently in use. The early chapters briefly explain the concept of the SHG and how it can produce an image from the solar spectrum. A comparison of the currently available narrow band solar filters is followed by a detailed analysis of the critical design, construction and assembly features of the SHG. The design and optimum layout of the instrument is discussed to allow evaluation of performance. This information explains how to assemble a fully functional SHG using readily available components. The software required to process the images is exp...

  15. Evaluating fracture healing using digital x-ray image analysis

    African Journals Online (AJOL)

    2011-03-02

    Mar 2, 2011 ... of Edinburgh, developing techniques for assessing fracture healing using digital X-ray image analysis. She currently works in ... Digital X-ray combined with image analysis could provide a simple and cost-effective solution to this problem. .... output in which post-processing can be controlled. If digital X-ray ...

  16. 3D flow investigation near the denticles of biomimetic shark skin model using Digital In-line Holographic Microscopy

    Science.gov (United States)

    Toloui, Mostafa; Hong, Jiarong

    2013-11-01

    It has been hypothesised that the complex microscopic denticles on a shark skin reduce the total drag for a swimming shark. However, the fundamental mechanism of this hydrodynamic function is not fully understood due to the inability to reproduce the complex shark surface and resolve the detailed flow around the skin denticles. Here we report a preliminary experiment using a 3D printed transparent rough surface replicating the morphological features of real shark skin. The model skin consists of closely-packed denticles of 2 mm in scale, i.e. ~ 10 times of the real size. Particle image velocimetry based on digital in-line holography is employed to measure 3D flow structures. To reduce optical abberration and enable imaging around the denticles, we use a fluid medium that has the same optical refractive index as that of the skin model. The experiment is conducted in 2'' ×2'' square channel at a moderate Re number matching the general flow around a cruising shark. Several samples of the 3D velocity field amid and above the denticles are obtained. The follow-up research envisions a large dataset of these samples over the rigid/deformable model operated in stationary/undulating mode to ellucidate the dominant flow structures generated by the denticals. This research is collaborated with Prof. George Lauder's group.

  17. Advanced techniques in digital mammographic images recognition

    International Nuclear Information System (INIS)

    Aliu, R. Azir

    2011-01-01

    Computer Aided Detection and Diagnosis is used in digital radiography as a second thought in the process of determining diagnoses, which reduces the percentage of wrong diagnoses of the established interpretation of mammographic images. The issues that are discussed in the dissertation are the analyses and improvement of advanced technologies in the field of artificial intelligence, more specifically in the field of machine learning for solving diagnostic problems and automatic detection of speculated lesions in digital mammograms. The developed of SVM-based ICAD system with cascade architecture for analyses and comparison mammographic images in both projections (CC and MLO) gives excellent result for detection and masses and microcalcifications. In order to develop a system with optimal performances of sensitivity, specificity and time complexity, a set of relevant characteristics need to be created which will show all the pathological regions that might be present in the mammographic image. The structure of the mammographic image, size and the large number of pathological structures in this area are the reason why the creation of a set of these features is necessary for the presentation of good indicators. These pathological structures are a real challenge today and the world of science is working in that direction. The doctoral dissertation showed that the system has optimal results, which are confirmed by experts, and institutions, which are dealing with these same issues. Also, the thesis presents a new approach for automatic identification of regions of interest in the mammographic image where regions of interest are automatically selected for further processing mammography in cases when the number of examined patients is higher. Out of 480 mammographic images downloaded from MIAS database and tested with ICAD system the author shows that, after separation and selection of relevant features of ICAD system the accuracy is 89.7% (96.4% for microcalcifications

  18. Panning artifacts in digital pathology images

    Science.gov (United States)

    Avanaki, Ali R. N.; Lanciault, Christian; Espig, Kathryn S.; Xthona, Albert; Kimpe, Tom R. L.

    2017-03-01

    In making a pathologic diagnosis, a pathologist uses cognitive processes: perception, attention, memory, and search (Pena and Andrade-Filho, 2009). Typically, this involves focus while panning from one region of a slide to another, using either a microscope in a traditional workflow or software program and display in a digital pathology workflow (DICOM Standard Committee, 2010). We theorize that during panning operation, the pathologist receives information important to diagnosis efficiency and/or correctness. As compared to an optical microscope, panning in a digital pathology image involves some visual artifacts due to the following: (i) the frame rate is finite; (ii) time varying visual signals are reconstructed using imperfect zero-order hold. Specifically, after pixel's digital drive is changed, it takes time for a pixel to emit the expected amount of light. Previous work suggests that 49% of navigation is conducted in low-power/overview with digital pathology (Molin et al., 2015), but the influence of display factors has not been measured. We conducted a reader study to establish a relationship between display frame rate, panel response time, and threshold panning speed (above which the artifacts become noticeable). Our results suggest visual tasks that involve tissue structure are more impacted by the simulated panning artifacts than those that only involve color (e.g., staining intensity estimation), and that the panning artifacts versus normalized panning speed has a peak behavior which is surprising and may change for a diagnostic task. This is work in progress and our final findings should be considered in designing future digital pathology systems.

  19. Integral imaging-based large-scale full-color 3-D display of holographic data by using a commercial LCD panel.

    Science.gov (United States)

    Dong, Xiao-Bin; Ai, Ling-Yu; Kim, Eun-Soo

    2016-02-22

    We propose a new type of integral imaging-based large-scale full-color three-dimensional (3-D) display of holographic data based on direct ray-optical conversion of holographic data into elemental images (EIs). In the proposed system, a 3-D scene is modeled as a collection of depth-sliced object images (DOIs), and three-color hologram patterns for that scene are generated by interfering each color DOI with a reference beam, and summing them all based on Fresnel convolution integrals. From these hologram patterns, full-color DOIs are reconstructed, and converted into EIs using a ray mapping-based direct pickup process. These EIs are then optically reconstructed to be a full-color 3-D scene with perspectives on the depth-priority integral imaging (DPII)-based 3-D display system employing a large-scale LCD panel. Experiments with a test video confirm the feasibility of the proposed system in the practical application fields of large-scale holographic 3-D displays.

  20. An image processing system for digital chest X-ray images

    International Nuclear Information System (INIS)

    Cocklin, M.; Gourlay, A.; Jackson, P.; Kaye, G.; Miessler, M.; Kerr, I.; Lams, P.

    1984-01-01

    This paper investigates the requirements for image processing of digital chest X-ray images. These images are conventionally recorded on film and are characterised by large size, wide dynamic range and high resolution. X-ray detection systems are now becoming available for capturing these images directly in photoelectronic-digital form. The hardware and software facilities required for handling these images are described. These facilities include high resolution digital image displays, programmable video look up tables, image stores for image capture and processing and a full range of software tools for image manipulation. Examples are given of the applications of digital image processing techniques to this class of image. (Auth.)

  1. Automated Three-Dimensional Microbial Sensing and Recognition Using Digital Holography and Statistical Sampling

    Directory of Open Access Journals (Sweden)

    Inkyu Moon

    2010-09-01

    Full Text Available We overview an approach to providing automated three-dimensional (3D sensing and recognition of biological micro/nanoorganisms integrating Gabor digital holographic microscopy and statistical sampling methods. For 3D data acquisition of biological specimens, a coherent beam propagates through the specimen and its transversely and longitudinally magnified diffraction pattern observed by the microscope objective is optically recorded with an image sensor array interfaced with a computer. 3D visualization of the biological specimen from the magnified diffraction pattern is accomplished by using the computational Fresnel propagation algorithm. For 3D recognition of the biological specimen, a watershed image segmentation algorithm is applied to automatically remove the unnecessary background parts in the reconstructed holographic image. Statistical estimation and inference algorithms are developed to the automatically segmented holographic image. Overviews of preliminary experimental results illustrate how the holographic image reconstructed from the Gabor digital hologram of biological specimen contains important information for microbial recognition.

  2. Facial Edema Evaluation Using Digital Image Processing

    Directory of Open Access Journals (Sweden)

    A. E. Villafuerte-Nuñez

    2013-01-01

    Full Text Available The main objective of the facial edema evaluation is providing the needed information to determine the effectiveness of the anti-inflammatory drugs in development. This paper presents a system that measures the four main variables present in facial edemas: trismus, blush (coloration, temperature, and inflammation. Measurements are obtained by using image processing and the combination of different devices such as a projector, a PC, a digital camera, a thermographic camera, and a cephalostat. Data analysis and processing are performed using MATLAB. Facial inflammation is measured by comparing three-dimensional reconstructions of inflammatory variations using the fringe projection technique. Trismus is measured by converting pixels to centimeters in a digitally obtained image of an open mouth. Blushing changes are measured by obtaining and comparing the RGB histograms from facial edema images at different times. Finally, temperature changes are measured using a thermographic camera. Some tests using controlled measurements of every variable are presented in this paper. The results allow evaluating the measurement system before its use in a real test, using the pain model approved by the US Food and Drug Administration (FDA, which consists in extracting the third molar to generate the facial edema.

  3. Detecting jaundice by using digital image processing

    Science.gov (United States)

    Castro-Ramos, J.; Toxqui-Quitl, C.; Villa Manriquez, F.; Orozco-Guillen, E.; Padilla-Vivanco, A.; Sánchez-Escobar, JJ.

    2014-03-01

    When strong Jaundice is presented, babies or adults should be subject to clinical exam like "serum bilirubin" which can cause traumas in patients. Often jaundice is presented in liver disease such as hepatitis or liver cancer. In order to avoid additional traumas we propose to detect jaundice (icterus) in newborns or adults by using a not pain method. By acquiring digital images in color, in palm, soles and forehead, we analyze RGB attributes and diffuse reflectance spectra as the parameter to characterize patients with either jaundice or not, and we correlate that parameters with the level of bilirubin. By applying support vector machine we distinguish between healthy and sick patients.

  4. Applications Of Digital Image Acquisition In Anthropometry

    Science.gov (United States)

    Woolford, Barbara; Lewis, James L.

    1981-10-01

    Anthropometric data on reach and mobility have traditionally been collected by time consuming and relatively inaccurate manual methods. Three dimensional digital image acquisition promises to radically increase the speed and ease of data collection and analysis. A three-camera video anthropometric system for collecting position, velocity, and force data in real time is under development for the Anthropometric Measurement Laboratory at NASA's Johnson Space Center. The use of a prototype of this system for collecting data on reach capabilities and on lateral stability is described. Two extensions of this system are planned.

  5. Multi-angle lensless digital holography for depth resolved imaging on a chip

    Science.gov (United States)

    Su, Ting-Wei; Isikman, Serhan O.; Bishara, Waheb; Tseng, Derek; Erlinger, Anthony; Ozcan, Aydogan

    2010-01-01

    A multi-angle lensfree holographic imaging platform that can accurately characterize both the axial and lateral positions of cells located within multi-layered micro-channels is introduced. In this platform, lensfree digital holograms of the micro-objects on the chip are recorded at different illumination angles using partially coherent illumination. These digital holograms start to shift laterally on the sensor plane as the illumination angle of the source is tilted. Since the exact amount of this lateral shift of each object hologram can be calculated with an accuracy that beats the diffraction limit of light, the height of each cell from the substrate can be determined over a large field of view without the use of any lenses. We demonstrate the proof of concept of this multi-angle lensless imaging platform by using light emitting diodes to characterize various sized microparticles located on a chip with sub-micron axial and lateral localization over ~60 mm2 field of view. Furthermore, we successfully apply this lensless imaging approach to simultaneously characterize blood samples located at multi-layered micro-channels in terms of the counts, individual thicknesses and the volumes of the cells at each layer. Because this platform does not require any lenses, lasers or other bulky optical/mechanical components, it provides a compact and high-throughput alternative to conventional approaches for cytometry and diagnostics applications involving lab on a chip systems. PMID:20588819

  6. Near-wall 3D velocity measurements above biomimetic shark skin denticles using Digital In-line Holographic Microscopy

    Science.gov (United States)

    Toloui, Mostafa; Brajkovic, David; Hong, Jiarong

    2014-11-01

    Digital In-line Holography is employed to image 3D flow structures in the vicinity of a transparent rough surface consisting of closely packed biomimetic shark skin denticles as roughness elements. The 3D printed surface replicates the morphological features of real shark skin, and the denticles have a geometrical scale of 2 mm, i.e. 10 times of the real ones. In order to minimize optical aberrations near the fluid-roughness interface and enable flow measurements around denticles, the optical refractive index of the fluid medium is maintained the same as that of the denticle model in an index-matched flow facility using NaI solution as the working fluid. The experiment is conducted in a 1.2 m long test section with 50 mm × 50 mm cross section. The sampling volume is located in the downstream region of a shark skin replica of 12'' stretch where the turbulent flow is fully-developed and the transitional effect from smooth to the rough surface becomes negligible. Several instantaneous realizations of the 3D velocity field are obtained and are used to illustrate turbulent coherent structures induced by shark-skin denticles. This information will provide insights on the hydrodynamic function of shark's unique surface ornamentation.

  7. Semiautomatic digital imaging system for cytogenetic analysis

    International Nuclear Information System (INIS)

    Chaubey, R.C.; Chauhan, P.C.; Bannur, S.V.; Kulgod, S.V.; Chadda, V.K.; Nigam, R.K.

    1999-08-01

    The paper describes a digital image processing system, developed indigenously at BARC for size measurement of microscopic biological objects such as cell, nucleus and micronucleus in mouse bone marrow; cytochalasin-B blocked human lymphocytes in-vitro; numerical counting and karyotyping of metaphase chromosomes of human lymphocytes. Errors in karyotyping of chromosomes by the imaging system may creep in due to lack of well-defined position of centromere or extensive bending of chromosomes, which may result due to poor quality of preparation. Good metaphase preparations are mandatory for precise and accurate analysis by the system. Additional new morphological parameters about each chromosome have to be incorporated to improve the accuracy of karyotyping. Though the experienced cytogenetisist is the final judge; however, the system assists him/her to carryout analysis much faster as compared to manual scoring. Further, experimental studies are in progress to validate different software packages developed for various cytogenetic applications. (author)

  8. From Digital Imaging to Computer Image Analysis of Fine Art

    Science.gov (United States)

    Stork, David G.

    An expanding range of techniques from computer vision, pattern recognition, image analysis, and computer graphics are being applied to problems in the history of art. The success of these efforts is enabled by the growing corpus of high-resolution multi-spectral digital images of art (primarily paintings and drawings), sophisticated computer vision methods, and most importantly the engagement of some art scholars who bring questions that may be addressed through computer methods. This paper outlines some general problem areas and opportunities in this new inter-disciplinary research program.

  9. SVD-based digital image watermarking using complex wavelet ...

    Indian Academy of Sciences (India)

    Keywords. Digital image watermarking; complex wavelet transform; singular ... In watermarking trial, SVD is applied to the image matrix; then watermark ..... IEEE. Trans. on Multimedia 4(1): 121–128. Loo P, Kingsbury N G 2000 Digital watermarking using complex wavelets. Int. Conf. on Image. Processing 29–32. Loo P ...

  10. The Neuro-Image: Alain Resnais's Digital Cinema without the Digits

    NARCIS (Netherlands)

    Pisters, P.

    2011-01-01

    This paper proposes to read cinema in the digital age as a new type of image, the neuroimage. Going back to Gilles Deleuze's cinema books and it is argued that the neuro-image is based in the future. The cinema of Alain Resnais is analyzed as a neuro-image and digital cinema .

  11. Remote Sensing Digital Image Analysis An Introduction

    CERN Document Server

    Richards, John A

    2013-01-01

    Remote Sensing Digital Image Analysis provides the non-specialist with a treatment of the quantitative analysis of satellite and aircraft derived remotely sensed data. Since the first edition of the book there have been significant developments in the algorithms used for the processing and analysis of remote sensing imagery; nevertheless many of the fundamentals have substantially remained the same.  This new edition presents material that has retained value since those early days, along with new techniques that can be incorporated into an operational framework for the analysis of remote sensing data. The book is designed as a teaching text for the senior undergraduate and postgraduate student, and as a fundamental treatment for those engaged in research using digital image processing in remote sensing.  The presentation level is for the mathematical non-specialist.  Since the very great number of operational users of remote sensing come from the earth sciences communities, the text is pitched at a leve...

  12. X-ray images in the digital mode

    International Nuclear Information System (INIS)

    Buchmann, F.; Balter, S.

    1981-01-01

    In addition to computed tomography which presents actually the most important processing and transfer procedure of digital X-ray images, application of real time addition and substraction of X-ray images in a digital mode has found considerable interest. An estimation of the information contents of both digital and analog images is made in close relation to applications. As example of an image processing system on digital base a recently developed system for intravenous arteriography is described: the Philips-DVI. (orig.) [de

  13. Multiscale image processing and antiscatter grids in digital radiography.

    Science.gov (United States)

    Lo, Winnie Y; Hornof, William J; Zwingenberger, Allison L; Robertson, Ian D

    2009-01-01

    Scatter radiation is a source of noise and results in decreased signal-to-noise ratio and thus decreased image quality in digital radiography. We determined subjectively whether a digitally processed image made without a grid would be of similar quality to an image made with a grid but without image processing. Additionally the effects of exposure dose and of a using a grid with digital radiography on overall image quality were studied. Thoracic and abdominal radiographs of five dogs of various sizes were made. Four acquisition techniques were included (1) with a grid, standard exposure dose, digital image processing; (2) without a grid, standard exposure dose, digital image processing; (3) without a grid, half the exposure dose, digital image processing; and (4) with a grid, standard exposure dose, no digital image processing (to mimic a film-screen radiograph). Full-size radiographs as well as magnified images of specific anatomic regions were generated. Nine reviewers rated the overall image quality subjectively using a five-point scale. All digitally processed radiographs had higher overall scores than nondigitally processed radiographs regardless of patient size, exposure dose, or use of a grid. The images made at half the exposure dose had a slightly lower quality than those made at full dose, but this was only statistically significant in magnified images. Using a grid with digital image processing led to a slight but statistically significant increase in overall quality when compared with digitally processed images made without a grid but whether this increase in quality is clinically significant is unknown.

  14. Digitizing radiographic films: a simple way to evaluate indirect digital images

    Directory of Open Access Journals (Sweden)

    Izabel Regina Fischer Rubia-Bullen

    2007-02-01

    Full Text Available OBJECTIVES: This study applied a simple method to evaluate the performance of three digital devices (two scanners and one digital camera using the reproducibility of pixel values attributed to the same radiographic image. METHODS: Using the same capture parameters, a radiographic image was repeatedly digitized in order to determine the variability of pixel values given to the image throughout the digitization process. One coefficient value was obtained and was called pixel value reproducibility. RESULTS: A significant difference in pixel values was observed among the three devices for the digitized images (ANOVA, p<0.00001. There was significant pixel value variability at the same digitization conditions for one scanner and the digital camera. CONCLUSIONS: Digital devices may assign pixel values differently in consecutive digitization depending on the optical density of the radiographic image and the equipment. The pixel value reproducibility was not satisfactory as tested for two devices. It is maybe advisable knowing the digitization variations regarding pixel values whenever using digital radiography images in longitudinal clinical examinations.

  15. New possibilities of digital luminescence radiography (DLR) and digital image processing for verification and portal imaging

    International Nuclear Information System (INIS)

    Zimmermann, J.S.; Blume, J.; Wendhausen, H.; Hebbinghaus, D.; Kovacs, G.; Eilf, K.; Schultze, J.; Kimmig, B.N.

    1995-01-01

    We developed a method, using digital luminescence radiography (DLR), not only for portal imaging of photon beams in an excellent quality, but also for verification of electron beams. Furtheron, DLR was used as basic instrument for image fusion of portal and verification film and simulation film respectively for image processing in ''beams-eye-view'' verification (BEVV) of rotating beams or conformation therapy. Digital radiographs of an excellent quality are gained for verification of photon and electron beams. In photon beams, quality improvement vs. conventional portal imaging may be dramatic, even more for high energy beams (e.g. 15-MV-photon beams) than for Co-60. In electron beams, excellent results may be easily obtained. By digital image fusion of 1 or more verification films on simulation film or MRI-planning film, more precise judgement even on small differences between simulation and verification films becomes possible. Using BEVV, it is possible to compare computer aided simulation in rotating beams or conformation therapy with the really applied treatment. The basic principle of BEVV is also suitable for dynamic multileaf collimation. (orig.) [de

  16. Incoherent Digital Holography: A Review

    Directory of Open Access Journals (Sweden)

    Jung-Ping Liu

    2018-01-01

    Full Text Available Digital holography (DH is a promising technique for modern three-dimensional (3D imaging. Coherent holography records the complex amplitude of a 3D object holographically, giving speckle noise upon reconstruction and presenting a serious drawback inherent in coherent optical systems. On the other hand, incoherent holography records the intensity distribution of the object, allowing a higher signal-to-noise ratio as compared to its coherent counterpart. Currently there are two incoherent digital holographic techniques: optical scanning holography (OSH and Fresnel incoherent correlation holography (FINCH. In this review, we first explain the principles of OSH and FINCH. We then compare, to some extent, the differences between OSH and FINCH. Finally, some of the recent applications of the two incoherent holographic techniques are reviewed.

  17. Making the Case for Embedded Metadata in Digital Images

    DEFF Research Database (Denmark)

    Smith, Kari R.; Saunders, Sarah; Kejser, U.B.

    2014-01-01

    exchange in heritage institutions and the culture sector. Our examples and findings support the case for embedded metadata in digital images and the opportunities for such use more broadly in non-heritage sectors as well. We encourage the adoption of embedded metadata by digital image content creators......This paper discusses the standards, methods, use cases, and opportunities for using embedded metadata in digital images. In this paper we explain the past and current work engaged with developing specifications, standards for embedding metadata of different types, and the practicalities of data...... and curators as well as those developing software and hardware that support the creation or re-use of digital images. We conclude that the usability of born digital images as well as physical objects that are digitized can be extended and the files preserved more readily with embedded metadata....

  18. Transformation of radiation levels into a digital image

    International Nuclear Information System (INIS)

    Hefnawy, M.

    2017-01-01

    This article introduces a new way of the data visualization. This new kind of data visualization is called Digital Measurements Image or Digital 'Application name' Image. It is known that the normal digital image is created by digital camera or digital scanner but digital measurements image is created by measurements of monitoring data. This work uses the data which is measured by some radiation monitoring stations and classifies it using a fuzzy logic classification technique to create some digital measurements images or digital radiation images. The main advantage of digital measurements image is that it expresses thousands of measurements in a very clear form through only one photo while the maximum number of measurements does not exceed 100 for conventional data visualization methods. This feature gives a facility to view all measurements taken in one year in a single photo. This photo helps the user to observe the behavior of thousands of measurements in few minutes instead of spending hours in reviewing hundreds of charts for the same measurements. This article also introduces a new way for forecasting Gamma radiation levels. This way uses image restoration technique to predict the gamma levels. (author)

  19. Enhanced resolution for amplitude object in lensless inline holographic microscope with grating illumination

    Science.gov (United States)

    Feng, Shaodong; Wang, Mingjun; Wu, Jigang

    2017-09-01

    In a compact digital lensless inline holographic microscope (LIHM), where the sample-to-sensor distance is short, the imaging resolution is often limited by sensor pixel size instead of the system numerical aperture. We propose to solve this problem by applying data interpolation with an iterative holographic reconstruction method while using grating illumination in the LIHM system. In the system setup, the Talbot self-image of a Ronchi grating was used to illuminate the sample, and the inline hologram was recorded by a CMOS imaging sensor located behind the sample. The hologram was then upsampled by data interpolation before the reconstruction process. In the iterative holographic reconstruction, the sample support was defined by the bright areas of the grating illumination pattern and was used as constraint. A wide-field image can also be obtained by shifting the grating illumination pattern. Furthermore, we assumed that the sample was amplitude object, i.e., no obvious phase change was caused by the sample, which provided additional constraint to refine the interpolated data values. Besides improved resolution, the iterative holographic reconstruction also helped to reduce the twin-image background. We demonstrated the effectiveness of our method with simulation and imaging experiment by using the USAF target and polystyrene microspheres with 1 μm diameter as the sample.

  20. Digital image archiving: challenges and choices.

    Science.gov (United States)

    Dumery, Barbara

    2002-01-01

    In the last five years, imaging exam volume has grown rapidly. In addition to increased image acquisition, there is more patient information per study. RIS-PACS integration and information-rich DICOM headers now provide us with more patient information relative to each study. The volume of archived digital images is increasing and will continue to rise at a steeper incline than film-based storage of the past. Many filmless facilities have been caught off guard by this increase, which has been stimulated by many factors. The most significant factor is investment in new digital and DICOM-compliant modalities. A huge volume driver is the increase in images per study from multi-slice technology. Storage requirements also are affected by disaster recovery initiatives and state retention mandates. This burgeoning rate of imaging data volume presents many challenges: cost of ownership, data accessibility, storage media obsolescence, database considerations, physical limitations, reliability and redundancy. There are two basic approaches to archiving--single tier and multi-tier. Each has benefits. With a single-tier approach, all the data is stored on a single media that can be accessed very quickly. A redundant copy of the data is then stored onto another less expensive media. This is usually a removable media. In this approach, the on-line storage is increased incrementally as volume grows. In a multi-tier approach, storage levels are set up based on access speed and cost. In other words, all images are stored at the deepest archiving level, which is also the least expensive. Images are stored on or moved back to the intermediate and on-line levels if they will need to be accessed more quickly. It can be difficult to decide what the best approach is for your organization. The options include RAIDs (redundant array of independent disks), direct attached RAID storage (DAS), network storage using RAIDs (NAS and SAN), removable media such as different types of tape, compact

  1. Holographic Optical Data Storage

    Science.gov (United States)

    Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)

    2000-01-01

    Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising

  2. Classroom multispectral imaging using inexpensive digital cameras.

    Science.gov (United States)

    Fortes, A. D.

    2007-12-01

    The proliferation of increasingly cheap digital cameras in recent years means that it has become easier to exploit the broad wavelength sensitivity of their CCDs (360 - 1100 nm) for classroom-based teaching. With the right tools, it is possible to open children's eyes to the invisible world of UVA and near-IR radiation either side of our narrow visual band. The camera-filter combinations I describe can be used to explore the world of animal vision, looking for invisible markings on flowers, or in bird plumage, for example. In combination with a basic spectroscope (such as the Project-STAR handheld plastic spectrometer, 25), it is possible to investigate the range of human vision and camera sensitivity, and to explore the atomic and molecular absorption lines from the solar and terrestrial atmospheres. My principal use of the cameras has been to teach multispectral imaging of the kind used to determine remotely the composition of planetary surfaces. A range of camera options, from 50 circuit-board mounted CCDs up to $900 semi-pro infrared camera kits (including mobile phones along the way), and various UV-vis-IR filter options will be presented. Examples of multispectral images taken with these systems are used to illustrate the range of classroom topics that can be covered. Particular attention is given to learning about spectral reflectance curves and comparing images from Earth and Mars taken using the same filter combination that it used on the Mars Rovers.

  3. A color image processing pipeline for digital microscope

    Science.gov (United States)

    Liu, Yan; Liu, Peng; Zhuang, Zhefeng; Chen, Enguo; Yu, Feihong

    2012-10-01

    Digital microscope has found wide application in the field of biology, medicine et al. A digital microscope differs from traditional optical microscope in that there is no need to observe the sample through an eyepiece directly, because the optical image is projected directly on the CCD/CMOS camera. However, because of the imaging difference between human eye and sensor, color image processing pipeline is needed for the digital microscope electronic eyepiece to get obtain fine image. The color image pipeline for digital microscope, including the procedures that convert the RAW image data captured by sensor into real color image, is of great concern to the quality of microscopic image. The color pipeline for digital microscope is different from digital still cameras and video cameras because of the specific requirements of microscopic image, which should have the characters of high dynamic range, keeping the same color with the objects observed and a variety of image post-processing. In this paper, a new color image processing pipeline is proposed to satisfy the requirements of digital microscope image. The algorithm of each step in the color image processing pipeline is designed and optimized with the purpose of getting high quality image and accommodating diverse user preferences. With the proposed pipeline implemented on the digital microscope platform, the output color images meet the various analysis requirements of images in the medicine and biology fields very well. The major steps of color imaging pipeline proposed include: black level adjustment, defect pixels removing, noise reduction, linearization, white balance, RGB color correction, tone scale correction and gamma correction.

  4. Digital image processing applied Rock Art tracing

    Directory of Open Access Journals (Sweden)

    Montero Ruiz, Ignacio

    1998-06-01

    Full Text Available Adequate graphic recording has been one of the main objectives of rock art research. Photography has increased its role as a documentary technique. Now, digital image and its treatment allows new ways to observe the details of the figures and to develop a recording procedure which is as, or more, accurate than direct tracing. This technique also avoid deterioration of the rock paintings. The mathematical basis of this method is also presented.

    La correcta documentación del arte rupestre ha sido una preocupación constante por parte de los investigadores. En el desarrollo de nuevas técnicas de registro, directas e indirectas, la fotografía ha ido adquiriendo mayor protagonismo. La imagen digital y su tratamiento permiten nuevas posibilidades de observación de las figuras representadas y, en consecuencia, una lectura mediante la realización de calcos indirectos de tanta o mayor fiabilidad que la observación directa. Este sistema evita los riesgos de deterioro que provocan los calcos directos. Se incluyen las bases matemáticas que sustentan el método.

  5. Simultaneous optical recording in multiple cells by digital holographic microscopy of chloride current associated to activation of the ligand-gated chloride channel GABA(A) receptor.

    Science.gov (United States)

    Jourdain, Pascal; Boss, Daniel; Rappaz, Benjamin; Moratal, Corinne; Hernandez, Maria-Clemencia; Depeursinge, Christian; Magistretti, Pierre Julius; Marquet, Pierre

    2012-01-01

    Chloride channels represent a group of targets for major clinical indications. However, molecular screening for chloride channel modulators has proven to be difficult and time-consuming as approaches essentially rely on the use of fluorescent dyes or invasive patch-clamp techniques which do not lend themselves to the screening of large sets of compounds. To address this problem, we have developed a non-invasive optical method, based on digital holographic microcopy (DHM), allowing monitoring of ion channel activity without using any electrode or fluorescent dye. To illustrate this approach, GABA(A) mediated chloride currents have been monitored with DHM. Practically, we show that DHM can non-invasively provide the quantitative determination of transmembrane chloride fluxes mediated by the activation of chloride channels associated with GABA(A) receptors. Indeed through an original algorithm, chloride currents elicited by application of appropriate agonists of the GABA(A) receptor can be derived from the quantitative phase signal recorded with DHM. Finally, chloride currents can be determined and pharmacologically characterized non-invasively simultaneously on a large cellular sampling by DHM.

  6. Simultaneous optical recording in multiple cells by digital holographic microscopy of chloride current associated to activation of the ligand-gated chloride channel GABA(A receptor.

    Directory of Open Access Journals (Sweden)

    Pascal Jourdain

    Full Text Available Chloride channels represent a group of targets for major clinical indications. However, molecular screening for chloride channel modulators has proven to be difficult and time-consuming as approaches essentially rely on the use of fluorescent dyes or invasive patch-clamp techniques which do not lend themselves to the screening of large sets of compounds. To address this problem, we have developed a non-invasive optical method, based on digital holographic microcopy (DHM, allowing monitoring of ion channel activity without using any electrode or fluorescent dye. To illustrate this approach, GABA(A mediated chloride currents have been monitored with DHM. Practically, we show that DHM can non-invasively provide the quantitative determination of transmembrane chloride fluxes mediated by the activation of chloride channels associated with GABA(A receptors. Indeed through an original algorithm, chloride currents elicited by application of appropriate agonists of the GABA(A receptor can be derived from the quantitative phase signal recorded with DHM. Finally, chloride currents can be determined and pharmacologically characterized non-invasively simultaneously on a large cellular sampling by DHM.

  7. Microelectronic devices digital X-ray image processing method development

    Science.gov (United States)

    Staroverov, N. E.; Gryaznov, A. Yu; Kholopova, E. D.; Guk, K. K.

    2018-02-01

    In this paper microelectronic devices digital X-ray image processing method development is described. The main steps of the algorithm work are presented. The results of using the algorithm for improving the printed circuit board image are shown

  8. Three dimensional digital imaging of environmental data

    International Nuclear Information System (INIS)

    Nichols, R.L.; Eddy, C.A.

    1991-01-01

    The Environmental Sciences Section (ESS) of the Savannah River Laboratory has recently acquired the computer hardware (Silicon Graphics Personal Iris Workstations) and software (Dynamic Graphics, Interactive Surface and Volume Modeling) to perform three dimensional analysis of hydrogeologic data. Three dimensional digital imaging of environmental data is a powerful technique that can be used to incorporate field, analytical, and modeling results from geologic, hydrologic, ecologic, and chemical studies into a comprehensive model for visualization and interpretation. This report covers the contamination of four different sites of the Savannah River Plant. Each section of this report has a computer graphic display of the concentration of contamination in the groundwater and/or sediments of each site

  9. Digital camera with apparatus for authentication of images produced from an image file

    Science.gov (United States)

    Friedman, Gary L. (Inventor)

    1993-01-01

    A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely based upon the private key that digital data encrypted with the private key by the processor may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating at any time the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature. The apparatus calculates from the image file an image hash using the same algorithm as before. By comparing this last image hash with the secure image hash, authenticity of the image file is determined if they match, since even one bit change in the image hash will cause the image hash to be totally different from the secure hash.

  10. X-ray imaging using digital cameras

    Science.gov (United States)

    Winch, Nicola M.; Edgar, Andrew

    2012-03-01

    The possibility of using the combination of a computed radiography (storage phosphor) cassette and a semiprofessional grade digital camera for medical or dental radiography is investigated. We compare the performance of (i) a Canon 5D Mk II single lens reflex camera with f1.4 lens and full-frame CMOS array sensor and (ii) a cooled CCD-based camera with a 1/3 frame sensor and the same lens system. Both systems are tested with 240 x 180 mm cassettes which are based on either powdered europium-doped barium fluoride bromide or needle structure europium-doped cesium bromide. The modulation transfer function for both systems has been determined and falls to a value of 0.2 at around 2 lp/mm, and is limited by light scattering of the emitted light from the storage phosphor rather than the optics or sensor pixelation. The modulation transfer function for the CsBr:Eu2+ plate is bimodal, with a high frequency wing which is attributed to the light-guiding behaviour of the needle structure. The detective quantum efficiency has been determined using a radioisotope source and is comparatively low at 0.017 for the CMOS camera and 0.006 for the CCD camera, attributed to the poor light harvesting by the lens. The primary advantages of the method are portability, robustness, digital imaging and low cost; the limitations are the low detective quantum efficiency and hence signal-to-noise ratio for medical doses, and restricted range of plate sizes. Representative images taken with medical doses are shown and illustrate the potential use for portable basic radiography.

  11. Digital pulse processor for ion beam microprobe imaging

    International Nuclear Information System (INIS)

    Bogovac, M.; Jaksic, M.; Wegrzynek, D.; Markowicz, A.

    2009-01-01

    Capabilities of spectroscopic ion beam analysis (IBA) techniques that are available in ion microprobe facilities can be greatly improved by the use of digital pulse processing. We report here development of a digital multi parameter data acquisition system suitable for IBA imaging applications. Input signals from charge sensitive preamplifier are conditioned by using a simple circuit and digitized with fast ADCs. The digitally converted signals are processed in real time using FPGA. Implementation of several components of the system is presented.

  12. Improving digital image watermarking by means of optimal channel selection

    NARCIS (Netherlands)

    Huynh-The, Thien; Banos Legran, Oresti; Lee, Sungyoung; Yoon, Yongik; Le-Tien, Thuong

    2016-01-01

    Supporting safe and resilient authentication and integrity of digital images is of critical importance in a time of enormous creation and sharing of these contents. This paper presents an improved digital image watermarking model based on a coefficient quantization technique that intelligently

  13. Image processing by use of the digital cross-correlator

    International Nuclear Information System (INIS)

    Katou, Yoshinori

    1982-01-01

    We manufactured for trial an instrument which achieved the image processing using digital correlators. A digital correlator perform 64-bit parallel correlation at 20 MH. The output of a digital correlator is a 7-bit word representing. An A-D converter is used to quantize it a precision of six bits. The resulting 6-bit word is fed to six correlators, wired in parallel. The image processing achieved in 12 bits, whose digital outputs converted an analog signal by a D-A converter. This instrument is named the digital cross-correlator. The method which was used in the image processing system calculated the convolution with the digital correlator. It makes various digital filters. In the experiment with the image processing video signals from TV camera were used. The digital image processing time was approximately 5 μs. The contrast was enhanced and smoothed. The digital cross-correlator has the image processing of 16 sorts, and was produced inexpensively. (author)

  14. Effects of optimization and image processing in digital chest radiography

    International Nuclear Information System (INIS)

    Kheddache, S.; Maansson, L.G.; Angelhed, J.E.; Denbratt, L.; Gottfridsson, B.; Schlossman, D.

    1991-01-01

    A digital system for chest radiography based on a large image intensifier was compared to a conventional film-screen system. The digital system was optimized with regard to spatial and contrast resolution and dose. The images were digitally processed for contrast and edge enhancement. A simulated pneumothorax and two and two simulated nodules were positioned over the lungs and the mediastinum of an anthro-pomorphic phantom. Observer performance was evaluated with Receiver Operating Characteristic (ROC) analysis. Five observers assessed the processed digital images and the conventional full-size radiographs. The time spent viewing the full-size radiographs and the digital images was recorded. For the simulated pneumothorax, the results showed perfect performance for the full-size radiographs and detectability was high also for the processed digital images. No significant differences in the detectability of the simulated nodules was seen between the two imaging systems. The results for the digital images showed a significantly improved detectability for the nodules in the mediastinum as compared to a previous ROC study where no optimization and image processing was available. No significant difference in detectability was seen between the former and the present ROC study for small nodules in the lung. No difference was seen in the time spent assessing the conventional full-size radiographs and the digital images. The study indicates that processed digital images produced by a large image intensifier are equal in image quality to conventional full-size radiographs for low-contrast objects such as nodules. (author). 38 refs.; 4 figs.; 1 tab

  15. Aspects of optical and digital processing of scintigraphic images

    International Nuclear Information System (INIS)

    Platzer, H.; Wahl, F.; Hofer, J.; Galosi, H.; Langhammer, H.

    1981-01-01

    The Anger camera, which is able to represent three-dimensional radioactivity distributions as two-dimensional projections, has become a standard tool in diagnostic nuclear medicine. The two-dimensional projections are reviewed under the aspects of imaging and image processing. Coherent optical image processing and digital image processing are discussed in particular. (WU) [de

  16. Investigation of physical imaging properties in various digital radiography systems

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hoi Woun [Dept. of Radiological Science, Baekseok Culture University, Cheonan (Korea, Republic of); Min, Jung Hwan [Dept. of Radiological technology, Shingu University, Seongnam (Korea, Republic of); Yoon, Yong Su [Dept. of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Kyushu (Japan); Kim, Jung Min [Dept. of Health and Environmental Science, College of Health Science, Korea University, Seoul (Korea, Republic of)

    2017-09-15

    We aimed to evaluate the physical imaging properties in various digital radiography systems with charged coupled device (CCD), computed radiography (CR), and indirect flat panel detector (FPD). The imaging properties measured in this study were modulation transfer function (MTF) wiener spectrum (WS), and detective quantum efficiency (DQE) to compare the performance of each digital radiography system. The system response of CCD were in a linear relationship with exposure and that of CR and FPD were proportional to the logarithm of exposure. The MTF of both CR and FPD indicated a similar tendency but in case of CCD, it showed lower MTF than that of CR and FPD. FPD showed the lowest WS and also indicated the highest DQE among three systems. According to the results, digital radiography system with different type of image receptor had its own image characteristics. Therefore, it is important to know the physical imaging characteristics of the digital radiography system accurately to obtain proper image quality.

  17. Digital image processing an algorithmic approach with Matlab

    CERN Document Server

    Qidwai, Uvais

    2009-01-01

    Introduction to Image Processing and the MATLAB EnvironmentIntroduction Digital Image Definitions: Theoretical Account Image Properties MATLAB Algorithmic Account MATLAB CodeImage Acquisition, Types, and File I/OImage Acquisition Image Types and File I/O Basics of Color Images Other Color Spaces Algorithmic Account MATLAB CodeImage ArithmeticIntroduction Operator Basics Theoretical TreatmentAlgorithmic Treatment Coding ExamplesAffine and Logical Operations, Distortions, and Noise in ImagesIntroduction Affine Operations Logical Operators Noise in Images Distortions in ImagesAlgorithmic Account

  18. 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.

  19. Digital image processing for two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Young; Lim, Jae Yun [Cheju National University, Cheju (Korea, Republic of); No, Hee Cheon [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1992-07-01

    A photographic method to measure the key parameters of two-phase flow is realized by using a digital image processing technique. The 8 bit gray level and 256 x 256 pixels are used to generates the image data which is treated to get the parameters of two-phase flow. It is observed that the key parameters could be identified by treating data obtained by the digital image processing technique.

  20. Lensless microscope based on iterative in-line holographic reconstruction

    Science.gov (United States)

    Wu, Jigang

    2014-11-01

    We propose a lensless microscopic imaging technique based on iteration algorithm with known constraint for image reconstruction in digital in-line holography. In our method, we introduce a constraint on the sample plane as known part in the lensless microscopy for iteration algorithm in order to eliminate the twin-image effect of holography and thus lead to better performance on microscopic imaging. We evaluate our method by numerical simulation and built a prototype in-line holographic imaging system and demonstrated its capability by preliminary experiments. In our proposed setup, a carefully designed photomask used to hold the sample is under illumination of a coherent light source. The in-line hologram is then recorded by a CMOS sensor. In the reconstruction, the known information of the illumination beam and the photomask is used as constraints in the iteration process. The improvement of image quality because of suppression of twin-images can be clearly seen by comparing the images obtained by direct holographic reconstruction and our iterative method.

  1. Topology of digital images visual pattern discovery in proximity spaces

    CERN Document Server

    Peters, James F

    2014-01-01

    This book carries forward recent work on visual patterns and structures in digital images and introduces a near set-based a topology of digital images. Visual patterns arise naturally in digital images viewed as sets of non-abstract points endowed with some form of proximity (nearness) relation. Proximity relations make it possible to construct uniform topolo- gies on the sets of points that constitute a digital image. In keeping with an interest in gaining an understanding of digital images themselves as a rich source of patterns, this book introduces the basics of digital images from a computer vision perspective. In parallel with a computer vision perspective on digital images, this book also introduces the basics of prox- imity spaces. Not only the traditional view of spatial proximity relations but also the more recent descriptive proximity relations are considered. The beauty of the descriptive proximity approach is that it is possible to discover visual set patterns among sets that are non-overlapping ...

  2. Quality assurance in digital dental imaging: a systematic review.

    Science.gov (United States)

    Metsälä, Eija; Henner, Anja; Ekholm, Marja

    2014-07-01

    Doses induced by individual dental examinations are low. However, dental radiography accounts for nearly one third of the total number of radiological examinations in the European Union. Therefore, special attention is needed with regard to radiation protection. In order to lower patient doses, the staff performing dental examinations must have competence in imaging as well as in radiation protection issues. This paper presents a systematic review about the core competencies needed by the healthcare staff in performing digital dental radiological imaging quality assurance. The following databases were searched: Pubmed, Cinahl, Pro Quest and IEEXplore digital library. Also volumes of some dental imaging journals and doctoral theses of the Finnish universities educating dentists were searched. The search was performed using both MeSH terms and keywords using the option 'search all text'. The original keywords were: dental imaging, digital, x-ray, panoramic, quality, assurance, competence, competency, skills, knowledge, radiographer, radiologist technician, dentist, oral hygienist, radiation protection and their Finnish synonyms. Core competencies needed by the healthcare staff performing digital dental radiological imaging quality assurance described in the selected studies were: management of dental imaging equipment, competence in image quality and factors associated with it, dose optimization and quality assurance. In the future there will be higher doses in dental imaging due to increasing use of CBCT and digital imaging. The staff performing dental imaging must have competence in dental imaging quality assurance issues found in this review. They also have to practice ethical radiation safety culture in clinical practice.

  3. Digital Image Correlation for Performance Monitoring.

    Energy Technology Data Exchange (ETDEWEB)

    Palaviccini, Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turner, Daniel Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Herzberg, Michael [National Security Campus, Kansas City, MO (United States)

    2016-02-01

    Evaluating the health of a mechanism requires more than just a binary evaluation of whether an operation was completed. It requires analyzing more comprehensive, full-field data. Health monitoring is a process of nondestructively identifying characteristics that indicate the fitness of an engineered component. In order to monitor unit health in a production setting, an automated test system must be created to capture the motion of mechanism parts in a real-time and non-intrusive manner. One way to accomplish this is by using high-speed video (HSV) and Digital Image Correlation (DIC). In this approach, individual frames of the video are analyzed to track the motion of mechanism components. The derived performance metrics allow for state-of-health monitoring and improved fidelity of mechanism modeling. The results are in-situ state-of-health identification and performance prediction. This paper introduces basic concepts of this test method, and discusses two main themes: the use of laser marking to add fiducial patterns to mechanism components, and new software developed to track objects with complex shapes, even as they move behind obstructions. Finally, the implementation of these tests into an automated tester is discussed.

  4. High-Resolution X-Ray Lensless Imaging by Differential Holographic Encoding

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Diling [Stanford Univ., CA (United States). Dept. of Applied Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Inst. for Material and Energy Science; Guizar-Sicairos, Manuel [Univ. of Rochester, NY (United States). Inst. of Optics; Wu, Benny [Stanford Univ., CA (United States). Dept. of Applied Physics; SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Inst. for Material and Energy Science; Scherz, Andreas [SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Inst. for Material and Energy Science; Acremann, Yves [SLAC National Accelerator Lab., Menlo Park, CA (United States). Photon Ultrafast Laser Science and Engineering Inst. (PULSE); Tyliszczak, Tolek [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Fischer, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Center for X-ray Optics; Friedenberger, Nina [Universitat Duisburg-Essen (Germany). Dept. of Physics and Center for Nanointegration Duisburg-Essen (CeNIDE); Ollefs, Katharina [Universitat Duisburg-Essen (Germany). Dept. of Physics and Center for Nanointegration Duisburg-Essen (CeNIDE); Farle, Michael [Universitat Duisburg-Essen (Germany). Dept. of Physics and Center for Nanointegration Duisburg-Essen (CeNIDE); Fienup, James R. [Univ. of Rochester, NY (United States). Inst. of Optics; Stöhr, Joachim [SLAC National Accelerator Lab., Menlo Park, CA (United States). Linac Coherent Light Source (LCLS)

    2010-07-01

    X-ray free electron lasers (X-FELs) will soon offer femtosecond pulses of laterally coherent x-rays with sufficient intensity to record single-shot coherent scattering patterns for nanoscale imaging. Pulse trains created by split and- delay techniques even open the door for cinematography on unprecedented nanometer length and femtosecond time scales. A key to real space ultrafast motion pictures is fast and reliable inversion of the recorded reciprocal space scattering patterns. Here we for the first time demonstrate in the x-ray regime the power of a novel technique for lensless high resolution imaging, previously suggested by Guizar-Sicairos and Fienup termed holography with extended reference by autocorrelation linear differential operation, HERALD0. We have achieved superior resolution over conventional x-ray Fourier transform holography (FTH) without sacrifices in SNR or significant increase in algorithmic complexity. By combining images obtained from individual sharp features on an extended reference, we further show that the resolution can be even extended beyond the reference fabrication limits. Direct comparison to iterative phase retrieval image reconstruction and images recorded with state of-the-art zone plate microscopes is presented. Our results demonstrate the power of HERALDO as a favorable candidate for robust inversion of single-shot coherent scattering patterns.

  5. High resolution x-ray lensless imaging by differential holographic encoding

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, D.; Guizar-Sicairos, M.; Wu, B.; Scherz, A.; Acremann, Y.; Tylisczcak, T.; Fischer, P.; Friedenberger, N.; Ollefs, K.; Farle, M.; Fienup, J. R.; Stohr, J.

    2009-11-02

    X-ray free electron lasers (X-FEL{sub s}) will soon offer femtosecond pulses of laterally coherent x-rays with sufficient intensity to record single-shot coherent scattering patterns for nanoscale imaging. Pulse trains created by splitand-delay techniques even open the door for cinematography on unprecedented nanometer length and femtosecond time scales. A key to real space ultrafast motion pictures is fast and reliable inversion of the recorded reciprocal space scattering patterns. Here we for the first time demonstrate in the x-ray regime the power of a novel technique for lensless high resolution imaging, previously suggested by Guizar-Sicairos and Fienup termed holography with extended reference by autocorrelation linear differential operation, HERALD0. We have achieved superior resolution over conventional x-ray Fourier transform holography (FTH) without sacrifices in SNR or significant increase in algorithmic complexity. By combining images obtained from individual sharp features on an extended reference, we further show that the resolution can be even extended beyond the reference fabrication limits. Direct comparison to iterative phase retrieval image reconstruction and images recorded with stateof- the-art zone plate microscopes is presented. Our results demonstrate the power of HERALDO as a favorable candidate for robust inversion of single-shot coherent scattering patterns.

  6. [Managing digital medical imaging projects in healthcare services: lessons learned].

    Science.gov (United States)

    Rojas de la Escalera, D

    2013-01-01

    Medical imaging is one of the most important diagnostic instruments in clinical practice. The technological development of digital medical imaging has enabled healthcare services to undertake large scale projects that require the participation and collaboration of many professionals of varied backgrounds and interests as well as substantial investments in infrastructures. Rather than focusing on systems for dealing with digital medical images, this article deals with the management of projects for implementing these systems, reviewing various organizational, technological, and human factors that are critical to ensure the success of these projects and to guarantee the compatibility and integration of digital medical imaging systems with other health information systems. To this end, the author relates several lessons learned from a review of the literature and the author's own experience in the technical coordination of digital medical imaging projects. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

  7. Epistemic Function and Ontology of Analog and Digital Images

    Directory of Open Access Journals (Sweden)

    Aleksandra Łukaszewicz Alcaraz

    2016-01-01

    Full Text Available The important epistemic function of photographic images is their active role in construction and reconstruction of our beliefs concerning the world and human identity, since we often consider photographs as presenting reality or even the Real itself. Because photography can convince people of how different social and ethnic groups and even they themselves look, documentary projects and the dissemination of photographic practices supported the transition from disciplinary society to the present-day society of control. While both analog and digital images are formed from the same basic materia, the ways in which this matter appears are distinctive. In the case of analog photography, we deal with physical and chemical matter, whereas with digital images we face electronic matter. Because digital photography allows endless modification of the image, we can no longer believe in the truthfulness of digital images.

  8. Copy-move forgery detection in digital image

    Science.gov (United States)

    Alamro, Loai; Yusoff, Nooraini

    2016-08-01

    Copy-move is considered as one of the most popular kind of digital image tempering, in which one or more parts of a digital image are copied and pasted into different locations. Geometric transformation is among the major challenges in detecting copy-move forgery of a digital image. In such forgery, the copied and moved parts of a forged image are either rotated or/and re-scaled. Hence, in this study we propose a combination of Discrete Wavelet Transform (DWT) and Speeded Up Robust Features (SURF) to detect a copy-move activity. The experiments results prove that the proposed method is superior with overall accuracy 95%. The copy-move attacks in digital image has been successfully detected and the method is also can detect the fraud parts exposed to rotation and scaling issue.

  9. The human CFTR protein expressed in CHO cells activates aquaporin-3 in a cAMP-dependent pathway: study by digital holographic microscopy

    KAUST Repository

    Jourdain, P.

    2013-12-11

    The transmembrane water movements during cellular processes and their relationship to ionic channel activity remain largely unknown. As an example, in epithelial cells it was proposed that the movement of water could be directly linked to cystic fibrosis transmembrane conductance regulator (CFTR) protein activity through a cAMP-stimulated aqueous pore, or be dependent on aquaporin. Here, we used digital holographic microscopy (DHM) an interferometric technique to quantify in situ the transmembrane water fluxes during the activity of the epithelial chloride channel, CFTR, measured by patch-clamp and iodide efflux techniques. We showed that the water transport measured by DHM is fully inhibited by the selective CFTR blocker CFTRinh172 and is absent in cells lacking CFTR. Of note, in cells expressing the mutated version of CFTR (F508del-CFTR), which mimics the most common genetic alteration encountered in cystic fibrosis, we also show that the water movement is profoundly altered but restored by pharmacological manipulation of F508del-CFTR-defective trafficking. Importantly, whereas activation of this endogenous water channel required a cAMP-dependent stimulation of CFTR, activation of CFTR or F508del-CFTR by two cAMP-independent CFTR activators, genistein and MPB91, failed to trigger water movements. Finally, using a specific small-interfering RNA against the endogenous aquaporin AQP3, the water transport accompanying CFTR activity decreased. We conclude that water fluxes accompanying CFTR activity are linked to AQP3 but not to a cAMP-stimulated aqueous pore in the CFTR protein.

  10. Using digital holographic microscopy for simultaneous measurements of 3D near wall velocity and wall shear stress in a turbulent boundary layer

    Science.gov (United States)

    Sheng, J.; Malkiel, E.; Katz, J.

    2008-12-01

    A digital holographic microscope is used to simultaneously measure the instantaneous 3D flow structure in the inner part of a turbulent boundary layer over a smooth wall, and the spatial distribution of wall shear stresses. The measurements are performed in a fully developed turbulent channel flow within square duct, at a moderately high Reynolds number. The sample volume size is 90 × 145 × 90 wall units, and the spatial resolution of the measurements is 3 8 wall units in streamwise and spanwise directions and one wall unit in the wall-normal direction. The paper describes the data acquisition and analysis procedures, including the particle tracking method and associated method for matching of particle pairs. The uncertainty in velocity is estimated to be better than 1 mm/s, less than 0.05% of the free stream velocity, by comparing the statistics of the normalized velocity divergence to divergence obtained by randomly adding an error of 1 mm/s to the data. Spatial distributions of wall shear stresses are approximated with the least square fit of velocity measurements in the viscous sublayer. Mean flow profiles and statistics of velocity fluctuations agree very well with expectations. Joint probability density distributions of instantaneous spanwise and streamwise wall shear stresses demonstrate the significance of near-wall coherent structures. The near wall 3D flow structures are classified into three groups, the first containing a pair of counter-rotating, quasi streamwise vortices and high streak-like shear stresses; the second group is characterized by multiple streamwise vortices and little variations in wall stress; and the third group has no buffer layer structures.

  11. Applications of Digital Image Analysis in Experimental Mechanics

    DEFF Research Database (Denmark)

    Lyngbye, J. : Ph.D.

    The present thesis "Application of Digital Image Analysis in Experimental Mechanics" has been prepared as a part of Janus Lyngbyes Ph.D. study during the period December 1988 to June 1992 at the Department of Building technology and Structural Engineering, University of Aalborg, Denmark....... In this thesis attention will be focused on optimal use and analysis of the information of digital images. This is realized during investigation and application of parametric methods in digital image analysis. The parametric methods will be implemented in applications representative for the area of experimental...

  12. Adaptive spatial filtering for off-axis digital holographic microscopy based on region recognition approach with iterative thresholding

    Science.gov (United States)

    He, Xuefei; Nguyen, Chuong Vinh; Pratap, Mrinalini; Zheng, Yujie; Wang, Yi; Nisbet, David R.; Rug, Melanie; Maier, Alexander G.; Lee, Woei Ming

    2016-12-01

    Here we propose a region-recognition approach with iterative thresholding, which is adaptively tailored to extract the appropriate region or shape of spatial frequency. In order to justify the method, we tested it with different samples and imaging conditions (different objectives). We demonstrate that our method provides a useful method for rapid imaging of cellular dynamics in microfluidic and cell cultures.

  13. Concealed explosive detection on personnel using a wideband holographic millimeter-wave imaging system

    Science.gov (United States)

    Sheen, David M.; McMakin, Douglas L.; Collins, H. D.; Hall, Thomas E.; Severtsen, Ronald H.

    1996-06-01

    A novel wideband millimeter-wave imaging system is presently being developed at Pacific Northwest National Laboratory (PNNL) that will allow rapid inspection of personnel for concealed explosives, handguns, or other threats. Millimeter-wavelength electromagnetic waves are effective for this application since they readily penetrate common clothing materials, while being partially reflected from the person under surveillance as well as any concealed items. To form an image rapidly, a linear array of 128 antennas is used to electronically scan over a horizontal aperture of 0.75 meters, while the linear array is mechanically swept over a vertical aperture of 2 meters. At each point over this 2-D aperture, coherent wideband data reflected from the target is gathered using wide-beamwidth antennas. The data is recorded coherently, and reconstructed (focused) using an efficient image reconstruction algorithm developed at PNNL. This algorithm works in the near-field of both the target and the scanned aperture and preserves the diffraction limited resolution of less than one-wavelength. The wide frequency bandwidth is used to provide depth resolution, which allows the image to be fully focused over a wide range of depths, resulting in a full 3-D image. This is not possible in a normal optical (or quasi-optical) imaging system. This system has been extensively tested using concealed metal and plastic weapons, and has recently been tested using real plastic explosives (C-4 and RDX) and simulated liquid explosives concealed on personnel. Millimeter-waves do not penetrate the human body, so it is necessary to view the subject from several angles in order to fully inspect for concealed weapons. Full animations containing 36 - 72 frames recorded from subjects rotated by 5 - 10 degrees, have been found to be extremely useful for rapid, effective inspection of personnel.

  14. A radiographic image archive system on digital optical disks

    International Nuclear Information System (INIS)

    Mankovich, N.J.; Taira, R.K.; Cho, P.S.; Wong, W.K.; Stewart, B.K.; Huang, H.K.

    1986-01-01

    The recent introduction of projection computed radiography (CR) systems allows radiology departments to consider digital operation in over 90% of performed procedures. Ideally, current patient procedures from CT, CT, and MR along with laser-digitized historical films should be centrally stored at their full digital resolution. Magnetic disks, because of their limited storage capacity and expense, can only retain these data on a limited basis. The author devised an optical disk archive system which automatically stores images directly onto 2.6-gigabyte optical cartridges without recourse to film. This system is in full clinical operation in the UCLA Pediatric Radiology Section of the authors' department. From this experience they present (a) an analysis of the digital archiving requirements of the Pediatric Radiology Section based on CR, CT, MR, and laser digitized films; (b) the archive and retrieval methods along with performance statistics; and (c) the procedure for assuring digital image integrity

  15. Dynamic imaging through turbid media based on digital holography.

    Science.gov (United States)

    Li, Shiping; Zhong, Jingang

    2014-03-01

    Imaging through turbid media using visible or IR light instead of harmful x ray is still a challenging problem, especially in dynamic imaging. A method of dynamic imaging through turbid media using digital holography is presented. In order to match the coherence length between the dynamic object wave and the reference wave, a cw laser is used. To solve the problem of difficult focusing in imaging through turbid media, an autofocus technology is applied. To further enhance the image contrast, a spatial filtering technique is used. A description of digital holography and experiments of imaging the objects hidden in turbid media are presented. The experimental result shows that dynamic images of the objects can be achieved by the use of digital holography.

  16. Sparsity-based multi-height phase recovery in holographic microscopy

    KAUST Repository

    Rivenson, Yair

    2016-11-30

    High-resolution imaging of densely connected samples such as pathology slides using digital in-line holographic microscopy requires the acquisition of several holograms, e.g., at >6–8 different sample-to-sensor distances, to achieve robust phase recovery and coherent imaging of specimen. Reducing the number of these holographic measurements would normally result in reconstruction artifacts and loss of image quality, which would be detrimental especially for biomedical and diagnostics-related applications. Inspired by the fact that most natural images are sparse in some domain, here we introduce a sparsity-based phase reconstruction technique implemented in wavelet domain to achieve at least 2-fold reduction in the number of holographic measurements for coherent imaging of densely connected samples with minimal impact on the reconstructed image quality, quantified using a structural similarity index. We demonstrated the success of this approach by imaging Papanicolaou smears and breast cancer tissue slides over a large field-of-view of ~20 mm2 using 2 in-line holograms that are acquired at different sample-to-sensor distances and processed using sparsity-based multi-height phase recovery. This new phase recovery approach that makes use of sparsity can also be extended to other coherent imaging schemes, involving e.g., multiple illumination angles or wavelengths to increase the throughput and speed of coherent imaging.

  17. Minimally Invasive Holographic Surface Scanning for Soft-Tissue Image Registration

    Science.gov (United States)

    Hackworth, Douglas M.; Webster, Robert J.

    2014-01-01

    Recent advances in registration have extended intra-surgical image guidance from its origins in bone-based procedures to new applications in soft tissues, thus enabling visualization of spatial relationships between surgical instruments and subsurface structures before incisions begin. Preoperative images are generally registered to soft tissues through aligning segmented volumetric image data with an intraoperatively sensed cloud of organ surface points. However, there is currently no viable noncontact minimally invasive scanning technology that can collect these points through a single laparoscopic port, which limits wider adoption of soft-tissue image guidance. In this paper, we describe a system based on conoscopic holography that is capable of minimally invasive surface scanning. We present the results of several validation experiments scanning ex vivo biological and phantom tissues with a system consisting of a tracked, off-the-shelf, relatively inexpensive conoscopic holography unit. These experiments indicate that conoscopic holography is suitable for use with biological tissues, and can provide surface scans of comparable quality to existing clinically used laser range scanning systems that require open surgery. We demonstrate experimentally that conoscopic holography can be used to guide a surgical needle to desired subsurface targets with an average tip error of less than 3 mm. PMID:20659823

  18. Minimally invasive holographic surface scanning for soft-tissue image registration.

    Science.gov (United States)

    Lathrop, Ray A; Hackworth, Douglas M; Webster, Robert J

    2010-06-01

    Recent advances in registration have extended intrasurgical image guidance from its origins in bone-based procedures to new applications in soft tissues, thus enabling visualization of spatial relationships between surgical instruments and subsurface structures before incisions begin. Preoperative images are generally registered to soft tissues through aligning segmented volumetric image data with an intraoperatively sensed cloud of organ surface points. However, there is currently no viable noncontact minimally invasive scanning technology that can collect these points through a single laparoscopic port, which limits wider adoption of soft-tissue image guidance. In this paper, we describe a system based on conoscopic holography that is capable of minimally invasive surface scanning. We present the results of several validation experiments scanning ex vivo biological and phantom tissues with a system consisting of a tracked, off-the-shelf, relatively inexpensive conoscopic holography unit. These experiments indicate that conoscopic holography is suitable for use with biological tissues, and can provide surface scans of comparable quality to existing clinically used laser range scanning systems that require open surgery. We demonstrate experimentally that conoscopic holography can be used to guide a surgical needle to desired subsurface targets with an average tip error of less than 3 mm.

  19. Ultrafast Holographic Image Recording by Single Shot Femtosecond Spectral Hole Burning

    National Research Council Canada - National Science Library

    Rebane, Aleksander

    2001-01-01

    .... This allowed us to record image holograms with 150-fs duration pulses without need to accumulate the SHB effect from many exposures. Results of this research show that it is possible to perform optical recording of data in frequency-domain on ultrafast time scale. These results can be used also as a new diagnostic tool for femtosecond dynamics in various ultrafast optical interactions.

  20. X-ray holographic imaging of magnetic order in meander domain structures

    Directory of Open Access Journals (Sweden)

    Jaouen Nicolas

    2013-01-01

    Full Text Available We performed x-ray holography experiments using synchrotron radiation. By analyzing the scattering of coherent circularly polarized x-rays tuned at the Co-2p resonance, we imaged perpendicular magnetic domains in a Co/Pd multilayer. We compare results obtained for continuous and laterally confined films.

  1. The clinical application of the digital imaging in urography

    International Nuclear Information System (INIS)

    Zhu Yuelong; Xie Sumin; Zhang Li; Li Huayu

    2003-01-01

    Objective: To evaluate the clinical application of the digital imaging in the urography. Methods: In total 112 patients underwent digital urography, including intravenous pyelography (IVP) in 38 cases and retrograde pyelography in 74 cases. Results: the entire urinary tract was better shown on digital imaging, which was accurate in locating the obstruction of urinary tract and helped the qualitative diagnosis. Digital urography was especially valuable in detecting urinary calculus. In 38 cases of IVP, the results were normal in 5 patients, renal stone in 12, ureteral stone in 13, ureteral stenosis in 6 and nephroblastom in 2. In the 74 cases of retrograde pyelography, benign ureteral stenosis was found in 31 patients, ureteral stone in 27, ureteral polyp in 2, urethral stone in 8 and benign urethral stenosis in 6. Conclusion: Digital imaging technique is of big value in the diagnosis of urinary tract lesions

  2. Digitalization of the radiological image. A new philosophy of the radiological imagery: the high resolution of the contrasts

    International Nuclear Information System (INIS)

    Schmidt, R.

    1983-01-01

    Three cases of digitalization are to be considered: static digitalization of the conventional radiographic image; static digitalization of the calculated image, like tomodensitometric images; dynamic digitalization of television images [fr

  3. Sliding mean edge estimation. [in digital image processing

    Science.gov (United States)

    Ford, G. E.

    1978-01-01

    A method for determining the locations of the major edges of objects in digital images is presented. The method is based on an algorithm utilizing maximum likelihood concepts. An image line-scan interval is processed to determine if an edge exists within the interval and its location. The proposed algorithm has demonstrated good results even in noisy images.

  4. Experiences with digital processing of images at INPE

    Science.gov (United States)

    Mascarenhas, N. D. A. (Principal Investigator)

    1984-01-01

    Four different research experiments with digital image processing at INPE will be described: (1) edge detection by hypothesis testing; (2) image interpolation by finite impulse response filters; (3) spatial feature extraction methods in multispectral classification; and (4) translational image registration by sequential tests of hypotheses.

  5. Factors to consider in the transition to digital radiological imaging.

    LENUS (Irish Health Repository)

    MacDonald, David

    2009-02-01

    The dentist considering adopting digital radiological technology should consider more than the type of detector with which to capture the image. He\\/she should also consider the mode of display, image enhancement, radiation dose reduction, how the image can be stored long term, and infection control.

  6. Full-field vibration measurements of the violin using digital stroboscopic holographic interferometry and electromagnetic stimulation of the strings

    Science.gov (United States)

    Keersmaekers, Lissa; Keustermans, William; De Greef, Daniël; Dirckx, Joris J. J.

    2016-06-01

    We developed a setup in which the strings of the violin are driven electromagnetically, and the resulting vibration of the instrument is measured with digital stroboscopic holography. A 250mW single mode green laser beam is chopped using an acousto-optic modulator, generating illumination pulses of 2% of the vibration period. The phase of the illumination pulse is controlled by a programmable function generator so that digital holograms can be recorded on a number of subsequent time positions within the vibration phase. From these recordings, the out of plane motion as a function of time is reconstructed in full field. We show results of full-field vibration amplitude and vibration phase maps, and time resolved full-field deformations of the violin back plane. Time resolved measurements show in detail how the deformation of the violin plane changes as a function of time at different frequencies. We found very different behavior under acoustic stimulation of the instrument and when using electromagnetic stimulation of a string. The aim of the work it to gather data which can be used in power flow calculations to study how the energy of the strings is conducted to the body of the violin and eventually is radiated as sound.

  7. Full-field vibration measurements of the violin using digital stroboscopic holographic interferometry and electromagnetic stimulation of the strings

    Energy Technology Data Exchange (ETDEWEB)

    Keersmaekers, Lissa; Keustermans, William, E-mail: william.keustermans@uantwerpen.be; De Greef, Daniël; Dirckx, Joris J. J. [University of Antwerp, Laboratory of Biophysics and Biomedical Physics, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2016-06-28

    We developed a setup in which the strings of the violin are driven electromagnetically, and the resulting vibration of the instrument is measured with digital stroboscopic holography. A 250 mW single mode green laser beam is chopped using an acousto-optic modulator, generating illumination pulses of 2% of the vibration period. The phase of the illumination pulse is controlled by a programmable function generator so that digital holograms can be recorded on a number of subsequent time positions within the vibration phase. From these recordings, the out of plane motion as a function of time is reconstructed in full field. We show results of full-field vibration amplitude and vibration phase maps, and time resolved full-field deformations of the violin back plane. Time resolved measurements show in detail how the deformation of the violin plane changes as a function of time at different frequencies. We found very different behavior under acoustic stimulation of the instrument and when using electromagnetic stimulation of a string. The aim of the work it to gather data which can be used in power flow calculations to study how the energy of the strings is conducted to the body of the violin and eventually is radiated as sound.

  8. Full-field vibration measurements of the violin using digital stroboscopic holographic interferometry and electromagnetic stimulation of the strings

    International Nuclear Information System (INIS)

    Keersmaekers, Lissa; Keustermans, William; De Greef, Daniël; Dirckx, Joris J. J.

    2016-01-01

    We developed a setup in which the strings of the violin are driven electromagnetically, and the resulting vibration of the instrument is measured with digital stroboscopic holography. A 250 mW single mode green laser beam is chopped using an acousto-optic modulator, generating illumination pulses of 2% of the vibration period. The phase of the illumination pulse is controlled by a programmable function generator so that digital holograms can be recorded on a number of subsequent time positions within the vibration phase. From these recordings, the out of plane motion as a function of time is reconstructed in full field. We show results of full-field vibration amplitude and vibration phase maps, and time resolved full-field deformations of the violin back plane. Time resolved measurements show in detail how the deformation of the violin plane changes as a function of time at different frequencies. We found very different behavior under acoustic stimulation of the instrument and when using electromagnetic stimulation of a string. The aim of the work it to gather data which can be used in power flow calculations to study how the energy of the strings is conducted to the body of the violin and eventually is radiated as sound.

  9. The digital revolution, images and X-rays.

    Science.gov (United States)

    Emmott, Lawrence F

    2005-01-01

    The digital revolution is upon us. Are you ready to take advantage of it? Do you even know what it means? If you begin with the basics, the rest falls into place. In this overview of the digital revolution and its impact on dentistry, we start from the beginning of an amazing, and magical, quest to capture the best images.

  10. Information Seeking Behavior in Digital Image Collections: A Cognitive Approach

    Science.gov (United States)

    Matusiak, Krystyna K.

    2006-01-01

    Presents the results of a qualitative study that focuses on search patterns of college students and community users interacting with a digital image collection. The study finds a distinct difference between the two groups of users and examines the role of mental models in information seeking behavior in digital libraries.

  11. Affordable, Accessible, Immediate: Capture Stunning Images with Digital Infrared Photography

    Science.gov (United States)

    Snyder, Mark

    2011-01-01

    Technology educators who teach digital photography should consider incorporating an infrared (IR) photography component into their program. This is an area where digital photography offers significant benefits. Either type of IR imaging is very interesting to explore, but traditional film-based IR photography is difficult and expensive. In…

  12. Digital image technology and a measurement tool in physical models

    CSIR Research Space (South Africa)

    Phelp, David

    2006-05-01

    Full Text Available to give useful information on the dynamics of waves, coastal structures and ship motions. The availability of digital cameras, at relatively low cost, has allowed easy transfer of digital images to the computer. This paper discusses recent advances of a...

  13. The Digital Microscope and Its Image Processing Utility

    Directory of Open Access Journals (Sweden)

    Tri Wahyu Supardi

    2011-12-01

    Full Text Available Many institutions, including high schools, own a large number of analog or ordinary microscopes. These microscopes are used to observe small objects. Unfortunately, object observations on the ordinary microscope require precision and visual acuity of the user. This paper discusses the development of a high-resolution digital microscope from an analog microscope, including the image processing utility, which allows the digital microscope users to capture, store and process the digital images of the object being observed. The proposed microscope is constructed from hardware components that can be easily found in Indonesia. The image processing software is capable of performing brightness adjustment, contrast enhancement, histogram equalization, scaling and cropping. The proposed digital microscope has a maximum magnification of 1600x, and image resolution can be varied from 320x240 pixels up to 2592x1944 pixels. The microscope was tested with various objects with a variety of magnification, and image processing was carried out on the image of the object. The results showed that the digital microscope and its image processing system were capable of enhancing the observed object and other operations in accordance with the user need. The digital microscope has eliminated the need for direct observation by human eye as with the traditional microscope.

  14. Off-axis holographic laser speckle contrast imaging of blood vessels in tissues

    Science.gov (United States)

    Abdurashitov, Arkady; Bragina, Olga; Sindeeva, Olga; Sergey, Sindeev; Semyachkina-Glushkovskaya, Oxana V.; Tuchin, Valery V.

    2017-09-01

    Laser speckle contrast imaging (LSCI) has become one of the most common tools for functional imaging in tissues. Incomplete theoretical description and sophisticated interpretation of measurement results are completely sidelined by a low-cost and simple hardware, fastness, consistent results, and repeatability. In addition to the relatively low measuring volume with around 700 μm of the probing depth for the visible spectral range of illumination, there is no depth selectivity in conventional LSCI configuration; furthermore, in a case of high NA objective, the actual penetration depth of light in tissues is greater than depth of field (DOF) of an imaging system. Thus, the information about these out-of-focus regions persists in the recorded frames but cannot be retrieved due to intensity-based registration method. We propose a simple modification of LSCI system based on the off-axis holography to introduce after-registration refocusing ability to overcome both depth-selectivity and DOF problems as well as to get the potential possibility of producing a cross-section view of the specimen.

  15. Application of digital image processing techniques to astronomical imagery 1977

    Science.gov (United States)

    Lorre, J. J.; Lynn, D. J.

    1978-01-01

    Nine specific techniques of combination of techniques developed for applying digital image processing technology to existing astronomical imagery are described. Photoproducts are included to illustrate the results of each of these investigations.

  16. Digital Imaging of Pipeline Mechanical Damage and Residual Stress

    Science.gov (United States)

    2010-02-19

    The purpose of this program was to enhance characterization of mechanical damage in pipelines through application of digital eddy current imaging. Lift-off maps can be used to develop quantitative representations of mechanical damage and magnetic per...

  17. Applying the digital-image-correlation technique to measure the ...

    Indian Academy of Sciences (India)

    digital-image-correlation) technique is used to measure the deformation of the retrofitted column. The result shows that the DIC technique can be successfully applied to measure the relative displacement of the column. Additionally, thismethod ...

  18. Digital image processing of bone - Problems and potentials

    Science.gov (United States)

    Morey, E. R.; Wronski, T. J.

    1980-01-01

    The development of a digital image processing system for bone histomorphometry and fluorescent marker monitoring is discussed. The system in question is capable of making measurements of UV or light microscope features on a video screen with either video or computer-generated images, and comprises a microscope, low-light-level video camera, video digitizer and display terminal, color monitor, and PDP 11/34 computer. Capabilities demonstrated in the analysis of an undecalcified rat tibia include the measurement of perimeter and total bone area, and the generation of microscope images, false color images, digitized images and contoured images for further analysis. Software development will be based on an existing software library, specifically the mini-VICAR system developed at JPL. It is noted that the potentials of the system in terms of speed and reliability far exceed any problems associated with hardware and software development.

  19. Digital enhancement of night vision and thermal images

    OpenAIRE

    Teo, Chek Koon

    2003-01-01

    Approved for public release, distribution is unlimited Low image contrast 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 digitally enhancing the image before presenting it to the user, thus increasing the information throughput. This thesis explores the effect of the Contrast Limited Adaptive Histogram Equalization (CLAHE) process on night vision and thermal ima...

  20. High Brightness X-Ray Source for Directed Energy and Holographic Imaging Applications

    Science.gov (United States)

    1992-03-31

    profound and unexpected influence on man’s spiritual perception of his world. The light microscope opened up an unseen universe, not only of strange plant ...Ionization of Atoms,’ Science 22W, 1345 (1985). 4. W. 8. Mori, C. Joshl, J. M. Dawson, 0. W. Forslund, and J. M. Kindel, ’ Evolution of Self- Focusing of...in 7 29 order to make the reference wave and object wave brightness comparable. Visible in the image is the cuticle of the Ascaris as well as

  1. Empirical concentration bounds for compressive holographic bubble imaging based on a Mie scattering model.

    Science.gov (United States)

    Chen, Wensheng; Tian, Lei; Rehman, Shakil; Zhang, Zhengyun; Lee, Heow Pueh; Barbastathis, George

    2015-02-23

    We use compressive in-line holography to image air bubbles in water and investigate the effect of bubble concentration on reconstruction performance by simulation. Our forward model treats bubbles as finite spheres and uses Mie scattering to compute the scattered field in a physically rigorous manner. Although no simple analytical bounds on maximum concentration can be derived within the classical compressed sensing framework due to the complexity of the forward model, the receiver operating characteristic (ROC) curves in our simulation provide an empirical concentration bound for accurate bubble detection by compressive holography at different noise levels, resulting in a maximum tolerable concentration much higher than the traditional back-propagation method.

  2. Holographic otoscope for nanodisplacement measurements of surfaces under dynamic excitation.

    Science.gov (United States)

    Flores-Moreno, J M; Furlong, Cosme; Rosowski, John J; Harrington, Ellery; Cheng, Jeffrey T; Scarpino, C; Santoyo, F Mendoza

    2011-01-01

    We describe a novel holographic otoscope system for measuring nanodisplacements of objects subjected to dynamic excitation. Such measurements are necessary to quantify the mechanical deformation of surfaces in mechanics, acoustics, electronics, biology, and many other fields. In particular, we are interested in measuring the sound-induced motion of biological samples, such as an eardrum. Our holographic otoscope system consists of laser illumination delivery (IS), optical head (OH), and image processing computer (IP) systems. The IS delivers the object beam (OB) and the reference beam (RB) to the OH. The backscattered light coming from the object illuminated by the OB interferes with the RB at the camera sensor plane to be digitally recorded as a hologram. The hologram is processed by the IP using the Fresnel numerical reconstruction algorithm, where the focal plane can be selected freely. Our holographic otoscope system is currently deployed in a clinic, and is packaged in a custom design. It is mounted in a mechatronic positioning system to increase its maneuverability degrees to be conveniently positioned in front of the object to be measured. We present representative results highlighting the versatility of our system to measure deformations of complex elastic surfaces in the wavelength scale including a copper foil membrane and postmortem tympanic membrane. SCANNING 33: 342-352, 2011. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc.

  3. Camac interface for digitally recording infrared camera images

    International Nuclear Information System (INIS)

    Dyer, G.R.

    1986-01-01

    An instrument has been built to store the digital signals from a modified imaging infrared scanner directly in a digital memory. This procedure avoids the signal-to-noise degradation and dynamic range limitations associated with successive analog-to-digital and digital-to-analog conversions and the analog recording method normally used to store data from the scanner. This technique also allows digital data processing methods to be applied directly to recorded data and permits processing and image reconstruction to be done using either a mainframe or a microcomputer. If a suitable computer and CAMAC-based data collection system are already available, digital storage of up to 12 scanner images can be implemented for less than $1750 in materials cost. Each image is stored as a frame of 60 x 80 eight-bit pixels, with an acquisition rate of one frame every 16.7 ms. The number of frames stored is limited only by the available memory. Initially, data processing for this equipment was done on a VAX 11-780, but images may also be displayed on the screen of a microcomputer. Software for setting the displayed gray scale, generating contour plots and false-color displays, and subtracting one image from another (e.g., background suppression) has been developed for IBM-compatible personal computers

  4. Micro-Structure Measurement and Imaging Based on Digital Holography

    International Nuclear Information System (INIS)

    Kim, Kyeong Suk; Jung, Hyun Chul; Chang, Ho Seob; Akhter, Naseem; Kee, Chang Doo

    2010-01-01

    Advancements in the imaging and computing technology have opened the path to digital holography for non-destructive investigations of technical samples, material property measurement, vibration analysis, flow visualization and stress analysis in aerospace industry which has widened the application of digital holography in the above fields. In this paper, we demonstrate the non-destructive investigation and micro-structure measurement application of digital holography to the small particles and a biological sample. This paper gives a brief description of the digital holograms recorded with this system and illustratively demonstrated

  5. NEWVIEW: an interactive software environment for digital image processing

    Science.gov (United States)

    Lee, Ho J.; Vasudev, Bhaskaran; Lee, Daniel T. L.

    1990-06-01

    NEWV.EEW is a highly interactive software environment designed especially for the manipulation, processing, analysis and display of digital image (two-dimensional) data. It is designed using the paradigm of an algorithm developer's workbench to support a wide variety of digital image processing applications, from remote sensing to desktop publishing. The system consists of a comprehensive library of image processing algorithms and a library of fast, novel, raster rendering routines for display manipulation. Combined with a mouse-driven, multi-window display manager, it provides a unified and versatile environment for the development and testing of image processing algorithms.

  6. Topology-Preserving Rigid Transformation of 2D Digital Images.

    Science.gov (United States)

    Ngo, Phuc; Passat, Nicolas; Kenmochi, Yukiko; Talbot, Hugues

    2014-02-01

    We provide conditions under which 2D digital images preserve their topological properties under rigid transformations. We consider the two most common digital topology models, namely dual adjacency and well-composedness. This paper leads to the proposal of optimal preprocessing strategies that ensure the topological invariance of images under arbitrary rigid transformations. These results and methods are proved to be valid for various kinds of images (binary, gray-level, label), thus providing generic and efficient tools, which can be used in particular in the context of image registration and warping.

  7. Digital signal processing techniques and applications in radar image processing

    CERN Document Server

    Wang, Bu-Chin

    2008-01-01

    A self-contained approach to DSP techniques and applications in radar imagingThe processing of radar images, in general, consists of three major fields: Digital Signal Processing (DSP); antenna and radar operation; and algorithms used to process the radar images. This book brings together material from these different areas to allow readers to gain a thorough understanding of how radar images are processed.The book is divided into three main parts and covers:* DSP principles and signal characteristics in both analog and digital domains, advanced signal sampling, and

  8. Pattern-Recognition Processor Using Holographic Photopolymer

    Science.gov (United States)

    Chao, Tien-Hsin; Cammack, Kevin

    2006-01-01

    proposed joint-transform optical correlator (JTOC) would be capable of operating as a real-time pattern-recognition processor. The key correlation-filter reading/writing medium of this JTOC would be an updateable holographic photopolymer. The high-resolution, high-speed characteristics of this photopolymer would enable pattern-recognition processing to occur at a speed three orders of magnitude greater than that of state-of-the-art digital pattern-recognition processors. There are many potential applications in biometric personal identification (e.g., using images of fingerprints and faces) and nondestructive industrial inspection. In order to appreciate the advantages of the proposed JTOC, it is necessary to understand the principle of operation of a conventional JTOC. In a conventional JTOC (shown in the upper part of the figure), a collimated laser beam passes through two side-by-side spatial light modulators (SLMs). One SLM displays a real-time input image to be recognized. The other SLM displays a reference image from a digital memory. A Fourier-transform lens is placed at its focal distance from the SLM plane, and a charge-coupled device (CCD) image detector is placed at the back focal plane of the lens for use as a square-law recorder. Processing takes place in two stages. In the first stage, the CCD records the interference pattern between the Fourier transforms of the input and reference images, and the pattern is then digitized and saved in a buffer memory. In the second stage, the reference SLM is turned off and the interference pattern is fed back to the input SLM. The interference pattern thus becomes Fourier-transformed, yielding at the CCD an image representing the joint-transform correlation between the input and reference images. This image contains a sharp correlation peak when the input and reference images are matched. The drawbacks of a conventional JTOC are the following: The CCD has low spatial resolution and is not an ideal square

  9. Review of holographic-based three-dimensional object recognition techniques [invited].

    Science.gov (United States)

    Tsang, P W M; Poon, T-C; Liu, J-P; Situ, W C

    2014-09-20

    With the advancement of computing and optical technologies, it is now possible to capture digital holograms of real-life object scenes. Theoretically, through the analysis of a hologram, the three-dimensional (3D) objects coded on the hologram can be identified. However, being different from an optical image, a hologram is composed of complicated fringes that cannot be analyzed easily with traditional computer vision methods. Over the years, numerous important research investigations have been attempted to provide viable solutions to this problem. The aim of this work is three-fold. First, we provide a quick walkthrough on the overall development of holographic-based 3D object recognition (H3DOR) in the past five decades, from film-based approaches to digital-based innovation. Second, we describe in more detail a number of selected H3DOR methods that are introduced at different timelines, starting from the late sixties and then from the seventies, where viable digital holographic-based 3D recognition methods began to emerge. Finally, we present our work on digital holographic, pose-invariant 3D object recognition that is based on a recently introduced virtual diffraction plane framework. As our method has not been reported elsewhere, we have included some experimental results to demonstrate the feasibility of the approach.

  10. Label free imaging of cell-substrate contacts by holographic total internal reflection microscopy.

    Science.gov (United States)

    Mandracchia, Biagio; Gennari, Oriella; Marchesano, Valentina; Paturzo, Melania; Ferraro, Pietro

    2017-09-01

    The study of cell adhesion contacts is pivotal to understand cell mechanics and interaction at substrates or chemical and physical stimuli. We designed and built a HoloTIR microscope for label-free quantitative phase imaging of total internal reflection. Here we show for the first time that HoloTIR is a good choice for label-free study of focal contacts and of cell/substrate interaction as its sensitivity is enhanced in comparison with standard TIR microscopy. Finally, the simplicity of implementation and relative low cost, due to the requirement of less optical components, make HoloTIR a reasonable alternative, or even an addition, to TIRF microscopy for mapping cell/substratum topography. As a proof of concept, we studied the formation of focal contacts of fibroblasts on three substrates with different levels of affinity for cell adhesion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The influence of software filtering in digital mammography image quality

    International Nuclear Information System (INIS)

    Michail, C; Spyropoulou, V; Valais, I; Panayiotakis, G; Kalyvas, N; Fountos, G; Kandarakis, I; Dimitropoulos, N

    2009-01-01

    Breast cancer is one of the most frequently diagnosed cancers among women. Several techniques have been developed to help in the early detection of breast cancer such as conventional and digital x-ray mammography, positron and single-photon emission mammography, etc. A key advantage in digital mammography is that images can be manipulated as simple computer image files. Thus non-dedicated commercially available image manipulation software can be employed to process and store the images. The image processing tools of the Photoshop (CS 2) software usually incorporate digital filters which may be used to reduce image noise, enhance contrast and increase spatial resolution. However, improving an image quality parameter may result in degradation of another. The aim of this work was to investigate the influence of three sharpening filters, named hereafter sharpen, sharpen more and sharpen edges on image resolution and noise. Image resolution was assessed by means of the Modulation Transfer Function (MTF).In conclusion it was found that the correct use of commercial non-dedicated software on digital mammograms may improve some aspects of image quality.

  12. The influence of software filtering in digital mammography image quality

    Science.gov (United States)

    Michail, C.; Spyropoulou, V.; Kalyvas, N.; Valais, I.; Dimitropoulos, N.; Fountos, G.; Kandarakis, I.; Panayiotakis, G.

    2009-05-01

    Breast cancer is one of the most frequently diagnosed cancers among women. Several techniques have been developed to help in the early detection of breast cancer such as conventional and digital x-ray mammography, positron and single-photon emission mammography, etc. A key advantage in digital mammography is that images can be manipulated as simple computer image files. Thus non-dedicated commercially available image manipulation software can be employed to process and store the images. The image processing tools of the Photoshop (CS 2) software usually incorporate digital filters which may be used to reduce image noise, enhance contrast and increase spatial resolution. However, improving an image quality parameter may result in degradation of another. The aim of this work was to investigate the influence of three sharpening filters, named hereafter sharpen, sharpen more and sharpen edges on image resolution and noise. Image resolution was assessed by means of the Modulation Transfer Function (MTF).In conclusion it was found that the correct use of commercial non-dedicated software on digital mammograms may improve some aspects of image quality.

  13. Color Channel Characteristics (CCC for Efficient Digital Image Forensics

    Directory of Open Access Journals (Sweden)

    S. Gupta

    2018-02-01

    Full Text Available Digital image forgery has become extremely easy as low-cost image processing programs are readily available. Digital image forensics is a science of classifying images as authentic or manipulated. This paper aims at implementing a novel digital image forensics technique by exploiting an image’s Color Channel Characteristics (CCC. The CCCs considered are the noise and edge characteristics of the image. Averaging, median, Gaussian and Wiener filters along with Sobel, Canny, Prewitt and Laplacian of Gaussian (LoG edge detectors are applied to get the noise and texture features. A complete, no reference, blind classifier for image tamper detection has been proposed and implemented. The proposed CCC classifier can detect copy-move as well as image splicing accurately with lower dimensionality. Support Vector Machine is used for classification of images as authentic or tampered. Experimental results have shown that the proposed technique outperforms the existing ones and may serve as a complete tool for digital image forensics.

  14. NAIP Digital Ortho Photo Image 2010

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set contains imagery from the National Agriculture Imagery Program (NAIP). NAIP acquires digital ortho imagery during the agricultural growing seasons in...

  15. Digital Image Quantitative Evaluations for Low Cost Film Digitizers Height Determination

    International Nuclear Information System (INIS)

    Khairul Anuar Mohd Salleh; Arshad Yassin; Ahmad Nasir Yusof; Noorhazleena Azaman

    2016-01-01

    Non Destructive Testing (NDT) technology contributes significant improvement to the quality of industrial products, and the integrity of equipment and plants. Introduction of powerful computers and reliable imaging technology has had significant impact on the traditional nuclear based NDT technology. Demand for faster, reliable, low cost, and flexible technology is rapidly increased. With the growing demand for more efficient digital archiving, digital image analysis, and reporting results with a low cost technology, one cannot deny the importance of having another cheaper solution. This project will apply fundamental principle of image digitization to be used in building up a low cost film digitization solution. The height of the film digitization was carefully determined by examining each digital images produced. Three (3) repetitive quantitative evaluations (Modulation Transfer Function [MTF], Characteristic Transfer Curve [CTC], and Contrast to Noise Ratio [CNR]) were performed at different condition to assist with the determination of the low cost film digitizers height. All 3 evaluations were successfully applied and the most appropriate height was successfully determined. (author)

  16. ANALYSIS OF THE EFFECTS OF IMAGE QUALITY ON DIGITAL MAP GENERATION FROM SATELLITE IMAGES

    Directory of Open Access Journals (Sweden)

    H. Kim

    2012-07-01

    Full Text Available High resolution satellite images are widely used to produce and update a digital map since they became widely available. It is well known that the accuracy of digital map produced from satellite images is decided largely by the accuracy of geometric modelling. However digital maps are made by a series of photogrammetric workflow. Therefore the accuracy of digital maps are also affected by the quality of satellite images, such as image interpretability. For satellite images, parameters such as Modulation Transfer Function(MTF, Signal to Noise Ratio(SNR and Ground Sampling Distance(GSD are used to present images quality. Our previous research stressed that such quality parameters may not represent the quality of image products such as digital maps and that parameters for image interpretability such as Ground Resolved Distance(GRD and National Imagery Interpretability Rating Scale(NIIRS need to be considered. In this study, we analyzed the effects of the image quality on accuracy of digital maps produced by satellite images. QuickBird, IKONOS and KOMPSAT-2 imagery were used to analyze as they have similar GSDs. We measured various image quality parameters mentioned above from these images. Then we produced digital maps from the images using a digital photogrammetric workstation. We analyzed the accuracy of the digital maps in terms of their location accuracy and their level of details. Then we compared the correlation between various image quality parameters and the accuracy of digital maps. The results of this study showed that GRD and NIIRS were more critical for map production then GSD, MTF or SNR.

  17. A CLASSICAL REVIEW ON ADVANCED DIGITAL IMAGE WATERMARKING TECHNIQUES

    OpenAIRE

    BAISA L. GUNJAL

    2018-01-01

    The world has become a global village in digital era due to advances in internet and communication technology. Presently, creation, copy and transmission of image data via internet and mobile phone are very common practices. The access, sharing, replication and manipulation of medical images have become daily needs. Image data distributed can be copied repeatedly without errors putting the rights of owners at risk. Even though encrypted for distribution, images can be unprotected after decryp...

  18. Digital image processing in NDT : Application to industrial radiography

    International Nuclear Information System (INIS)

    Aguirre, J.; Gonzales, C.; Pereira, D.

    1988-01-01

    Digital image processing techniques are applied to image enhancement discontinuity detection and characterization is radiographic test. Processing is performed mainly by image histogram modification, edge enhancement, texture and user interactive segmentation. Implementation was achieved in a microcomputer with video image capture system. Results are compared with those obtained through more specialized equipment main frame computers and high precision mechanical scanning digitisers. Procedures are intended as a precious stage for automatic defect detection

  19. Image quality of digital mammography images produced using wet and dry laser imaging systems

    International Nuclear Information System (INIS)

    Al Khalifah, K.; Brindhaban, A.; AlArfaj, R.; Jassim, O.

    2006-01-01

    Introduction: A study was carried out to compare the quality of digital mammographic images printed or processed by a wet laser imaging system and a dedicated mammographic dry laser imaging system. Material and methods: Digital images of a tissue equivalent breast phantom were obtained using a GE Senographe 2000D digital mammography system and different target/filter combinations of the X-ray tube. These images were printed on films using the Fuji FL-IM D wet laser imaging system and the Kodak DryView 8600 dry laser imaging system. The quality of images was assessed in terms of detectability of microcalcifications and simulated tumour masses by five radiologists. In addition, the contrast index and speed index of the two systems were measured using the step wedge in the phantom. The unpaired, unequal variance t-test was used to test any statistically significant differences. Results: There were no significant (p < 0.05) differences between the images printed using the two systems in terms of microcalcification and tumour mass detectability. The wet system resulted in slightly higher contrast index while the dry system showed significantly higher speed index. Conclusion: Both wet and dry laser imaging systems can produce mammography images of good quality on which 0.2 mm microcalcifications and 2 mm tumour masses can be detected. Dry systems are preferable due to the absence of wet chemical processing and solid or liquid chemical waste. The wet laser imaging systems, however, still represent a useful alternative to dry laser imaging systems for mammography studies

  20. A report on digital image processing and analysis

    International Nuclear Information System (INIS)

    Singh, B.; Alex, J.; Haridasan, G.

    1989-01-01

    This report presents developments in software, connected with digital image processing and analysis in the Centre. In image processing, one resorts to either alteration of grey level values so as to enhance features in the image or resorts to transform domain operations for restoration or filtering. Typical transform domain operations like Karhunen-Loeve transforms are statistical in nature and are used for a good registration of images or template - matching. Image analysis procedures segment grey level images into images contained within selectable windows, for the purpose of estimating geometrical features in the image, like area, perimeter, projections etc. In short, in image processing both the input and output are images, whereas in image analyses, the input is an image whereas the output is a set of numbers and graphs. (author). 19 refs

  1. Algorithm for total suspended solids mapping using digital camera images

    Science.gov (United States)

    Mat Jafri, Mohammad Z.; Abdullah, Khiruddin; Lim, Hwe San; Abu Bakar, Mohd Noordin b.; Din, Zubir B.; Marshall, Steve

    2003-05-01

    An algorithm was developed based on reflectance model of inherent properties of seawater. A digital camera was used to capture digital images of river estuaries of Prai, Muda, and Merbok from a low altitude flying light aircraft. Water samples were collected simultaneously with the airborne image acquisition and later analyzed in the laboratory. Vertical images were captured through a special hole at the floor of the aircraft. Atmospheric correction for multidate images was performed by selecting average digital number of grass as a reference. The digital colour images of the study areas were separated into three bands (red, green and blue) for multi-spectral analysis. The digital numbers for each band corresponding to the sea-truth locations were extracted and used to calibrate the algorithm. The calibrated total suspended solids (TSS) algorithm was then used to generate the water quality maps of the study areas. This study indicates that a digital camera can be a useful tool for airborne remote sensing. The newly developed algorithm can estimate TSS concentration with linear correlation coefficient square (R2) of 0.94.

  2. VO1/VO2 MARS VISUAL IMAGING SUBSYSTEM DIGITAL IMAGING MODEL

    Data.gov (United States)

    National Aeronautics and Space Administration — This digital image map of Mars is a cartographic extension of a previously released set of CD volumes containing individual Viking Orbiter Images (PDS volumes...

  3. Application of digital-image-correlation techniques in analysing ...

    Indian Academy of Sciences (India)

    experimental results obtained using the digital image correlation analysis is used to demonstrate the crack development ... of applying DIC technique to monitor pipeline cracks is tested in this research by designing and applying a new test to be .... The appropriate sub-image size must be determined in accordance with the ...

  4. Digital Images of Breast Biopsies using a Silicon Strip Detector

    International Nuclear Information System (INIS)

    Montano, Luis M.; Diaz, Claudia C.; Leyva, Antonio; Cabal, Fatima; Ortiz, Carlos M.

    2006-01-01

    In our study we have used a silicon strip detector to obtain digital images of some breast tissues with micro calcifications. Some of those images will be shown and we will discuss the perspectives of using this technique as an improvement of breast cancer diagnostics

  5. New modified map for digital image encryption and its performance

    Science.gov (United States)

    Suryadi, MT; Yus Trinity Irsan, Maria; Satria, Yudi

    2017-10-01

    Protection to classified digital data becomes so important in avoiding data manipulation and alteration. The focus of this paper is in data and information protection of digital images form. Protection is provided in the form of encrypted digital image. The encryption process uses a new map, {x}n+1=\\frac{rλ {x}n}{1+λ {(1-{x}n)}2}\\quad ({mod} 1), which is called MS map. This paper will show: the results of digital image encryption using MS map and how the performance is regarding the average time needed for encryption/decryption process; randomness of key stream sequence with NIST test, histogram analysis and goodness of fit test, quality of the decrypted image by PSNR, initial value sensitivity level, and key space. The results show that the average time of the encryption process is relatively same as the decryption process and it depends to types and sizes of the image. Cipherimage (encrypted image) is uniformly distributed since: it passes the goodness of fit test and also the histogram of the cipherimage is flat; key stream, that are generated by MS map, passes frequency (monobit) test, and runs test, which means the key stream is a random sequence; the decrypted image has same quality as the original image; and initial value sensitivity reaches 10-17, and key space reaches 3.24 × 10634. So, that encryption algorithm generated by MS map is more resistant to brute-force attack and known plaintext attack.

  6. Digital Data Processing of Images | Lotter | South African Medical ...

    African Journals Online (AJOL)

    Digital data processing was investigated to perform image processing. Image smoothing and restoration were explored and promising results obtained. The use of the computer, not only as a data management device, but as an important tool to render quantitative information, was illustrated by lung function determination.

  7. The study of image processing of parallel digital signal processor

    International Nuclear Information System (INIS)

    Liu Jie

    2000-01-01

    The author analyzes the basic characteristic of parallel DSP (digital signal processor) TMS320C80 and proposes related optimized image algorithm and the parallel processing method based on parallel DSP. The realtime for many image processing can be achieved in this way

  8. Application of digital imaging techniques to flare monitoring

    International Nuclear Information System (INIS)

    Rodrigues, Shaun J; Yan, Yong

    2011-01-01

    This paper presents a technique for detecting and monitoring flares in harsh industrial environments with the use of an imaging sensor combined with digital image processing. Flare images are captured via an imaging fibre and analysed to detect the flare's presence and region of interest. The flare characteristics are then determined using various image processing algorithms. A prototype system is designed, constructed and evaluated on a purpose built laboratory scale flare test rig. Results indicate that the imaging based technique has potential for the detection, monitoring and analysis of flares amidst various background conditions in the chemical and oil industries for plant safety, pollution prevention and control.

  9. Quantification of image persistence in a digital angiography system

    International Nuclear Information System (INIS)

    Okkalides, D.P.; Raptou, P.D.

    1993-01-01

    Image persistence, as a characteristic of video imaging systems affecting the quality of fast moving fluoroscopic images, is shown to vary considerably. A simple quantitative method for measuring image persistence in a digital angiography system is presented, together with a series of image intensifier exposure-response curves. For the Saticon tube, used with the Siemens 3VA Digitron, it was found that persistence increased for low exposure rates and may increase to 31% at a 120 ms interval. In addition, a sharp increase in image persistence, from 8.3% to 33%, was observed within 18 months from installation of the system. (author)

  10. HOMER: the Holographic Optical Microscope for Education and Research

    Science.gov (United States)

    Luviano, Anali

    Holography was invented in 1948 by Dennis Gabor and has undergone major advancements since the 2000s leading to the development of commercial digital holographic microscopes (DHM). This noninvasive form of microscopy produces a three-dimensional (3-D) digital model of a sample without altering or destroying the sample, thus allowing the same sample to be studied multiple times. HOMER-the Holographic Optical Microscope for Education and Research-produces a 3-D image from a two-dimensional (2-D) interference pattern captured by a camera that is then put through reconstruction software. This 2-D pattern is created when a reference wave interacts with the sample to produce a secondary wave that interferes with the unaltered part of the reference wave. I constructed HOMER to be an efficient, portable in-line DHM using inexpensive material and free reconstruction software. HOMER uses three different-colored LEDs as light sources. I am testing the performance of HOMER with the goal of producing tri-color images of samples. I'm using small basic biological samples to test the effectiveness of HOMER and plan to transition to complex cellular and biological specimens as I pursue my interest in biophysics. Norwich University.

  11. Two-wavelength volume holographic recording in thick PQ-doped PMMA photopolymer

    Science.gov (United States)

    Lin, June H.; Hsu, Ken Y.; Lin, Shiuan H.

    2013-05-01

    We report holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer material via the two-wavelength technique. By using gating light at 325 nm and writing light at 647 nm two-wavelength holographic recording is achieved. Non-volatile readout of a holographic image under 24 hours continuous reconstruction is demonstrated. A four-level modeling for the photochemical procedures of the two-wavelength holographic recording is proposed, and dynamic behaviors of the holograms are illustrated. A planar integrated optical correlator system is constructed by selective writing of holographic optical elements via two-wavelength holographic recording on a photopolymer disk.

  12. The traveltime holographic principle

    KAUST Repository

    Huang, Y.

    2014-11-06

    Fermat\\'s interferometric principle is used to compute interior transmission traveltimes τpq from exterior transmission traveltimes τsp and τsq. Here, the exterior traveltimes are computed for sources s on a boundary B that encloses a volume V of interior points p and q. Once the exterior traveltimes are computed, no further ray tracing is needed to calculate the interior times τpq. Therefore this interferometric approach can be more efficient than explicitly computing interior traveltimes τpq by ray tracing. Moreover, the memory requirement of the traveltimes is reduced by one dimension, because the boundary B is of one fewer dimension than the volume V. An application of this approach is demonstrated with interbed multiple (IM) elimination. Here, the IMs in the observed data are predicted from the migration image and are subsequently removed by adaptive subtraction. This prediction is enabled by the knowledge of interior transmission traveltimes τpq computed according to Fermat\\'s interferometric principle. We denote this principle as the ‘traveltime holographic principle’, by analogy with the holographic principle in cosmology where information in a volume is encoded on the region\\'s boundary.

  13. The FBI compression standard for digitized fingerprint images

    Energy Technology Data Exchange (ETDEWEB)

    Brislawn, C.M.; Bradley, J.N. [Los Alamos National Lab., NM (United States); Onyshczak, R.J. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Hopper, T. [Federal Bureau of Investigation, Washington, DC (United States)

    1996-10-01

    The FBI has formulated national standards for digitization and compression of gray-scale fingerprint images. The compression algorithm for the digitized images is based on adaptive uniform scalar quantization of a discrete wavelet transform subband decomposition, a technique referred to as the wavelet/scalar quantization method. The algorithm produces archival-quality images at compression ratios of around 15 to 1 and will allow the current database of paper fingerprint cards to be replaced by digital imagery. A compliance testing program is also being implemented to ensure high standards of image quality and interchangeability of data between different implementations. We will review the current status of the FBI standard, including the compliance testing process and the details of the first-generation encoder.

  14. The task of control digital image compression

    OpenAIRE

    TASHMANOV E.B.; МАМАTOV М.S.

    2014-01-01

    In this paper we consider the relationship of control tasks and image compression losses. The main idea of this approach is to allocate structural lines simplified image and further compress the selected data

  15. Metadata Guidelines for Digital Moving Images

    National Research Council Canada - National Science Library

    Flynn, Marcy

    2000-01-01

    ...." Examples for each data element and sample records are presented. Technical metadata essential to the preservation and management of digital materials is also addressed in the Guidelines. This manual is also available at the Defense Virtual Library Web site, http://dvl.dtic.mil:8100/notes.html.

  16. Image enhancement of digital periapical radiographs according to diagnostic tasks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-03-15

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  17. Low-Light Image Enhancement Using Adaptive Digital Pixel Binning

    Directory of Open Access Journals (Sweden)

    Yoonjong Yoo

    2015-06-01

    Full Text Available This paper presents an image enhancement algorithm for low-light scenes in an environment with insufficient illumination. Simple amplification of intensity exhibits various undesired artifacts: noise amplification, intensity saturation, and loss of resolution. In order to enhance low-light images without undesired artifacts, a novel digital binning algorithm is proposed that considers brightness, context, noise level, and anti-saturation of a local region in the image. The proposed algorithm does not require any modification of the image sensor or additional frame-memory; it needs only two line-memories in the image signal processor (ISP. Since the proposed algorithm does not use an iterative computation, it can be easily embedded in an existing digital camera ISP pipeline containing a high-resolution image sensor.

  18. Comparison of the automated evaluation of phantom mama in digital and digitalized images

    International Nuclear Information System (INIS)

    Santana, Priscila do Carmo

    2011-01-01

    Mammography is an essential tool for diagnosis and early detection of breast cancer if it is provided as a very good quality service. The process of evaluating the quality of radiographic images in general, and mammography in particular, can be much more accurate, practical and fast with the help of computer analysis tools. This work compare the automated methodology for the evaluation of scanned digital images the phantom mama. By applied the DIP method techniques was possible determine geometrical and radiometric images evaluated. The evaluated parameters include circular details of low contrast, contrast ratio, spatial resolution, tumor masses, optical density and background in Phantom Mama scanned and digitized images. The both results of images were evaluated. Through this comparison was possible to demonstrate that this automated methodology is presented as a promising alternative for the reduction or elimination of subjectivity in both types of images, but the Phantom Mama present insufficient parameters for spatial resolution evaluation. (author)

  19. A New Approach for Speckle Reduction in Holographic 3D printer

    International Nuclear Information System (INIS)

    Utsugi, Takeru; Yamaguchi, Masahiro

    2013-01-01

    A Holographic 3D printer produces a high quality 3D image reproduced by a full-color, full-parallax holographic stereogram with high-density light-ray recording. But speckle-pattern noise localized behind the reconstructed image is causing a loss of the display quality. This noise is originated from the speckle generated by a diffuser for equalizing the intensity distribution of the object light on the recording medium. We analyze some conventional ways for speckle reduction using a band-limited diffuser, and it is found that these ways cannot reduce the noise sufficiently. Then we propose two methods, one introduces a moving diffuser and the other introduces multiple exposures and a digital diffuser called as 4L-PRPS.

  20. Communication and storage of digital medical images in database.

    Science.gov (United States)

    Evangelista, N; Camapum, J; Amemiya, E

    2005-01-01

    This paper presents the development of an application for communication and storage of clinical images based upon the Digital Imaging and Communications in Medicine (DICOM) protocol. The proposed solution is composed of three different databases servers, PostgreSQL, Firebird and Oracle, and a DICOM client software, that uses the protocol TCP/IP. It provides the communication services, transmission, storage and administration of medical images.

  1. Information quantity in a pixel of digital image

    OpenAIRE

    Kharinov, M.

    2014-01-01

    The paper is devoted to the problem of integer-valued estimating of information quantity in a pixel of digital image. The definition of an integer estimation of information quantity based on constructing of the certain binary hierarchy of pixel clusters is proposed. The methods for constructing hierarchies of clusters and generating of hierarchical sequences of image approximations that minimally differ from the image by a standard deviation are developed. Experimental results on integer-valu...

  2. Digital image processing of earth observation sensor data

    Science.gov (United States)

    Bernstein, R.

    1976-01-01

    This paper describes digital image processing techniques that were developed to precisely correct Landsat multispectral earth observation data and gives illustrations of the results achieved, e.g., geometric corrections with an error of less than one picture element, a relative error of one-fourth picture element, and no radiometric error effect. Techniques for enhancing the sensor data, digitally mosaicking multiple scenes, and extracting information are also illustrated.

  3. Utilization of MATLAB for Digital Image Transmission Simulation.,

    Directory of Open Access Journals (Sweden)

    T. Kratochvil

    2003-12-01

    Full Text Available The paper deals with the utilization of Matlab for simulation andanalysis of the digital image transmission and transmission distortionsin DTV (Digital Television and DVB (Digital Video Broadcasting area.The simulation model that covers selected phenomena of DVB standardbaseband signal processing applied in Matlab is presented and featuresof the protection against transmission errors are outlined. Thepractical results of FEC (Forward Error Correction codes efficiencyare presented and at the end the GUI application for experimentalsimulation and education is outlined with a simulation example.

  4. A computer program for planimetric analysis of digitized images

    DEFF Research Database (Denmark)

    Lynnerup, N; Lynnerup, O; Homøe, P

    1992-01-01

    bones as seen on X-rays. By placing the X-rays on a digitizer tablet and tracing the outline of the cell system, the area was calculated by the program. The calculated data and traced images could be stored and printed. The program is written in BASIC; necessary hardware is an IBM-compatible personal......Planimetrical measurements are made to calculate the area of an entity. By digitizing the entity the planimetrical measurements may be done by computer. This computer program was developed in conjunction with a research project involving measurement of the pneumatized cell system of the temporal...... computer, a digitizer tablet and a printer....

  5. Study on the improvement of overall optical image quality via digital image processing

    Science.gov (United States)

    Tsai, Cheng-Mu; Fang, Yi Chin; Lin, Yu Chin

    2008-12-01

    This paper studies the effects of improving overall optical image quality via Digital Image Processing (DIP) and compares the promoted optical image with the non-processed optical image. Seen from the optical system, the improvement of image quality has a great influence on chromatic aberration and monochromatic aberration. However, overall image capture systems-such as cellphones and digital cameras-include not only the basic optical system but also many other factors, such as the electronic circuit system, transducer system, and so forth, whose quality can directly affect the image quality of the whole picture. Therefore, in this thesis Digital Image Processing technology is utilized to improve the overall image. It is shown via experiments that system modulation transfer function (MTF) based on the proposed DIP technology and applied to a comparatively bad optical system can be comparable to, even possibly superior to, the system MTF derived from a good optical system.

  6. Dynamic deformation image de-blurring and image processing for digital imaging correlation measurement

    Science.gov (United States)

    Guo, X.; Li, Y.; Suo, T.; Liu, H.; Zhang, C.

    2017-11-01

    This paper proposes a method for de-blurring of images captured in the dynamic deformation of materials. De-blurring is achieved based on the dynamic-based approach, which is used to estimate the Point Spread Function (PSF) during the camera exposure window. The deconvolution process involving iterative matrix calculations of pixels, is then performed on the GPU to decrease the time cost. Compared to the Gauss method and the Lucy-Richardson method, it has the best result of the image restoration. The proposed method has been evaluated by using the Hopkinson bar loading system. In comparison to the blurry image, the proposed method has successfully restored the image. It is also demonstrated from image processing applications that the de-blurring method can improve the accuracy and the stability of the digital imaging correlation measurement.

  7. Real-time digital x-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.; Kruger, R.A.; Houk, T.L.

    1982-01-01

    A method of producing visible difference images derived from an x-ray image of an anatomical subject is described. X-rays are directed through the subject, and the image is converted into television fields comprising trains of analog video signals. The analog signals are converted into digital signals, which are then integrated over a predetermined time corresponding to several television fields. Difference video signals are produced by performing a subtraction between the ongoing video signals and the corresponding integrated signals, and are converted into visible television difference images representing changes in the x-ray image

  8. Experience with CANDID: Comparison algorithm for navigating digital image databases

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, P.; Cannon, M.

    1994-10-01

    This paper presents results from the authors experience with CANDID (Comparison Algorithm for Navigating Digital Image Databases), which was designed to facilitate image retrieval by content using a query-by-example methodology. A global signature describing the texture, shape, or color content is first computed for every image stored in a database, and a normalized similarity measure between probability density functions of feature vectors is used to match signatures. This method can be used to retrieve images from a database that are similar to a user-provided example image. Results for three test applications are included.

  9. Dual Level Digital Watermarking for Images

    Science.gov (United States)

    Singh, V. K.; Singh, A. K.

    2010-11-01

    More than 700 years ago, watermarks were used in Italy to indicate the paper brand and the mill that produced it. By the 18th century watermarks began to be used as anti counterfeiting measures on money and other documents.The term watermark was introduced near the end of the 18th century. It was probably given because the marks resemble the effects of water on paper. The first example of a technology similar to digital watermarking is a patent filed in 1954 by Emil Hembrooke for identifying music works. In 1988, Komatsu and Tominaga appear to be the first to use the term "digital watermarking". Consider the following hypothetical situations. You go to a shop, buy some goods and at the counter you are given a currency note you have never come across before. How do you verify that it is not counterfeit? Or say you go to a stationery shop and ask for a ream of bond paper. How do you verify that you have actually been given what you asked for? How does a philatelist verify the authenticity of a stamp? In all these cases, the watermark is used to authenticate. Watermarks have been in existence almost from the time paper has been in use. The impression created by the mesh moulds on the slurry of fibre and water remains on the paper. It serves to identify the manufacturer and thus authenticate the product without actually degrading the aesthetics and utility of the stock. It also makes forgery significantly tougher. Even today, important government and legal documents are watermarked. But what is watermarking, when it comes to digital data? Information is no longer present on a physical material but is represented as a series of zeros and ones. Duplication of information is achieved easily by just reproducing that combination of zeros and ones. How then can one protect ownership rights and authenticate data? The digital watermark is the same as that of conventional watermarks.

  10. Fuzzy Index to Evaluate Edge Detection in Digital Images

    Science.gov (United States)

    Perez-Ornelas, Felicitas; Mendoza, Olivia; Melin, Patricia; Castro, Juan R.; Rodriguez-Diaz, Antonio; Castillo, Oscar

    2015-01-01

    In literature, we can find different metrics to evaluate the detected edges in digital images, like Pratt's figure of merit (FOM), Jaccard’s index (JI) and Dice’s coefficient (DC). These metrics compare two images, the first one is the reference edges image, and the second one is the detected edges image. It is important to mention that all existing metrics must binarize images before their evaluation. Binarization step causes information to be lost because an incomplete image is being evaluated. In this paper, we propose a fuzzy index (FI) for edge evaluation that does not use a binarization step. In order to process all detected edges, images are represented in their fuzzy form and all calculations are made with fuzzy sets operators and fuzzy Euclidean distance between both images. Our proposed index is compared to the most used metrics using synthetic images, with good results. PMID:26115362

  11. Application of Super-Resolution Image Reconstruction to Digital Holography

    Directory of Open Access Journals (Sweden)

    Zhang Shuqun

    2006-01-01

    Full Text Available We describe a new application of super-resolution image reconstruction to digital holography which is a technique for three-dimensional information recording and reconstruction. Digital holography has suffered from the low resolution of CCD sensors, which significantly limits the size of objects that can be recorded. The existing solution to this problem is to use optics to bandlimit the object to be recorded, which can cause the loss of details. Here super-resolution image reconstruction is proposed to be applied in enhancing the spatial resolution of digital holograms. By introducing a global camera translation before sampling, a high-resolution hologram can be reconstructed from a set of undersampled hologram images. This permits the recording of larger objects and reduces the distance between the object and the hologram. Practical results from real and simulated holograms are presented to demonstrate the feasibility of the proposed technique.

  12. Latin American image quality survey in digital mammography studies

    International Nuclear Information System (INIS)

    Mora, Patricia; Khoury, Helen; Bitelli, Regina; Quintero, Ana Rosa; Garay, Fernando; Garcia Aguilar, Juan; Gamarra, Mirtha; Ubeda, Carlos

    2017-01-01

    Under International Atomic Energy Agency regional programme TSA3 Radiological Protection of Patients in Medical Exposures, Latin American countries evaluated the image quality and glandular doses for digital mammography equipment with the purpose of seeing the performance and compliance with international recommendations. Totally, 24 institutions participated from Brazil, Chile, Costa Rica, El Salvador, Mexico, Paraguay and Venezuela. Signal difference noise ratio results showed for CR poor compliance with tolerances; better results were obtained for full-field digital mammography equipment. Mean glandular dose results showed that the majority of units have values below the acceptable dose levels. This joint Latin American project identified common problems: difficulty in working with digital images and lack of specific training by medical physicists from the region. Image quality is a main issue not being satisfied in accordance with international recommendations; optimisation processes in which the doses are increased should be very carefully done in order to improve early detection of any cancer signs. (authors)

  13. Moiré Effect: Index and the Digital Image

    Directory of Open Access Journals (Sweden)

    Stella Baraklianou

    2014-10-01

    Full Text Available The moiré effect and phenomena are natural occurring geometric formations that appear during the super-position of grid structures. Most widely recognisable in colour printing practices, generally viewed on screens (computer and TV they are in most cases examples of interference within a signal or a code, unwanted visual mis-alignment. Especially in digital image capture, moiré patternings appear when a geometrically even pattern, like a fabric or close-up of fine texture, has an appearance of rippled water with blue or red hues of concentric circle formations. The intriguing pattern formation in this case points back not only to the mis-alignment of frequencies, but can be further seen as the intersection point of a speculative ontology for the index of the digital image. Moiré not only as a visually reproducible phenomenon or effect, but a field of vision that blurs the boundaries between analogue and digital, perception and affect, manifesting the photographic as a constant site of becoming, a site of immanence. The philosophy of Henri Bergson, Brian Massumi and Francois Laruelle will be explored alongside the moiré image and phenomenon, to see if there is such a speculative site underlining the becoming of the digital image and its repercussions in contemporary digital culture.

  14. DMD based digital speckle illumination for high resolution imaging

    Science.gov (United States)

    Shinde, Anant; Mishra, Ayush; Perinchery, Sandeep M.; Murukeshan, V. M.

    2017-06-01

    Spatially non-uniform illumination patterns have shown significant potential to improve the imaging. Recent developments in the patterned illumination microscopy have demonstrated that the use of an optical speckle as an illumination pattern significantly improves the imaging resolution at the same time reducing the computational overheads. We present a DMD based method for generation of digital speckle pattern. The generated digital speckle and uniform white light illumination are used as two illuminations to acquire images. The image reconstruction algorithm for blind structured illumination microscopy is used to get the high resolution image. Our approach does not require any calibration step or stringent control of the illumination, and dramatically simplifies the experimental set-up.

  15. Fisheye image rectification using spherical and digital distortion models

    Science.gov (United States)

    Li, Xin; Pi, Yingdong; Jia, Yanling; Yang, Yuhui; Chen, Zhiyong; Hou, Wenguang

    2018-02-01

    Fisheye cameras have been widely used in many applications including close range visual navigation and observation and cyber city reconstruction because its field of view is much larger than that of a common pinhole camera. This means that a fisheye camera can capture more information than a pinhole camera in the same scenario. However, the fisheye image contains serious distortion, which may cause trouble for human observers in recognizing the objects within. Therefore, in most practical applications, the fisheye image should be rectified to a pinhole perspective projection image to conform to human cognitive habits. The traditional mathematical model-based methods cannot effectively remove the distortion, but the digital distortion model can reduce the image resolution to some extent. Considering these defects, this paper proposes a new method that combines the physical spherical model and the digital distortion model. The distortion of fisheye images can be effectively removed according to the proposed approach. Many experiments validate its feasibility and effectiveness.

  16. The role of camera-bundled image management software in the consumer digital imaging value chain

    Science.gov (United States)

    Mueller, Milton; Mundkur, Anuradha; Balasubramanian, Ashok; Chirania, Virat

    2005-02-01

    This research was undertaken by the Convergence Center at the Syracuse University School of Information Studies (www.digital-convergence.info). Project ICONICA, the name for the research, focuses on the strategic implications of digital Images and the CONvergence of Image management and image CApture. Consumer imaging - the activity that we once called "photography" - is now recognized as in the throes of a digital transformation. At the end of 2003, market researchers estimated that about 30% of the households in the U.S. and 40% of the households in Japan owned digital cameras. In 2004, of the 86 million new cameras sold (excluding one-time use cameras), a majority (56%) were estimated to be digital cameras. Sales of photographic film, while still profitable, are declining precipitously.

  17. Holographic Vortex Coronagraph

    Science.gov (United States)

    Palacios, David

    2010-01-01

    A holographic vortex coronagraph (HVC) has been proposed as an improvement over conventional coronagraphs for use in high-contrast astronomical imaging for detecting planets, dust disks, and other broadband light scatterers in the vicinities of stars other than the Sun. Because such light scatterers are so faint relative to their parent stars, in order to be able to detect them, it is necessary to effect ultra-high-contrast (typically by a factor of the order of 1010) suppression of broadband light from the stars. Unfortunately, the performances of conventional coronagraphs are limited by low throughput, dispersion, and difficulty of satisfying challenging manufacturing requirements. The HVC concept offers the potential to overcome these limitations.

  18. Guidelines for reducing image retakes of general digital radiography

    Directory of Open Access Journals (Sweden)

    Chih-Sheng Lin

    2016-04-01

    Full Text Available Image retake of radiological examinations not only increases the risk of radiation exposure of the patients, but also wastes the medical resource and degrades the quality of services of the hospitals. This study aimed at discovering factors affecting image retake of general digital radiography for setting guidelines to reduce the image retaking rate. A total of 98,503 general X-ray images retrieved from the picture archiving and communication system database of a medical center in central Taiwan were analyzed. The results showed that the total retaking rate was 4.89% with the position error (56.05% was the main factor causing image retakes and chest examination showed the highest frequency (1544 cases. On the other hand, skull/face exhibited the highest retaking rate (9.81% among various types of examinations. After discovering the factors affecting the image retaking rate, suitable guidelines were proposed and introduced. The image retake rate had been significantly reduced to 4.38% and 3.57% 1 month and 6 months, respectively, after the introduction of guidelines. In conclusion, image retake analysis is a quality indicator and is effective for quality assurance of digital radiology. Regular analysis of image retake can find factors inducing image retake and is useful for designing guidelines to reduce the image retake rate.

  19. Transforming Dermatologic Imaging for the Digital Era: Metadata and Standards.

    Science.gov (United States)

    Caffery, Liam J; Clunie, David; Curiel-Lewandrowski, Clara; Malvehy, Josep; Soyer, H Peter; Halpern, Allan C

    2018-01-17

    Imaging is increasingly being used in dermatology for documentation, diagnosis, and management of cutaneous disease. The lack of standards for dermatologic imaging is an impediment to clinical uptake. Standardization can occur in image acquisition, terminology, interoperability, and metadata. This paper presents the International Skin Imaging Collaboration position on standardization of metadata for dermatologic imaging. Metadata is essential to ensure that dermatologic images are properly managed and interpreted. There are two standards-based approaches to recording and storing metadata in dermatologic imaging. The first uses standard consumer image file formats, and the second is the file format and metadata model developed for the Digital Imaging and Communication in Medicine (DICOM) standard. DICOM would appear to provide an advantage over using consumer image file formats for metadata as it includes all the patient, study, and technical metadata necessary to use images clinically. Whereas, consumer image file formats only include technical metadata and need to be used in conjunction with another actor-for example, an electronic medical record-to supply the patient and study metadata. The use of DICOM may have some ancillary benefits in dermatologic imaging including leveraging DICOM network and workflow services, interoperability of images and metadata, leveraging existing enterprise imaging infrastructure, greater patient safety, and better compliance to legislative requirements for image retention.

  20. Digital image processing and analysis human and computer vision applications with CVIPtools

    CERN Document Server

    Umbaugh, Scott E

    2010-01-01

    Section I Introduction to Digital Image Processing and AnalysisDigital Image Processing and AnalysisOverviewImage Analysis and Computer VisionImage Processing and Human VisionKey PointsExercisesReferencesFurther ReadingComputer Imaging SystemsImaging Systems OverviewImage Formation and SensingCVIPtools SoftwareImage RepresentationKey PointsExercisesSupplementary ExercisesReferencesFurther ReadingSection II Digital Image Analysis and Computer VisionIntroduction to Digital Image AnalysisIntroductionPreprocessingBinary Image AnalysisKey PointsExercisesSupplementary ExercisesReferencesFurther Read

  1. Digital radiography and advanced imaging techniques in dentistry

    Directory of Open Access Journals (Sweden)

    Burcu Keles Evlice

    2013-04-01

    Full Text Available Since the discovery of x-rays in 1895, film has been the primary medium for capturing, displaying and storing radiographic images. Digital or filmless radiography is slowly being adopted by the dental profession. Digital radiography offers a number of capabilities compared with conventional radiography, such as postprocessing, electronic archiving, concurrent access to images, and improved data distribution. Computer based applications which are used for quantitative measurements and evaluations on digital images for better user interpretation. New diagnostic imaging processes are improved connected with the technological progress of computer systems. Since the first clinical use of computed tomography (CT scans in 1972, technological development has been rapid. Dental volumetric tomography (DVT, uniquely used for dentomaxillofacial imaging came to the market owing to recent rapid developments in digital radiology technology and is becoming more popular in dental applications. Low radiation dose cone beam computed tomography (CBCT units that are commercially available at a lower cost than CT units, has performed valuable diagnostic information for dentists. [Archives Medical Review Journal 2013; 22(2.000: 230-238

  2. Digital training platform for interpreting radiographic images of the chest.

    Science.gov (United States)

    McLaughlin, L; Woznitza, N; Cairns, A; McFadden, S L; Bond, R; Hughes, C M; Elsayed, A; Finlay, D; McConnell, J

    2018-05-01

    Time delays and errors exist which lead to delays in patient care and misdiagnosis. Reporting clinicians follow guidance to form their own search strategy. However, little research has tested these training guides. With the use of eye tracking technology and expert input we developed a digital training platform to be used in chest image interpretation learning. Two sections of a digital training platform were planned and developed; A) a search strategy training tool to assist reporters during their interpretation of images, and B) an educational tool to communicate the search strategies of expert viewers to trainees by using eye tracking technology. A digital training platform for use in chest image interpretation was created based on evidence within the literature, expert input and two search strategies previously used in clinical practice. Images and diagrams, aiding translation of the platform content, were incorporated where possible. The platform is structured to allow the chest image interpretation process to be clear, concise and methodical. A search strategy was incorporated within the tool to investigate its use, with the possibility that it could be recommended as an evidence based approach for use by reporting clinicians. Eye tracking, a checklist and voice recordings have been combined to form a multi-dimensional learning tool, which has never been used in chest image interpretation learning before. The training platform for use in chest image interpretation learning has been designed, created and digitised. Future work will establish the efficacy of the developed approaches. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  3. Performance of the SIR-B digital image processing subsystem

    Science.gov (United States)

    Curlander, J. C.

    1986-01-01

    A ground-based system to generate digital SAR image products has been developed and implemented in support of the SIR-B mission. This system is designed to achieve the maximum throughput while meeting strict image fidelity criteria. Its capabilities include: automated radiometric and geometric correction of the output imagery; high-precision absolute location without tiepoint registration; filtering of the raw data to remove spurious signals from alien radars; and automated catologing to maintain a full set of radar and image production facility in support of the SIR-B science investigators routinely produces over 80 image frames per week.

  4. eCTG: an automatic procedure to extract digital cardiotocographic signals from digital images.

    Science.gov (United States)

    Sbrollini, Agnese; Agostinelli, Angela; Marcantoni, Ilaria; Morettini, Micaela; Burattini, Luca; Di Nardo, Francesco; Fioretti, Sandro; Burattini, Laura

    2018-03-01

    Cardiotocography (CTG), consisting in the simultaneous recording of fetal heart rate (FHR) and maternal uterine contractions (UC), is a popular clinical test to assess fetal health status. Typically, CTG machines provide paper reports that are visually interpreted by clinicians. Consequently, visual CTG interpretation depends on clinician's experience and has a poor reproducibility. The lack of databases containing digital CTG signals has limited number and importance of retrospective studies finalized to set up procedures for automatic CTG analysis that could contrast visual CTG interpretation subjectivity. In order to help overcoming this problem, this study proposes an electronic procedure, termed eCTG, to extract digital CTG signals from digital CTG images, possibly obtainable by scanning paper CTG reports. eCTG was specifically designed to extract digital CTG signals from digital CTG images. It includes four main steps: pre-processing, Otsu's global thresholding, signal extraction and signal calibration. Its validation was performed by means of the "CTU-UHB Intrapartum Cardiotocography Database" by Physionet, that contains digital signals of 552 CTG recordings. Using MATLAB, each signal was plotted and saved as a digital image that was then submitted to eCTG. Digital CTG signals extracted by eCTG were eventually compared to corresponding signals directly available in the database. Comparison occurred in terms of signal similarity (evaluated by the correlation coefficient ρ, and the mean signal error MSE) and clinical features (including FHR baseline and variability; number, amplitude and duration of tachycardia, bradycardia, acceleration and deceleration episodes; number of early, variable, late and prolonged decelerations; and UC number, amplitude, duration and period). The value of ρ between eCTG and reference signals was 0.85 (P < 10 -560 ) for FHR and 0.97 (P < 10 -560 ) for UC. On average, MSE value was 0.00 for both FHR and UC. No CTG feature

  5. Holographic Read-Only Memory

    Science.gov (United States)

    Mok, F.; Zhou, G.; Psaltis, D.

    The most successful use of optical memories so far has been as read-only memories (ROM). A main reason for this success has been the availability of inexpensive methods to mass-produce copies of recorded disks. This has made it possible to publish data (audio, video, databases, computer games) and distribute it widely through normal retail channels. In this chapter, we show results of a holographic read-only memory (HROM) of which digital data on a master disk can be copied onto replicate disks efficiently.

  6. Matching rendered and real world images by digital image processing

    Science.gov (United States)

    Mitjà, Carles; Bover, Toni; Bigas, Miquel; Escofet, Jaume

    2010-05-01

    Recent advances in computer-generated images (CGI) have been used in commercial and industrial photography providing a broad scope in product advertising. Mixing real world images with those rendered from virtual space software shows a more or less visible mismatching between corresponding image quality performance. Rendered images are produced by software which quality performance is only limited by the resolution output. Real world images are taken with cameras with some amount of image degradation factors as lens residual aberrations, diffraction, sensor low pass anti aliasing filters, color pattern demosaicing, etc. The effect of all those image quality degradation factors can be characterized by the system Point Spread Function (PSF). Because the image is the convolution of the object by the system PSF, its characterization shows the amount of image degradation added to any taken picture. This work explores the use of image processing to degrade the rendered images following the parameters indicated by the real system PSF, attempting to match both virtual and real world image qualities. The system MTF is determined by the slanted edge method both in laboratory conditions and in the real picture environment in order to compare the influence of the working conditions on the device performance; an approximation to the system PSF is derived from the two measurements. The rendered images are filtered through a Gaussian filter obtained from the taking system PSF. Results with and without filtering are shown and compared measuring the contrast achieved in different final image regions.

  7. Operational digital image processing within the Bureau of Land Management

    International Nuclear Information System (INIS)

    Work, E.A.; Story, M.

    1991-01-01

    An overview of the use of operational digital image processing at the U.S. Bureau of Land Management (BLM) is presented. The BLM digital image analysis facility for the processing and analysis of aerial photography and satellite data is described, and its role within the Bureau's operational structure is explained. Attention is given to examples of BLM digital data analysis projects that have utilized Landsat (MSS and TM), NOAA-AVHRR, or SPOT data. These projects include: landcover mapping to assist land use planning or special projects; monitoring of wilderness units to detect unauthorized activities; stratification aid for detailed field inventories; identification/quantification of unauthorized use (agricultural and mineral trespass); and fire fuels mapping and updates. 3 refs

  8. Removing the twin image in digital holography by segmented filtering of in-focus twin image

    OpenAIRE

    McElhinney, C.; Hennelly, B.M.; Ahrenberg, L.; Naughton, T.J.

    2008-01-01

    We propose and investigate a new digital method for the reduction of twin-image noise from digital Fresnel holograms. For the case of in-line Fresnel holography the unwanted twin is present as a highly corruptive noise when the object image is numerically reconstructed. We propose to firstly reconstruct the unwanted twin-image when it is in-focus and in this plane we calculate a segmentation mask that borders this in focus image. The twin-image is then segmented and removed by sim...

  9. Digital Forensics Tool Testing - Image Metadata in the Cloud

    OpenAIRE

    Clark, Philip

    2011-01-01

    As cloud based services are becoming a common way for users to store and share images on the internet, this adds a new layer to the traditional digital forensics examination, which could cause additional potential errors in the investigation. Courtroom forensics evidence has historically been criticised for lacking a scientific basis. This thesis aims to present an approach for testing to what extent cloud based services alter or remove metadata in the images stored through such services. ...

  10. Radiation oncology digital image chart and digital radiotherapy record system at Samsung medical center

    International Nuclear Information System (INIS)

    Huh, Seung Jae; Ahn, Yong Chan; Lim, Do Hoon; Cho, Chung Keun; Kim, Dae Yong; Yeo, Inhwan Jason; Kim, Moon Kyung; Chang, Seung Hee; Park, Suk Won

    2000-01-01

    The authors have developed a Digital Image Chart (DIC) and digital Radiotherapy Record System (DRRS). We have evaluated the DIC and DRRS for reliability, usefulness, ease of use, and efficiency. The basic design of the DIC and DRRS was to build an digital image database of radiation therapy patient records for a more efficient and timely flow of critical image information throughout the department. This system is a subunit of comprehensive radiation oncology management system (C-ROMS) and composed of a picture archiving and communication system (PACS), a radiotherapy information database, and a radiotherapy imaging database. The DIC and DRRS were pampered using Delphi under a Windows 95 environment and is capable of displaying the digital images of patients identification photos, simulation films, radiotherapy setup, diagnostic radiology images, gross lesion photos, and radiotherapy planning isodose charts with beam arrangements. Twenty-three clients in the department are connected by Ethernet (10 Mbps) to the central image server (Sun Ultrasparc 1 workstation). From the introduction of this system in February 1998 through December 1999, we have accumulated a total of 15,732 individual images for 2,556 patients. We can organize radiation therapy in a paperless environment in 120 patients with breast cancer. Using this system, we have succeeded in the prompt, accurate, and simultaneous access to patient care information from multiple locations throughout the department. This coordination has resulted in improved operational efficiency within the department. The authors believe that the DIC and DRRS has contributed to the improvement of radiation oncology department efficacy as well as to time and resource savings by providing necessary visual information throughout the department conveniently and simultaneously. As a result, we can also achieve the 'paperless and 'Filmless' practice of radiation oncology with this system

  11. Compression of the digitized X-ray images

    International Nuclear Information System (INIS)

    Terae, Satoshi; Miyasaka, Kazuo; Fujita, Nobuyuki; Takamura, Akio; Irie, Goro; Inamura, Kiyonari.

    1987-01-01

    Medical images are using an increased amount of space in the hospitals, while they are not accessed easily. Thus, suitable data filing system and precise data compression will be necessitated. Image quality was evaluated before and after image data compression, using local filing system (MediFile 1000, NEC Co.) and forty-seven modes of compression parameter. For this study X-ray images of 10 plain radiographs and 7 contrast examinations were digitized using a film reader of CCD sensor in MediFile 1000. Those images were compressed into forty-seven kinds of image data to save in an optical disc and then the compressed images were reconstructed. Each reconstructed image was compared with non-compressed images in respect to several regions of our interest by four radiologists. Compression and extension of radiological images were promptly made by employing the local filing system. Image quality was much more affected by the ratio of data compression than by the mode of parameter itself. In another word, the higher compression ratio became, the worse the image quality were. However, image quality was not significantly degraded until the compression ratio was about 15: 1 on plain radiographs and about 8: 1 on contrast studies. Image compression by this technique will be admitted by diagnostic radiology. (author)

  12. Digital autoradiography using room temperature CCD and CMOS imaging technology

    International Nuclear Information System (INIS)

    Cabello, Jorge; Bailey, Alexis; Kitchen, Ian; Prydderch, Mark; Clark, Andy; Turchetta, Renato; Wells, Kevin

    2007-01-01

    CCD (charged coupled device) and CMOS imaging technologies can be applied to thin tissue autoradiography as potential imaging alternatives to using conventional film. In this work, we compare two particular devices: a CCD operating in slow scan mode and a CMOS-based active pixel sensor, operating at near video rates. Both imaging sensors have been operated at room temperature using direct irradiation with images produced from calibrated microscales and radiolabelled tissue samples. We also compare these digital image sensor technologies with the use of conventional film. We show comparative results obtained with 14 C calibrated microscales and 35 S radiolabelled tissue sections. We also present the first results of 3 H images produced under direct irradiation of a CCD sensor operating at room temperature. Compared to film, silicon-based imaging technologies exhibit enhanced sensitivity, dynamic range and linearity

  13. Digital Image Processing application to spray and flammability studies

    Science.gov (United States)

    Hernan, M. A.; Parikh, P.; Sarohia, V.

    1985-01-01

    Digital Image Processing has been integrated into a new technique for measurements of fuel spray characteristics. The advantages of this technique are: a wide dynamic range of droplet sizes, accounting for nonspherical droplet shapes not possible with other spray assessment techniques. Finally, the technique has been applied to the study of turbojet engine fuel nozzle atomization performance with Jet A and antimisting fuel.

  14. Development of digital image correlation method to analyse crack ...

    Indian Academy of Sciences (India)

    The wall deficiency is very difficult to detect in practical experiments because crack formation and development cannot be measured accurately. Therefore, the digital image correlation method is proposed in this study to observe the surface deformation of brick wall; the feasibility of applying this method for crack observation ...

  15. Digital image monitoring to optimise safe port operation

    CSIR Research Space (South Africa)

    Phelp, D

    2008-11-01

    Full Text Available This paper describes a low cost video system ‘Harbour Watch’, which can be used to support safe port operations, especially in developing countries. Preset digital images are geo-referenced and then archived for later analysis to improve...

  16. Full-body digital radiographic imaging of the injured child

    African Journals Online (AJOL)

    interests include computer-assisted diagnosis of tuberculosis and fetal alcohol syndrome, and paediatric applications of digital X-ray imaging. RICHARD .... in emergency departments have. 110. A precursor to. Statscan was employed for theft surveillance in the South African diamond mining industry. The effective radiation ...

  17. A Generalization of DPCM for Digital Image Compression.

    Science.gov (United States)

    Hung, S H

    1979-01-01

    A natural generalization of two-dimensional digital pulsecode modulations (DPCM) has been used to handle the compression of images for human eyes only. It shows that by ignoring the mean-square error (MSE) and wisely arranging the errors in the right place, a simple method can achieve very good results.

  18. Fundamental color classification systems for the digital imaging colorimetry

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Jaroslav; Hrdý, J.; Hrdý, jr., J.

    2006-01-01

    Roč. 51, č. 6 (2006), s. 175-178 ISSN 0447-6441 Institutional research plan: CEZ:AV0Z10100522 Keywords : color classification systems * color coordinates * analog and digital imaging colorimetry Subject RIV: BH - Optics, Masers, Lasers

  19. Application of digital image correlation method for analysing crack ...

    Indian Academy of Sciences (India)

    The Digital Image Correlation (DIC) method is a fast-growing emerging technology that provides a low-cost method for measuring the strain of an object. In this study, the feasibility of using this method to observe cracks developed in reinforced concrete beams will be explored so that a practical application can be proposed.

  20. Determining storage related egg quality changes via digital image ...

    African Journals Online (AJOL)

    Ahnir Anida

    changes using computer assisted digital image analysis (CADIA) in an 18-month old moulted brown layer. (Lohmann .... tatistical analyses of the data were performed according to the analysis of variance technique, and mean .... of the albumen structure that surrounds the yolk, which normally provides stability to the yolk. C.

  1. Determining storage related egg quality changes via digital image ...

    African Journals Online (AJOL)

    Area and length measurements related to exterior and interior egg quality were determined by digital image analysis. In general, excluding the outer thin albumen area, all of the area measurements such as total egg content area and inner thick albumen area were larger in stored eggs than in fresh eggs (52.28 vs.

  2. Identification and Quantification Soil Redoximorphic Features by Digital Image Processing

    Science.gov (United States)

    Soil redoximorphic features (SRFs) have provided scientists and land managers with insight into relative soil moisture for approximately 60 years. The overall objective of this study was to develop a new method of SRF identification and quantification from soil cores using a digital camera and imag...

  3. Comparison between Digital Image Processing and Spectrophotometric Measurements Methods

    Directory of Open Access Journals (Sweden)

    Bogdan Adnan HAIFA

    2011-03-01

    Full Text Available Background: Spectrophotometer is a very common instrument in various scientific fields and gives accurate information about light absorbance and transmittance through materials using monochromatic light source. Though, devices used in spectrophotometry can be quite expensive, using components with high technical specifications and the procedure itself is time consuming. Regular digital image acquisition instruments like scanners and cameras on the other hand uses very cheap electronic components to record the information on 3 wide band channels (Red, Green, Blue. Purpose: This paper studies the possibility of correlating the measurements from the spectrophotometer with raw data from digital image acquisition instruments. Materials and Methods: Because the results will be used in protein electrophoresis, we prepared o set of plates with blood serum in different dilutions, stained with Coomassie Brilliant Blue. The absorbance of the resulting plates has been measured using a spectrophotometer and after that, the plates were scanned with a regular office scanner. The digital image was converted in different color spaces (gray scale, RGB, HSV, HSL, CIEXYZ and CIELAB using custom developed software in C++. We statistically measured the correlation coefficient of different parameters from the color space with the absorption measured with the spectrophotometer. Results and Discussion: The findings of this work show that a consumer digital scanner can be used as a fast and inexpensive alternative to spectrophotometers. This offers the possibility of using scanned images of protein electrophoresis to make quantitative estimations regarding the proteinogram.

  4. Numerical Algorithm For Digital Image Enhancement And Noise ...

    African Journals Online (AJOL)

    We adopt the approach of Vogel and Oman, 1998 and introduce a Lagrange multiplier Ibiejugba, 1985, to obtain an appropriate discrete energy which we minimize, in order to minimize equivalently, the unwanted vibration (noise) associated with a digitally transmitted image. An iterative algorithm is developed for this ...

  5. Application of digital-image-correlation techniques in analysing ...

    Indian Academy of Sciences (India)

    experimental results obtained using the digital image correlation analysis is used to demonstrate the crack ... The analysis procedure of the DIC method is shown in figure 1. The analysis region is divided .... The observation also proves the accuracy of the qualitative analyses by using the DIC technique. However, fig-.

  6. Development of digital image correlation method to analyse crack ...

    Indian Academy of Sciences (India)

    theory and digital image correlation method, and applying the interpolation theory to expand its applications with ... measured data and proposed a method of reducing the noise to less than 0.01 pixels. Many ancient ..... (iv) The grid size has big influence on the evaluation of crack formation in brick walls; small grid size is ...

  7. Problems and image processing in X-ray film digitization

    International Nuclear Information System (INIS)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru

    1992-01-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author)

  8. Problems and image processing in X-ray film digitization

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital)

    1992-11-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author).

  9. Estimating Crop Cover Fraction from Digital Color Images

    Science.gov (United States)

    Karakus, P.; Karabork, H.

    2017-11-01

    The use of automated methods to estimate crop cover fraction from digital color images has increased in recent years. Crop cover fraction can determine accurate, fast and inexpensive with this methods. A digital color images was acquired over each of the 30 sample fields in 2014 year at 2-3 week intervals. Study area has 15 sunflower fields and 15 corn fields. Digital color images were collected during 4 months, namely over the course of the growing season from sowing until harvesting to determine crop cover fraction. We used two approach to estimate crop cover fraction. In first method, the images were transformed from the RGB (red, green, blue) color space to the HSI (hue, intensity, saturation) color space. We used an object-based image analysis approach to classify the images into green vegetation and the other materials. In the second method, The Green Crop Tracker is less labor and time intensive than the object-based classification approach, is a viable alternative to ground-based methods. By comparing object-based classification method and Green Crop Tracker software 2014 growing season, results were obtained: There were high correlations between the estimations obtained by object-based classification method and Green Crop Tracker software (for 2014 R2 = 0.89). The relationship between two methods for 2014-23 sunflower field was calculated R2 = 0.97.

  10. Digital image processing of mandibular trabeculae on radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Ogino, Toshi

    1987-06-01

    The present study was aimed to reveal the texture patterns of the radiographs of the mandibular trabeculae by digital image processing. The 32 cases of normal subjects and the 13 cases of patients with mandibular diseases of ameloblastoma, primordial cysts, squamous cell carcinoma and odontoma were analyzed by their intra-oral radiographs in the right premolar regions. The radiograms were digitized by the use of a drum scanner densitometry method. The input radiographic images were processed by a histogram equalization method. The result are as follows : First, the histogram equalization method enhances the image contrast of the textures. Second, the output images of the textures for normal mandible-trabeculae radiograms are of network pattern in nature. Third, the output images for the patients are characterized by the non-network pattern and replaced by the patterns of the fabric texture, intertwined plants (karakusa-pattern), scattered small masses and amorphous texture. Thus, these results indicates that the present digital image system is expected to be useful for revealing the texture patterns of the radiographs and in the future for the texture analysis of the clinical radiographs to obtain quantitative diagnostic findings.

  11. Digital image processing of mandibular trabeculae on radiographs

    International Nuclear Information System (INIS)

    Ogino, Toshi

    1987-01-01

    The present study was aimed to reveal the texture patterns of the radiographs of the mandibular trabeculae by digital image processing. The 32 cases of normal subjects and the 13 cases of patients with mandibular diseases of ameloblastoma, primordial cysts, squamous cell carcinoma and odontoma were analyzed by their intra-oral radiographs in the right premolar regions. The radiograms were digitized by the use of a drum scanner densitometry method. The input radiographic images were processed by a histogram equalization method. The result are as follows : First, the histogram equalization method enhances the image contrast of the textures. Second, the output images of the textures for normal mandible-trabeculae radiograms are of network pattern in nature. Third, the output images for the patients are characterized by the non-network pattern and replaced by the patterns of the fabric texture, intertwined plants (karakusa-pattern), scattered small masses and amorphous texture. Thus, these results indicates that the present digital image system is expected to be useful for revealing the texture patterns of the radiographs and in the future for the texture analysis of the clinical radiographs to obtain quantitative diagnostic findings. (author)

  12. The iconic image in a digital age

    DEFF Research Database (Denmark)

    Mortensen, Mette; Allan, Stuart; Peters, Chris

    2017-01-01

    This article investigates selected newspapers’ editorial mediations over contrasting perceptions regarding the significance of a controversial set of “iconic” news photographs, namely images of Alan Kurdi, a three-year-old Syrian refugee, whose drowned corpse washed ashore in September, 2015. Spe...

  13. Advantages of digital imaging for radiological diagnostic; Ventajas de la imagen digital para el diagnostico radiologico

    Energy Technology Data Exchange (ETDEWEB)

    Trapero, M. A.; Gonzalez, S.; Albillos, J. C.; Martel, J.; Rebollo, M.

    2006-07-01

    The advantages and limitations of radiological digital images in comparison with analogic ones are analyzed. We discuss three main topics: acquisition, post-procedure manipulation, and visualization, archive and communication. Digital acquisition with computed radiology systems present a global sensitivity very close to conventional film for diagnostic purposes. However, flat panel digital systems seems to achieve some advantages in particular clinical situations. A critical issue is the radiation dose-reduction that can be accomplished without reducing image quality nor diagnostic exactitude. The post-procedure manipulation allows, particularly in multiplanar modalities like CT or MR, to extract all implicit diagnostic information in the images: Main procedures are multiplanar and three-dimensional reformations, dynamic acquisitions, functional studies and image fusion. The use of PACS for visualization, archive and communication of images, improves the effectiveness and the efficiency of the workflow, allows a more comfortable diagnosis for the radiologist and gives way to improvements in the communication of images, allowing tele consulting and the tele radiology. (Author) 6 refs.

  14. Holographic reflector for reflective LCDs

    Science.gov (United States)

    Sato, Atsushi; Murillo-Mora, Luis M.; Iwata, Fujio

    1997-05-01

    We describe a new holographic optical element to improve the image's quality of a reflective liquid crystal displays (LCDs). This new holographic reflector consists basically of 2 layers: a volume type transmission hologram layer and a metallic reflection layer. Compared with conventional reflectors for reflective LCDs, a high optical efficiency can be obtained because the hologram is able to concentrate the reflected light to the observer's eyes. Also, it avoids the problems of glare in the LCDs by deviating the reflected incident light (used for display) away from the direction of the direct reflection light. The transmission hologram's low wavelength selectivity permits us to obtain a near white color reflector for reflective LCDs which for multiple applications is the preferable color for the background.

  15. Distributed image coding for digital image recovery from the print-scan channel.

    Science.gov (United States)

    Samadani, Ramin; Mukherjee, Debargha

    2010-03-01

    A printed digital photograph is difficult to reuse because the digital information that generated the print may no longer be available. This paper describes a method for approximating the original digital image by combining a scan of the printed photograph with digital auxiliary information kept together with the print. We formulate and solve the approximation problem using a Wyner-Ziv coding framework. During encoding, the Wyner-Ziv auxiliary information consists of a small amount of digital data composed of a number of sampled luminance pixel blocks and a number of sampled color pixel values to enable subsequent accurate registration and color-reproduction during decoding. The registration and color information is augmented by an additional amount of digital data encoded using Wyner-Ziv coding techniques that recovers residual errors and lost high spatial frequencies. The decoding process consists of scanning the printed photograph, together with a two step decoding process. The first decoding step, using the registration and color auxiliary information, generates a side-information image which registers and color corrects the scanned image. The second decoding step uses the additional Wyner-Ziv layer together with the side-information image to provide a closer approximation of the original, reducing residual errors and restoring the lost high spatial frequencies. The experimental results confirm the reduced digital storage needs when the scanned print assists in the digital reconstruction.

  16. The radon transform in digital image processing

    International Nuclear Information System (INIS)

    Beyerer, J.; Leon, F.P.

    2002-01-01

    The Radon transform develops an image according to a ''system of functions'' consisting of δ-lines. Thus, the Radon transform of a signal b(x 1 , x 2 ) represents the set of all parallel projections of b(x 1 , x 2 ). The Radon transform maps linear signal components onto pronounced extrema which can be detected very robustly. The coordinates of these peaks are reliable estimates of the geometrical parameters of collinear structures. In the paper, the increase of the signal-to-noise ratio for such structures in the Radon domain is discussed quantitatively. Moreover, the application of the Radon transform for image enhancement is demonstrated. Further topics concern its efficient implementation based on the central slice theorem, the connection with the Hough transform as well as examples on more complex applications. (orig.) [de

  17. Digital signal and image processing using MATLAB

    CERN Document Server

    Blanchet, Gérard

    2006-01-01

    This title provides the most important theoretical aspects of Image and Signal Processing (ISP) for both deterministic and random signals. The theory is supported by exercises and computer simulations relating to real applications.More than 200 programs and functions are provided in the MATLAB® language, with useful comments and guidance, to enable numerical experiments to be carried out, thus allowing readers to develop a deeper understanding of both the theoretical and practical aspects of this subject.

  18. Ultrasonic imaging in LMFBRs using digital techniques

    International Nuclear Information System (INIS)

    Fothergill, J.R.; McKnight, J.A.; Barrett, L.M.

    Ultrasonic technology for providing images of components immersed in the opaque sodium of LMFBRs is being developed at RNL. For many years the application has been restricted by the unavailability of convenient ultrasonic sources and receivers capable of withstanding the reactor environment. Until recently, for example, important ultrasonic instrument design, such as for future sweep arms, had to be based on waveguided ultrasonics. RNL have developed an economic immersible transducer that can be deployed during reactor shut-down, when many demands for ultrasonic imaging are made. The transducer design is not suited at present to the sophisticated techniques of phased arrays; consequently image formation must depend on the physical scanning of a target using one or more transducers in pulse-echo mode. The difficulties of access into a fast reactor impose further restrictions. Some applications may involve easy scanning sequences, thus the sweep arm requires only a rotation to provide a map of the reactor core area. For a more detailed examination of the same area, however, special engineering solutions are needed to provide a more satisfactory scanning sequence. A compromise solution involving the rotating shield movement is being used for a PFR experiment to examine a limited area of the core. (author)

  19. The Digital Image Processing And Quantitative Analysis In Microscopic Image Characterization

    International Nuclear Information System (INIS)

    Ardisasmita, M. Syamsa

    2000-01-01

    Many electron microscopes although have produced digital images, but not all of them are equipped with a supporting unit to process and analyse image data quantitatively. Generally the analysis of image has to be made visually and the measurement is realized manually. The development of mathematical method for geometric analysis and pattern recognition, allows automatic microscopic image analysis with computer. Image processing program can be used for image texture and structure periodic analysis by the application of Fourier transform. Because the development of composite materials. Fourier analysis in frequency domain become important for measure the crystallography orientation. The periodic structure analysis and crystal orientation are the key to understand many material properties like mechanical strength. stress, heat conductivity, resistance, capacitance and other material electric and magnetic properties. In this paper will be shown the application of digital image processing in microscopic image characterization and analysis in microscopic image

  20. A Mach-Zender Holographic Microscope for Quantifying Bacterial Motility

    Science.gov (United States)

    Niraula, B.; Nadeau, J. L.; Serabyn, E.; Wallace, J. K.; Liewer, K.; Kuhn, J.; Graff, E.; Lindensmith, C.

    2014-12-01

    New microscopic techniques have revolutionized cell biology over the past two decades. However, there are still biological processes whose details elude us, especially those involving motility: e.g. feeding behavior of microorganisms in the ocean, or migration of cancer cells to form metastases. Imaging prokaryotes, which range in size from several hundred nm to a few microns, is especially challenging. An emerging technique to address these issues is Digital Holographic Microscopy (DHM). DHM is an imaging technique that uses the interference of light to record and reproduce three-dimensional magnified images of objects. This approach has several advantages over ordinary brightfield microscopy for fieldwork: a larger depth of field, hands-off operation, robustness regarding environmental conditions, and large sampling volumes with quantitative 3D records of motility behavior. Despite these promising features, real-time DHM was thought to be impractical for technological and computational reasons until recently, and there has so far been very limited application of DHM to biology. Most existing instruments are limited in performance by their particular (e.g. in-line, lens-less, phase-shifting) approach to holography. These limitations can be mitigated with an off-axis dual-path configuration. Here we describe the design and implementation of a design for a Mach-Zehnder-type holographic microscope with diffraction-limited lateral resolution, with intended applications in environmental microbiology. We have achieved sub-micron resolution and three-dimensional tracking of prokaryotic and eukaryotic test strains designed to represent different modes and speeds of microbial motility. Prokaryotes are Escherichia coli, Vibrio alginolyticus, and Bacillus subtilis. Each shows a characteristic motility pattern, as we illustrate in holographic videos in sample chambers 0.6 mm in depth. The ability to establish gradients of attractants with bacterial taxis towards the