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Sample records for camera path reconstruction

  1. Nonholonomic catheter path reconstruction using electromagnetic tracking

    NASA Astrophysics Data System (ADS)

    Lugez, Elodie; Sadjadi, Hossein; Akl, Selim G.; Fichtinger, Gabor

    2015-03-01

    Catheter path reconstruction is a necessary step in many clinical procedures, such as cardiovascular interventions and high-dose-rate brachytherapy. To overcome limitations of standard imaging modalities, electromagnetic tracking has been employed to reconstruct catheter paths. However, tracking errors pose a challenge in accurate path reconstructions. We address this challenge by means of a filtering technique incorporating the electromagnetic measurements with the nonholonomic motion constraints of the sensor inside a catheter. The nonholonomic motion model of the sensor within the catheter and the electromagnetic measurement data were integrated using an extended Kalman filter. The performance of our proposed approach was experimentally evaluated using the Ascension's 3D Guidance trakStar electromagnetic tracker. Sensor measurements were recorded during insertions of an electromagnetic sensor (model 55) along ten predefined ground truth paths. Our method was implemented in MATLAB and applied to the measurement data. Our reconstruction results were compared to raw measurements as well as filtered measurements provided by the manufacturer. The mean of the root-mean-square (RMS) errors along the ten paths was 3.7 mm for the raw measurements, and 3.3 mm with manufacturer's filters. Our approach effectively reduced the mean RMS error to 2.7 mm. Compared to other filtering methods, our approach successfully improved the path reconstruction accuracy by exploiting the sensor's nonholonomic motion constraints in its formulation. Our approach seems promising for a variety of clinical procedures involving reconstruction of a catheter path.

  2. 3D Surface Reconstruction and Automatic Camera Calibration

    NASA Technical Reports Server (NTRS)

    Jalobeanu, Andre

    2004-01-01

    Illustrations in this view-graph presentation are presented on a Bayesian approach to 3D surface reconstruction and camera calibration.Existing methods, surface analysis and modeling,preliminary surface reconstruction results, and potential applications are addressed.

  3. Localization and trajectory reconstruction in surveillance cameras with nonoverlapping views.

    PubMed

    Pflugfelder, Roman; Bischof, Horst

    2010-04-01

    This paper proposes a method that localizes two surveillance cameras and simultaneously reconstructs object trajectories in 3D space. The method is an extension of the Direct Reference Plane method, which formulates the localization and the reconstruction as a system of linear equations that is globally solvable by Singular Value Decomposition. The method's assumptions are static synchronized cameras, smooth trajectories, known camera internal parameters, and the rotation between the cameras in a world coordinate system. The paper describes the method in the context of self-calibrating cameras, where the internal parameters and the rotation can be jointly obtained assuming a man-made scene with orthogonal structures. Experiments with synthetic and real--image data show that the method can recover the camera centers with an error less than half a meter even in the presence of a 4 meter gap between the fields of view. PMID:20224125

  4. Effects of camera location on the reconstruction of 3D flare trajectory with two cameras

    NASA Astrophysics Data System (ADS)

    Özsaraç, Seçkin; Yeşilkaya, Muhammed

    2015-05-01

    Flares are used as valuable electronic warfare assets for the battle against infrared guided missiles. The trajectory of the flare is one of the most important factors that determine the effectiveness of the counter measure. Reconstruction of the three dimensional (3D) position of a point, which is seen by multiple cameras, is a common problem. Camera placement, camera calibration, corresponding pixel determination in between the images of different cameras and also the triangulation algorithm affect the performance of 3D position estimation. In this paper, we specifically investigate the effects of camera placement on the flare trajectory estimation performance by simulations. Firstly, 3D trajectory of a flare and also the aircraft, which dispenses the flare, are generated with simple motion models. Then, we place two virtual ideal pinhole camera models on different locations. Assuming the cameras are tracking the aircraft perfectly, the view vectors of the cameras are computed. Afterwards, using the view vector of each camera and also the 3D position of the flare, image plane coordinates of the flare on both cameras are computed using the field of view (FOV) values. To increase the fidelity of the simulation, we have used two sources of error. One is used to model the uncertainties in the determination of the camera view vectors, i.e. the orientations of the cameras are measured noisy. Second noise source is used to model the imperfections of the corresponding pixel determination of the flare in between the two cameras. Finally, 3D position of the flare is estimated using the corresponding pixel indices, view vector and also the FOV of the cameras by triangulation. All the processes mentioned so far are repeated for different relative camera placements so that the optimum estimation error performance is found for the given aircraft and are trajectories.

  5. Iterative reconstruction of detector response of an Anger gamma camera.

    PubMed

    Morozov, A; Solovov, V; Alves, F; Domingos, V; Martins, R; Neves, F; Chepel, V

    2015-05-21

    Statistical event reconstruction techniques can give better results for gamma cameras than the traditional centroid method. However, implementation of such techniques requires detailed knowledge of the photomultiplier tube light-response functions. Here we describe an iterative method which allows one to obtain the response functions from flood irradiation data without imposing strict requirements on the spatial uniformity of the event distribution. A successful application of the method for medical gamma cameras is demonstrated using both simulated and experimental data. An implementation of the iterative reconstruction technique capable of operating in real time is presented. We show that this technique can also be used for monitoring photomultiplier gain variations. PMID:25951792

  6. Iterative reconstruction of detector response of an Anger gamma camera

    NASA Astrophysics Data System (ADS)

    Morozov, A.; Solovov, V.; Alves, F.; Domingos, V.; Martins, R.; Neves, F.; Chepel, V.

    2015-05-01

    Statistical event reconstruction techniques can give better results for gamma cameras than the traditional centroid method. However, implementation of such techniques requires detailed knowledge of the photomultiplier tube light-response functions. Here we describe an iterative method which allows one to obtain the response functions from flood irradiation data without imposing strict requirements on the spatial uniformity of the event distribution. A successful application of the method for medical gamma cameras is demonstrated using both simulated and experimental data. An implementation of the iterative reconstruction technique capable of operating in real time is presented. We show that this technique can also be used for monitoring photomultiplier gain variations.

  7. Plenoptic camera image simulation for reconstruction algorithm verification

    NASA Astrophysics Data System (ADS)

    Schwiegerling, Jim

    2014-09-01

    Plenoptic cameras have emerged in recent years as a technology for capturing light field data in a single snapshot. A conventional digital camera can be modified with the addition of a lenslet array to create a plenoptic camera. Two distinct camera forms have been proposed in the literature. The first has the camera image focused onto the lenslet array. The lenslet array is placed over the camera sensor such that each lenslet forms an image of the exit pupil onto the sensor. The second plenoptic form has the lenslet array relaying the image formed by the camera lens to the sensor. We have developed a raytracing package that can simulate images formed by a generalized version of the plenoptic camera. Several rays from each sensor pixel are traced backwards through the system to define a cone of rays emanating from the entrance pupil of the camera lens. Objects that lie within this cone are integrated to lead to a color and exposure level for that pixel. To speed processing three-dimensional objects are approximated as a series of planes at different depths. Repeating this process for each pixel in the sensor leads to a simulated plenoptic image on which different reconstruction algorithms can be tested.

  8. Analytical reconstruction formula for one-dimensional Compton camera

    SciTech Connect

    Basko, R.; Zeng, G.L.; Gullberg, G.T.

    1996-12-31

    The Compton camera has been proposed as an alternative to the Anger camera in SPECT. The advantage of the Compton camera is its high geometric efficiency due to electronic collimation. The Compton camera collects projections that are integrals over cone surfaces. Although some progress has been made toward image reconstruction from cone projections, at present no filtered backprojection algorithm exists. This paper investigates a simpler 2D version of the imaging problem. An analytical formula is developed for 2D reconstruction from data acquired by a 1D Compton camera that consists of two linear detectors, one behind the other. Coincidence photon detection allows the localization of the 2D source distribution to two lines in the shape of a {open_quotes}V{close_quotes} with the vertex on the front detector. A set of {open_quotes}V{close_quotes} projection data can be divided into subsets whose elements can be viewed as line-integrals of the original image added with its mirrored shear transformation. If the detector has infinite extent, reconstruction of the original image is possible using data from only one such subset. Computer simulations were performed to verify the newly developed algorithm.

  9. Real-Time Camera Guidance for 3d Scene Reconstruction

    NASA Astrophysics Data System (ADS)

    Schindler, F.; Förstner, W.

    2012-07-01

    We propose a framework for operator guidance during the image acquisition process for reliable multi-view stereo reconstruction. Goal is to achieve full coverage of the object and sufficient overlap. Multi-view stereo is a commonly used method to reconstruct both camera trajectory and 3D object shape. After determining an initial solution, a globally optimal reconstruction is usually obtained by executing a bundle adjustment involving all images. Acquiring suitable images, however, still requires an experienced operator to ensure accuracy and completeness of the final solution. We propose an interactive framework for guiding unexperienced users or possibly an autonomous robot. Using approximate camera orientations and object points we estimate point uncertainties within a sliding bundle adjustment and suggest appropriate camera movements. A visual feedback system communicates the decisions to the user in an intuitive way. We demonstrate the suitability of our system with a virtual image acquisition simulation as well as in real-world scenarios. We show that when following the camera movements suggested by our system, the proposed framework is able to generate good approximate values for the bundle adjustment, leading to accurate results compared to ground truth after few iterations. Possible applications are non-professional 3D acquisition systems on low-cost platforms like mobile phones, autonomously navigating robots as well as online flight planning of unmanned aerial vehicles.

  10. Superficial vessel reconstruction with a multiview camera system.

    PubMed

    Marreiros, Filipe M M; Rossitti, Sandro; Karlsson, Per M; Wang, Chunliang; Gustafsson, Torbjörn; Carleberg, Per; Smedby, Örjan

    2016-01-01

    We aim at reconstructing superficial vessels of the brain. Ultimately, they will serve to guide the deformation methods to compensate for the brain shift. A pipeline for three-dimensional (3-D) vessel reconstruction using three mono-complementary metal-oxide semiconductor cameras has been developed. Vessel centerlines are manually selected in the images. Using the properties of the Hessian matrix, the centerline points are assigned direction information. For correspondence matching, a combination of methods was used. The process starts with epipolar and spatial coherence constraints (geometrical constraints), followed by relaxation labeling and an iterative filtering where the 3-D points are compared to surfaces obtained using the thin-plate spline with decreasing relaxation parameter. Finally, the points are shifted to their local centroid position. Evaluation in virtual, phantom, and experimental images, including intraoperative data from patient experiments, shows that, with appropriate camera positions, the error estimates (root-mean square error and mean error) are [Formula: see text]. PMID:26759814

  11. Plasma tomographic reconstruction from tangentially viewing camera with background subtraction

    SciTech Connect

    Odstrčil, M.; Mlynář, J.; Weinzettl, V.; Háček, P.; Verdoolaege, G.; Berta, M.

    2014-01-15

    Light reflections are one of the main and often underestimated issues of plasma emissivity reconstruction in visible light spectral range. Metallic and other specular components of tokamak generate systematic errors in the optical measurements that could lead to wrong interpretation of data. Our analysis is performed at data from the tokamak COMPASS. It is a D-shaped tokamak with specular metallic vessel and possibility of the H-mode plasma. Data from fast visible light camera were used for tomographic reconstruction with background reflections subtraction to study plasma boundary. In this article, we show that despite highly specular tokamak wall, it is possible to obtain a realistic reconstruction. The developed algorithm shows robust results despite of systematic errors in the optical measurements and calibration. The motivation is to obtain an independent estimate of the plasma boundary shape.

  12. Plasma tomographic reconstruction from tangentially viewing camera with background subtraction.

    PubMed

    Odstrčil, M; Mlynář, J; Weinzettl, V; Háček, P; Odstrčil, T; Verdoolaege, G; Berta, M; Szabolics, T; Bencze, A

    2014-01-01

    Light reflections are one of the main and often underestimated issues of plasma emissivity reconstruction in visible light spectral range. Metallic and other specular components of tokamak generate systematic errors in the optical measurements that could lead to wrong interpretation of data. Our analysis is performed at data from the tokamak COMPASS. It is a D-shaped tokamak with specular metallic vessel and possibility of the H-mode plasma. Data from fast visible light camera were used for tomographic reconstruction with background reflections subtraction to study plasma boundary. In this article, we show that despite highly specular tokamak wall, it is possible to obtain a realistic reconstruction. The developed algorithm shows robust results despite of systematic errors in the optical measurements and calibration. The motivation is to obtain an independent estimate of the plasma boundary shape. PMID:24517767

  13. Sensor Fusion of Cameras and a Laser for City-Scale 3D Reconstruction

    PubMed Central

    Bok, Yunsu; Choi, Dong-Geol; Kweon, In So

    2014-01-01

    This paper presents a sensor fusion system of cameras and a 2D laser sensor for large-scale 3D reconstruction. The proposed system is designed to capture data on a fast-moving ground vehicle. The system consists of six cameras and one 2D laser sensor, and they are synchronized by a hardware trigger. Reconstruction of 3D structures is done by estimating frame-by-frame motion and accumulating vertical laser scans, as in previous works. However, our approach does not assume near 2D motion, but estimates free motion (including absolute scale) in 3D space using both laser data and image features. In order to avoid the degeneration associated with typical three-point algorithms, we present a new algorithm that selects 3D points from two frames captured by multiple cameras. The problem of error accumulation is solved by loop closing, not by GPS. The experimental results show that the estimated path is successfully overlaid on the satellite images, such that the reconstruction result is very accurate. PMID:25375758

  14. Sensor fusion of cameras and a laser for city-scale 3D reconstruction.

    PubMed

    Bok, Yunsu; Choi, Dong-Geol; Kweon, In So

    2014-01-01

    This paper presents a sensor fusion system of cameras and a 2D laser sensorfor large-scale 3D reconstruction. The proposed system is designed to capture data on afast-moving ground vehicle. The system consists of six cameras and one 2D laser sensor,and they are synchronized by a hardware trigger. Reconstruction of 3D structures is doneby estimating frame-by-frame motion and accumulating vertical laser scans, as in previousworks. However, our approach does not assume near 2D motion, but estimates free motion(including absolute scale) in 3D space using both laser data and image features. In orderto avoid the degeneration associated with typical three-point algorithms, we present a newalgorithm that selects 3D points from two frames captured by multiple cameras. The problemof error accumulation is solved by loop closing, not by GPS. The experimental resultsshow that the estimated path is successfully overlaid on the satellite images, such that thereconstruction result is very accurate. PMID:25375758

  15. D Animation Reconstruction from Multi-Camera Coordinates Transformation

    NASA Astrophysics Data System (ADS)

    Jhan, J. P.; Rau, J. Y.; Chou, C. M.

    2016-06-01

    Reservoir dredging issues are important to extend the life of reservoir. The most effective and cost reduction way is to construct a tunnel to desilt the bottom sediment. Conventional technique is to construct a cofferdam to separate the water, construct the intake of tunnel inside and remove the cofferdam afterwards. In Taiwan, the ZengWen reservoir dredging project will install an Elephant-trunk Steel Pipe (ETSP) in the water to connect the desilting tunnel without building the cofferdam. Since the installation is critical to the whole project, a 1:20 model was built to simulate the installation steps in a towing tank, i.e. launching, dragging, water injection, and sinking. To increase the construction safety, photogrammetry technic is adopted to record images during the simulation, compute its transformation parameters for dynamic analysis and reconstruct the 4D animations. In this study, several Australiscoded targets are fixed on the surface of ETSP for auto-recognition and measurement. The cameras orientations are computed by space resection where the 3D coordinates of coded targets are measured. Two approaches for motion parameters computation are proposed, i.e. performing 3D conformal transformation from the coordinates of cameras and relative orientation computation by the orientation of single camera. Experimental results show the 3D conformal transformation can achieve sub-mm simulation results, and relative orientation computation shows the flexibility for dynamic motion analysis which is easier and more efficiency.

  16. Filtered backprojection proton CT reconstruction along most likely paths

    SciTech Connect

    Rit, Simon; Dedes, George; Freud, Nicolas; Sarrut, David; Letang, Jean Michel

    2013-03-15

    Purpose: Proton CT (pCT) has the potential to accurately measure the electron density map of tissues at low doses but the spatial resolution is prohibitive if the curved paths of protons in matter is not accounted for. The authors propose to account for an estimate of the most likely path of protons in a filtered backprojection (FBP) reconstruction algorithm. Methods: The energy loss of protons is first binned in several proton radiographs at different distances to the proton source to exploit the depth-dependency of the estimate of the most likely path. This process is named the distance-driven binning. A voxel-specific backprojection is then used to select the adequate radiograph in the distance-driven binning in order to propagate in the pCT image the best achievable spatial resolution in proton radiographs. The improvement in spatial resolution is demonstrated using Monte Carlo simulations of resolution phantoms. Results: The spatial resolution in the distance-driven binning depended on the distance of the objects from the source and was optimal in the binned radiograph corresponding to that distance. The spatial resolution in the reconstructed pCT images decreased with the depth in the scanned object but it was always better than previous FBP algorithms assuming straight line paths. In a water cylinder with 20 cm diameter, the observed range of spatial resolutions was 0.7 - 1.6 mm compared to 1.0 - 2.4 mm at best with a straight line path assumption. The improvement was strongly enhanced in shorter 200 Degree-Sign scans. Conclusions: Improved spatial resolution was obtained in pCT images with filtered backprojection reconstruction using most likely path estimates of protons. The improvement in spatial resolution combined with the practicality of FBP algorithms compared to iterative reconstruction algorithms makes this new algorithm a candidate of choice for clinical pCT.

  17. Court Reconstruction for Camera Calibration in Broadcast Basketball Videos.

    PubMed

    Wen, Pei-Chih; Cheng, Wei-Chih; Wang, Yu-Shuen; Chu, Hung-Kuo; Tang, Nick C; Liao, Hong-Yuan Mark

    2016-05-01

    We introduce a technique of calibrating camera motions in basketball videos. Our method particularly transforms player positions to standard basketball court coordinates and enables applications such as tactical analysis and semantic basketball video retrieval. To achieve a robust calibration, we reconstruct the panoramic basketball court from a video, followed by warping the panoramic court to a standard one. As opposed to previous approaches, which individually detect the court lines and corners of each video frame, our technique considers all video frames simultaneously to achieve calibration; hence, it is robust to illumination changes and player occlusions. To demonstrate the feasibility of our technique, we present a stroke-based system that allows users to retrieve basketball videos. Our system tracks player trajectories from broadcast basketball videos. It then rectifies the trajectories to a standard basketball court by using our camera calibration method. Consequently, users can apply stroke queries to indicate how the players move in gameplay during retrieval. The main advantage of this interface is an explicit query of basketball videos so that unwanted outcomes can be prevented. We show the results in Figs. 1, 7, 9, 10 and our accompanying video to exhibit the feasibility of our technique. PMID:27504515

  18. Stereo Reconstruction of Atmospheric Cloud Surfaces from Fish-Eye Camera Images

    NASA Astrophysics Data System (ADS)

    Katai-Urban, G.; Otte, V.; Kees, N.; Megyesi, Z.; Bixel, P. S.

    2016-06-01

    In this article a method for reconstructing atmospheric cloud surfaces using a stereo camera system is presented. The proposed camera system utilizes fish-eye lenses in a flexible wide baseline camera setup. The entire workflow from the camera calibration to the creation of the 3D point set is discussed, but the focus is mainly on cloud segmentation and on the image processing steps of stereo reconstruction. Speed requirements, geometric limitations, and possible extensions of the presented method are also covered. After evaluating the proposed method on artificial cloud images, this paper concludes with results and discussion of possible applications for such systems.

  19. Phase and amplitude wave front sensing and reconstruction with a modified plenoptic camera

    NASA Astrophysics Data System (ADS)

    Wu, Chensheng; Ko, Jonathan; Nelson, William; Davis, Christopher C.

    2014-10-01

    A plenoptic camera is a camera that can retrieve the direction and intensity distribution of light rays collected by the camera and allows for multiple reconstruction functions such as: refocusing at a different depth, and for 3D microscopy. Its principle is to add a micro-lens array to a traditional high-resolution camera to form a semi-camera array that preserves redundant intensity distributions of the light field and facilitates back-tracing of rays through geometric knowledge of its optical components. Though designed to process incoherent images, we found that the plenoptic camera shows high potential in solving coherent illumination cases such as sensing both the amplitude and phase information of a distorted laser beam. Based on our earlier introduction of a prototype modified plenoptic camera, we have developed the complete algorithm to reconstruct the wavefront of the incident light field. In this paper the algorithm and experimental results will be demonstrated, and an improved version of this modified plenoptic camera will be discussed. As a result, our modified plenoptic camera can serve as an advanced wavefront sensor compared with traditional Shack- Hartmann sensors in handling complicated cases such as coherent illumination in strong turbulence where interference and discontinuity of wavefronts is common. Especially in wave propagation through atmospheric turbulence, this camera should provide a much more precise description of the light field, which would guide systems in adaptive optics to make intelligent analysis and corrections.

  20. Resolving multiple propagation paths in time of flight range cameras using direct and global separation methods

    NASA Astrophysics Data System (ADS)

    Whyte, Refael; Streeter, Lee; Cree, Michael J.; Dorrington, Adrian A.

    2015-11-01

    Time of flight (ToF) range cameras illuminate the scene with an amplitude-modulated continuous wave light source and measure the returning modulation envelopes: phase and amplitude. The phase change of the modulation envelope encodes the distance travelled. This technology suffers from measurement errors caused by multiple propagation paths from the light source to the receiving pixel. The multiple paths can be represented as the summation of a direct return, which is the return from the shortest path length, and a global return, which includes all other returns. We develop the use of a sinusoidal pattern from which a closed form solution for the direct and global returns can be computed in nine frames with the constraint that the global return is a spatially lower frequency than the illuminated pattern. In a demonstration on a scene constructed to have strong multipath interference, we find the direct return is not significantly different from the ground truth in 33/136 pixels tested; where for the full-field measurement, it is significantly different for every pixel tested. The variance in the estimated direct phase and amplitude increases by a factor of eight compared with the standard time of flight range camera technique.

  1. Effects of light refraction on the accuracy of camera calibration and reconstruction in underwater motion analysis.

    PubMed

    Kwon, Young-Hoo; Casebolt, Jeffrey B

    2006-01-01

    One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water-air interface plane (glass) owing to the density difference. Camera calibration-reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction-induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a through review of: the nature of the refraction-induced image deformation and its behaviour in underwater object-space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration-reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration-reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double-plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction. PMID:16521625

  2. Effects of light refraction on the accuracy of camera calibration and reconstruction in underwater motion analysis.

    PubMed

    Kwon, Young-Hoo; Casebolt, Jeffrey B

    2006-07-01

    One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water-air interface plane (glass) owing to the density difference. Camera calibration-reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction-induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a thorough review of: the nature of the refraction-induced image deformation and its behaviour in underwater object-space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration-reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration-reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double-plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction. PMID:16939159

  3. Towards direct reconstruction from a gamma camera based on compton scattering

    SciTech Connect

    Cree, M.J.; Bones, P.J. . Dept. of Electrical and Electronic Engineering)

    1994-06-01

    The Compton scattering camera (sometimes called the electronically collimated camera) has been shown by others to have the potential to better the photon counting statistics and the energy resolution of the Anger camera for imaging in SPECT. By using coincident detection of Compton scattering events on two detecting planes, a photon can be localized to having been sourced on the surface of a cone. New algorithms are needed to achieve fully three-dimensional reconstruction of the source distribution from such a camera. If a complete set of cone-surface projections are collected over an infinitely extending plane, it is shown that the reconstruction problem is not only analytically solvable, but also overspecified in the absence of measurement uncertainties. Two approaches to direct reconstruction are proposed, both based on the photons which travel perpendicularly between the detector planes. Results of computer simulations are presented which demonstrate the ability of the algorithms to achieve useful reconstructions in the absence of measurement uncertainties (other than those caused by quantization). The modifications likely to be required in the presence of realistic measurement uncertainties are discussed.

  4. A fast 3D reconstruction system with a low-cost camera accessory

    PubMed Central

    Zhang, Yiwei; Gibson, Graham M.; Hay, Rebecca; Bowman, Richard W.; Padgett, Miles J.; Edgar, Matthew P.

    2015-01-01

    Photometric stereo is a three dimensional (3D) imaging technique that uses multiple 2D images, obtained from a fixed camera perspective, with different illumination directions. Compared to other 3D imaging methods such as geometry modeling and 3D-scanning, it comes with a number of advantages, such as having a simple and efficient reconstruction routine. In this work, we describe a low-cost accessory to a commercial digital single-lens reflex (DSLR) camera system allowing fast reconstruction of 3D objects using photometric stereo. The accessory consists of four white LED lights fixed to the lens of a commercial DSLR camera and a USB programmable controller board to sequentially control the illumination. 3D images are derived for different objects with varying geometric complexity and results are presented, showing a typical height error of <3 mm for a 50 mm sized object. PMID:26057407

  5. A fast 3D reconstruction system with a low-cost camera accessory

    NASA Astrophysics Data System (ADS)

    Zhang, Yiwei; Gibson, Graham M.; Hay, Rebecca; Bowman, Richard W.; Padgett, Miles J.; Edgar, Matthew P.

    2015-06-01

    Photometric stereo is a three dimensional (3D) imaging technique that uses multiple 2D images, obtained from a fixed camera perspective, with different illumination directions. Compared to other 3D imaging methods such as geometry modeling and 3D-scanning, it comes with a number of advantages, such as having a simple and efficient reconstruction routine. In this work, we describe a low-cost accessory to a commercial digital single-lens reflex (DSLR) camera system allowing fast reconstruction of 3D objects using photometric stereo. The accessory consists of four white LED lights fixed to the lens of a commercial DSLR camera and a USB programmable controller board to sequentially control the illumination. 3D images are derived for different objects with varying geometric complexity and results are presented, showing a typical height error of <3 mm for a 50 mm sized object.

  6. Full 3-D cluster-based iterative image reconstruction tool for a small animal PET camera

    NASA Astrophysics Data System (ADS)

    Valastyán, I.; Imrek, J.; Molnár, J.; Novák, D.; Balkay, L.; Emri, M.; Trón, L.; Bükki, T.; Kerek, A.

    2007-02-01

    Iterative reconstruction methods are commonly used to obtain images with high resolution and good signal-to-noise ratio in nuclear imaging. The aim of this work was to develop a scalable, fast, cluster based, fully 3-D iterative image reconstruction package for our small animal PET camera, the miniPET. The reconstruction package is developed to determine the 3-D radioactivity distribution from list mode type of data sets and it can also simulate noise-free projections of digital phantoms. We separated the system matrix generation and the fully 3-D iterative reconstruction process. As the detector geometry is fixed for a given camera, the system matrix describing this geometry is calculated only once and used for every image reconstruction, making the process much faster. The Poisson and the random noise sensitivity of the ML-EM iterative algorithm were studied for our small animal PET system with the help of the simulation and reconstruction tool. The reconstruction tool has also been tested with data collected by the miniPET from a line and a cylinder shaped phantom and also a rat.

  7. Minimizing camera-eye optical aberrations during the 3D reconstruction of retinal structures

    NASA Astrophysics Data System (ADS)

    Aldana-Iuit, Javier; Martinez-Perez, M. Elena; Espinosa-Romero, Arturo; Diaz-Uribe, Rufino

    2010-05-01

    3D reconstruction of blood vessels is a powerful visualization tool for physicians, since it allows them to refer to qualitative representation of their subject of study. In this paper we propose a 3D reconstruction method of retinal vessels from fundus images. The reconstruction method propose herein uses images of the same retinal structure in epipolar geometry. Images are preprocessed by RISA system for segmenting blood vessels and obtaining feature points for correspondences. The correspondence points process is solved using correlation. The LMedS analysis and Graph Transformation Matching algorithm are used for outliers suppression. Camera projection matrices are computed with the normalized eight point algorithm. Finally, we retrieve 3D position of the retinal tree points by linear triangulation. In order to increase the power of visualization, 3D tree skeletons are represented by surfaces via generalized cylinders whose radius correspond to morphological measurements obtained by RISA. In this paper the complete calibration process including the fundus camera and the optical properties of the eye, the so called camera-eye system is proposed. On one hand, the internal parameters of the fundus camera are obtained by classical algorithms using a reference pattern. On the other hand, we minimize the undesirable efects of the aberrations induced by the eyeball optical system assuming that contact enlarging lens corrects astigmatism, spherical and coma aberrations are reduced changing the aperture size and eye refractive errors are suppressed adjusting camera focus during image acquisition. Evaluation of two self-calibration proposals and results of 3D blood vessel surface reconstruction are presented.

  8. Methods of bronchial tree reconstruction and camera distortion corrections for virtual endoscopic environments.

    PubMed

    Socha, Mirosław; Duplaga, Mariusz; Turcza, Paweł

    2004-01-01

    The use of three-dimensional visualization of anatomical structures in diagnostics and medical training is growing. The main components of virtual respiratory tract environments include reconstruction and simulation algorithms as well as correction methods of endoscope camera distortions in the case of virtually-enhanced navigation systems. Reconstruction methods rely usually on initial computer tomography (CT) image segmentation to trace contours of the tracheobronchial tree, which in turn are used in the visualization process. The main segmentation methods, including relatively simple approaches such as adaptive region-growing algorithms and more complex methods, e.g. hybrid algorithms based on region growing and mathematical morphology methods, are described in this paper. The errors and difficulties in the process of tracheobronchial tree reconstruction depend on the occurrence of distortions during CT image acquisition. They are usually related to the inability to exactly fulfil the sampling theorem's conditions. Other forms of distortions and noise such as additive white Gaussian noise, may also appear. The impact of these distortions on the segmentation and reconstruction may be diminished through the application of appropriately selected image prefiltering, which is also demonstrated in this paper. Methods of surface rendering (ray-casting, ray-tracing techniques) and volume rendering will be shown, with special focus on aspects of hardware and software implementations. Finally, methods of camera distortions correction and simulation are presented. The mathematical camera models, the scope of their applications and types of distortions were have also been indicated. PMID:15718617

  9. Semantically Documenting Virtual Reconstruction: Building a Path to Knowledge Provenance

    NASA Astrophysics Data System (ADS)

    Bruseker, G.; Guillem, A.; Carboni, N.

    2015-08-01

    The outcomes of virtual reconstructions of archaeological monuments are not just images for aesthetic consumption but rather present a scholarly argument and decision making process. They are based on complex chains of reasoning grounded in primary and secondary evidence that enable a historically probable whole to be reconstructed from the partial remains left in the archaeological record. This paper will explore the possibilities for documenting and storing in an information system the phases of the reasoning, decision and procedures that a modeler, with the support of an archaeologist, uses during the virtual reconstruction process and how they can be linked to the reconstruction output. The goal is to present a documentation model such that the foundations of evidence for the reconstructed elements, and the reasoning around them, are made not only explicit and interrogable but also can be updated, extended and reused by other researchers in future work. Using as a case-study the reconstruction of a kitchen in a Roman domus in Grand, we will examine the necessary documentation requirements, and the capacity to express it using semantic technologies. For our study we adopt the CIDOC-CRM ontological model, and its extensions CRMinf, CRMBa and CRMgeo as a starting point for modelling the arguments and relations.

  10. Differentiating Biological Colours with Few and Many Sensors: Spectral Reconstruction with RGB and Hyperspectral Cameras

    PubMed Central

    Garcia, Jair E.; Girard, Madeline B.; Kasumovic, Michael; Petersen, Phred; Wilksch, Philip A.; Dyer, Adrian G.

    2015-01-01

    Background The ability to discriminate between two similar or progressively dissimilar colours is important for many animals as it allows for accurately interpreting visual signals produced by key target stimuli or distractor information. Spectrophotometry objectively measures the spectral characteristics of these signals, but is often limited to point samples that could underestimate spectral variability within a single sample. Algorithms for RGB images and digital imaging devices with many more than three channels, hyperspectral cameras, have been recently developed to produce image spectrophotometers to recover reflectance spectra at individual pixel locations. We compare a linearised RGB and a hyperspectral camera in terms of their individual capacities to discriminate between colour targets of varying perceptual similarity for a human observer. Main Findings (1) The colour discrimination power of the RGB device is dependent on colour similarity between the samples whilst the hyperspectral device enables the reconstruction of a unique spectrum for each sampled pixel location independently from their chromatic appearance. (2) Uncertainty associated with spectral reconstruction from RGB responses results from the joint effect of metamerism and spectral variability within a single sample. Conclusion (1) RGB devices give a valuable insight into the limitations of colour discrimination with a low number of photoreceptors, as the principles involved in the interpretation of photoreceptor signals in trichromatic animals also apply to RGB camera responses. (2) The hyperspectral camera architecture provides means to explore other important aspects of colour vision like the perception of certain types of camouflage and colour constancy where multiple, narrow-band sensors increase resolution. PMID:25965264

  11. D Reconstruction of AN Underwater Archaelogical Site: Comparison Between Low Cost Cameras

    NASA Astrophysics Data System (ADS)

    Capra, A.; Dubbini, M.; Bertacchini, E.; Castagnetti, C.; Mancini, F.

    2015-04-01

    The 3D reconstruction with a metric content of a submerged area, where objects and structures of archaeological interest are found, could play an important role in the research and study activities and even in the digitization of the cultural heritage. The reconstruction of 3D object, of interest for archaeologists, constitutes a starting point in the classification and description of object in digital format and for successive fruition by user after delivering through several media. The starting point is a metric evaluation of the site obtained with photogrammetric surveying and appropriate 3D restitution. The authors have been applying the underwater photogrammetric technique since several years using underwater digital cameras and, in this paper, digital low cost cameras (off-the-shelf). Results of tests made on submerged objects with three cameras are presented: Canon Power Shot G12, Intova Sport HD e GoPro HERO 2. The experimentation had the goal to evaluate the precision in self-calibration procedures, essential for multimedia underwater photogrammetry, and to analyze the quality of 3D restitution. Precisions obtained in the calibration and orientation procedures was assessed by using three cameras, and an homogeneous set control points. Data were processed with Agisoft Photoscan. Successively, 3D models were created and the comparison of the models derived from the use of different cameras was performed. Different potentialities of the used cameras are reported in the discussion section. The 3D restitution of objects and structures was integrated with sea bottom floor morphology in order to achieve a comprehensive description of the site. A possible methodology of survey and representation of submerged objects is therefore illustrated, considering an automatic and a semi-automatic approach.

  12. Path method for reconstructing images in fluorescence optical tomography

    SciTech Connect

    Kravtsenyuk, Olga V; Lyubimov, Vladimir V; Kalintseva, Natalie A

    2006-11-30

    A reconstruction method elaborated for the optical diffusion tomography of the internal structure of objects containing absorbing and scattering inhomogeneities is considered. The method is developed for studying objects with fluorescing inhomogeneities and can be used for imaging of distributions of artificial fluorophores whose aggregations indicate the presence of various diseases or pathological deviations. (special issue devoted to multiple radiation scattering in random media)

  13. A comparison of dense matching algorithms for scaled surface reconstruction using stereo camera rigs

    NASA Astrophysics Data System (ADS)

    Ahmadabadian, Ali Hosseininaveh; Robson, Stuart; Boehm, Jan; Shortis, Mark; Wenzel, Konrad; Fritsch, Dieter

    2013-04-01

    Photogrammetric methods for dense 3D surface reconstruction are increasingly available to both professional and amateur users who have requirements that span a wide variety of applications. One of the key concerns in choosing an appropriate method is to understand the achievable accuracy and how choices made within the workflow can alter that outcome. In this paper we consider accuracy in two components: the ability to generate a correctly scaled 3D model; and the ability to automatically deliver a high quality data set that provides good agreement to a reference surface. The determination of scale information is particularly important, since a network of images usually only provides angle measurements and thus leads to unscaled geometry. A solution is the introduction of known distances in object space, such as base lines between camera stations or distances between control points. In order to avoid using known object distances, the method presented in this paper exploits a calibrated stereo camera utilizing the calibrated base line information from the camera pair as an observational based geometric constraint. The method provides distance information throughout the object volume by orbiting the object. In order to test the performance of this approach, four topical surface matching methods have been investigated to determine their ability to produce accurate, dense point clouds. The methods include two versions of Semi-Global Matching as well as MicMac and Patch-based Multi-View Stereo (PMVS). These methods are implemented on a set of stereo images captured from four carefully selected objects by using (1) an off-the-shelf low cost 3D camera and (2) a pair of Nikon D700 DSLR cameras rigidly mounted in close proximity to each other. Inter-comparisons demonstrate the subtle differences between each of these permutations. The point clouds are also compared to a dataset obtained with a Nikon MMD laser scanner. Finally, the established process of achieving accurate

  14. Precise Trajectory Reconstruction of CE-3 Hovering Stage By Landing Camera Images

    NASA Astrophysics Data System (ADS)

    Yan, W.; Liu, J.; Li, C.; Ren, X.; Mu, L.; Gao, X.; Zeng, X.

    2014-12-01

    Chang'E-3 (CE-3) is part of the second phase of the Chinese Lunar Exploration Program, incorporating a lander and China's first lunar rover. It was landed on 14 December, 2013 successfully. Hovering and obstacle avoidance stages are essential for CE-3 safety soft landing so that precise spacecraft trajectory in these stages are of great significance to verify orbital control strategy, to optimize orbital design, to accurately determine the landing site of CE-3, and to analyze the geological background of the landing site. Because the time consumption of these stages is just 25s, it is difficult to present spacecraft's subtle movement by Measurement and Control System or by radio observations. Under this background, the trajectory reconstruction based on landing camera images can be used to obtain the trajectory of CE-3 because of its technical advantages such as unaffecting by lunar gravity field spacecraft kinetic model, high resolution, high frame rate, and so on. In this paper, the trajectory of CE-3 before and after entering hovering stage was reconstructed by landing camera images from frame 3092 to frame 3180, which lasted about 9s, under Single Image Space Resection (SISR). The results show that CE-3's subtle changes during hovering stage can be emerged by the reconstructed trajectory. The horizontal accuracy of spacecraft position was up to 1.4m while vertical accuracy was up to 0.76m. The results can be used for orbital control strategy analysis and some other application fields.

  15. Realtime Reconstruction of an Animating Human Body from a Single Depth Camera.

    PubMed

    Chen, Yin; Cheng, Zhi-Quan; Lai, Chao; Martin, Ralph R; Dang, Gang

    2016-08-01

    We present a method for realtime reconstruction of an animating human body,which produces a sequence of deforming meshes representing a given performance captured by a single commodity depth camera. We achieve realtime single-view mesh completion by enhancing the parameterized SCAPE model.Our method, which we call Realtime SCAPE, performs full-body reconstruction without the use of markers.In Realtime SCAPE, estimations of body shape parameters and pose parameters, needed for reconstruction, are decoupled. Intrinsic body shape is first precomputed for a given subject, by determining shape parameters with the aid of a body shape database. Subsequently, per-frame pose parameter estimation is performed by means of linear blending skinning (LBS); the problem is decomposed into separately finding skinning weights and transformations. The skinning weights are also determined offline from the body shape database,reducing online reconstruction to simply finding the transformations in LBS. Doing so is formulated as a linear variational problem;carefully designed constraints are used to impose temporal coherence and alleviate artifacts. Experiments demonstrate that our method can produce full-body mesh sequences with high fidelity. PMID:26390493

  16. Reconstruction of long horizontal-path images under anisoplanatic conditions using multiframe blind deconvolution

    NASA Astrophysics Data System (ADS)

    Archer, Glen E.; Bos, Jeremy P.; Roggemann, Michael C.

    2013-08-01

    All optical systems that operate in or through the atmosphere suffer from turbulence induced image blur. Both military and civilian surveillance, gun sighting, and target identification systems are interested in terrestrial imaging over very long horizontal paths, but atmospheric turbulence can blur the resulting images beyond usefulness. This work explores the mean square error (MSE) performance of a multiframe blind deconvolution (MFBD) technique applied under anisoplanatic conditions for both Gaussian and Poisson noise model assumptions. The technique is evaluated for use in reconstructing images of scenes corrupted by turbulence in long horizontal-path imaging scenarios. Performance is evaluated via the reconstruction of a common object from three sets of simulated turbulence degraded imagery representing low, moderate, and severe turbulence conditions. Each set consisted of 1000 simulated turbulence degraded images. The MSE performance of the estimator is evaluated as a function of the number of images, and the number of Zernike polynomial terms used to characterize the point spread function. A Gaussian noise model-based MFBD algorithm reconstructs objects that showed as much as 40% improvement in MSE with as few as 14 frames and 30 Zernike coefficients used in the reconstruction, despite the presence of anisoplanatism in the data. An MFBD algorithm based on the Poisson noise model required a minimum of 50 frames to achieve significant improvement over the average MSE for the data set. Reconstructed objects show as much as 38% improvement in MSE using 175 frames and 30 Zernike coefficients in the reconstruction.

  17. Moving beyond flat earth: dense 3D scene reconstruction from a single FL-LWIR camera

    NASA Astrophysics Data System (ADS)

    Stone, K.; Keller, J. M.; Anderson, D. T.

    2013-06-01

    In previous work an automatic detection system for locating buried explosive hazards in forward-looking longwave infrared (FL-LWIR) and forward-looking ground penetrating radar (FL-GPR) data was presented. This system consists of an ensemble of trainable size-contrast filters prescreener coupled with a secondary classification step which extracts cell-structured image space features, such as local binary patterns (LBP), histogram of oriented gradients (HOG), and edge histogram descriptors (EHD), from multiple looks and classifies the resulting feature vectors using a support vector machine. Previously, this system performed image space to UTM coordinate mapping under a flat earth assumption. This limited its applicability to flat terrain and short standoff distances. This paper demonstrates a technique for dense 3D scene reconstruction from a single vehicle mounted FL-LWIR camera. This technique utilizes multiple views and standard stereo vision algorithms such as polar rectification and optimal correction. Results for the detection algorithm using this 3D scene reconstruction approach on data from recent collections at an arid US Army test site are presented. These results are compared to those obtained under the flat earth assumption, with special focus on rougher terrain and longer standoff distance than in previous experiments. The most recent collection also allowed comparison between uncooled and cooled FL-LWIR cameras for buried explosive hazard detection.

  18. Real-time depth controllable integral imaging pickup and reconstruction method with a light field camera.

    PubMed

    Jeong, Youngmo; Kim, Jonghyun; Yeom, Jiwoon; Lee, Chang-Kun; Lee, Byoungho

    2015-12-10

    In this paper, we develop a real-time depth controllable integral imaging system. With a high-frame-rate camera and a focus controllable lens, light fields from various depth ranges can be captured. According to the image plane of the light field camera, the objects in virtual and real space are recorded simultaneously. The captured light field information is converted to the elemental image in real time without pseudoscopic problems. In addition, we derive characteristics and limitations of the light field camera as a 3D broadcasting capturing device with precise geometry optics. With further analysis, the implemented system provides more accurate light fields than existing devices without depth distortion. We adapt an f-number matching method at the capture and display stage to record a more exact light field and solve depth distortion, respectively. The algorithm allows the users to adjust the pixel mapping structure of the reconstructed 3D image in real time. The proposed method presents a possibility of a handheld real-time 3D broadcasting system in a cheaper and more applicable way as compared to the previous methods. PMID:26836855

  19. Reconstructing phonon mean-free-path contributions to thermal conductivity using nanoscale membranes

    NASA Astrophysics Data System (ADS)

    Cuffe, John; Eliason, Jeffrey K.; Maznev, A. A.; Collins, Kimberlee C.; Johnson, Jeremy A.; Shchepetov, Andrey; Prunnila, Mika; Ahopelto, Jouni; Sotomayor Torres, Clivia M.; Chen, Gang; Nelson, Keith A.

    2015-06-01

    Knowledge of the mean-free-path distribution of heat-carrying phonons is key to understanding phonon-mediated thermal transport. We demonstrate that thermal conductivity measurements of thin membranes spanning a wide thickness range can be used to characterize how bulk thermal conductivity is distributed over phonon mean free paths. A noncontact transient thermal grating technique was used to measure the thermal conductivity of suspended Si membranes ranging from 15-1500 nm in thickness. A decrease in the thermal conductivity from 74-13% of the bulk value is observed over this thickness range, which is attributed to diffuse phonon boundary scattering. Due to the well-defined relation between the membrane thickness and phonon mean-free-path suppression, combined with the range and accuracy of the measurements, we can reconstruct the bulk thermal conductivity accumulation vs. phonon mean free path, and compare with theoretical models.

  20. Calibration of time-of-flight cameras for accurate intraoperative surface reconstruction

    SciTech Connect

    Mersmann, Sven; Seitel, Alexander; Maier-Hein, Lena; Erz, Michael; Jähne, Bernd; Nickel, Felix; Mieth, Markus; Mehrabi, Arianeb

    2013-08-15

    Purpose: In image-guided surgery (IGS) intraoperative image acquisition of tissue shape, motion, and morphology is one of the main challenges. Recently, time-of-flight (ToF) cameras have emerged as a new means for fast range image acquisition that can be used for multimodal registration of the patient anatomy during surgery. The major drawbacks of ToF cameras are systematic errors in the image acquisition technique that compromise the quality of the measured range images. In this paper, we propose a calibration concept that, for the first time, accounts for all known systematic errors affecting the quality of ToF range images. Laboratory and in vitro experiments assess its performance in the context of IGS.Methods: For calibration the camera-related error sources depending on the sensor, the sensor temperature and the set integration time are corrected first, followed by the scene-specific errors, which are modeled as function of the measured distance, the amplitude and the radial distance to the principal point of the camera. Accounting for the high accuracy demands in IGS, we use a custom-made calibration device to provide reference distance data, the cameras are calibrated too. To evaluate the mitigation of the error, the remaining residual error after ToF depth calibration was compared with that arising from using the manufacturer routines for several state-of-the-art ToF cameras. The accuracy of reconstructed ToF surfaces was investigated after multimodal registration with computed tomography (CT) data of liver models by assessment of the target registration error (TRE) of markers introduced in the livers.Results: For the inspected distance range of up to 2 m, our calibration approach yielded a mean residual error to reference data ranging from 1.5 ± 4.3 mm for the best camera to 7.2 ± 11.0 mm. When compared to the data obtained from the manufacturer routines, the residual error was reduced by at least 78% from worst calibration result to most accurate

  1. Incremental Multi-view 3D Reconstruction Starting from Two Images Taken by a Stereo Pair of Cameras

    NASA Astrophysics Data System (ADS)

    El hazzat, Soulaiman; Saaidi, Abderrahim; Karam, Antoine; Satori, Khalid

    2015-03-01

    In this paper, we present a new method for multi-view 3D reconstruction based on the use of a binocular stereo vision system constituted of two unattached cameras to initialize the reconstruction process. Afterwards , the second camera of stereo vision system (characterized by varying parameters) moves to capture more images at different times which are used to obtain an almost complete 3D reconstruction. The first two projection matrices are estimated by using a 3D pattern with known properties. After that, 3D scene points are recovered by triangulation of the matched interest points between these two images. The proposed approach is incremental. At each insertion of a new image, the camera projection matrix is estimated using the 3D information already calculated and new 3D points are recovered by triangulation from the result of the matching of interest points between the inserted image and the previous image. For the refinement of the new projection matrix and the new 3D points, a local bundle adjustment is performed. At first, all projection matrices are estimated, the matches between consecutive images are detected and Euclidean sparse 3D reconstruction is obtained. So, to increase the number of matches and have a more dense reconstruction, the Match propagation algorithm, more suitable for interesting movement of the camera, was applied on the pairs of consecutive images. The experimental results show the power and robustness of the proposed approach.

  2. A Trajectory and Orientation Reconstruction Method for Moving Objects Based on a Moving Monocular Camera

    PubMed Central

    Zhou, Jian; Shang, Yang; Zhang, Xiaohu; Yu, Wenxian

    2015-01-01

    We propose a monocular trajectory intersection method to solve the problem that a monocular moving camera cannot be used for three-dimensional reconstruction of a moving object point. The necessary and sufficient condition of when this method has the unique solution is provided. An extended application of the method is to not only achieve the reconstruction of the 3D trajectory, but also to capture the orientation of the moving object, which would not be obtained by PnP problem methods due to lack of features. It is a breakthrough improvement that develops the intersection measurement from the traditional “point intersection” to “trajectory intersection” in videometrics. The trajectory of the object point can be obtained by using only linear equations without any initial value or iteration; the orientation of the object with poor conditions can also be calculated. The required condition for the existence of definite solution of this method is derived from equivalence relations of the orders of the moving trajectory equations of the object, which specifies the applicable conditions of the method. Simulation and experimental results show that it not only applies to objects moving along a straight line, or a conic and another simple trajectory, but also provides good result for more complicated trajectories, making it widely applicable. PMID:25760053

  3. The Effect of Tissue Inhomogeneities on the Accuracy of Proton Path Reconstruction for Proton Computed Tomography

    NASA Astrophysics Data System (ADS)

    Wong, Kent; Erdelyi, Bela; Schulte, Reinhard; Bashkirov, Vladimir; Coutrakon, George; Sadrozinski, Hartmut; Penfold, Scott; Rosenfeld, Anatoly

    2009-03-01

    Maintaining a high degree of spatial resolution in proton computed tomography (pCT) is a challenge due to the statistical nature of the proton path through the object. Recent work has focused on the formulation of the most likely path (MLP) of protons through a homogeneous water object and the accuracy of this approach has been tested experimentally with a homogeneous PMMA phantom. Inhomogeneities inside the phantom, consisting of, for example, air and bone will lead to unavoidable inaccuracies of this approach. The purpose of this ongoing work is to characterize systematic errors that are introduced by regions of bone and air density and how this affects the accuracy of proton CT in surrounding voxels both in terms of spatial and density reconstruction accuracy. Phantoms containing tissue-equivalent inhomogeneities have been designed and proton transport through them has been simulated with the GEANT 4.9.0 Monte Carlo tool kit. Various iterative reconstruction techniques, including the classical fully sequential algebraic reconstruction technique (ART) and block-iterative techniques, are currently being tested, and we will select the most accurate method for this study.

  4. The Effect of Tissue Inhomogeneities on the Accuracy of Proton Path Reconstruction for Proton Computed Tomography

    SciTech Connect

    Wong, Kent; Erdelyi, Bela; Schulte, Reinhard; Bashkirov, Vladimir; Coutrakon, George; Sadrozinski, Hartmut; Penfold, Scott; Rosenfeld, Anatoly

    2009-03-10

    Maintaining a high degree of spatial resolution in proton computed tomography (pCT) is a challenge due to the statistical nature of the proton path through the object. Recent work has focused on the formulation of the most likely path (MLP) of protons through a homogeneous water object and the accuracy of this approach has been tested experimentally with a homogeneous PMMA phantom. Inhomogeneities inside the phantom, consisting of, for example, air and bone will lead to unavoidable inaccuracies of this approach. The purpose of this ongoing work is to characterize systematic errors that are introduced by regions of bone and air density and how this affects the accuracy of proton CT in surrounding voxels both in terms of spatial and density reconstruction accuracy. Phantoms containing tissue-equivalent inhomogeneities have been designed and proton transport through them has been simulated with the GEANT 4.9.0 Monte Carlo tool kit. Various iterative reconstruction techniques, including the classical fully sequential algebraic reconstruction technique (ART) and block-iterative techniques, are currently being tested, and we will select the most accurate method for this study.

  5. [Reconstruction of possible paths of the origin and morphological evolution of bacteriophages].

    PubMed

    Letarov, A V

    1998-11-01

    The problem of the origin and evolution of viruses and, in particular, the origin and evolution of bacteriophages is of considerable interest. However, so far, this problem has not been solved with quantitative methods of molecular systematics. In the present study, an attempt to reconstruct the possible paths of appearance and evolution of bacteriophages based on their structural features and morphogenesis, as well as general characteristics of their life cycles and genome organization, was carried out. A scheme describing phylogeny of the main bacteriophage groups and evolution of their life cycles is suggested. Existence of two independently evaluating types of morphogenesis ("budding outward" and "budding inward") is postulated. PMID:10096023

  6. An accelerated threshold-based back-projection algorithm for Compton camera image reconstruction

    SciTech Connect

    Mundy, Daniel W.; Herman, Michael G.

    2011-01-15

    Purpose: Compton camera imaging (CCI) systems are currently under investigation for radiotherapy dose reconstruction and verification. The ability of such a system to provide real-time images during dose delivery will be limited by the computational speed of the image reconstruction algorithm. In this work, the authors present a fast and simple method by which to generate an initial back-projected image from acquired CCI data, suitable for use in a filtered back-projection algorithm or as a starting point for iterative reconstruction algorithms, and compare its performance to the current state of the art. Methods: Each detector event in a CCI system describes a conical surface that includes the true point of origin of the detected photon. Numerical image reconstruction algorithms require, as a first step, the back-projection of each of these conical surfaces into an image space. The algorithm presented here first generates a solution matrix for each slice of the image space by solving the intersection of the conical surface with the image plane. Each element of the solution matrix is proportional to the distance of the corresponding voxel from the true intersection curve. A threshold function was developed to extract those pixels sufficiently close to the true intersection to generate a binary intersection curve. This process is repeated for each image plane for each CCI detector event, resulting in a three-dimensional back-projection image. The performance of this algorithm was tested against a marching algorithm known for speed and accuracy. Results: The threshold-based algorithm was found to be approximately four times faster than the current state of the art with minimal deficit to image quality, arising from the fact that a generically applicable threshold function cannot provide perfect results in all situations. The algorithm fails to extract a complete intersection curve in image slices near the detector surface for detector event cones having axes nearly

  7. A comparison of multi-view 3D reconstruction of a rock wall using several cameras and a laser scanner

    NASA Astrophysics Data System (ADS)

    Thoeni, K.; Giacomini, A.; Murtagh, R.; Kniest, E.

    2014-06-01

    This work presents a comparative study between multi-view 3D reconstruction using various digital cameras and a terrestrial laser scanner (TLS). Five different digital cameras were used in order to estimate the limits related to the camera type and to establish the minimum camera requirements to obtain comparable results to the ones of the TLS. The cameras used for this study range from commercial grade to professional grade and included a GoPro Hero 1080 (5 Mp), iPhone 4S (8 Mp), Panasonic Lumix LX5 (9.5 Mp), Panasonic Lumix ZS20 (14.1 Mp) and Canon EOS 7D (18 Mp). The TLS used for this work was a FARO Focus 3D laser scanner with a range accuracy of ±2 mm. The study area is a small rock wall of about 6 m height and 20 m length. The wall is partly smooth with some evident geological features, such as non-persistent joints and sharp edges. Eight control points were placed on the wall and their coordinates were measured by using a total station. These coordinates were then used to georeference all models. A similar number of images was acquired from a distance of between approximately 5 to 10 m, depending on field of view of each camera. The commercial software package PhotoScan was used to process the images, georeference and scale the models, and to generate the dense point clouds. Finally, the open-source package CloudCompare was used to assess the accuracy of the multi-view results. Each point cloud obtained from a specific camera was compared to the point cloud obtained with the TLS. The latter is taken as ground truth. The result is a coloured point cloud for each camera showing the deviation in relation to the TLS data. The main goal of this study is to quantify the quality of the multi-view 3D reconstruction results obtained with various cameras as objectively as possible and to evaluate its applicability to geotechnical problems.

  8. DIC image reconstruction using an energy minimization framework to visualize optical path length distribution

    PubMed Central

    Koos, Krisztian; Molnár, József; Kelemen, Lóránd; Tamás, Gábor; Horvath, Peter

    2016-01-01

    Label-free microscopy techniques have numerous advantages such as low phototoxicity, simple setup and no need for fluorophores or other contrast materials. Despite their advantages, most label-free techniques cannot visualize specific cellular compartments or the location of proteins and the image formation limits quantitative evaluation. Differential interference contrast (DIC) is a qualitative microscopy technique that shows the optical path length differences within a specimen. We propose a variational framework for DIC image reconstruction. The proposed method largely outperforms state-of-the-art methods on synthetic, artificial and real tests and turns DIC microscopy into an automated high-content imaging tool. Image sets and the source code of the examined algorithms are made publicly available. PMID:27453091

  9. DIC image reconstruction using an energy minimization framework to visualize optical path length distribution.

    PubMed

    Koos, Krisztian; Molnár, József; Kelemen, Lóránd; Tamás, Gábor; Horvath, Peter

    2016-01-01

    Label-free microscopy techniques have numerous advantages such as low phototoxicity, simple setup and no need for fluorophores or other contrast materials. Despite their advantages, most label-free techniques cannot visualize specific cellular compartments or the location of proteins and the image formation limits quantitative evaluation. Differential interference contrast (DIC) is a qualitative microscopy technique that shows the optical path length differences within a specimen. We propose a variational framework for DIC image reconstruction. The proposed method largely outperforms state-of-the-art methods on synthetic, artificial and real tests and turns DIC microscopy into an automated high-content imaging tool. Image sets and the source code of the examined algorithms are made publicly available. PMID:27453091

  10. An irrotation correction on pressure gradient and orthogonal-path integration for PIV-based pressure reconstruction

    NASA Astrophysics Data System (ADS)

    Wang, Zhongyi; Gao, Qi; Wang, Chengyue; Wei, Runjie; Wang, Jinjun

    2016-06-01

    Particle image velocimetry (PIV)-based pressure reconstruction has become a popular technique in experimental fluid mechanics. Noise or errors in raw velocity field would significantly affect the quality of pressure reconstruction in PIV measurement. To reduce experimental errors in pressure gradient and improve the precision of reconstructed pressure field, a minimal 2-norm criteria-based new technique called irrotation correction (IC) with orthogonal decomposition is developed. The pressure reconstruction is therefore composed of three steps: calculation of pressure gradient from time-resolved velocity fields of PIV, an irrotation correction on the pressure gradient field, and finally a simple orthogonal-path integration (OPI) for pressure. Systematic assessments of IC algorithm are performed on synthetic solid-body rotation flow, direct numerical simulations of a channel flow and an isotropic turbulent flow. The results show that IC is a robust algorithm which can significantly improve the accuracy of pressure reconstruction primarily in the low wave number domain. After irrotation correction, noisy pressure gradient field ideally becomes an irrotational field on which the pressure integration is independent of integrating paths. Therefore, an OPI algorithm is proposed to perform the pressure integration in an efficient way with very few integration paths. This makes the new technique to be a doable method on three-dimensional pressure reconstruction with acceptable computational cost.

  11. Three-dimensional reconstruction of helicopter blade-tip vortices using a multi-camera BOS system

    NASA Astrophysics Data System (ADS)

    Bauknecht, André; Ewers, Benjamin; Wolf, Christian; Leopold, Friedrich; Yin, Jianping; Raffel, Markus

    2015-01-01

    Noise and structural vibrations in rotorcraft are strongly influenced by interactions between blade-tip vortices and the structural components of a helicopter. As a result, knowing the three-dimensional location of vortices is highly desirable, especially for the case of full-scale helicopters under realistic flight conditions. In the current study, we present results from a flight test with a full-scale BO 105 in an open-pit mine. A background-oriented schlieren measurement system consisting of ten cameras with a natural background was used to visualize the vortices of the helicopter during maneuvering flight. Vortex filaments could be visualized and extracted up to a vortex age of 360°. Vortex instability effects were found for several flight conditions. For the camera calibration, an iterative approach using points on the helicopter fuselage was applied. Point correspondence between vortex curves in the evaluated images was established by means of epipolar geometry. A three-dimensional reconstruction of the main part of the vortex system was carried out for the first time using stereophotogrammetry. The reconstructed vortex system had good qualitative agreement with the result of an unsteady free-wake panel method simulation. A quantitative evaluation of the 3D vortex system was carried out, demonstrating the potential of the multi-camera background-oriented schlieren measurement technique for the analysis of blade-vortex interaction effects on rotorcraft.

  12. Adaptive algorithms of position and energy reconstruction in Anger-camera type detectors: experimental data processing in ANTS

    NASA Astrophysics Data System (ADS)

    Morozov, A.; Defendi, I.; Engels, R.; Fraga, F. A. F.; Fraga, M. M. F. R.; Gongadze, A.; Guerard, B.; Jurkovic, M.; Kemmerling, G.; Manzin, G.; Margato, L. M. S.; Niko, H.; Pereira, L.; Petrillo, C.; Peyaud, A.; Piscitelli, F.; Raspino, D.; Rhodes, N. J.; Sacchetti, F.; Schooneveld, E. M.; Solovov, V.; Van Esch, P.; Zeitelhack, K.

    2013-05-01

    The software package ANTS (Anger-camera type Neutron detector: Toolkit for Simulations), developed for simulation of Anger-type gaseous detectors for thermal neutron imaging was extended to include a module for experimental data processing. Data recorded with a sensor array containing up to 100 photomultiplier tubes (PMT) or silicon photomultipliers (SiPM) in a custom configuration can be loaded and the positions and energies of the events can be reconstructed using the Center-of-Gravity, Maximum Likelihood or Least Squares algorithm. A particular strength of the new module is the ability to reconstruct the light response functions and relative gains of the photomultipliers from flood field illumination data using adaptive algorithms. The performance of the module is demonstrated with simulated data generated in ANTS and experimental data recorded with a 19 PMT neutron detector. The package executables are publicly available at http://coimbra.lip.pt/~andrei/

  13. Filtered back-projection reconstruction for attenuation proton CT along most likely paths.

    PubMed

    Quiñones, C T; Létang, J M; Rit, S

    2016-05-01

    This work investigates the attenuation of a proton beam to reconstruct the map of the linear attenuation coefficient of a material which is mainly caused by the inelastic interactions of protons with matter. Attenuation proton computed tomography (pCT) suffers from a poor spatial resolution due to multiple Coulomb scattering (MCS) of protons in matter, similarly to the conventional energy-loss pCT. We therefore adapted a recent filtered back-projection algorithm along the most likely path (MLP) of protons for energy-loss pCT (Rit et al 2013) to attenuation pCT assuming a pCT scanner that can track the position and the direction of protons before and after the scanned object. Monte Carlo simulations of pCT acquisitions of density and spatial resolution phantoms were performed to characterize the new algorithm using Geant4 (via Gate). Attenuation pCT assumes an energy-independent inelastic cross-section, and the impact of the energy dependence of the inelastic cross-section below 100 MeV showed a capping artifact when the residual energy was below 100 MeV behind the object. The statistical limitation has been determined analytically and it was found that the noise in attenuation pCT images is 411 times and 278 times higher than the noise in energy-loss pCT images for the same imaging dose at 200 MeV and 300 MeV, respectively. Comparison of the spatial resolution of attenuation pCT images with a conventional straight-line path binning showed that incorporating the MLP estimates during reconstruction improves the spatial resolution of attenuation pCT. Moreover, regardless of the significant noise in attenuation pCT images, the spatial resolution of attenuation pCT was better than that of conventional energy-loss pCT in some studied situations thanks to the interplay of MCS and attenuation known as the West-Sherwood effect. PMID:27032330

  14. Filtered back-projection reconstruction for attenuation proton CT along most likely paths

    NASA Astrophysics Data System (ADS)

    Quiñones, C. T.; Létang, J. M.; Rit, S.

    2016-05-01

    This work investigates the attenuation of a proton beam to reconstruct the map of the linear attenuation coefficient of a material which is mainly caused by the inelastic interactions of protons with matter. Attenuation proton computed tomography (pCT) suffers from a poor spatial resolution due to multiple Coulomb scattering (MCS) of protons in matter, similarly to the conventional energy-loss pCT. We therefore adapted a recent filtered back-projection algorithm along the most likely path (MLP) of protons for energy-loss pCT (Rit et al 2013) to attenuation pCT assuming a pCT scanner that can track the position and the direction of protons before and after the scanned object. Monte Carlo simulations of pCT acquisitions of density and spatial resolution phantoms were performed to characterize the new algorithm using Geant4 (via Gate). Attenuation pCT assumes an energy-independent inelastic cross-section, and the impact of the energy dependence of the inelastic cross-section below 100 MeV showed a capping artifact when the residual energy was below 100 MeV behind the object. The statistical limitation has been determined analytically and it was found that the noise in attenuation pCT images is 411 times and 278 times higher than the noise in energy-loss pCT images for the same imaging dose at 200 MeV and 300 MeV, respectively. Comparison of the spatial resolution of attenuation pCT images with a conventional straight-line path binning showed that incorporating the MLP estimates during reconstruction improves the spatial resolution of attenuation pCT. Moreover, regardless of the significant noise in attenuation pCT images, the spatial resolution of attenuation pCT was better than that of conventional energy-loss pCT in some studied situations thanks to the interplay of MCS and attenuation known as the West–Sherwood effect.

  15. Matching Images to Models: Camera Calibration for 3-D Surface Reconstruction

    NASA Technical Reports Server (NTRS)

    Morris, Robin D.; Smelyanskiy, Vadim N.; Cheeseman. Peter C.; Norvig, Peter (Technical Monitor)

    2001-01-01

    In a previous paper we described a system which recursively recovers a super-resolved three dimensional surface model from a set of images of the surface. In that paper we assumed that the camera calibration for each image was known. In this paper we solve two problems. Firstly, if an estimate of the surface is already known, the problem is to calibrate a new image relative to the existing surface model. Secondly, if no surface estimate is available, the relative camera calibration between the images in the set must be estimated. This will allow an initial surface model to be estimated. Results of both types of estimation are given.

  16. Reconstruction of Indoor Models Using Point Clouds Generated from Single-Lens Reflex Cameras and Depth Images

    NASA Astrophysics Data System (ADS)

    Tsai, F.; Wu, T.-S.; Lee, I.-C.; Chang, H.; Su, A. Y. S.

    2015-05-01

    This paper presents a data acquisition system consisting of multiple RGB-D sensors and digital single-lens reflex (DSLR) cameras. A systematic data processing procedure for integrating these two kinds of devices to generate three-dimensional point clouds of indoor environments is also developed and described. In the developed system, DSLR cameras are used to bridge the Kinects and provide a more accurate ray intersection condition, which takes advantage of the higher resolution and image quality of the DSLR cameras. Structure from Motion (SFM) reconstruction is used to link and merge multiple Kinect point clouds and dense point clouds (from DSLR color images) to generate initial integrated point clouds. Then, bundle adjustment is used to resolve the exterior orientation (EO) of all images. Those exterior orientations are used as the initial values to combine these point clouds at each frame into the same coordinate system using Helmert (seven-parameter) transformation. Experimental results demonstrate that the design of the data acquisition system and the data processing procedure can generate dense and fully colored point clouds of indoor environments successfully even in featureless areas. The accuracy of the generated point clouds were evaluated by comparing the widths and heights of identified objects as well as coordinates of pre-set independent check points against in situ measurements. Based on the generated point clouds, complete and accurate three-dimensional models of indoor environments can be constructed effectively.

  17. Increasing signal-to-noise ratio of reconstructed digital holograms by using light spatial noise portrait of camera's photosensor

    NASA Astrophysics Data System (ADS)

    Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.

    2015-01-01

    Digital holography is technique which includes recording of interference pattern with digital photosensor, processing of obtained holographic data and reconstruction of object wavefront. Increase of signal-to-noise ratio (SNR) of reconstructed digital holograms is especially important in such fields as image encryption, pattern recognition, static and dynamic display of 3D scenes, and etc. In this paper compensation of photosensor light spatial noise portrait (LSNP) for increase of SNR of reconstructed digital holograms is proposed. To verify the proposed method, numerical experiments with computer generated Fresnel holograms with resolution equal to 512×512 elements were performed. Simulation of shots registration with digital camera Canon EOS 400D was performed. It is shown that solo use of the averaging over frames method allows to increase SNR only up to 4 times, and further increase of SNR is limited by spatial noise. Application of the LSNP compensation method in conjunction with the averaging over frames method allows for 10 times SNR increase. This value was obtained for LSNP measured with 20 % error. In case of using more accurate LSNP, SNR can be increased up to 20 times.

  18. Data Acquisition and Image Reconstruction Systems from the miniPET Scanners to the CARDIOTOM Camera

    SciTech Connect

    Valastvan, I.; Imrek, J.; Hegyesi, G.; Molnar, J.; Novak, D.; Bone, D.; Kerek, A.

    2007-11-26

    Nuclear imaging devices play an important role in medical diagnosis as well as drug research. The first and second generation data acquisition systems and the image reconstruction library developed provide a unified hardware and software platform for the miniPET-I, miniPET-II small animal PET scanners and for the CARDIOTOM{sup TM}.

  19. D Reconstruction of Cultural Tourism Attractions from Indoor to Outdoor Based on Portable Four-Camera Stereo Vision System

    NASA Astrophysics Data System (ADS)

    Shao, Z.; Li, C.; Zhong, S.; Liu, B.; Jiang, H.; Wen, X.

    2015-05-01

    Building the fine 3D model from outdoor to indoor is becoming a necessity for protecting the cultural tourism resources. However, the existing 3D modelling technologies mainly focus on outdoor areas. Actually, a 3D model should contain detailed descriptions of both its appearance and its internal structure, including architectural components. In this paper, a portable four-camera stereo photographic measurement system is developed, which can provide a professional solution for fast 3D data acquisition, processing, integration, reconstruction and visualization. Given a specific scene or object, it can directly collect physical geometric information such as positions, sizes and shapes of an object or a scene, as well as physical property information such as the materials and textures. On the basis of the information, 3D model can be automatically constructed. The system has been applied to the indooroutdoor seamless modelling of distinctive architecture existing in two typical cultural tourism zones, that is, Tibetan and Qiang ethnic minority villages in Sichuan Jiuzhaigou Scenic Area and Tujia ethnic minority villages in Hubei Shennongjia Nature Reserve, providing a new method and platform for protection of minority cultural characteristics, 3D reconstruction and cultural tourism.

  20. Straightforward reconstruction of 3D surfaces and topography with a camera: Accuracy and geoscience application

    NASA Astrophysics Data System (ADS)

    James, M. R.; Robson, S.

    2012-09-01

    Topographic measurements for detailed studies of processes such as erosion or mass movement are usually acquired by expensive laser scanners or rigorous photogrammetry. Here, we test and use an alternative technique based on freely available computer vision software which allows general geoscientists to easily create accurate 3D models from field photographs taken with a consumer-grade camera. The approach integrates structure-from-motion (SfM) and multiview-stereo (MVS) algorithms and, in contrast to traditional photogrammetry techniques, it requires little expertise and few control measurements, and processing is automated. To assess the precision of the results, we compare SfM-MVS models spanning spatial scales of centimeters (a hand sample) to kilometers (the summit craters of Piton de la Fournaise volcano) with data acquired from laser scanning and formal close-range photogrammetry. The relative precision ratio achieved by SfM-MVS (measurement precision: observation distance) is limited by the straightforward camera calibration model used in the software, but generally exceeds 1:1000 (i.e., centimeter-level precision over measurement distances of 10 s of meters). We apply SfM-MVS at an intermediate scale, to determine erosion rates along a ˜50-m-long coastal cliff. Seven surveys carried out over a year indicate an average retreat rate of 0.70 ± 0.05 m a-1. Sequential erosion maps (at ˜0.05 m grid resolution) highlight the spatiotemporal variability in the retreat, with semivariogram analysis indicating a correlation between volume loss and length scale. Compared with a laser scanner survey of the same site, SfM-MVS produced comparable data and reduced data collection time by ˜80%.

  1. A particle filter to reconstruct a free-surface flow from a depth camera

    NASA Astrophysics Data System (ADS)

    Combés, Benoit; Heitz, Dominique; Guibert, Anthony; Mémin, Etienne

    2015-10-01

    We investigate the combined use of a kinect depth sensor and of a stochastic data assimilation (DA) method to recover free-surface flows. More specifically, we use a weighted ensemble Kalman filter method to reconstruct the complete state of free-surface flows from a sequence of depth images only. This particle filter accounts for model and observations errors. This DA scheme is enhanced with the use of two observations instead of one classically. We evaluate the developed approach on two numerical test cases: a collapse of a water column as a toy-example and a flow in an suddenly expanding flume as a more realistic flow. The robustness of the method to depth data errors and also to initial and inflow conditions is considered. We illustrate the interest of using two observations instead of one observation into the correction step, especially for unknown inflow boundary conditions. Then, the performance of the Kinect sensor in capturing the temporal sequences of depth observations is investigated. Finally, the efficiency of the algorithm is qualified for a wave in a real rectangular flat bottomed tank. It is shown that for basic initial conditions, the particle filter rapidly and remarkably reconstructs the velocity and height of the free surface flow based on noisy measurements of the elevation alone.

  2. Multi-Camera Reconstruction of Fine Scale High Speed Auroral Dynamics

    NASA Astrophysics Data System (ADS)

    Hirsch, M.; Semeter, J. L.; Zettergren, M. D.; Dahlgren, H.; Goenka, C.; Akbari, H.

    2014-12-01

    The fine spatial structure of dispersive aurora is known to have ground-observable scales of less than 100 meters. The lifetime of prompt emissions is much less than 1 millisecond, and high-speed cameras have observed auroral forms with millisecond scale morphology. Satellite observations have corroborated these spatial and temporal findings. Satellite observation platforms give a very valuable yet passing glance at the auroral region and the precipitation driving the aurora. To gain further insight into the fine structure of accelerated particles driven into the ionosphere, ground-based optical instruments staring at the same region of sky can capture the evolution of processes evolving on time scales from milliseconds to many hours, with continuous sample rates of 100Hz or more. Legacy auroral tomography systems have used baselines of hundreds of kilometers, capturing a "side view" of the field-aligned auroral structure. We show that short baseline (less than 10 km), high speed optical observations fill a measurement gap between legacy long baseline optical observations and incoherent scatter radar. The ill-conditioned inverse problem typical of auroral tomography, accentuated by short baseline optical ground stations is tackled with contemporary data inversion algorithms. We leverage the disruptive electron multiplying charge coupled device (EMCCD) imaging technology and solve the inverse problem via eigenfunctions obtained from a first-principles 1-D electron penetration ionospheric model. We present the latest analysis of observed auroral events from the Poker Flat Research Range near Fairbanks, Alaska. We discuss the system-level design and performance verification measures needed to ensure consistent performance for nightly multi-terabyte data acquisition synchronized between stations to better than 1 millisecond.

  3. Numerical analysis of the crack growth path in the cement mantle of the reconstructed acetabulum.

    PubMed

    Benbarek, Smaïl; Bachir Bouiadjra, Bel Abbes; El Mokhtar, Bouziane Mohamed; Achour, Tarik; Serier, Boualem

    2013-01-01

    In this study, we use the finite element method to analyze the propagation's path of the crack in the orthopedic cement of the total hip replacement. In fact, a small python statement was incorporated with the Abaqus software to do in loop the following operations: extracting the crack propagation direction from the previous study using the maximal circumferential stresses criterion, drawing the new path, meshing and calculating again (stresses and fracture parameters). The loop is broken when the user's desired crack length is reached (number of propagations) or the value of the mode I stress intensity factor is negative. Results show that the crack propagation's path can be influenced by human body posture. The existing of a cavity in the vicinity of the crack can change its propagation path or can absolutely attract it enough to meet it. Crack can propagate in the outward direction (toward the acetabulum bone) and cannot propagate in the opposite direction, the mode I stress intensity factor increases with the crack length and that of mode II vanishes. PMID:25428108

  4. Terminal area automatic navigation, guidance, and control research using the Microwave Landing System (MLS). Part 4: Transition path reconstruction along a straight line path containing a glideslope change waypoint

    NASA Technical Reports Server (NTRS)

    Pines, S.

    1982-01-01

    The necessary algorithms to reconstruct the glideslope change waypoint along a straight line in the event the aircraft encounters a valid MLS update and transition in the terminal approach area are presented. Results of a simulation of the Langley B737 aircraft utilizing these algorithms are presented. The method is shown to reconstruct the necessary flight path during MLS transition resulting in zero cross track error, zero track angle error, and zero altitude error, thus requiring minimal aircraft response.

  5. Reconstructing the Most Probable Folding Transition Path from Replica Exchange Molecular Dynamics Simulations.

    PubMed

    Jimenez-Cruz, Camilo Andres; Garcia, Angel E

    2013-08-13

    The characterization of transition pathways between long-lived states, and the identification of the corresponding transition state ensembles are useful tools in the study of rare events such as protein folding. In this work we demonstrate how the most probable transition path between metastable states can be recovered from replica exchange molecular dynamic simulation data by using the dynamic string method. The local drift vector in collective variables is determined via short continuous trajectories between replica exchanges at a given temperature, and points along the string are updated based on this drift vector to produce reaction pathways between the folded and unfolded state. The method is applied to a designed beta hairpin-forming peptide to obtain information on the folding mechanism and transition state using different sets of collective variables at various temperatures. Two main folding pathways differing in the order of events are found and discussed, and the relative free energy differences for each path estimated. Finally, the structures near the transition state are found and described. PMID:26584126

  6. Game of thrown bombs in 3D: using high speed cameras and photogrammetry techniques to reconstruct bomb trajectories at Stromboli (Italy)

    NASA Astrophysics Data System (ADS)

    Gaudin, D.; Taddeucci, J.; Scarlato, P.; Del Bello, E.; Houghton, B. F.; Orr, T. R.; Andronico, D.; Kueppers, U.

    2015-12-01

    Large juvenile bombs and lithic clasts, produced and ejected during explosive volcanic eruptions, follow ballistic trajectories. Of particular interest are: 1) the determination of ejection velocity and launch angle, which give insights into shallow conduit conditions and geometry; 2) particle trajectories, with an eye on trajectory evolution caused by collisions between bombs, as well as the interaction between bombs and ash/gas plumes; and 3) the computation of the final emplacement of bomb-sized clasts, which is important for hazard assessment and risk management. Ground-based imagery from a single camera only allows the reconstruction of bomb trajectories in a plan perpendicular to the line of sight, which may lead to underestimation of bomb velocities and does not allow the directionality of the ejections to be studied. To overcome this limitation, we adapted photogrammetry techniques to reconstruct 3D bomb trajectories from two or three synchronized high-speed video cameras. In particular, we modified existing algorithms to consider the errors that may arise from the very high velocity of the particles and the impossibility of measuring tie points close to the scene. Our method was tested during two field campaigns at Stromboli. In 2014, two high-speed cameras with a 500 Hz frame rate and a ~2 cm resolution were set up ~350m from the crater, 10° apart and synchronized. The experiment was repeated with similar parameters in 2015, but using three high-speed cameras in order to significantly reduce uncertainties and allow their estimation. Trajectory analyses for tens of bombs at various times allowed for the identification of shifts in the mean directivity and dispersal angle of the jets during the explosions. These time evolutions are also visible on the permanent video-camera monitoring system, demonstrating the applicability of our method to all kinds of explosive volcanoes.

  7. Evaluation of unmanned aerial vehicle shape, flight path and camera type for waterfowl surveys: disturbance effects and species recognition.

    PubMed

    McEvoy, John F; Hall, Graham P; McDonald, Paul G

    2016-01-01

    The use of unmanned aerial vehicles (UAVs) for ecological research has grown rapidly in recent years, but few studies have assessed the disturbance impacts of these tools on focal subjects, particularly when observing easily disturbed species such as waterfowl. In this study we assessed the level of disturbance that a range of UAV shapes and sizes had on free-living, non-breeding waterfowl surveyed in two sites in eastern Australia between March and May 2015, as well as the capability of airborne digital imaging systems to provide adequate resolution for unambiguous species identification of these taxa. We found little or no obvious disturbance effects on wild, mixed-species flocks of waterfowl when UAVs were flown at least 60m above the water level (fixed wing models) or 40m above individuals (multirotor models). Disturbance in the form of swimming away from the UAV through to leaving the water surface and flying away from the UAV was visible at lower altitudes and when fixed-wing UAVs either approached subjects directly or rapidly changed altitude and/or direction near animals. Using tangential approach flight paths that did not cause disturbance, commercially available onboard optical equipment was able to capture images of sufficient quality to identify waterfowl and even much smaller taxa such as swallows. Our results show that with proper planning of take-off and landing sites, flight paths and careful UAV model selection, UAVs can provide an excellent tool for accurately surveying wild waterfowl populations and provide archival data with fewer logistical issues than traditional methods such as manned aerial surveys. PMID:27020132

  8. Evaluation of unmanned aerial vehicle shape, flight path and camera type for waterfowl surveys: disturbance effects and species recognition

    PubMed Central

    Hall, Graham P.; McDonald, Paul G.

    2016-01-01

    The use of unmanned aerial vehicles (UAVs) for ecological research has grown rapidly in recent years, but few studies have assessed the disturbance impacts of these tools on focal subjects, particularly when observing easily disturbed species such as waterfowl. In this study we assessed the level of disturbance that a range of UAV shapes and sizes had on free-living, non-breeding waterfowl surveyed in two sites in eastern Australia between March and May 2015, as well as the capability of airborne digital imaging systems to provide adequate resolution for unambiguous species identification of these taxa. We found little or no obvious disturbance effects on wild, mixed-species flocks of waterfowl when UAVs were flown at least 60m above the water level (fixed wing models) or 40m above individuals (multirotor models). Disturbance in the form of swimming away from the UAV through to leaving the water surface and flying away from the UAV was visible at lower altitudes and when fixed-wing UAVs either approached subjects directly or rapidly changed altitude and/or direction near animals. Using tangential approach flight paths that did not cause disturbance, commercially available onboard optical equipment was able to capture images of sufficient quality to identify waterfowl and even much smaller taxa such as swallows. Our results show that with proper planning of take-off and landing sites, flight paths and careful UAV model selection, UAVs can provide an excellent tool for accurately surveying wild waterfowl populations and provide archival data with fewer logistical issues than traditional methods such as manned aerial surveys. PMID:27020132

  9. Estimating where and how animals travel: an optimal framework for path reconstruction from autocorrelated tracking data.

    PubMed

    Fleming, C H; Fagan, W F; Mueller, T; Olson, K A; Leimgruber, P; Calabrese, J M

    2016-03-01

    An animal's trajectory is a fundamental object of interest in movement ecology, as it directly informs a range of topics from resource selection to energy expenditure and behavioral states. Optimally inferring the mostly unobserved movement path and its dynamics from a limited sample of telemetry observations is a key unsolved problem, however. The field of geostatistics has focused significant attention on a mathematically analogous problem that has a statistically optimal solution coined after its inventor, Krige. Kriging revolutionized geostatistics and is now the gold standard for interpolating between a limited number of autocorrelated spatial point observations. Here we translate Kriging for use with animal movement data. Our Kriging formalism encompasses previous methods to estimate animal's trajectories--the Brownian bridge and continuous-time correlated random walk library--as special cases, informs users as to when these previous methods are appropriate, and provides a more general method when they are not. We demonstrate the capabilities of Kriging on a case study with Mongolian gazelles where, compared to the Brownian bridge, Kriging with a more optimal model was 10% more precise in interpolating locations and 500% more precise in estimating occurrence areas. PMID:27197385

  10. A Proposal and Implement of Detection and Reconstruction Method of Contact Shape with Horizon View Camera for Calligraphy Education Support System

    NASA Astrophysics Data System (ADS)

    Tobitani, Kensuke; Yamamoto, Kazuhiko; Kato, Kunihito

    In this study, we are concerned with calligraphy education support system. In current calligraphy education in Japan, teachers evaluate character written by students and they teach correct writing process based on the evaluation of the written character. Professionals in calligraphy can estimate writing process of character and balance of character which are important points for evaluation of character by estimating movement of contact shape (contact faces with paper and brush). But it takes a lot of time for students to be able to learn how to write correct character in this education way. If teachers and students can know movement of the contact shape, calligraphy education will be more efficient. However, it is difficult to detect contact shape from an images captured by cameras set in general angle. Because brush and ink are black either. So, contact shape is hided under the brush. In this paper, we propose new camera system consists of four Horizon View Cameras (HVC) which are special camera setting to detect and reconstruct contact shape, experiment with this system, and compare movement of contact shape of professionals and amateurs.

  11. Image-based path planning for automated virtual colonoscopy navigation

    NASA Astrophysics Data System (ADS)

    Hong, Wei

    2008-03-01

    Virtual colonoscopy (VC) is a noninvasive method for colonic polyp screening, by reconstructing three-dimensional models of the colon using computerized tomography (CT). In virtual colonoscopy fly-through navigation, it is crucial to generate an optimal camera path for efficient clinical examination. In conventional methods, the centerline of the colon lumen is usually used as the camera path. In order to extract colon centerline, some time consuming pre-processing algorithms must be performed before the fly-through navigation, such as colon segmentation, distance transformation, or topological thinning. In this paper, we present an efficient image-based path planning algorithm for automated virtual colonoscopy fly-through navigation without the requirement of any pre-processing. Our algorithm only needs the physician to provide a seed point as the starting camera position using 2D axial CT images. A wide angle fisheye camera model is used to generate a depth image from the current camera position. Two types of navigational landmarks, safe regions and target regions are extracted from the depth images. Camera position and its corresponding view direction are then determined using these landmarks. The experimental results show that the generated paths are accurate and increase the user comfort during the fly-through navigation. Moreover, because of the efficiency of our path planning algorithm and rendering algorithm, our VC fly-through navigation system can still guarantee 30 FPS.

  12. Digital X-ray camera for quality evaluation three-dimensional topographic reconstruction of single crystals of biological macromolecules

    NASA Technical Reports Server (NTRS)

    Borgstahl, Gloria (Inventor); Lovelace, Jeff (Inventor); Snell, Edward Holmes (Inventor); Bellamy, Henry (Inventor)

    2008-01-01

    The present invention provides a digital topography imaging system for determining the crystalline structure of a biological macromolecule, wherein the system employs a charge coupled device (CCD) camera with antiblooming circuitry to directly convert x-ray signals to electrical signals without the use of phosphor and measures reflection profiles from the x-ray emitting source after x-rays are passed through a sample. Methods for using said system are also provided.

  13. Development of event reconstruction algorithm for full-body gamma-camera based on SiPMs

    NASA Astrophysics Data System (ADS)

    Philippov, D. E.; Belyaev, V. N.; Buzhan, P. Zh; Ilyin, A. L.; Popova, E. V.; Stifutkin, A. A.

    2016-02-01

    The gamma-camera is the detector for nuclear medical imaging where the photomultiplier tubes (PMTs) could be replaced by the silicon photomultipliers (SiPMs). Common systems have the energy resolution about 10% and intrinsic spatial resolution about 3 mm (FWHM). In order to achieve the requirement energy and spatial resolution the classical Anger's logic should be modified. In case of a standard monolithic thallium activated sodium iodide scintillator (500x400x10 mm3) and SiPM readout it could be done with identification of the clusters. We show that this approach has a good results with the simulated data.

  14. An automatic time lapse camera setup for multi-vision 3D-reconstruction of morphological changes

    NASA Astrophysics Data System (ADS)

    Kaiser, Andreas; Neugirg, Fabian; Vláčilová, Markéta; Haas, Florian; Schmidt, Jürgen

    2015-04-01

    In the cause of a five year monitoring campaign on an Alpine slope in the Lainbach catchment, Southern Germany, high erosion rates were documented by terrestrial laser scanners (TLS) and unmanned airborne vehicles (UAV). As a result of different denudation processes erosion rates differ between summer and winter periods. The latter became evident after comparing both TLS-measured time spans. However, process differentiation and their contribution to the overall denudation remained challenging due to the discontinuous data collection every few weeks. In order to record these erosion processes an array of four automatically triggered cameras was installed capturing frames in ten minutes time steps as long as there is daylight. This work in progress aims to produce long term time series of morphodynamic changes in an active catchment by applying multi-vision structure from motion algorithms from a set of four cameras. Geomorphic processes caused by special weather phenomena can thus be interpreted in combination with climatic data acquired right next to the slope. Preliminary model calculations from the chosen perspectives produced adequate results with point counts of around 5.5 Mio for the 120m² slope. The point density proved to be dependent on the weather conditions, thus foggy and dull images will be excluded. A validation of the approach will be achieved by comparison of the time lapse point clouds with the TLS scans and UAV surveys as the monitoring will continue.

  15. Image reconstruction algorithm for a spinning strip CZT SPECT camera with a parallel slat collimator and small pixels

    SciTech Connect

    Zeng, Gengsheng L.; Gagnon, Daniel

    2004-12-01

    This paper discusses the use of small pixels in a spinning CdZnTe single photon emission computed tomography (SPECT) camera that is mounted with a parallel slat collimator. In a conventional slat collimation configuration, there is a detector pixel between two adjacent collimator slats. In our design, the pixel size is halved. That is, there are two smaller pixels to replace a regular pixel between two adjacent slats while the collimator remains unchanged. It has an advantage over our older design that uses tilted slats. In order to acquire a complete data set the tilted-slat collimator must spin 360 deg. at each SPECT view while the proposed design requires only 180 deg. at each SPECT view. Computer simulations and phantom experiments have been carried out to investigate the performance of the small-pixel configuration. It is observed that this design has the potential to increase the spatial resolution of the detector while keeping photon counts the same.

  16. A new target reconstruction method considering atmospheric refraction

    NASA Astrophysics Data System (ADS)

    Zuo, Zhengrong; Yu, Lijuan

    2015-12-01

    In this paper, a new target reconstruction method considering the atmospheric refraction is presented to improve 3D reconstruction accuracy in long rang surveillance system. The basic idea of the method is that the atmosphere between the camera and the target is partitioned into several thin layers radially in which the density is regarded as uniform; Then the reverse tracking of the light propagation path from sensor to target was carried by applying Snell's law at the interface between layers; and finally the average of the tracked target's positions from different cameras is regarded as the reconstructed position. The reconstruction experiments were carried, and the experiment results showed that the new method have much better reconstruction accuracy than the traditional stereoscopic reconstruction method.

  17. Field experiment and image reconstruction using a Fourier telescopy imaging system over a 600-m-long horizontal path.

    PubMed

    Yu, Shu-Hai; Dong, Lei; Liu, Xin-Yue; Lin, Xu-Dong; Megn, Hao-Ran; Zhong, Xing

    2016-08-20

    To confirm the effect of uplink atmospheric turbulence on Fourier telescopy (FT), we designed a system for far-field imaging, utilizing a T-type laser transmitting configuration with commercially available hardware, except for a green imaging laser. The horizontal light transmission distance for both uplink and downlink was ∼300  m. For both the transmitting and received beams, the height upon the ground was below 1 m. The imaging laser's pointing accuracy was ∼9.3  μrad. A novel image reconstruction approach was proposed, yielding significantly improved quality and Strehl ratio of reconstructed images. From the reconstruction result, we observed that the tip/tilt aberration is tolerated by the FT system even for Changchun's atmospheric coherence length parameter (r0) below 3 cm. The resolution of the reconstructed images was ∼0.615  μrad. PMID:27556991

  18. SLAM using camera and IMU sensors.

    SciTech Connect

    Rothganger, Fredrick H.; Muguira, Maritza M.

    2007-01-01

    Visual simultaneous localization and mapping (VSLAM) is the problem of using video input to reconstruct the 3D world and the path of the camera in an 'on-line' manner. Since the data is processed in real time, one does not have access to all of the data at once. (Contrast this with structure from motion (SFM), which is usually formulated as an 'off-line' process on all the data seen, and is not time dependent.) A VSLAM solution is useful for mobile robot navigation or as an assistant for humans exploring an unknown environment. This report documents the design and implementation of a VSLAM system that consists of a small inertial measurement unit (IMU) and camera. The approach is based on a modified Extended Kalman Filter. This research was performed under a Laboratory Directed Research and Development (LDRD) effort.

  19. Open-path TDL-Spectrometry for a Tomographic Reconstruction of 2D H2O-Concentration Fields in the Soil-Air-Boundary-Layer of Permafrost

    NASA Astrophysics Data System (ADS)

    Seidel, Anne; Wagner, Steven; Dreizler, Andreas; Ebert, Volker

    2013-04-01

    .9 ppmv?m??Hz. For absorption path lengths of up to 2 m and time resolution of 0.2 sec, we attained detection limits of 1 ppmv. Furthermore we realized a wide dynamic range covering concentrations between 200 ppmv and 12300 ppmv. The static spectrometer will now be extended to a spatially scanning TDL sensor using rapidly rotating polygon mirrors. In combination with tomographic reconstruction methods, spatially resolved 2D-fields will be measured and retrieved. The aim is to capture concentration fields with at least 1 m2 spatial coverage with concentration detection faster than 1 Hz rate. We simulated various measurements from typical concentration distributions ("phantoms") and used Algebraic Reconstruction Techniques (ART) to compute the according 2D-fields. The reconstructions look very promising and demonstrate the potential of the measurement method. In the presentation we will describe and discuss the optical setup of the stationary instrument and explain the concept of extending this instrument to a spatially scanning tomographic TDL instrument for soil studies. Further we present first results evaluating the capabilities of the selected ART reconstruction on tomographic phantoms. [1] E. Schuur, J. G. Vogel, K. G. Crummer, H. Lee, J. O. Sickman, and T. E. Osterkamp, "The effect of permafrost thaw on old carbon release and net carbon exchange from tundra.," Nature, vol. 459, no. 7246, pp. 556-9, May 2009. [2] A. Seidel, S. Wagner, and V. Ebert, "TDLAS-based open-path laser hygrometer using simple reflective foils as scattering targets," Applied Physics B, vol. 109, no. 3, pp. 497-504, Oct. 2012.

  20. Nanoscale three-dimensional reconstruction of elastic and inelastic mean free path lengths by electron holographic tomography

    SciTech Connect

    Lubk, A.; Wolf, D.; Kern, F.; Röder, F.; Lichte, H.; Prete, P.; Lovergine, N.

    2014-10-27

    Electron holography at medium resolution simultaneously probes projected electrostatic and magnetostatic potentials as well as elastic and inelastic attenuation coefficients with a spatial resolution of a few nanometers. In this work, we derive how the elastic and inelastic attenuation can be disentangled. Using that result, we perform the first three dimensional tomographic reconstruction of potential and (in)elastic attenuation in parallel. The technique can be applied to distinguish between functional potentials and composition changes in nanostructures, as demonstrated using the example of a GaAs—Al{sub 0.33}Ga{sub 0.67}As core-shell nanowire.

  1. How physics teachers approach innovation: An empirical study for reconstructing the appropriation path in the case of special relativity

    NASA Astrophysics Data System (ADS)

    de Ambrosis, Anna; Levrini, Olivia

    2010-07-01

    This paper concerns an empirical study carried out with a group of high school physics teachers engaged in the Module on relativity of a Master course on the teaching of modern physics. The study is framed within the general research issue of how to promote innovation in school via teachers’ education and how to foster fruitful interactions between research and school practice via the construction of networks of researchers and teachers. In the paper, the problems related to innovation are addressed by focusing on the phase during which teachers analyze an innovative teaching proposal in the perspective of designing their own paths for the class work. The proposal analyzed in this study is Taylor and Wheeler’s approach for teaching special relativity. The paper aims to show that the roots of problems known in the research literature about teachers’ difficulties in coping with innovative proposals, and usually related to the implementation process, can be found and addressed already when teachers approach the proposal and try to appropriate it. The study is heuristic and has been carried out in order to trace the “appropriation path,” followed by the group of teachers, in terms of the main steps and factors triggering the progressive evolution of teachers’ attitudes and competences.

  2. Accurate optical wavefront reconstruction based on reciprocity of an optical path using low resolution spatial light modulators

    NASA Astrophysics Data System (ADS)

    Li, Zhiyang

    2010-10-01

    A method for high precision optical wavefront reconstruction using low resolution spatial light modulators (SLMs) was proposed. It utilizes an adiabatic waveguide taper consisting of a plurality of single-mode waveguides to decompose an incident light field into simple fundamental modes of the single-mode waveguides. By digital generation of the conjugate fields of those simple fundamental modes a field proportional to the original incident light field might be reconstructed accurately based on reciprocity. Devices based on the method using transparent and reflective SLMs possess no aberration like that of a conventional optic lens and are able to achieve diffraction limited resolution. Specifically on the surface of the narrow end of a taper a resolution much higher than half of the wavelength is attainable. The device may work in linear mode and possesses unlimited theoretical 3D space-bandwidth product (SBP). The SBP of a real device is limited by the accuracy of SLMs. A pair of 8-bit SLMs with 1000 × 1000 = 10 6 pixels could provide a SBP of about 5 × 10 4. The SBP may expand by 16 times if 10-bit SLMs with the same number of pixels are employed or 16 successive frames are used to display one scene. The device might be used as high precision optical tweezers, or employed for continuous or discrete real-time 3D display, 3D measurement, machine vision, etc.

  3. Parametric 3D Atmospheric Reconstruction in Highly Variable Terrain with Recycled Monte Carlo Paths and an Adapted Bayesian Inference Engine

    NASA Technical Reports Server (NTRS)

    Langmore, Ian; Davis, Anthony B.; Bal, Guillaume; Marzouk, Youssef M.

    2012-01-01

    We describe a method for accelerating a 3D Monte Carlo forward radiative transfer model to the point where it can be used in a new kind of Bayesian retrieval framework. The remote sensing challenge is to detect and quantify a chemical effluent of a known absorbing gas produced by an industrial facility in a deep valley. The available data is a single low resolution noisy image of the scene in the near IR at an absorbing wavelength for the gas of interest. The detected sunlight has been multiply reflected by the variable terrain and/or scattered by an aerosol that is assumed partially known and partially unknown. We thus introduce a new class of remote sensing algorithms best described as "multi-pixel" techniques that call necessarily for a 3D radaitive transfer model (but demonstrated here in 2D); they can be added to conventional ones that exploit typically multi- or hyper-spectral data, sometimes with multi-angle capability, with or without information about polarization. The novel Bayesian inference methodology uses adaptively, with efficiency in mind, the fact that a Monte Carlo forward model has a known and controllable uncertainty depending on the number of sun-to-detector paths used.

  4. SU-E-J-141: Activity-Equivalent Path Length Approach for the 3D PET-Based Dose Reconstruction in Proton Therapy

    SciTech Connect

    Attili, A; Vignati, A; Giordanengo, S; Kraan, A; Dalmasso, F; Battistoni, G

    2015-06-15

    Purpose: Ion beam therapy is sensitive to uncertainties from treatment planning and dose delivery. PET imaging of induced positron emitter distributions is a practical approach for in vivo, in situ verification of ion beam treatments. Treatment verification is usually done by comparing measured activity distributions with reference distributions, evaluated in nominal conditions. Although such comparisons give valuable information on treatment quality, a proper clinical evaluation of the treatment ultimately relies on the knowledge of the actual delivered dose. Analytical deconvolution methods relating activity and dose have been studied in this context, but were not clinically applied. In this work we present a feasibility study of an alternative approach for dose reconstruction from activity data, which is based on relating variations in accumulated activity to tissue density variations. Methods: First, reference distributions of dose and activity were calculated from the treatment plan and CT data. Then, the actual measured activity data were cumulatively matched with the reference activity distributions to obtain a set of activity-equivalent path lengths (AEPLs) along the rays of the pencil beams. Finally, these AEPLs were used to deform the original dose distribution, yielding the actual delivered dose. The method was tested by simulating a proton therapy treatment plan delivering 2 Gy on a homogeneous water phantom (the reference), which was compared with the same plan delivered on a phantom containing inhomogeneities. Activity and dose distributions were were calculated by means of the FLUKA Monte Carlo toolkit. Results: The main features of the observed dose distribution in the inhomogeneous situation were reproduced using the AEPL approach. Variations in particle range were reproduced and the positions, where these deviations originated, were properly identified. Conclusions: For a simple inhomogeneous phantom the 3D dose reconstruction from PET

  5. A Compton camera application for the GAMOS GEANT4-based framework

    NASA Astrophysics Data System (ADS)

    Harkness, L. J.; Arce, P.; Judson, D. S.; Boston, A. J.; Boston, H. C.; Cresswell, J. R.; Dormand, J.; Jones, M.; Nolan, P. J.; Sampson, J. A.; Scraggs, D. P.; Sweeney, A.; Lazarus, I.; Simpson, J.

    2012-04-01

    Compton camera systems can be used to image sources of gamma radiation in a variety of applications such as nuclear medicine, homeland security and nuclear decommissioning. To locate gamma-ray sources, a Compton camera employs electronic collimation, utilising Compton kinematics to reconstruct the paths of gamma rays which interact within the detectors. The main benefit of this technique is the ability to accurately identify and locate sources of gamma radiation within a wide field of view, vastly improving the efficiency and specificity over existing devices. Potential advantages of this imaging technique, along with advances in detector technology, have brought about a rapidly expanding area of research into the optimisation of Compton camera systems, which relies on significant input from Monte-Carlo simulations. In this paper, the functionality of a Compton camera application that has been integrated into GAMOS, the GEANT4-based Architecture for Medicine-Oriented Simulations, is described. The application simplifies the use of GEANT4 for Monte-Carlo investigations by employing a script based language and plug-in technology. To demonstrate the use of the Compton camera application, simulated data have been generated using the GAMOS application and acquired through experiment for a preliminary validation, using a Compton camera configured with double sided high purity germanium strip detectors. Energy spectra and reconstructed images for the data sets are presented.

  6. A method to minimise error in 2D-DLT reconstruction of non-planar markers filmed with a moving camera.

    PubMed

    Holden-Douilly, Laurène; Pourcelot, Philippe; Chateau, Henry; Falala, Sylvain; Crevier-Denoix, Nathalie

    2013-01-01

    This article describes a method that allows estimating, with the 2D version of the direct linear transformation (DLT), the actual 2D coordinates of a point when the latter is not strictly in the calibration plane. Markers placed in vertical line, above, below and in the centre of a horizontal calibration plane were filmed by a moving camera. Without correction, strong errors (up to 64.5%) were noticed for markers out of the calibration plane. After correction, calculated coordinates were consistent with actual values (error < 0.55%). The method was then applied to slip distance measurement, using a marker fixed on the hoof of a horse trotting on a calibrated track while being followed with a camera. The correction effect represented 6.6% of slip distance. Combined with the 2D-DLT transformation, the proposed corrective method allows an accurate measurement of slip distances, for high-speed outdoor locomotion analysis, using a moving camera. PMID:22225468

  7. The underwater camera calibration based on virtual camera lens distortion

    NASA Astrophysics Data System (ADS)

    Qin, Dahui; Mao, Ting; Cheng, Peng; Zhang, Zhiliang

    2011-08-01

    The machine view is becoming more and more popular in underwater. It is a challenge to calibrate the camera underwater because of the complicated light ray path in underwater and air environment. In this paper we firstly analyzed characteristic of the camera when light transported from air to water. Then we proposed a new method that takes the high-level camera distortion model to compensate the deviation of the light refraction when light ray come through the water and air media. In the end experience result shows the high-level distortion model can simulate the effect made by the underwater light refraction which also makes effect on the camera's image in the process of the camera underwater calibration.

  8. Space Camera

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Nikon's F3 35mm camera was specially modified for use by Space Shuttle astronauts. The modification work produced a spinoff lubricant. Because lubricants in space have a tendency to migrate within the camera, Nikon conducted extensive development to produce nonmigratory lubricants; variations of these lubricants are used in the commercial F3, giving it better performance than conventional lubricants. Another spinoff is the coreless motor which allows the F3 to shoot 140 rolls of film on one set of batteries.

  9. Biplane reconstruction and visualization of virtual endoscopic and fluoroscopic views for interventional device navigation

    NASA Astrophysics Data System (ADS)

    Wagner, Martin G.; Strother, Charles M.; Schafer, Sebastian; Mistretta, Charles A.

    2016-03-01

    Biplane fluoroscopic imaging is an important tool for minimally invasive procedures for the treatment of cerebrovascular diseases. However, finding a good working angle for the C-arms of the angiography system as well as navigating based on the 2D projection images can be a difficult task. The purpose of this work is to propose a novel 4D reconstruction algorithm for interventional devices from biplane fluoroscopy images and to propose new techniques for a better visualization of the results. The proposed reconstruction methods binarizes the fluoroscopic images using a dedicated noise reduction algorithm for curvilinear structures and a global thresholding approach. A topology preserving thinning algorithm is then applied and a path search algorithm minimizing the curvature of the device is used to extract the 2D device centerlines. Finally, the 3D device path is reconstructed using epipolar geometry. The point correspondences are determined by a monotonic mapping function that minimizes the reconstruction error. The three dimensional reconstruction of the device path allows the rendering of virtual fluoroscopy images from arbitrary angles as well as 3D visualizations like virtual endoscopic views or glass pipe renderings, where the vessel wall is rendered with a semi-transparent material. This work also proposes a combination of different visualization techniques in order to increase the usability and spatial orientation for the user. A combination of synchronized endoscopic and glass pipe views is proposed, where the virtual endoscopic camera position is determined based on the device tip location as well as the previous camera position using a Kalman filter in order to create a smooth path. Additionally, vessel centerlines are displayed and the path to the target is highlighted. Finally, the virtual endoscopic camera position is also visualized in the glass pipe view to further improve the spatial orientation. The proposed techniques could considerably improve

  10. Advanced camera for the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Ford, Holland C.; Feldman, Paul D.; Golimowski, David A.; Tsvetanov, Zlatan; Bartko, Frank; Crocker, James H.; Bely, Pierre Y.; Brown, Robert A.; Burrows, Christopher J.; Clampin, Mark; Hartig, George F.; Postman, Marc; Rafal, Marc D.; Sparks, William B.; White, Richard L.; Broadhurst, Tom; Illingworth, Garth; Kelly, Tim; Woodruff, Robert A.; Cheng, Edward; Kimble, Randy A.; Krebs, Carolyn A.; Neff, Susan G.; Lesser, Michael P.; Miley, George

    1996-10-01

    The Advanced Camera for the Hubble Space Telescope will have three cameras. The first, the Wide Field Camera, will be a high throughput (45% at 700 nm, including the HST optical telescope assembly), wide field (200' X 204'), optical and I-band camera that is half critically sampled at 500 nm. The second, the High Resolution Camera (HRC), is critically sampled at 500 nm, and has a 26' X 29' field of view and 25% throughput at 600 nm. The HRC optical path will include a coronagraph which will improve the HST contrast near bright objects by a factor of approximately 10. The third camera is a far ultraviolet, Solar-Blind Camera that has a relatively high throughput (6% at 121.6 nm) over a 26' X 29' field of view. The Advanced Camera for Surveys will increase HST's capability for surveys and discovery by at least a factor of ten.

  11. Infrared Camera

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A sensitive infrared camera that observes the blazing plumes from the Space Shuttle or expendable rocket lift-offs is capable of scanning for fires, monitoring the environment and providing medical imaging. The hand-held camera uses highly sensitive arrays in infrared photodetectors known as quantum well infrared photo detectors (QWIPS). QWIPS were developed by the Jet Propulsion Laboratory's Center for Space Microelectronics Technology in partnership with Amber, a Raytheon company. In October 1996, QWIP detectors pointed out hot spots of the destructive fires speeding through Malibu, California. Night vision, early warning systems, navigation, flight control systems, weather monitoring, security and surveillance are among the duties for which the camera is suited. Medical applications are also expected.

  12. Richardson-Lucy deblurring for the star scene under a thinning motion path

    NASA Astrophysics Data System (ADS)

    Su, Laili; Shao, Xiaopeng; Wang, Lin; Wang, Haixin; Huang, Yining

    2015-05-01

    This paper puts emphasis on how to model and correct image blur that arises from a camera's ego motion while observing a distant star scene. Concerning the significance of accurate estimation of point spread function (PSF), a new method is employed to obtain blur kernel by thinning star motion path. In particular, how the blurred star image can be corrected to reconstruct the clear scene with a thinning motion blur model which describes the camera's path is presented. This thinning motion path to build blur kernel model is more effective at modeling the spatially motion blur introduced by camera's ego motion than conventional blind estimation of kernel-based PSF parameterization. To gain the reconstructed image, firstly, an improved thinning algorithm is used to obtain the star point trajectory, so as to extract the blur kernel of the motion-blurred star image. Then how motion blur model can be incorporated into the Richardson-Lucy (RL) deblurring algorithm, which reveals its overall effectiveness, is detailed. In addition, compared with the conventional estimated blur kernel, experimental results show that the proposed method of using thinning algorithm to get the motion blur kernel is of less complexity, higher efficiency and better accuracy, which contributes to better restoration of the motion-blurred star images.

  13. Nikon Camera

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Nikon FM compact has simplification feature derived from cameras designed for easy, yet accurate use in a weightless environment. Innovation is a plastic-cushioned advance lever which advances the film and simultaneously switches on a built in light meter. With a turn of the lens aperture ring, a glowing signal in viewfinder confirms correct exposure.

  14. CCD Camera

    DOEpatents

    Roth, Roger R.

    1983-01-01

    A CCD camera capable of observing a moving object which has varying intensities of radiation eminating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other.

  15. CCD Camera

    DOEpatents

    Roth, R.R.

    1983-08-02

    A CCD camera capable of observing a moving object which has varying intensities of radiation emanating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other. 7 figs.

  16. Neutron Imaging Camera

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley; deNolfo, G. A.; Barbier, L. M.; Link, J. T.; Son, S.; Floyd, S. R.; Guardala, N.; Skopec, M.; Stark, B.

    2008-01-01

    The Neutron Imaging Camera (NIC) is based on the Three-dimensional Track Imager (3DTI) technology developed at GSFC for gamma-ray astrophysics applications. The 3-DTI, a large volume time-projection chamber, provides accurate, approximately 0.4 mm resolution, 3-D tracking of charged particles. The incident direction of fast neutrons, En > 0.5 MeV, are reconstructed from the momenta and energies of the proton and triton fragments resulting from (sup 3)He(n,p) (sup 3)H interactions in the 3-DTI volume. The performance of the NIC from laboratory and accelerator tests is presented.

  17. Novel double path shearing interferometer in corneal topography measurements

    NASA Astrophysics Data System (ADS)

    Licznerski, Tomasz J.; Jaronski, Jaroslaw; Kosz, Dariusz

    2005-09-01

    The paper presents an approach for measurements of corneal topography by use of a patent pending double path shearing interferometer (DPSI). Laser light reflected from the surface of the cornea is divided and directed to the inputs of two interferometers. The interferometers use lateral shearing of wavefronts in two orthogonal directions. A tilt of one of the mirrors in each interferometric setup perpendicularly to the lateral shear introduces parallel carrier frequency fringes at the output of each interferometer. There is orthogonal linear polarization of the laser light used in two DPSI. Two images of fringe patters are recorded by a high resolution digital camera. The obtained fringe patterns are used for phase difference reconstruction. The phase of the wavefront was reconstructed by use of algorithms for a large grid based on discrete integration. The in vivo method can also be used for tear film stability measurement, artificial tears and contact lens tests.

  18. Holographic motion picture camera with Doppler shift compensation

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1976-01-01

    A holographic motion picture camera is reported for producing three dimensional images by employing an elliptical optical system. There is provided in one of the beam paths (the object or reference beam path) a motion compensator which enables the camera to photograph faster moving objects.

  19. The Advanced Camera for Surveys

    NASA Astrophysics Data System (ADS)

    Clampin, M.; Ford, H. C.; Feldman, P.; Golimowski, D.; Tsvetanov, Z.; Bartko, F.; Brown, B.; Burrows, C.; Hartig, G.; Postman, M.; Rafal, M.; Sparks, B.; White, R.; Crocker, J.; Bely, P.; Cheng, E.; Krebs, C.; Kimble, R.; Neff, S.; Illingworth, G.; Lesser, M.; Broadhurst, T.; Miley, G.; Lajeunesse, T.; Woodruff, B.

    1998-01-01

    The Advanced Camera for Surveys (ACS) is to be installed in the Hubble Space Telescope (HST) during the third HST servicing mission in December 1999. The ACS comprises three cameras each designed to achieve specific goals. The first, the Wide Field Camera, will be a high throughput, wide field (200" x 204"), visible to nar-IR camera that is half critically sampled at 500 nm. The second, the High Resolution Camera (HRC), is critically sampled at 500 nm, and has a 26" x 29" field of view. The HRC optical path includes a coronagraph which will improve the HST's contrast near bright objects by a factor of 10. The third camera is a far ultraviolet, Solar-Blind Camera (SBC),with a field of 26" x 29". ACS will increase HST's capability for imaging surveys and discovery by at least a factor of 10. We give an overview of the ACS design and discuss image the quality of the optics and the performance of the CCD and MAMA detectors. The plans for the GTO science program are reviewed, and specific scientific capabilities of the instrument reviewed.

  20. Path Finder

    Energy Science and Technology Software Center (ESTSC)

    2014-01-07

    PathFinder is a graph search program, traversing a directed cyclic graph to find pathways between labeled nodes. Searches for paths through ordered sequences of labels are termed signatures. Determining the presence of signatures within one or more graphs is the primary function of Path Finder. Path Finder can work in either batch mode or interactively with an analyst. Results are limited to Path Finder whether or not a given signature is present in the graph(s).

  1. Calibration and Epipolar Geometry of Generic Heterogenous Camera Systems

    NASA Astrophysics Data System (ADS)

    Luber, A.; Rueß, D.; Manthey, K.; Reulke, R.

    2012-07-01

    The application of perspective camera systems in photogrammetry and computer vision is state of the art. In recent years nonperspective and especially omnidirectional camera systems were increasingly used in close-range photogrammetry tasks. In general perspective camera model, i. e. pinhole model, cannot be applied when using non-perspective camera systems. However, several camera models for different omnidirectional camera systems are proposed in literature. Using different types of cameras in a heterogeneous camera system may lead to an advantageous combination. The advantages of different camera systems, e. g. field of view and resolution, result in a new enhanced camera system. If these different kinds of cameras can be modeled, using a unified camera model, the total calibration process can be simplified. Sometimes it is not possible to give the specific camera model in advance. In these cases a generic approach is helpful. Furthermore, a simple stereo reconstruction becomes possible using a fisheye and a perspective camera for example. In this paper camera models for perspective, wide-angle and omnidirectional camera systems are evaluated. The crucial initialization of the model's parameters is conducted using a generic method that is independent of the particular camera system. The accuracy of this generic camera calibration approach is evaluated by calibration of a dozen of real camera systems. It will be shown, that a unified method of modeling, parameter approximation and calibration of interior and exterior orientation can be applied to derive 3D object data.

  2. HIGH SPEED KERR CELL FRAMING CAMERA

    DOEpatents

    Goss, W.C.; Gilley, L.F.

    1964-01-01

    The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

  3. Phase-Space Reconstruction: a Path Towards the Next Generation of Nonlinear Differential Equation Based Models and Its Implications Towards Non-Uniform Sampling Theory

    SciTech Connect

    Charles R. Tolle; Mark Pengitore

    2009-08-01

    This paper explores the overlaps between the Control community’s work on System Identification (SysID) and the Physics, Mathematics, Chaos, and Complexity communities’ work on phase-space reconstruction via time-delay embedding. There are numerous overlaps between the goals of each community. Nevertheless, the Controls community can gain new insight as well as some new very powerful tools for SysID from the latest developments within the Physics, Mathematics, Chaos, and Complexity communities. These insights are gained via the work on phase-space reconstruction of non-linear dynamics. New methods for discovering non-linear differential based equations that evolved from embedding operations can shed new light on hybrid-systems theory, Nyquest-Shannon’s Theories, and network based control theory. This paper strives to guide the Controls community towards a closer inspection of the tools and additional insights being developed within the Physics, Mathematics, Chaos, and Complexity communities for discovery of system dynamics, the first step in control system development. The paper introduces the concepts of phase-space reconstruction via time-delay embedding (made famous byWhitney, Takens, and Sauer’s Thoreoms), intergrate-and-fire embedding, and non-linear differential equation discovery based on Perona’s method.

  4. Analysis of an Optimized MLOS Tomographic Reconstruction Algorithm and Comparison to the MART Reconstruction Algorithm

    NASA Astrophysics Data System (ADS)

    La Foy, Roderick; Vlachos, Pavlos

    2011-11-01

    An optimally designed MLOS tomographic reconstruction algorithm for use in 3D PIV and PTV applications is analyzed. Using a set of optimized reconstruction parameters, the reconstructions produced by the MLOS algorithm are shown to be comparable to reconstructions produced by the MART algorithm for a range of camera geometries, camera numbers, and particle seeding densities. The resultant velocity field error calculated using PIV and PTV algorithms is further minimized by applying both pre and post processing to the reconstructed data sets.

  5. Shortest Paths.

    ERIC Educational Resources Information Center

    Shore, M. L.

    1980-01-01

    There are many uses for the shortest path algorithm presented which are limited only by our ability to recognize when a problem may be converted into the shortest path in a graph representation. (Author/TG)

  6. 3D camera tracking from disparity images

    NASA Astrophysics Data System (ADS)

    Kim, Kiyoung; Woo, Woontack

    2005-07-01

    In this paper, we propose a robust camera tracking method that uses disparity images computed from known parameters of 3D camera and multiple epipolar constraints. We assume that baselines between lenses in 3D camera and intrinsic parameters are known. The proposed method reduces camera motion uncertainty encountered during camera tracking. Specifically, we first obtain corresponding feature points between initial lenses using normalized correlation method. In conjunction with matching features, we get disparity images. When the camera moves, the corresponding feature points, obtained from each lens of 3D camera, are robustly tracked via Kanade-Lukas-Tomasi (KLT) tracking algorithm. Secondly, relative pose parameters of each lens are calculated via Essential matrices. Essential matrices are computed from Fundamental matrix calculated using normalized 8-point algorithm with RANSAC scheme. Then, we determine scale factor of translation matrix by d-motion. This is required because the camera motion obtained from Essential matrix is up to scale. Finally, we optimize camera motion using multiple epipolar constraints between lenses and d-motion constraints computed from disparity images. The proposed method can be widely adopted in Augmented Reality (AR) applications, 3D reconstruction using 3D camera, and fine surveillance systems which not only need depth information, but also camera motion parameters in real-time.

  7. SPEIR: A Ge Compton Camera

    SciTech Connect

    Mihailescu, L; Vetter, K M; Burks, M T; Hull, E L; Craig, W W

    2004-02-11

    The SPEctroscopic Imager for {gamma}-Rays (SPEIR) is a new concept of a compact {gamma}-ray imaging system of high efficiency and spectroscopic resolution with a 4-{pi} field-of-view. The system behind this concept employs double-sided segmented planar Ge detectors accompanied by the use of list-mode photon reconstruction methods to create a sensitive, compact Compton scatter camera.

  8. Reconstruction of passive open-path FTIR ambient spectra using meteorological measurements and its application for detection of aerosol cloud drift.

    PubMed

    Kira, Oz; Dubowski, Yael; Linker, Raphael

    2015-07-27

    Remote sensing of atmospheric aerosols is of great importance to public and environmental health. This research promotes a simple way of detecting an aerosol cloud using a passive Open Path FTIR (OP-FTIR) system, without utilizing radiative transfer models and without relying on an artificial light source. Meteorological measurements (temperature, relative humidity and solar irradiance), and chemometric methods (multiple linear regression and artificial neural networks) together with previous cloud-free OP-FTIR measurements were used to estimate the ambient spectrum in real time. The cloud detection process included a statistical comparison between the estimated cloud-free signal and the measured OP-FTIR signal. During the study we were able to successfully detect several aerosol clouds (water spray) in controlled conditions as well as during agricultural pesticide spraying in an orchard. PMID:26367691

  9. Moving Human Path Tracking Based on Video Surveillance in 3d Indoor Scenarios

    NASA Astrophysics Data System (ADS)

    Zhou, Yan; Zlatanova, Sisi; Wang, Zhe; Zhang, Yeting; Liu, Liu

    2016-06-01

    Video surveillance systems are increasingly used for a variety of 3D indoor applications. We can analyse human behaviour, discover and avoid crowded areas, monitor human traffic and so forth. In this paper we concentrate on use of surveillance cameras to track and reconstruct the path a person has followed. For the purpose we integrated video surveillance data with a 3D indoor model of the building and develop a single human moving path tracking method. We process the surveillance videos to detected single human moving traces; then we match the depth information of 3D scenes to the constructed 3D indoor network model and define the human traces in the 3D indoor space. Finally, the single human traces extracted from multiple cameras are connected with the help of the connectivity provided by the 3D network model. Using this approach, we can reconstruct the entire walking path. The provided experiments with a single person have verified the effectiveness and robustness of the method.

  10. Neutron Imaging Camera

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.; DeNolfo, Georgia; Floyd, Sam; Krizmanic, John; Link, Jason; Son, Seunghee; Guardala, Noel; Skopec, Marlene; Stark, Robert

    2008-01-01

    We describe the Neutron Imaging Camera (NIC) being developed for DTRA applications by NASA/GSFC and NSWC/Carderock. The NIC is based on the Three-dimensional Track Imager (3-DTI) technology developed at GSFC for gamma-ray astrophysics applications. The 3-DTI, a large volume time-projection chamber, provides accurate, approximately 0.4 mm resolution. 3-D tracking of charged particles. The incident direction of fast neutrons, E(sub N) > 0.5 MeV. arc reconstructed from the momenta and energies of the proton and triton fragments resulting from 3He(n,p)3H interactions in the 3-DTI volume. We present angular and energy resolution performance of the NIC derived from accelerator tests.

  11. A novel super-resolution camera model

    NASA Astrophysics Data System (ADS)

    Shao, Xiaopeng; Wang, Yi; Xu, Jie; Wang, Lin; Liu, Fei; Luo, Qiuhua; Chen, Xiaodong; Bi, Xiangli

    2015-05-01

    Aiming to realize super resolution(SR) to single image and video reconstruction, a super resolution camera model is proposed for the problem that the resolution of the images obtained by traditional cameras behave comparatively low. To achieve this function we put a certain driving device such as piezoelectric ceramics in the camera. By controlling the driving device, a set of continuous low resolution(LR) images can be obtained and stored instantaneity, which reflect the randomness of the displacements and the real-time performance of the storage very well. The low resolution image sequences have different redundant information and some particular priori information, thus it is possible to restore super resolution image factually and effectively. The sample method is used to derive the reconstruction principle of super resolution, which analyzes the possible improvement degree of the resolution in theory. The super resolution algorithm based on learning is used to reconstruct single image and the variational Bayesian algorithm is simulated to reconstruct the low resolution images with random displacements, which models the unknown high resolution image, motion parameters and unknown model parameters in one hierarchical Bayesian framework. Utilizing sub-pixel registration method, a super resolution image of the scene can be reconstructed. The results of 16 images reconstruction show that this camera model can increase the image resolution to 2 times, obtaining images with higher resolution in currently available hardware levels.

  12. Caught on Camera.

    ERIC Educational Resources Information Center

    Milshtein, Amy

    2002-01-01

    Describes the benefits of and rules to be followed when using surveillance cameras for school security. Discusses various camera models, including indoor and outdoor fixed position cameras, pan-tilt zoom cameras, and pinhole-lens cameras for covert surveillance. (EV)

  13. Path ANalysis

    SciTech Connect

    Snell, Mark K.

    2007-07-14

    The PANL software determines path through an Adversary Sequence Diagram (ASD) with minimum Probability of Interruption, P(I), given the ASD information and data about site detection, delay, and response force times. To accomplish this, the software generates each path through the ASD, then applies the Estimate of Adversary Sequence Interruption (EASI) methodology for calculating P(I) to each path, and keeps track of the path with the lowest P(I). Primary use is for training purposes during courses on physical security design. During such courses PANL will be used to demonstrate to students how more complex software codes are used by the US Department of Energy to determine the most-vulnerable paths and, where security needs improvement, how such codes can help determine physical security upgrades.

  14. Path ANalysis

    Energy Science and Technology Software Center (ESTSC)

    2007-07-14

    The PANL software determines path through an Adversary Sequence Diagram (ASD) with minimum Probability of Interruption, P(I), given the ASD information and data about site detection, delay, and response force times. To accomplish this, the software generates each path through the ASD, then applies the Estimate of Adversary Sequence Interruption (EASI) methodology for calculating P(I) to each path, and keeps track of the path with the lowest P(I). Primary use is for training purposes duringmore » courses on physical security design. During such courses PANL will be used to demonstrate to students how more complex software codes are used by the US Department of Energy to determine the most-vulnerable paths and, where security needs improvement, how such codes can help determine physical security upgrades.« less

  15. Proactive PTZ Camera Control

    NASA Astrophysics Data System (ADS)

    Qureshi, Faisal Z.; Terzopoulos, Demetri

    We present a visual sensor network—comprising wide field-of-view (FOV) passive cameras and pan/tilt/zoom (PTZ) active cameras—capable of automatically capturing closeup video of selected pedestrians in a designated area. The passive cameras can track multiple pedestrians simultaneously and any PTZ camera can observe a single pedestrian at a time. We propose a strategy for proactive PTZ camera control where cameras plan ahead to select optimal camera assignment and handoff with respect to predefined observational goals. The passive cameras supply tracking information that is used to control the PTZ cameras.

  16. Reconstruction Of Anatomical Shapes From Moire Contourographs

    NASA Astrophysics Data System (ADS)

    Saunders, Carl G.

    1983-07-01

    A Moire system which rotates an object in front of a slit camera has been used to obtain continuous photographic maps around amputee socket and shoe last shapes. Previous analysis methods required the use of IBM 370 hardware and extensive software overhead. Using a systematic manual digitizing technique and user-interactive FORTRAN software, the shape reconstruction has been easily performed on a PDP-11 minicomputer system. Both the digitizing technique and the software are oriented towards the shape reproduction process. Numerically controlled machining parameters are used to identify a "skewed" grid of required points along the cutter path. Linear interpolation and anti-interference techniques resulted in reproduction of shoe lasts to within 0.05 inches (1.2 millimeters) from the sensing axis. Difficulties were experienced in obtaining information to resolve the ends of the shapes. Current efforts focus on circumferential shape sensing of live subjects and automatic digitization of sensed data.

  17. Path Pascal

    NASA Technical Reports Server (NTRS)

    Campbell, R. H.; Kolstad, R. B.; Holle, D. F.; Miller, T. J.; Krause, P.; Horton, K.; Macke, T.

    1983-01-01

    Path Pascal is high-level experimental programming language based on PASCAL, which incorporates extensions for systems and real-time programming. Pascal is extended to treat real-time concurrent systems.

  18. A new inclination shallowing correction of the Mauch Chunk Formation of Pennsylvania, based on high-field AIR results: Implications for the Carboniferous North American APW path and Pangea reconstructions

    NASA Astrophysics Data System (ADS)

    Bilardello, Dario; Kodama, Kenneth P.

    2010-10-01

    A new magnetic anisotropy study was performed on samples of the Lower Carboniferous Mauch Chunk Formation of Pennsylvania. These red beds had been sampled for an inclination shallowing study by Tan and Kodama (2002), however, application of a high-field anisotropy of isothermal remanence magnetization (hf-AIR) technique specifically designed to measure the anisotropy of hematite provides considerably different results from those previously reported. The newly measured fabric has smaller anisotropy (~ 9-17% as opposed to ~ 25-40%) and shows a pronounced ENE-WSW magnetic lineation that is sub-parallel to the trend of the Appalachians and interpretable as a hematite intersection lineation that occurred during local NNW-directed shortening. The measured magnetic fabric yields a new inclination correction with a corrected paleopole that is in better agreement with recently corrected Carboniferous paleopoles than the previously corrected Mauch Chunk paleopole, defining a more consistent APW path. The corrected paleopoles allow calculation of new mean Early (~ 325 Ma) and Late (~ 312 Ma) Carboniferous inclination-corrected paleopoles for North America, which can be compared to coeval, but uncorrected, paleopoles from Gondwana. Results suggest a Pangea B assemblage unless inclination shallowing is considered for Gondwana. Estimating an inclination correction for Gondwana sedimentary rock-derived paleopoles permits a Pangea A-type assemblage at higher southern latitudes than previous reconstructions, which we term Pangea A3.

  19. Determining Camera Gain in Room Temperature Cameras

    SciTech Connect

    Joshua Cogliati

    2010-12-01

    James R. Janesick provides a method for determining the amplification of a CCD or CMOS camera when only access to the raw images is provided. However, the equation that is provided ignores the contribution of dark current. For CCD or CMOS cameras that are cooled well below room temperature, this is not a problem, however, the technique needs adjustment for use with room temperature cameras. This article describes the adjustment made to the equation, and a test of this method.

  20. Unified framework for recognition, localization and mapping using wearable cameras.

    PubMed

    Vázquez-Martín, Ricardo; Bandera, Antonio

    2012-08-01

    Monocular approaches to simultaneous localization and mapping (SLAM) have recently addressed with success the challenging problem of the fast computation of dense reconstructions from a single, moving camera. Thus, if these approaches initially relied on the detection of a reduced set of interest points to estimate the camera position and the map, they are currently able to reconstruct dense maps from a handheld camera while the camera coordinates are simultaneously computed. However, these maps of 3-dimensional points usually remain meaningless, that is, with no memorable items and without providing a way of encoding spatial relationships between objects and paths. In humans and mobile robotics, landmarks play a key role in the internalization of a spatial representation of an environment. They are memorable cues that can serve to define a region of the space or the location of other objects. In a topological representation of the space, landmarks can be identified and located according to its structural, perceptive or semantic significance and distinctiveness. But on the other hand, landmarks may be difficult to be located in a metric representation of the space. Restricted to the domain of visual landmarks, this work describes an approach where the map resulting from a point-based, monocular SLAM is annotated with the semantic information provided by a set of distinguished landmarks. Both features are obtained from the image. Hence, they can be linked by associating to each landmark all those point-based features that are superimposed to the landmark in a given image (key-frame). Visual landmarks will be obtained by means of an object-based, bottom-up attention mechanism, which will extract from the image a set of proto-objects. These proto-objects could not be always associated with natural objects, but they will typically constitute significant parts of these scene objects and can be appropriately annotated with semantic information. Moreover, they will be

  1. Line profile reconstruction: validation and comparison of reconstruction methods

    NASA Astrophysics Data System (ADS)

    Tsai, Ming-Yi; Yost, Michael G.; Wu, Chang-Fu; Hashmonay, Ram A.; Larson, Timothy V.

    Currently, open path Fourier transform infrared (OP-FTIR) spectrometers have been applied in some fenceline monitoring, but their use has been limited because path-integrated concentration measurements typically only provide an estimate of the average concentration. We present a series of experiments that further explore the use of path-integrated measurements to reconstruct various pollutant distributions along a linear path. Our experiments were conducted in a ventilation chamber using an OP-FTIR instrument to monitor a tracer-gas release over a fenceline configuration. These experiments validate a line profile method (1-D reconstruction). Additionally, we expand current reconstruction techniques by applying the Bootstrap to our measurements. We compared our reconstruction results to our point samplers using the concordance correlation factor (CCF). Of the four different release types, three were successfully reconstructed with CCFs greater than 0.9. The difficult reconstruction involved a narrow release where the pollutant was limited to one segment of the segmented beampath. In general, of the three reconstruction methods employed, the average of the bootstrapped reconstructions was found to have the highest CCFs when compared to the point samplers. Furthermore, the bootstrap method was the most flexible and allowed a determination of the uncertainty surrounding our reconstructions.

  2. Spirit's Path to Bonneville

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Scientists created this overlay map by laying navigation and panoramic camera images taken from the surface of Mars on top of one of Spirit's descent images taken as the spacecraft descended to the martian surface. The map was created to help track the path that Spirit has traveled through sol 44 and to put into perspective the distance left to travel before reaching the edge of the large crater nicknamed 'Bonneville.'

    The area boxed in yellow contains the ground images that have been matched to and layered on top of the descent image. The yellow line shows the path that Spirit has traveled and the red dashed line shows the intended path for future sols. The blue circles highlight hollowed areas on the surface, such as Sleepy Hollow, near the lander, and Laguna Hollow, the sol 45 drive destination. Scientists use these hollowed areas - which can be seen in both the ground images and the descent image - to correctly match up the overlay.

    Field geologists on Earth create maps like this to assist them in tracking their observations.

  3. Action selection for single-camera SLAM.

    PubMed

    Vidal-Calleja, Teresa A; Sanfeliu, Alberto; Andrade-Cetto, Juan

    2010-12-01

    A method for evaluating, at video rate, the quality of actions for a single camera while mapping unknown indoor environments is presented. The strategy maximizes mutual information between measurements and states to help the camera avoid making ill-conditioned measurements that are appropriate to lack of depth in monocular vision systems. Our system prompts a user with the appropriate motion commands during 6-DOF visual simultaneous localization and mapping with a handheld camera. Additionally, the system has been ported to a mobile robotic platform, thus closing the control-estimation loop. To show the viability of the approach, simulations and experiments are presented for the unconstrained motion of a handheld camera and for the motion of a mobile robot with nonholonomic constraints. When combined with a path planner, the technique safely drives to a marked goal while, at the same time, producing an optimal estimated map. PMID:20350845

  4. Evaluating intensified camera systems

    SciTech Connect

    S. A. Baker

    2000-06-30

    This paper describes image evaluation techniques used to standardize camera system characterizations. The authors group is involved with building and fielding several types of camera systems. Camera types include gated intensified cameras, multi-frame cameras, and streak cameras. Applications range from X-ray radiography to visible and infrared imaging. Key areas of performance include sensitivity, noise, and resolution. This team has developed an analysis tool, in the form of image processing software, to aid an experimenter in measuring a set of performance metrics for their camera system. These performance parameters are used to identify a camera system's capabilities and limitations while establishing a means for camera system comparisons. The analysis tool is used to evaluate digital images normally recorded with CCD cameras. Electro-optical components provide fast shuttering and/or optical gain to camera systems. Camera systems incorporate a variety of electro-optical components such as microchannel plate (MCP) or proximity focused diode (PFD) image intensifiers; electro-static image tubes; or electron-bombarded (EB) CCDs. It is often valuable to evaluate the performance of an intensified camera in order to determine if a particular system meets experimental requirements.

  5. Vacuum Camera Cooler

    NASA Technical Reports Server (NTRS)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  6. Novel fundus camera design

    NASA Astrophysics Data System (ADS)

    Dehoog, Edward A.

    A fundus camera a complex optical system that makes use of the principle of reflex free indirect ophthalmoscopy to image the retina. Despite being in existence as early as 1900's, little has changed in the design of a fundus camera and there is minimal information about the design principles utilized. Parameters and specifications involved in the design of fundus camera are determined and their affect on system performance are discussed. Fundus cameras incorporating different design methods are modeled and a performance evaluation based on design parameters is used to determine the effectiveness of each design strategy. By determining the design principles involved in the fundus camera, new cameras can be designed to include specific imaging modalities such as optical coherence tomography, imaging spectroscopy and imaging polarimetry to gather additional information about properties and structure of the retina. Design principles utilized to incorporate such modalities into fundus camera systems are discussed. Design, implementation and testing of a snapshot polarimeter fundus camera are demonstrated.

  7. Advanced camera for surveys

    NASA Astrophysics Data System (ADS)

    Clampin, Mark; Ford, Holland C.; Bartko, Frank; Bely, Pierre Y.; Broadhurst, Tom; Burrows, Christopher J.; Cheng, Edward S.; Crocker, James H.; Franx, Marijn; Feldman, Paul D.; Golimowski, David A.; Hartig, George F.; Illingworth, Garth; Kimble, Randy A.; Lesser, Michael P.; Miley, George H.; Postman, Marc; Rafal, Marc D.; Rosati, Piero; Sparks, William B.; Tsvetanov, Zlatan; White, Richard L.; Sullivan, Pamela; Volmer, Paul; LaJeunesse, Tom

    2000-07-01

    The Advanced Camera for Surveys (ACS) is a third generation instrument for the Hubble Space Telescope (HST). It is currently planned for installation in HST during the fourth servicing mission in Summer 2001. The ACS will have three cameras.

  8. Constrained space camera assembly

    DOEpatents

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  9. Making Ceramic Cameras

    ERIC Educational Resources Information Center

    Squibb, Matt

    2009-01-01

    This article describes how to make a clay camera. This idea of creating functional cameras from clay allows students to experience ceramics, photography, and painting all in one unit. (Contains 1 resource and 3 online resources.)

  10. Nanosecond frame cameras

    SciTech Connect

    Frank, A M; Wilkins, P R

    2001-01-05

    The advent of CCD cameras and computerized data recording has spurred the development of several new cameras and techniques for recording nanosecond images. We have made a side by side comparison of three nanosecond frame cameras, examining them for both performance and operational characteristics. The cameras include; Micro-Channel Plate/CCD, Image Diode/CCD and Image Diode/Film; combinations of gating/data recording. The advantages and disadvantages of each device will be discussed.

  11. Convex accelerated maximum entropy reconstruction

    NASA Astrophysics Data System (ADS)

    Worley, Bradley

    2016-04-01

    Maximum entropy (MaxEnt) spectral reconstruction methods provide a powerful framework for spectral estimation of nonuniformly sampled datasets. Many methods exist within this framework, usually defined based on the magnitude of a Lagrange multiplier in the MaxEnt objective function. An algorithm is presented here that utilizes accelerated first-order convex optimization techniques to rapidly and reliably reconstruct nonuniformly sampled NMR datasets using the principle of maximum entropy. This algorithm - called CAMERA for Convex Accelerated Maximum Entropy Reconstruction Algorithm - is a new approach to spectral reconstruction that exhibits fast, tunable convergence in both constant-aim and constant-lambda modes. A high-performance, open source NMR data processing tool is described that implements CAMERA, and brief comparisons to existing reconstruction methods are made on several example spectra.

  12. Digital Pinhole Camera

    ERIC Educational Resources Information Center

    Lancor, Rachael; Lancor, Brian

    2014-01-01

    In this article we describe how the classic pinhole camera demonstration can be adapted for use with digital cameras. Students can easily explore the effects of the size of the pinhole and its distance from the sensor on exposure time, magnification, and image quality. Instructions for constructing a digital pinhole camera and our method for…

  13. Evaluating intensified camera systems

    SciTech Connect

    S. A. Baker

    2000-07-01

    This paper describes image evaluation techniques used to standardize camera system characterizations. Key areas of performance include resolution, noise, and sensitivity. This team has developed a set of analysis tools, in the form of image processing software used to evaluate camera calibration data, to aid an experimenter in measuring a set of camera performance metrics. These performance metrics identify capabilities and limitations of the camera system, while establishing a means for comparing camera systems. Analysis software is used to evaluate digital camera images recorded with charge-coupled device (CCD) cameras. Several types of intensified camera systems are used in the high-speed imaging field. Electro-optical components are used to provide precise shuttering or optical gain for a camera system. These components including microchannel plate or proximity focused diode image intensifiers, electro-static image tubes, or electron-bombarded CCDs affect system performance. It is important to quantify camera system performance in order to qualify a system as meeting experimental requirements. The camera evaluation tool is designed to provide side-by-side camera comparison and system modeling information.

  14. Harpicon camera for HDTV

    NASA Astrophysics Data System (ADS)

    Tanada, Jun

    1992-08-01

    Ikegami has been involved in broadcast equipment ever since it was established as a company. In conjunction with NHK it has brought forth countless television cameras, from black-and-white cameras to color cameras, HDTV cameras, and special-purpose cameras. In the early days of HDTV (high-definition television, also known as "High Vision") cameras the specifications were different from those for the cameras of the present-day system, and cameras using all kinds of components, having different arrangements of components, and having different appearances were developed into products, with time spent on experimentation, design, fabrication, adjustment, and inspection. But recently the knowhow built up thus far in components, , printed circuit boards, and wiring methods has been incorporated in camera fabrication, making it possible to make HDTV cameras by metbods similar to the present system. In addition, more-efficient production, lower costs, and better after-sales service are being achieved by using the same circuits, components, mechanism parts, and software for both HDTV cameras and cameras that operate by the present system.

  15. Opportunity's Path

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This Long Term Planning graphic was created from a mosaic of navigation camera images overlain by a polar coordinate grid with the center point as Opportunity's original landing site. The blue dots represent the rover position at various locations.

    The red dots represent the center points of the target areas for the instruments on the rover mast (the panoramic camera and miniature thermal emission spectrometer). Opportunity visited Stone Mountain on Feb. 5. Stone Mountain was named after the southernmost point of the Appalachian Mountains outside of Atlanta, Ga. On Earth, Stone Mountain is the last big mountain before the Piedmont flatlands, and on Mars, Stone Mountain is at one end of Opportunity Ledge. El Capitan is a target of interest on Mars named after the second highest peak in Texas in Guadaloupe National Park, which is one of the most visited outcrops in the United States by geologists. It has been a training ground for students and professional geologists to understand what the layering means in relation to the formation of Earth, and scientists will study this prominent point of Opportunity Ledge to understand what the layering means on Mars.

    The yellow lines show the midpoint where the panoramic camera has swept and will sweep a 120-degree area from the three waypoints on the tour of the outcrop. Imagine a fan-shaped wedge from left to right of the yellow line.

    The white contour lines are one meter apart, and each drive has been roughly about 2-3 meters in length over the last few sols. The large white blocks are dropouts in the navigation camera data.

    Opportunity is driving along and taking a photographic panorama of the entire outcrop. Scientists will stitch together these images and use the new mosaic as a 'base map' to decide on geology targets of interest for a more detailed study of the outcrop using the instruments on the robotic arm. Once scientists choose their targets of interest, they plan to study the outcrop for roughly five to

  16. 2. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH CAMERA STATION ABOVE LOOKING WEST TAKEN FROM RESERVOIR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  17. 7. VAL CAMERA CAR, DETAIL OF 'FLARE' OR TRAJECTORY CAMERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VAL CAMERA CAR, DETAIL OF 'FLARE' OR TRAJECTORY CAMERA INSIDE CAMERA CAR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  18. 6. VAL CAMERA CAR, DETAIL OF COMMUNICATION EQUIPMENT INSIDE CAMERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VAL CAMERA CAR, DETAIL OF COMMUNICATION EQUIPMENT INSIDE CAMERA CAR WITH CAMERA MOUNT IN FOREGROUND. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  19. Tower Camera Handbook

    SciTech Connect

    Moudry, D

    2005-01-01

    The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.

  20. Automated Camera Calibration

    NASA Technical Reports Server (NTRS)

    Chen, Siqi; Cheng, Yang; Willson, Reg

    2006-01-01

    Automated Camera Calibration (ACAL) is a computer program that automates the generation of calibration data for camera models used in machine vision systems. Machine vision camera models describe the mapping between points in three-dimensional (3D) space in front of the camera and the corresponding points in two-dimensional (2D) space in the camera s image. Calibrating a camera model requires a set of calibration data containing known 3D-to-2D point correspondences for the given camera system. Generating calibration data typically involves taking images of a calibration target where the 3D locations of the target s fiducial marks are known, and then measuring the 2D locations of the fiducial marks in the images. ACAL automates the analysis of calibration target images and greatly speeds the overall calibration process.

  1. Overview in two parts: Right view showing orchard path on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview in two parts: Right view showing orchard path on left eucalyptus windbreak bordering knoll on right. Camera facing 278" west. - Goerlitz House, 9893 Highland Avenue, Rancho Cucamonga, San Bernardino County, CA

  2. A new inclination shallowing correction of the Mauch Chunk Formation of Pennsylvania, based on high field-AIR results: Implications for the Carboniferous North American APW path and Pangea reconstructions

    NASA Astrophysics Data System (ADS)

    Bilardello, D.; Kodama, K. P.

    2010-12-01

    A new rock-magnetic study was performed on samples of the Lower Carboniferous Mauch Chunk Formation of Pennsylvania. These red beds had been sampled for an inclination shallowing study by Tan and Kodama (2002). High anisotropy values lead Kodama (2009) to suspect that the Formation had been affected by strain. However, more detailed rock-magnetic measurements also show that both magnetite and hematite contribute to the remanence, leading to the application of a high field anisotropy of isothermal remanence magnetization (hf-AIR) technique specifically designed to isolate the anisotropy of the hematite, the characteristic remanence carrier. The newly measured fabric has a smaller anisotropy than Kodama (2009) observed (~9-17% as opposed to ~25-40%) and shows a pronounced ENE-WSW magnetic lineation that is sub-parallel to the trend of the Appalachians and interpretable as a hematite intersection lineation that occurred during local NNW-directed shortening. Results also yield a much different AIR/ anisotropy of magnetic susceptibility (AMS) relationship than previously reported. We attribute the differences in the AIR/AMS relationship to varying concentrations of magnetite. Because the AIR/AMS relationship has been used to constrain the individual particle anisotropy we suggest this approach to determine grain anisotropy is invalid, at least until the AIR/AMS relationship for single domain hematite only is measured. The measured magnetic fabric yields a new inclination correction with a corrected paleopole that is in better agreement with recently corrected Carboniferous paleopoles than the previously corrected Mauch Chunk paleopole, defining a more consistent APW path. The corrected paleopoles allow calculation of new mean Early (~325 Ma) and Late (~312 Ma) Carboniferous inclination-corrected paleopoles for North America, which can be compared to coeval, but uncorrected, paleopoles from Gondwana. Results suggest a Pangea B assemblage unless Gondwanan sedimentary

  3. Structured light optical microscopy for three-dimensional reconstruction of technical surfaces

    NASA Astrophysics Data System (ADS)

    Kettel, Johannes; Reinecke, Holger; Müller, Claas

    2016-04-01

    In microsystems technology quality control of micro structured surfaces with different surface properties is playing an ever more important role. The process of quality control incorporates three-dimensional (3D) reconstruction of specularand diffusive reflecting technical surfaces. Due to the demand on high measurement accuracy and data acquisition rates, structured light optical microscopy has become a valuable solution to solve this problem providing high vertical and lateral resolution. However, 3D reconstruction of specular reflecting technical surfaces still remains a challenge to optical measurement principles. In this paper we present a measurement principle based on structured light optical microscopy which enables 3D reconstruction of specular- and diffusive reflecting technical surfaces. It is realized using two light paths of a stereo microscope equipped with different magnification levels. The right optical path of the stereo microscope is used to project structured light onto the object surface. The left optical path is used to capture the structured illuminated object surface with a camera. Structured light patterns are generated by a Digital Light Processing (DLP) device in combination with a high power Light Emitting Diode (LED). Structured light patterns are realized as a matrix of discrete light spots to illuminate defined areas on the object surface. The introduced measurement principle is based on multiple and parallel processed point measurements. Analysis of the measured Point Spread Function (PSF) by pattern recognition and model fitting algorithms enables the precise calculation of 3D coordinates. Using exemplary technical surfaces we demonstrate the successful application of our measurement principle.

  4. Microchannel plate streak camera

    DOEpatents

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  5. GRACE star camera noise

    NASA Astrophysics Data System (ADS)

    Harvey, Nate

    2016-08-01

    Extending results from previous work by Bandikova et al. (2012) and Inacio et al. (2015), this paper analyzes Gravity Recovery and Climate Experiment (GRACE) star camera attitude measurement noise by processing inter-camera quaternions from 2003 to 2015. We describe a correction to star camera data, which will eliminate a several-arcsec twice-per-rev error with daily modulation, currently visible in the auto-covariance function of the inter-camera quaternion, from future GRACE Level-1B product releases. We also present evidence supporting the argument that thermal conditions/settings affect long-term inter-camera attitude biases by at least tens-of-arcsecs, and that several-to-tens-of-arcsecs per-rev star camera errors depend largely on field-of-view.

  6. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1989-03-21

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras is disclosed. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1,000 KeV x-rays. 3 figs.

  7. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1984-09-28

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (uv to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 keV x-rays.

  8. Calibration of multi-camera photogrammetric systems

    NASA Astrophysics Data System (ADS)

    Detchev, I.; Mazaheri, M.; Rondeel, S.; Habib, A.

    2014-11-01

    Due to the low-cost and off-the-shelf availability of consumer grade cameras, multi-camera photogrammetric systems have become a popular means for 3D reconstruction. These systems can be used in a variety of applications such as infrastructure monitoring, cultural heritage documentation, biomedicine, mobile mapping, as-built architectural surveys, etc. In order to ensure that the required precision is met, a system calibration must be performed prior to the data collection campaign. This system calibration should be performed as efficiently as possible, because it may need to be completed many times. Multi-camera system calibration involves the estimation of the interior orientation parameters of each involved camera and the estimation of the relative orientation parameters among the cameras. This paper first reviews a method for multi-camera system calibration with built-in relative orientation constraints. A system stability analysis algorithm is then presented which can be used to assess different system calibration outcomes. The paper explores the required calibration configuration for a specific system in two situations: major calibration (when both the interior orientation parameters and relative orientation parameters are estimated), and minor calibration (when the interior orientation parameters are known a-priori and only the relative orientation parameters are estimated). In both situations, system calibration results are compared using the system stability analysis methodology.

  9. Analytical multicollimator camera calibration

    USGS Publications Warehouse

    Tayman, W.P.

    1978-01-01

    Calibration with the U.S. Geological survey multicollimator determines the calibrated focal length, the point of symmetry, the radial distortion referred to the point of symmetry, and the asymmetric characteristiecs of the camera lens. For this project, two cameras were calibrated, a Zeiss RMK A 15/23 and a Wild RC 8. Four test exposures were made with each camera. Results are tabulated for each exposure and averaged for each set. Copies of the standard USGS calibration reports are included. ?? 1978.

  10. LSST Camera Optics Design

    SciTech Connect

    Riot, V J; Olivier, S; Bauman, B; Pratuch, S; Seppala, L; Gilmore, D; Ku, J; Nordby, M; Foss, M; Antilogus, P; Morgado, N

    2012-05-24

    The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope mirrors to optimize performance. We discuss the rationale for the LSST camera optics design, describe the methodology for fabricating, coating, mounting and testing the lenses and filters, and present the results of detailed analyses demonstrating that the camera optics will meet their performance goals.

  11. Polarization encoded color camera.

    PubMed

    Schonbrun, Ethan; Möller, Guðfríður; Di Caprio, Giuseppe

    2014-03-15

    Digital cameras would be colorblind if they did not have pixelated color filters integrated into their image sensors. Integration of conventional fixed filters, however, comes at the expense of an inability to modify the camera's spectral properties. Instead, we demonstrate a micropolarizer-based camera that can reconfigure its spectral response. Color is encoded into a linear polarization state by a chiral dispersive element and then read out in a single exposure. The polarization encoded color camera is capable of capturing three-color images at wavelengths spanning the visible to the near infrared. PMID:24690806

  12. Ringfield lithographic camera

    DOEpatents

    Sweatt, William C.

    1998-01-01

    A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D.sub.source .apprxeq.0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry with an increased etendue for the camera system. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors.

  13. Stereoscopic liver surface reconstruction

    PubMed Central

    Karwan, Adam; Rudnicki, Jerzy; Wróblewski, Tadeusz

    2012-01-01

    The paper presents a practical approach to measuring liver motion, both respiratory and laparoscopic, with a tool guided in the operating room. The presented method is based on standard operating room equipment, i.e. rigid laparoscopic cameras and a single incision laparoscopic surgery trocar. The triangulation algorithm is used and stereo correspondence points are marked manually by two independent experts. To calibrate the cameras two perpendicular chessboards, a pinhole camera model and a Tsai algorithm are used. The data set consists of twelve real liver surgery video sequences: ten open surgery and two laparoscopic, gathered from different patients. The setup equipment and methodology are presented. The proposed evaluation method based on both calibration points of the chessboard reconstruction and measurements made by the Polaris Vicra tracking system are used as a reference system. In the analysis stage we focused on two specific goals, measuring respiration and laparoscopic tool guided liver motions. We have presented separate examples for left and right liver lobes. It is possible to reconstruct liver motion using the SILS trocar. Our approach was made without additional position or movement sensors. Diffusion of cameras and laser for distance measurement seems to be less practical for in vivo laparoscopic data, but we do not exclude exploring such sensors in further research. PMID:23256023

  14. Prediction of Viking lander camera image quality

    NASA Technical Reports Server (NTRS)

    Huck, F. O.; Burcher, E. E.; Jobson, D. J.; Wall, S. D.

    1976-01-01

    Formulations are presented that permit prediction of image quality as a function of camera performance, surface radiance properties, and lighting and viewing geometry. Predictions made for a wide range of surface radiance properties reveal that image quality depends strongly on proper camera dynamic range command and on favorable lighting and viewing geometry. Proper camera dynamic range commands depend mostly on the surface albedo that will be encountered. Favorable lighting and viewing geometries depend mostly on lander orientation with respect to the diurnal sun path over the landing site, and tend to be independent of surface albedo and illumination scattering function. Side lighting with low sun elevation angles (10 to 30 deg) is generally favorable for imaging spatial details and slopes, whereas high sun elevation angles are favorable for measuring spectral reflectances.

  15. Computational imaging for miniature cameras

    NASA Astrophysics Data System (ADS)

    Salahieh, Basel

    Miniature cameras play a key role in numerous imaging applications ranging from endoscopy and metrology inspection devices to smartphones and head-mount acquisition systems. However, due to the physical constraints, the imaging conditions, and the low quality of small optics, their imaging capabilities are limited in terms of the delivered resolution, the acquired depth of field, and the captured dynamic range. Computational imaging jointly addresses the imaging system and the reconstructing algorithms to bypass the traditional limits of optical systems and deliver better restorations for various applications. The scene is encoded into a set of efficient measurements which could then be computationally decoded to output a richer estimate of the scene as compared with the raw images captured by conventional imagers. In this dissertation, three task-based computational imaging techniques are developed to make low-quality miniature cameras capable of delivering realistic high-resolution reconstructions, providing full-focus imaging, and acquiring depth information for high dynamic range objects. For the superresolution task, a non-regularized direct superresolution algorithm is developed to achieve realistic restorations without being penalized by improper assumptions (e.g., optimizers, priors, and regularizers) made in the inverse problem. An adaptive frequency-based filtering scheme is introduced to upper bound the reconstruction errors while still producing more fine details as compared with previous methods under realistic imaging conditions. For the full-focus imaging task, a computational depth-based deconvolution technique is proposed to bring a scene captured by an ordinary fixed-focus camera to a full-focus based on a depth-variant point spread function prior. The ringing artifacts are suppressed on three levels: block tiling to eliminate boundary artifacts, adaptive reference maps to reduce ringing initiated by sharp edges, and block-wise deconvolution or

  16. Spectral characterization of an ophthalmic fundus camera

    NASA Astrophysics Data System (ADS)

    Miller, Clayton T.; Bassi, Carl J.; Brodsky, Dale; Holmes, Timothy

    2010-02-01

    A fundus camera is an optical system designed to illuminate and image the retina while minimizing stray light and backreflections. Modifying such a device requires characterization of the optical path in order to meet the new design goals and avoid introducing problems. This work describes the characterization of one system, the Topcon TRC-50F, necessary for converting this camera from film photography to spectral imaging with a CCD. This conversion consists of replacing the camera's original xenon flash tube with a monochromatic light source and the film back with a CCD. A critical preliminary step of this modification is determining the spectral throughput of the system, from source to sensor, and ensuring there are sufficient photons at the sensor for imaging. This was done for our system by first measuring the transmission efficiencies of the camera's illumination and imaging optical paths with a spectrophotometer. Combining these results with existing knowledge of the eye's reflectance, a relative sensitivity profile is developed for the system. Image measurements from a volunteer were then made using a few narrowband sources of known power and a calibrated CCD. With these data, a relationship between photoelectrons/pixel collected at the CCD and narrowband illumination source power is developed.

  17. Automated flight path planning for virtual endoscopy.

    PubMed

    Paik, D S; Beaulieu, C F; Jeffrey, R B; Rubin, G D; Napel, S

    1998-05-01

    In this paper, a novel technique for rapid and automatic computation of flight paths for guiding virtual endoscopic exploration of three-dimensional medical images is described. While manually planning flight paths is a tedious and time consuming task, our algorithm is automated and fast. Our method for positioning the virtual camera is based on the medial axis transform but is much more computationally efficient. By iteratively correcting a path toward the medial axis, the necessity of evaluating simple point criteria during morphological thinning is eliminated. The virtual camera is also oriented in a stable viewing direction, avoiding sudden twists and turns. We tested our algorithm on volumetric data sets of eight colons, one aorta and one bronchial tree. The algorithm computed the flight paths in several minutes per volume on an inexpensive workstation with minimal computation time added for multiple paths through branching structures (10%-13% per extra path). The results of our algorithm are smooth, centralized paths that aid in the task of navigation in virtual endoscopic exploration of three-dimensional medical images. PMID:9608471

  18. Lightweight, Compact, Long Range Camera Design

    NASA Astrophysics Data System (ADS)

    Shafer, Donald V.

    1983-08-01

    The model 700 camera is the latest in a 30-year series of LOROP cameras developed by McDonnell Douglas Astronautics Company (MDAC) and their predecessor companies. The design achieves minimum size and weight and is optimized for low-contrast performance. The optical system includes a 66-inch focal length, f/5.6, apochromatic lens and three folding mirrors imaging on a 4.5-inch square format. A three-axis active stabilization system provides the capability for long exposure time and, hence, fine grain films can be used. The optical path forms a figure "4" behind the lens. In front of the lens is a 45° pointing mirror. This folded configuration contributed greatly to the lightweight and compact design. This sequential autocycle frame camera has three modes of operation with one, two, and three step positions to provide a choice of swath widths within the range of lateral coverage. The magazine/shutter assembly rotates in relationship with the pointing mirror and aircraft drift angle to maintain film format alignment with the flight path. The entire camera is angular rate stabilized in roll, pitch, and yaw. It also employs a lightweight, electro-magnetically damped, low-natural-frequency spring suspension for passive isolation from aircraft vibration inputs. The combined film transport and forward motion compensation (FMC) mechanism, which is operated by a single motor, is contained in a magazine that can, depending on accessibility which is installation dependent, be changed in flight. The design also stresses thermal control, focus control, structural stiffness, and maintainability. The camera is operated from a remote control panel. This paper describes the leading particulars and features of the camera as related to weight and configuration.

  19. A method for selecting training samples based on camera response

    NASA Astrophysics Data System (ADS)

    Zhang, Leihong; Li, Bei; Pan, Zilan; Liang, Dong; Kang, Yi; Zhang, Dawei; Ma, Xiuhua

    2016-09-01

    In the process of spectral reflectance reconstruction, sample selection plays an important role in the accuracy of the constructed model and in reconstruction effects. In this paper, a method for training sample selection based on camera response is proposed. It has been proved that the camera response value has a close correlation with the spectral reflectance. Consequently, in this paper we adopt the technique of drawing a sphere in camera response value space to select the training samples which have a higher correlation with the test samples. In addition, the Wiener estimation method is used to reconstruct the spectral reflectance. Finally, we find that the method of sample selection based on camera response value has the smallest color difference and root mean square error after reconstruction compared to the method using the full set of Munsell color charts, the Mohammadi training sample selection method, and the stratified sampling method. Moreover, the goodness of fit coefficient of this method is also the highest among the four sample selection methods. Taking all the factors mentioned above into consideration, the method of training sample selection based on camera response value enhances the reconstruction accuracy from both the colorimetric and spectral perspectives.

  20. Global Calibration of Multiple Cameras Based on Sphere Targets

    PubMed Central

    Sun, Junhua; He, Huabin; Zeng, Debing

    2016-01-01

    Global calibration methods for multi-camera system are critical to the accuracy of vision measurement. Proposed in this paper is such a method based on several groups of sphere targets and a precision auxiliary camera. Each camera to be calibrated observes a group of spheres (at least three), while the auxiliary camera observes all the spheres. The global calibration can be achieved after each camera reconstructs the sphere centers in its field of view. In the process of reconstructing a sphere center, a parameter equation is used to describe the sphere projection model. Theoretical analysis and computer simulation are carried out to analyze the factors that affect the calibration accuracy. Simulation results show that the parameter equation can largely improve the reconstruction accuracy. In the experiments, a two-camera system calibrated by our method is used to measure a distance about 578 mm, and the root mean squared error is within 0.14 mm. Furthermore, the experiments indicate that the method has simple operation and good flexibility, especially for the onsite multiple cameras without common field of view. PMID:26761007

  1. Mechanical Design of the LSST Camera

    SciTech Connect

    Nordby, Martin; Bowden, Gordon; Foss, Mike; Guiffre, Gary; Ku, John; Schindler, Rafe; /SLAC

    2008-06-13

    The LSST camera is a tightly packaged, hermetically-sealed system that is cantilevered into the main beam of the LSST telescope. It is comprised of three refractive lenses, on-board storage for five large filters, a high-precision shutter, and a cryostat that houses the 3.2 giga-pixel CCD focal plane along with its support electronics. The physically large optics and focal plane demand large structural elements to support them, but the overall size of the camera and its components must be minimized to reduce impact on the image stability. Also, focal plane and optics motions must be minimized to reduce systematic errors in image reconstruction. Design and analysis for the camera body and cryostat will be detailed.

  2. Ice and thermal cameras for stream flow observations

    NASA Astrophysics Data System (ADS)

    Tauro, Flavia; Petroselli, Andrea; Grimaldi, Salvatore

    2016-04-01

    Flow measurements are instrumental to establish discharge rating curves and to enable flood risk forecast. Further, they are crucial to study erosion dynamics and to comprehend the organization of drainage networks in natural catchments. Flow observations are typically executed with intrusive instrumentation, such as current meters or acoustic devices. Alternatively, non-intrusive instruments, such as radars and microwave sensors, are applied to estimate surface velocity. Both approaches enable flow measurements over areas of limited extent, and their implementation can be costly. Optical methods, such as large scale particle image velocimetry, have proved beneficial for non-intrusive and spatially-distributed environmental monitoring. In this work, a novel optical-based approach is utilized for surface flow velocity observations based on the combined use of a thermal camera and ice dices. Different from RGB imagery, thermal images are relatively unaffected by illumination conditions and water reflections. Therefore, such high-quality images allow to readily identify and track tracers against the background. Further, the optimal environmental compatibility of ice dices and their relative ease of preparation and storage suggest that the technique can be easily implemented to rapidly characterize surface flows. To demonstrate the validity of the approach, we present a set of experiments performed on the Brenta stream, Italy. In the experimental setup, the axis of the camera is maintained perpendicular with respect to the water surface to circumvent image orthorectification through ground reference points. Small amounts of ice dices are deployed onto the stream water surface during image acquisition. Particle tracers' trajectories are reconstructed off-line by analyzing thermal images with a particle tracking velocimetry (PTV) algorithm. Given the optimal visibility of the tracers and their low seeding density, PTV allows for efficiently following tracers' paths in

  3. The Camera Cook Book.

    ERIC Educational Resources Information Center

    Education Development Center, Inc., Newton, MA.

    Intended for use with the photographic materials available from the Workshop for Learning Things, Inc., this "camera cookbook" describes procedures that have been tried in classrooms and workshops and proven to be the most functional and inexpensive. Explicit starting off instructions--directions for exploring and loading the camera and for taking…

  4. The DSLR Camera

    NASA Astrophysics Data System (ADS)

    Berkó, Ernő; Argyle, R. W.

    Cameras have developed significantly in the past decade; in particular, digital Single-Lens Reflex Cameras (DSLR) have appeared. As a consequence we can buy cameras of higher and higher pixel number, and mass production has resulted in the great reduction of prices. CMOS sensors used for imaging are increasingly sensitive, and the electronics in the cameras allows images to be taken with much less noise. The software background is developing in a similar way—intelligent programs are created for after-processing and other supplementary works. Nowadays we can find a digital camera in almost every household, most of these cameras are DSLR ones. These can be used very well for astronomical imaging, which is nicely demonstrated by the amount and quality of the spectacular astrophotos appearing in different publications. These examples also show how much post-processing software contributes to the rise in the standard of the pictures. To sum up, the DSLR camera serves as a cheap alternative for the CCD camera, with somewhat weaker technical characteristics. In the following, I will introduce how we can measure the main parameters (position angle and separation) of double stars, based on the methods, software and equipment I use. Others can easily apply these for their own circumstances.

  5. Constrained space camera assembly

    DOEpatents

    Heckendorn, F.M.; Anderson, E.K.; Robinson, C.W.; Haynes, H.B.

    1999-05-11

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity is disclosed. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras. 17 figs.

  6. CCD Luminescence Camera

    NASA Technical Reports Server (NTRS)

    Janesick, James R.; Elliott, Tom

    1987-01-01

    New diagnostic tool used to understand performance and failures of microelectronic devices. Microscope integrated to low-noise charge-coupled-device (CCD) camera to produce new instrument for analyzing performance and failures of microelectronics devices that emit infrared light during operation. CCD camera also used to indentify very clearly parts that have failed where luminescence typically found.

  7. Camera Operator and Videographer

    ERIC Educational Resources Information Center

    Moore, Pam

    2007-01-01

    Television, video, and motion picture camera operators produce images that tell a story, inform or entertain an audience, or record an event. They use various cameras to shoot a wide range of material, including television series, news and sporting events, music videos, motion pictures, documentaries, and training sessions. Those who film or…

  8. A magnetic source imaging camera

    NASA Astrophysics Data System (ADS)

    Dolgovskiy, V.; Fescenko, I.; Sekiguchi, N.; Colombo, S.; Lebedev, V.; Zhang, J.; Weis, A.

    2016-07-01

    We describe a magnetic source imaging camera (MSIC) allowing a direct dynamic visualization of the two-dimensional spatial distribution of the individual components Bx(x ,y ), By(x ,y ) and Bz(x ,y ) of a magnetic field. The field patterns allow—in principle—a reconstruction of the distribution of sources that produce the field B → by inverse problem analysis. We compare experimentally recorded point-spread functions, i.e., field patterns produced by point-like magnetic dipoles of different orientations with anticipated field patterns. Currently, the MSIC can resolve fields of ≈10 pT (1 s measurement time) range in a field of view up to ˜20 × 20 mm2. The device has a large range of possible applications. As an example, we demonstrate the MSIC's use for recording the spatially resolved Néel magnetorelaxation of blocked magnetic nanoparticles.

  9. Dry imaging cameras

    PubMed Central

    Indrajit, IK; Alam, Aftab; Sahni, Hirdesh; Bhatia, Mukul; Sahu, Samaresh

    2011-01-01

    Dry imaging cameras are important hard copy devices in radiology. Using dry imaging camera, multiformat images of digital modalities in radiology are created from a sealed unit of unexposed films. The functioning of a modern dry camera, involves a blend of concurrent processes, in areas of diverse sciences like computers, mechanics, thermal, optics, electricity and radiography. Broadly, hard copy devices are classified as laser and non laser based technology. When compared with the working knowledge and technical awareness of different modalities in radiology, the understanding of a dry imaging camera is often superficial and neglected. To fill this void, this article outlines the key features of a modern dry camera and its important issues that impact radiology workflow. PMID:21799589

  10. 3. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH THE VAL TO THE RIGHT, LOOKING NORTHEAST. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  11. 7. VAL CAMERA STATION, INTERIOR VIEW OF CAMERA MOUNT, COMMUNICATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VAL CAMERA STATION, INTERIOR VIEW OF CAMERA MOUNT, COMMUNICATION EQUIPMENT AND STORAGE CABINET. - Variable Angle Launcher Complex, Camera Stations, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  12. Traffic monitoring with distributed smart cameras

    NASA Astrophysics Data System (ADS)

    Sidla, Oliver; Rosner, Marcin; Ulm, Michael; Schwingshackl, Gert

    2012-01-01

    The observation and monitoring of traffic with smart visions systems for the purpose of improving traffic safety has a big potential. Today the automated analysis of traffic situations is still in its infancy--the patterns of vehicle motion and pedestrian flow in an urban environment are too complex to be fully captured and interpreted by a vision system. 3In this work we present steps towards a visual monitoring system which is designed to detect potentially dangerous traffic situations around a pedestrian crossing at a street intersection. The camera system is specifically designed to detect incidents in which the interaction of pedestrians and vehicles might develop into safety critical encounters. The proposed system has been field-tested at a real pedestrian crossing in the City of Vienna for the duration of one year. It consists of a cluster of 3 smart cameras, each of which is built from a very compact PC hardware system in a weatherproof housing. Two cameras run vehicle detection and tracking software, one camera runs a pedestrian detection and tracking module based on the HOG dectection principle. All 3 cameras use sparse optical flow computation in a low-resolution video stream in order to estimate the motion path and speed of objects. Geometric calibration of the cameras allows us to estimate the real-world co-ordinates of detected objects and to link the cameras together into one common reference system. This work describes the foundation for all the different object detection modalities (pedestrians, vehicles), and explains the system setup, tis design, and evaluation results which we have achieved so far.

  13. Replacing 16 mm film cameras with high definition digital cameras

    SciTech Connect

    Balch, K.S.

    1995-12-31

    For many years 16 mm film cameras have been used in severe environments. These film cameras are used on Hy-G automotive sleds, airborne gun cameras, range tracking and other hazardous environments. The companies and government agencies using these cameras are in need of replacing them with a more cost effective solution. Film-based cameras still produce the best resolving capability, however, film development time, chemical disposal, recurring media cost, and faster digital analysis are factors influencing the desire for a 16 mm film camera replacement. This paper will describe a new camera from Kodak that has been designed to replace 16 mm high speed film cameras.

  14. Night Vision Camera

    NASA Technical Reports Server (NTRS)

    1996-01-01

    PixelVision, Inc. developed the Night Video NV652 Back-illuminated CCD Camera, based on the expertise of a former Jet Propulsion Laboratory employee and a former employee of Scientific Imaging Technologies, Inc. The camera operates without an image intensifier, using back-illuminated and thinned CCD technology to achieve extremely low light level imaging performance. The advantages of PixelVision's system over conventional cameras include greater resolution and better target identification under low light conditions, lower cost and a longer lifetime. It is used commercially for research and aviation.

  15. Kitt Peak speckle camera

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Mcalister, H. A.; Robinson, W. G.

    1979-01-01

    The speckle camera in regular use at Kitt Peak National Observatory since 1974 is described in detail. The design of the atmospheric dispersion compensation prisms, the use of film as a recording medium, the accuracy of double star measurements, and the next generation speckle camera are discussed. Photographs of double star speckle patterns with separations from 1.4 sec of arc to 4.7 sec of arc are shown to illustrate the quality of image formation with this camera, the effects of seeing on the patterns, and to illustrate the isoplanatic patch of the atmosphere.

  16. Structured light camera calibration

    NASA Astrophysics Data System (ADS)

    Garbat, P.; Skarbek, W.; Tomaszewski, M.

    2013-03-01

    Structured light camera which is being designed with the joined effort of Institute of Radioelectronics and Institute of Optoelectronics (both being large units of the Warsaw University of Technology within the Faculty of Electronics and Information Technology) combines various hardware and software contemporary technologies. In hardware it is integration of a high speed stripe projector and a stripe camera together with a standard high definition video camera. In software it is supported by sophisticated calibration techniques which enable development of advanced application such as real time 3D viewer of moving objects with the free viewpoint or 3D modeller for still objects.

  17. Ringfield lithographic camera

    DOEpatents

    Sweatt, W.C.

    1998-09-08

    A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D{sub source} {approx_equal} 0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors. 11 figs.

  18. Volumetric particle image velocimetry with a single plenoptic camera

    NASA Astrophysics Data System (ADS)

    Fahringer, Timothy W.; Lynch, Kyle P.; Thurow, Brian S.

    2015-11-01

    A novel three-dimensional (3D), three-component (3C) particle image velocimetry (PIV) technique based on volume illumination and light field imaging with a single plenoptic camera is described. A plenoptic camera uses a densely packed microlens array mounted near a high resolution image sensor to sample the spatial and angular distribution of light collected by the camera. The multiplicative algebraic reconstruction technique (MART) computed tomography algorithm is used to reconstruct a volumetric intensity field from individual snapshots and a cross-correlation algorithm is used to estimate the velocity field from a pair of reconstructed particle volumes. This work provides an introduction to the basic concepts of light field imaging with a plenoptic camera and describes the unique implementation of MART in the context of plenoptic image data for 3D/3C PIV measurements. Simulations of a plenoptic camera using geometric optics are used to generate synthetic plenoptic particle images, which are subsequently used to estimate the quality of particle volume reconstructions at various particle number densities. 3D reconstructions using this method produce reconstructed particles that are elongated by a factor of approximately 4 along the optical axis of the camera. A simulated 3D Gaussian vortex is used to test the capability of single camera plenoptic PIV to produce a 3D/3C vector field, where it was found that lateral displacements could be measured to approximately 0.2 voxel accuracy in the lateral direction and 1 voxel in the depth direction over a 300× 200× 200 voxel volume. The feasibility of the technique is demonstrated experimentally using a home-built plenoptic camera based on a 16-megapixel interline CCD camera and a 289× 193 array of microlenses and a pulsed Nd:YAG laser. 3D/3C measurements were performed in the wake of a low Reynolds number circular cylinder and compared with measurements made using a conventional 2D/2C PIV system. Overall, single camera

  19. Digital camera system built on JPEG2000 compression and decompression

    NASA Astrophysics Data System (ADS)

    Atsumi, Eiji

    2003-05-01

    Processing architecture for digital camera has been built on JPEG2000 compression system. Concerns are to minimize processing power and data traffic inside (data-bandwidth at interface) and out-side (compression efficiency) of camera system. Key idea is to decompose Bayer matrix data given from image sensor into four half-resolution planes instead of interpolating to three full-resolution planes. With a new compression standard, JPEG2000, capable of handling multi-component image, the four-plane representation can be encoded into a single bit-stream. The representation saves data traffic between image reconstruction stage and compression stage by 1/3 to 1/2 compared to the Bayer-interpolated data. Not only reduced processing power prior to and during compression but also competitive or superior compression efficiency is achieved. On reconstruction to full resolution is Bayer-interpolation and/or edge-enhancement required as a post-processing to a standard decoder, while half or smaller resolution image is reconstructed without a post-processing. For mobile terminals with an integrated camera (image reconstruction in camera h/w and compression in terminal processor), this scheme helps to accommodate increased resolution with all the limited data-bandwidth from camera to terminal processor and limited processing capability.

  20. Targetless Camera Calibration

    NASA Astrophysics Data System (ADS)

    Barazzetti, L.; Mussio, L.; Remondino, F.; Scaioni, M.

    2011-09-01

    In photogrammetry a camera is considered calibrated if its interior orientation parameters are known. These encompass the principal distance, the principal point position and some Additional Parameters used to model possible systematic errors. The current state of the art for automated camera calibration relies on the use of coded targets to accurately determine the image correspondences. This paper presents a new methodology for the efficient and rigorous photogrammetric calibration of digital cameras which does not require any longer the use of targets. A set of images depicting a scene with a good texture are sufficient for the extraction of natural corresponding image points. These are automatically matched with feature-based approaches and robust estimation techniques. The successive photogrammetric bundle adjustment retrieves the unknown camera parameters and their theoretical accuracies. Examples, considerations and comparisons with real data and different case studies are illustrated to show the potentialities of the proposed methodology.

  1. Miniature TV Camera

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Originally devised to observe Saturn stage separation during Apollo flights, Marshall Space Flight Center's Miniature Television Camera, measuring only 4 x 3 x 1 1/2 inches, quickly made its way to the commercial telecommunications market.

  2. The MKID Camera

    NASA Astrophysics Data System (ADS)

    Maloney, P. R.; Czakon, N. G.; Day, P. K.; Duan, R.; Gao, J.; Glenn, J.; Golwala, S.; Hollister, M.; LeDuc, H. G.; Mazin, B.; Noroozian, O.; Nguyen, H. T.; Sayers, J.; Schlaerth, J.; Vaillancourt, J. E.; Vayonakis, A.; Wilson, P.; Zmuidzinas, J.

    2009-12-01

    The MKID Camera project is a collaborative effort of Caltech, JPL, the University of Colorado, and UC Santa Barbara to develop a large-format, multi-color millimeter and submillimeter-wavelength camera for astronomy using microwave kinetic inductance detectors (MKIDs). These are superconducting, micro-resonators fabricated from thin aluminum and niobium films. We couple the MKIDs to multi-slot antennas and measure the change in surface impedance produced by photon-induced breaking of Cooper pairs. The readout is almost entirely at room temperature and can be highly multiplexed; in principle hundreds or even thousands of resonators could be read out on a single feedline. The camera will have 576 spatial pixels that image simultaneously in four bands at 750, 850, 1100 and 1300 microns. It is scheduled for deployment at the Caltech Submillimeter Observatory in the summer of 2010. We present an overview of the camera design and readout and describe the current status of testing and fabrication.

  3. Advanced CCD camera developments

    SciTech Connect

    Condor, A.

    1994-11-15

    Two charge coupled device (CCD) camera systems are introduced and discussed, describing briefly the hardware involved, and the data obtained in their various applications. The Advanced Development Group Defense Sciences Engineering Division has been actively designing, manufacturing, fielding state-of-the-art CCD camera systems for over a decade. These systems were originally developed for the nuclear test program to record data from underground nuclear tests. Today, new and interesting application for these systems have surfaced and development is continuing in the area of advanced CCD camera systems, with the new CCD camera that will allow experimenters to replace film for x-ray imaging at the JANUS, USP, and NOVA laser facilities.

  4. Gamma ray camera

    SciTech Connect

    Robbins, C.D.; Wang, S.

    1980-09-09

    An anger gamma ray camera is improved by the substitution of a gamma ray sensitive, proximity type image intensifier tube for the scintillator screen in the anger camera, the image intensifier tube having a negatively charged flat scintillator screen and a flat photocathode layer and a grounded, flat output phosphor display screen all of the same dimension (Unity image magnification) and all within a grounded metallic tube envelope and having a metallic, inwardly concaved input window between the scintillator screen and the collimator.

  5. Camera Edge Response

    NASA Astrophysics Data System (ADS)

    Zisk, Stanley H.; Wittels, Norman

    1988-02-01

    Edge location is an important machine vision task. Machine vision systems perform mathematical operations on rectangular arrays of numbers that are intended to faithfully represent the spatial distribution of scene luminance. The numbers are produced by periodic sampling and quantization of the camera's video output. This sequence can cause artifacts to appear in the data with a noise spectrum that is high in power at high spatial frequencies. This is a problem because most edge detection algorithms are preferentially sensitive to the high-frequency content in an image. Solid state cameras can introduce errors because of the spatial periodicity of their sensor elements. This can result in problems when image edges are aligned with camera pixel boundaries: (a) some cameras introduce transients into the video signal while switching between sensor elements; (b) most cameras use analog low-pass filters to minimize sampling artifacts and these introduce video phase delays that shift the locations of edges. The problems compound when the vision system samples asynchronously with the camera's pixel rate. Moire patterns (analogous to beat frequencies) can result. In this paper, we examine and model quantization effects in a machine vision system with particular emphasis on edge detection performance. We also compare our models with experimental measurements.

  6. Spacecraft camera image registration

    NASA Technical Reports Server (NTRS)

    Kamel, Ahmed A. (Inventor); Graul, Donald W. (Inventor); Chan, Fred N. T. (Inventor); Gamble, Donald W. (Inventor)

    1987-01-01

    A system for achieving spacecraft camera (1, 2) image registration comprises a portion external to the spacecraft and an image motion compensation system (IMCS) portion onboard the spacecraft. Within the IMCS, a computer (38) calculates an image registration compensation signal (60) which is sent to the scan control loops (84, 88, 94, 98) of the onboard cameras (1, 2). At the location external to the spacecraft, the long-term orbital and attitude perturbations on the spacecraft are modeled. Coefficients (K, A) from this model are periodically sent to the onboard computer (38) by means of a command unit (39). The coefficients (K, A) take into account observations of stars and landmarks made by the spacecraft cameras (1, 2) themselves. The computer (38) takes as inputs the updated coefficients (K, A) plus synchronization information indicating the mirror position (AZ, EL) of each of the spacecraft cameras (1, 2), operating mode, and starting and stopping status of the scan lines generated by these cameras (1, 2), and generates in response thereto the image registration compensation signal (60). The sources of periodic thermal errors on the spacecraft are discussed. The system is checked by calculating measurement residuals, the difference between the landmark and star locations predicted at the external location and the landmark and star locations as measured by the spacecraft cameras (1, 2).

  7. 9. VIEW OF CAMERA STATIONS UNDER CONSTRUCTION INCLUDING CAMERA CAR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF CAMERA STATIONS UNDER CONSTRUCTION INCLUDING CAMERA CAR ON RAILROAD TRACK AND FIXED CAMERA STATION 1400 (BUILDING NO. 42021) ABOVE, ADJACENT TO STATE HIGHWAY 39, LOOKING WEST, March 23, 1948. (Original photograph in possession of Dave Willis, San Diego, California.) - Variable Angle Launcher Complex, Camera Stations, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  8. 1. VARIABLEANGLE LAUNCHER CAMERA CAR, VIEW OF CAMERA CAR AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VARIABLE-ANGLE LAUNCHER CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH CAMERA STATION ABOVE LOOKING NORTH TAKEN FROM RESERVOIR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  9. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  10. Uncooled radiometric camera performance

    NASA Astrophysics Data System (ADS)

    Meyer, Bill; Hoelter, T.

    1998-07-01

    Thermal imaging equipment utilizing microbolometer detectors operating at room temperature has found widespread acceptance in both military and commercial applications. Uncooled camera products are becoming effective solutions to applications currently using traditional, photonic infrared sensors. The reduced power consumption and decreased mechanical complexity offered by uncooled cameras have realized highly reliable, low-cost, hand-held instruments. Initially these instruments displayed only relative temperature differences which limited their usefulness in applications such as Thermography. Radiometrically calibrated microbolometer instruments are now available. The ExplorIR Thermography camera leverages the technology developed for Raytheon Systems Company's first production microbolometer imaging camera, the Sentinel. The ExplorIR camera has a demonstrated temperature measurement accuracy of 4 degrees Celsius or 4% of the measured value (whichever is greater) over scene temperatures ranges of minus 20 degrees Celsius to 300 degrees Celsius (minus 20 degrees Celsius to 900 degrees Celsius for extended range models) and camera environmental temperatures of minus 10 degrees Celsius to 40 degrees Celsius. Direct temperature measurement with high resolution video imaging creates some unique challenges when using uncooled detectors. A temperature controlled, field-of-view limiting aperture (cold shield) is not typically included in the small volume dewars used for uncooled detector packages. The lack of a field-of-view shield allows a significant amount of extraneous radiation from the dewar walls and lens body to affect the sensor operation. In addition, the transmission of the Germanium lens elements is a function of ambient temperature. The ExplorIR camera design compensates for these environmental effects while maintaining the accuracy and dynamic range required by today's predictive maintenance and condition monitoring markets.

  11. The CAMCAO infrared camera

    NASA Astrophysics Data System (ADS)

    Amorim, Antonio; Melo, Antonio; Alves, Joao; Rebordao, Jose; Pinhao, Jose; Bonfait, Gregoire; Lima, Jorge; Barros, Rui; Fernandes, Rui; Catarino, Isabel; Carvalho, Marta; Marques, Rui; Poncet, Jean-Marc; Duarte Santos, Filipe; Finger, Gert; Hubin, Norbert; Huster, Gotthard; Koch, Franz; Lizon, Jean-Louis; Marchetti, Enrico

    2004-09-01

    The CAMCAO instrument is a high resolution near infrared (NIR) camera conceived to operate together with the new ESO Multi-conjugate Adaptive optics Demonstrator (MAD) with the goal of evaluating the feasibility of Multi-Conjugate Adaptive Optics techniques (MCAO) on the sky. It is a high-resolution wide field of view (FoV) camera that is optimized to use the extended correction of the atmospheric turbulence provided by MCAO. While the first purpose of this camera is the sky observation, in the MAD setup, to validate the MCAO technology, in a second phase, the CAMCAO camera is planned to attach directly to the VLT for scientific astrophysical studies. The camera is based on the 2kx2k HAWAII2 infrared detector controlled by an ESO external IRACE system and includes standard IR band filters mounted on a positional filter wheel. The CAMCAO design requires that the optical components and the IR detector should be kept at low temperatures in order to avoid emitting radiation and lower detector noise in the region analysis. The cryogenic system inclues a LN2 tank and a sptially developed pulse tube cryocooler. Field and pupil cold stops are implemented to reduce the infrared background and the stray-light. The CAMCAO optics provide diffraction limited performance down to J Band, but the detector sampling fulfills the Nyquist criterion for the K band (2.2mm).

  12. The Dark Energy Camera

    SciTech Connect

    Flaugher, B.

    2015-04-11

    The Dark Energy Camera is a new imager with a 2.2-degree diameter field of view mounted at the prime focus of the Victor M. Blanco 4-meter telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration, and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five element optical corrector, seven filters, a shutter with a 60 cm aperture, and a CCD focal plane of 250-μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 Mpixel focal plane comprises 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. The CCDs have 15μm x 15μm pixels with a plate scale of 0.263" per pixel. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 seconds with 6-9 electrons readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  13. CAOS-CMOS camera.

    PubMed

    Riza, Nabeel A; La Torre, Juan Pablo; Amin, M Junaid

    2016-06-13

    Proposed and experimentally demonstrated is the CAOS-CMOS camera design that combines the coded access optical sensor (CAOS) imager platform with the CMOS multi-pixel optical sensor. The unique CAOS-CMOS camera engages the classic CMOS sensor light staring mode with the time-frequency-space agile pixel CAOS imager mode within one programmable optical unit to realize a high dynamic range imager for extreme light contrast conditions. The experimentally demonstrated CAOS-CMOS camera is built using a digital micromirror device, a silicon point-photo-detector with a variable gain amplifier, and a silicon CMOS sensor with a maximum rated 51.3 dB dynamic range. White light imaging of three different brightness simultaneously viewed targets, that is not possible by the CMOS sensor, is achieved by the CAOS-CMOS camera demonstrating an 82.06 dB dynamic range. Applications for the camera include industrial machine vision, welding, laser analysis, automotive, night vision, surveillance and multispectral military systems. PMID:27410361

  14. The Dark Energy Camera

    NASA Astrophysics Data System (ADS)

    Flaugher, B.; Diehl, H. T.; Honscheid, K.; Abbott, T. M. C.; Alvarez, O.; Angstadt, R.; Annis, J. T.; Antonik, M.; Ballester, O.; Beaufore, L.; Bernstein, G. M.; Bernstein, R. A.; Bigelow, B.; Bonati, M.; Boprie, D.; Brooks, D.; Buckley-Geer, E. J.; Campa, J.; Cardiel-Sas, L.; Castander, F. J.; Castilla, J.; Cease, H.; Cela-Ruiz, J. M.; Chappa, S.; Chi, E.; Cooper, C.; da Costa, L. N.; Dede, E.; Derylo, G.; DePoy, D. L.; de Vicente, J.; Doel, P.; Drlica-Wagner, A.; Eiting, J.; Elliott, A. E.; Emes, J.; Estrada, J.; Fausti Neto, A.; Finley, D. A.; Flores, R.; Frieman, J.; Gerdes, D.; Gladders, M. D.; Gregory, B.; Gutierrez, G. R.; Hao, J.; Holland, S. E.; Holm, S.; Huffman, D.; Jackson, C.; James, D. J.; Jonas, M.; Karcher, A.; Karliner, I.; Kent, S.; Kessler, R.; Kozlovsky, M.; Kron, R. G.; Kubik, D.; Kuehn, K.; Kuhlmann, S.; Kuk, K.; Lahav, O.; Lathrop, A.; Lee, J.; Levi, M. E.; Lewis, P.; Li, T. S.; Mandrichenko, I.; Marshall, J. L.; Martinez, G.; Merritt, K. W.; Miquel, R.; Muñoz, F.; Neilsen, E. H.; Nichol, R. C.; Nord, B.; Ogando, R.; Olsen, J.; Palaio, N.; Patton, K.; Peoples, J.; Plazas, A. A.; Rauch, J.; Reil, K.; Rheault, J.-P.; Roe, N. A.; Rogers, H.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R. H.; Schmidt, R.; Schmitt, R.; Schubnell, M.; Schultz, K.; Schurter, P.; Scott, L.; Serrano, S.; Shaw, T. M.; Smith, R. C.; Soares-Santos, M.; Stefanik, A.; Stuermer, W.; Suchyta, E.; Sypniewski, A.; Tarle, G.; Thaler, J.; Tighe, R.; Tran, C.; Tucker, D.; Walker, A. R.; Wang, G.; Watson, M.; Weaverdyck, C.; Wester, W.; Woods, R.; Yanny, B.; DES Collaboration

    2015-11-01

    The Dark Energy Camera is a new imager with a 2.°2 diameter field of view mounted at the prime focus of the Victor M. Blanco 4 m telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five-element optical corrector, seven filters, a shutter with a 60 cm aperture, and a charge-coupled device (CCD) focal plane of 250 μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 megapixel focal plane comprises 62 2k × 4k CCDs for imaging and 12 2k × 2k CCDs for guiding and focus. The CCDs have 15 μm × 15 μm pixels with a plate scale of 0.″263 pixel-1. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 s with 6-9 electron readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  15. Satellite camera image navigation

    NASA Technical Reports Server (NTRS)

    Kamel, Ahmed A. (Inventor); Graul, Donald W. (Inventor); Savides, John (Inventor); Hanson, Charles W. (Inventor)

    1987-01-01

    Pixels within a satellite camera (1, 2) image are precisely located in terms of latitude and longitude on a celestial body, such as the earth, being imaged. A computer (60) on the earth generates models (40, 50) of the satellite's orbit and attitude, respectively. The orbit model (40) is generated from measurements of stars and landmarks taken by the camera (1, 2), and by range data. The orbit model (40) is an expression of the satellite's latitude and longitude at the subsatellite point, and of the altitude of the satellite, as a function of time, using as coefficients (K) the six Keplerian elements at epoch. The attitude model (50) is based upon star measurements taken by each camera (1, 2). The attitude model (50) is a set of expressions for the deviations in a set of mutually orthogonal reference optical axes (x, y, z) as a function of time, for each camera (1, 2). Measured data is fit into the models (40, 50) using a walking least squares fit algorithm. A transformation computer (66 ) transforms pixel coordinates as telemetered by the camera (1, 2) into earth latitude and longitude coordinates, using the orbit and attitude models (40, 50).

  16. Mars PathFinder Rover Traverse Image

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This figure contains an azimuth-elevation projection of the 'Gallery Panorama.' The original Simple Cylindrical mosaic has been reprojected to the inside of a sphere so that lines of constant azimuth radiate from the center and lines of constant elevation are concentric circles. This projection preserves the resolution of the original panorama. Overlaid onto the projected Martian surface is a delineation of the Sojourner rover traverse path during the 83 Sols (Martian days) of Pathfinder surface operations. The rover path was reproduced using IMP camera 'end of day' and 'Rover movie' image sequences and rover vehicle telemetry data as references.

  17. Synchronizing A Television Camera With An External Reference

    NASA Technical Reports Server (NTRS)

    Rentsch, Edward M.

    1993-01-01

    Improvement in genlock subsystem consists in incorporation of controllable delay circuit into path of composite synchronization signal obtained from external video source. Delay circuit helps to eliminate potential jitter in video display and ensures setup requirements for digital timing circuits of video camera satisfied.

  18. Selective-imaging camera

    NASA Astrophysics Data System (ADS)

    Szu, Harold; Hsu, Charles; Landa, Joseph; Cha, Jae H.; Krapels, Keith A.

    2015-05-01

    How can we design cameras that image selectively in Full Electro-Magnetic (FEM) spectra? Without selective imaging, we cannot use, for example, ordinary tourist cameras to see through fire, smoke, or other obscurants contributing to creating a Visually Degraded Environment (VDE). This paper addresses a possible new design of selective-imaging cameras at firmware level. The design is consistent with physics of the irreversible thermodynamics of Boltzmann's molecular entropy. It enables imaging in appropriate FEM spectra for sensing through the VDE, and displaying in color spectra for Human Visual System (HVS). We sense within the spectra the largest entropy value of obscurants such as fire, smoke, etc. Then we apply a smart firmware implementation of Blind Sources Separation (BSS) to separate all entropy sources associated with specific Kelvin temperatures. Finally, we recompose the scene using specific RGB colors constrained by the HVS, by up/down shifting Planck spectra at each pixel and time.

  19. Solid state television camera

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The design, fabrication, and tests of a solid state television camera using a new charge-coupled imaging device are reported. An RCA charge-coupled device arranged in a 512 by 320 format and directly compatible with EIA format standards was the sensor selected. This is a three-phase, sealed surface-channel array that has 163,840 sensor elements, which employs a vertical frame transfer system for image readout. Included are test results of the complete camera system, circuit description and changes to such circuits as a result of integration and test, maintenance and operation section, recommendations to improve the camera system, and a complete set of electrical and mechanical drawing sketches.

  20. HIGH SPEED CAMERA

    DOEpatents

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  1. Path Separability of Graphs

    NASA Astrophysics Data System (ADS)

    Diot, Emilie; Gavoille, Cyril

    In this paper we investigate the structural properties of k-path separable graphs, that are the graphs that can be separated by a set of k shortest paths. We identify several graph families having such path separability, and we show that this property is closed under minor taking. In particular we establish a list of forbidden minors for 1-path separable graphs.

  2. Calibration of multi-camera systems with refractive interfaces

    NASA Astrophysics Data System (ADS)

    Belden, Jesse

    2013-02-01

    A method for performing bundle adjustment-based calibration of a multi-camera setup with refractive interfaces in the optical path is presented. The method contributes to volumetric multi-camera fluid experiments, where it is desirable to avoid tedious alignment of calibration grids in multiple locations and where a premium is placed on accurately locating world points. Cameras are calibrated from image point correspondences of unknown world points, and the location of the refractive interface need not be accurately known a priori. Physical models for two practically relevant imaging configurations are presented; the first is a planar wall separating cameras and a liquid, and the second is a liquid-containing cylindrical tank with finite wall thickness. Each model allows the cameras to be in general location and orientation relative to the interface. A thorough numerical study demonstrates the ability of the calibration method to accurately estimate camera parameters, interface orientation, and world point locations. The numerical study explores the convergence, accuracy, and sensitivity of the calibration method as a function of initialization, camera configuration, volume size, and interface type. The technique is applied to real calibration data where the algorithm is supplied with errant initial parameter estimates and shown to provide accurate results. The ease of implementation and accuracy of the refractive calibration method make the approach attractive for three-dimensional multi-camera fluid measurement methods.

  3. Electronic Still Camera

    NASA Technical Reports Server (NTRS)

    Holland, S. Douglas (Inventor)

    1992-01-01

    A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

  4. Photometric Lunar Surface Reconstruction

    NASA Technical Reports Server (NTRS)

    Nefian, Ara V.; Alexandrov, Oleg; Morattlo, Zachary; Kim, Taemin; Beyer, Ross A.

    2013-01-01

    Accurate photometric reconstruction of the Lunar surface is important in the context of upcoming NASA robotic missions to the Moon and in giving a more accurate understanding of the Lunar soil composition. This paper describes a novel approach for joint estimation of Lunar albedo, camera exposure time, and photometric parameters that utilizes an accurate Lunar-Lambertian reflectance model and previously derived Lunar topography of the area visualized during the Apollo missions. The method introduced here is used in creating the largest Lunar albedo map (16% of the Lunar surface) at the resolution of 10 meters/pixel.

  5. Artificial human vision camera

    NASA Astrophysics Data System (ADS)

    Goudou, J.-F.; Maggio, S.; Fagno, M.

    2014-10-01

    In this paper we present a real-time vision system modeling the human vision system. Our purpose is to inspire from human vision bio-mechanics to improve robotic capabilities for tasks such as objects detection and tracking. This work describes first the bio-mechanical discrepancies between human vision and classic cameras and the retinal processing stage that takes place in the eye, before the optic nerve. The second part describes our implementation of these principles on a 3-camera optical, mechanical and software model of the human eyes and associated bio-inspired attention model.

  6. Volumetric PIV with a Plenoptic Camera

    NASA Astrophysics Data System (ADS)

    Thurow, Brian; Fahringer, Tim

    2012-11-01

    Plenoptic cameras have received attention recently due to their ability to computationally refocus an image after it has been acquired. We describe the development of a robust, economical and easy-to-use volumetric PIV technique using a unique plenoptic camera built in our laboratory. The tomographic MART algorithm is used to reconstruct pairs of 3D particle volumes with velocity determined using conventional cross-correlation techniques. 3D/3C velocity measurements (volumetric dimensions of 2 . 8 ' ' × 1 . 9 ' ' × 1 . 6 ' ') of a turbulent boundary layer produced on the wall of a conventional wind tunnel are presented. This work has been supported by the Air Force Office of Scientific Research,(Grant #FA9550-100100576).

  7. Aquatic Debris Detection Using Embedded Camera Sensors

    PubMed Central

    Wang, Yong; Wang, Dianhong; Lu, Qian; Luo, Dapeng; Fang, Wu

    2015-01-01

    Aquatic debris monitoring is of great importance to human health, aquatic habitats and water transport. In this paper, we first introduce the prototype of an aquatic sensor node equipped with an embedded camera sensor. Based on this sensing platform, we propose a fast and accurate debris detection algorithm. Our method is specifically designed based on compressive sensing theory to give full consideration to the unique challenges in aquatic environments, such as waves, swaying reflections, and tight energy budget. To upload debris images, we use an efficient sparse recovery algorithm in which only a few linear measurements need to be transmitted for image reconstruction. Besides, we implement the host software and test the debris detection algorithm on realistically deployed aquatic sensor nodes. The experimental results demonstrate that our approach is reliable and feasible for debris detection using camera sensors in aquatic environments. PMID:25647741

  8. Calibration of Low Cost RGB and NIR Uav Cameras

    NASA Astrophysics Data System (ADS)

    Fryskowska, A.; Kedzierski, M.; Grochala, A.; Braula, A.

    2016-06-01

    Non-metric digital cameras are being widely used for photogrammetric studies. The increase in resolution and quality of images obtained by non-metric cameras, allows to use it in low-cost UAV and terrestrial photogrammetry. Imagery acquired with non-metric cameras can be used in 3D modeling of objects or landscapes, reconstructing of historical sites, generating digital elevation models (DTM), orthophotos, or in the assessment of accidents. Non-metric digital camcorders are characterized by instability and ignorance of the interior orientation parameters. Therefore, the use of these devices requires prior calibration. Calibration research was conducted using non-metric camera, different calibration tests and various software. The first part of the paper contains a brief theoretical introduction including the basic definitions, like the construction of non-metric cameras or description of different optical distortions. The second part of the paper contains cameras calibration process, details of the calibration methods and models that have been used. Sony Nex 5 camera calibration has been done using software: Image Master Calib, Matlab - Camera Calibrator application and Agisoft Lens. For the study 2D test fields has been used. As a part of the research a comparative analysis of the results have been done.

  9. Versatility of the CFR (Constrained Fourier Reconstruction) algorithm for limited angle reconstruction

    SciTech Connect

    Fujieda, I.; Heiskanen, K.; Perez-Mendez, V.

    1989-08-01

    The Constrained Fourier Reconstruction (CFR) algorithm and the Iterative Reconstruction-Reprojection (IRR) algorithm are evaluated based on their accuracy for three types of limited angle reconstruction problems. The CFR algorithm performs better for problems such as Xray CT imaging of a nuclear reactor core with one large data gap due to structural blocking of the source and detector pair. For gated heart imaging by Xray CT, radioisotope distribution imaging by PET or SPECT, using a polygonal array of gamma cameras with insensitive gaps between camera boundaries, the IRR algorithm has a slight advantage over the CFR algorithm but the difference is not significant. 3 refs., 5 figs.

  10. Object recognition through turbulence with a modified plenoptic camera

    NASA Astrophysics Data System (ADS)

    Wu, Chensheng; Ko, Jonathan; Davis, Christopher

    2015-03-01

    Atmospheric turbulence adds accumulated distortion to images obtained by cameras and surveillance systems. When the turbulence grows stronger or when the object is further away from the observer, increasing the recording device resolution helps little to improve the quality of the image. Many sophisticated methods to correct the distorted images have been invented, such as using a known feature on or near the target object to perform a deconvolution process, or use of adaptive optics. However, most of the methods depend heavily on the object's location, and optical ray propagation through the turbulence is not directly considered. Alternatively, selecting a lucky image over many frames provides a feasible solution, but at the cost of time. In our work, we propose an innovative approach to improving image quality through turbulence by making use of a modified plenoptic camera. This type of camera adds a micro-lens array to a traditional high-resolution camera to form a semi-camera array that records duplicate copies of the object as well as "superimposed" turbulence at slightly different angles. By performing several steps of image reconstruction, turbulence effects will be suppressed to reveal more details of the object independently (without finding references near the object). Meanwhile, the redundant information obtained by the plenoptic camera raises the possibility of performing lucky image algorithmic analysis with fewer frames, which is more efficient. In our work, the details of our modified plenoptic cameras and image processing algorithms will be introduced. The proposed method can be applied to coherently illuminated object as well as incoherently illuminated objects. Our result shows that the turbulence effect can be effectively suppressed by the plenoptic camera in the hardware layer and a reconstructed "lucky image" can help the viewer identify the object even when a "lucky image" by ordinary cameras is not achievable.

  11. Camera calibration correction in shape from inconsistent silhouette

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of shape from silhouette for reconstruction tasks is plagued by two types of real-world errors: camera calibration error and silhouette segmentation error. When either error is present, we call the problem the Shape from Inconsistent Silhouette (SfIS) problem. In this paper, we show how sm...

  12. Nonholonomic camera-space manipulation using cameras mounted on a mobile base

    NASA Astrophysics Data System (ADS)

    Goodwine, Bill; Seelinger, Michael J.; Skaar, Steven B.; Ma, Qun

    1998-10-01

    The body of work called `Camera Space Manipulation' is an effective and proven method of robotic control. Essentially, this technique identifies and refines the input-output relationship of the plant using estimation methods and drives the plant open-loop to its target state. 3D `success' of the desired motion, i.e., the end effector of the manipulator engages a target at a particular location with a particular orientation, is guaranteed when there is camera space success in two cameras which are adequately separated. Very accurate, sub-pixel positioning of a robotic end effector is possible using this method. To date, however, most efforts in this area have primarily considered holonomic systems. This work addresses the problem of nonholonomic camera space manipulation by considering the problem of a nonholonomic robot with two cameras and a holonomic manipulator on board the nonholonomic platform. While perhaps not as common in robotics, such a combination of holonomic and nonholonomic degrees of freedom are ubiquitous in industry: fork lifts and earth moving equipment are common examples of a nonholonomic system with an on-board holonomic actuator. The nonholonomic nature of the system makes the automation problem more difficult due to a variety of reasons; in particular, the target location is not fixed in the image planes, as it is for holonomic systems (since the cameras are attached to a moving platform), and there is a fundamental `path dependent' nature of nonholonomic kinematics. This work focuses on the sensor space or camera-space-based control laws necessary for effectively implementing an autonomous system of this type.

  13. Underwater camera with depth measurement

    NASA Astrophysics Data System (ADS)

    Wang, Wei-Chih; Lin, Keng-Ren; Tsui, Chi L.; Schipf, David; Leang, Jonathan

    2016-04-01

    The objective of this study is to develop an RGB-D (video + depth) camera that provides three-dimensional image data for use in the haptic feedback of a robotic underwater ordnance recovery system. Two camera systems were developed and studied. The first depth camera relies on structured light (as used by the Microsoft Kinect), where the displacement of an object is determined by variations of the geometry of a projected pattern. The other camera system is based on a Time of Flight (ToF) depth camera. The results of the structural light camera system shows that the camera system requires a stronger light source with a similar operating wavelength and bandwidth to achieve a desirable working distance in water. This approach might not be robust enough for our proposed underwater RGB-D camera system, as it will require a complete re-design of the light source component. The ToF camera system instead, allows an arbitrary placement of light source and camera. The intensity output of the broadband LED light source in the ToF camera system can be increased by putting them into an array configuration and the LEDs can be modulated comfortably with any waveform and frequencies required by the ToF camera. In this paper, both camera were evaluated and experiments were conducted to demonstrate the versatility of the ToF camera.

  14. Photogrammetric camera calibration

    USGS Publications Warehouse

    Tayman, W.P.; Ziemann, H.

    1984-01-01

    Section 2 (Calibration) of the document "Recommended Procedures for Calibrating Photogrammetric Cameras and Related Optical Tests" from the International Archives of Photogrammetry, Vol. XIII, Part 4, is reviewed in the light of recent practical work, and suggestions for changes are made. These suggestions are intended as a basis for a further discussion. ?? 1984.

  15. Spas color camera

    NASA Technical Reports Server (NTRS)

    Toffales, C.

    1983-01-01

    The procedures to be followed in assessing the performance of the MOS color camera are defined. Aspects considered include: horizontal and vertical resolution; value of the video signal; gray scale rendition; environmental (vibration and temperature) tests; signal to noise ratios; and white balance correction.

  16. Imaging phoswich anger camera

    NASA Astrophysics Data System (ADS)

    Manchanda, R. K.; Sood, R. K.

    1991-08-01

    High angular resolution and low background are the primary requisites for detectors for future astronomy experiments in the low energy gamma-ray region. Scintillation counters are still the only available large area detector for studies in this energy range. Preliminary details of a large area phoswich anger camera designed for coded aperture imaging is described and its background and position characteristics are discussed.

  17. Communities, Cameras, and Conservation

    ERIC Educational Resources Information Center

    Patterson, Barbara

    2012-01-01

    Communities, Cameras, and Conservation (CCC) is the most exciting and valuable program the author has seen in her 30 years of teaching field science courses. In this citizen science project, students and community volunteers collect data on mountain lions ("Puma concolor") at four natural areas and public parks along the Front Range of Colorado.…

  18. Advanced Virgo phase cameras

    NASA Astrophysics Data System (ADS)

    van der Schaaf, L.; Agatsuma, K.; van Beuzekom, M.; Gebyehu, M.; van den Brand, J.

    2016-05-01

    A century after the prediction of gravitational waves, detectors have reached the sensitivity needed to proof their existence. One of them, the Virgo interferometer in Pisa, is presently being upgraded to Advanced Virgo (AdV) and will come into operation in 2016. The power stored in the interferometer arms raises from 20 to 700 kW. This increase is expected to introduce higher order modes in the beam, which could reduce the circulating power in the interferometer, limiting the sensitivity of the instrument. To suppress these higher-order modes, the core optics of Advanced Virgo is equipped with a thermal compensation system. Phase cameras, monitoring the real-time status of the beam constitute a critical component of this compensation system. These cameras measure the phases and amplitudes of the laser-light fields at the frequencies selected to control the interferometer. The measurement combines heterodyne detection with a scan of the wave front over a photodetector with pin-hole aperture. Three cameras observe the phase front of these laser sidebands. Two of them monitor the in-and output of the interferometer arms and the third one is used in the control of the aberrations introduced by the power recycling cavity. In this paper the working principle of the phase cameras is explained and some characteristic parameters are described.

  19. The LSST Camera Overview

    SciTech Connect

    Gilmore, Kirk; Kahn, Steven A.; Nordby, Martin; Burke, David; O'Connor, Paul; Oliver, John; Radeka, Veljko; Schalk, Terry; Schindler, Rafe; /SLAC

    2007-01-10

    The LSST camera is a wide-field optical (0.35-1um) imager designed to provide a 3.5 degree FOV with better than 0.2 arcsecond sampling. The detector format will be a circular mosaic providing approximately 3.2 Gigapixels per image. The camera includes a filter mechanism and, shuttering capability. It is positioned in the middle of the telescope where cross-sectional area is constrained by optical vignetting and heat dissipation must be controlled to limit thermal gradients in the optical beam. The fast, f/1.2 beam will require tight tolerances on the focal plane mechanical assembly. The focal plane array operates at a temperature of approximately -100 C to achieve desired detector performance. The focal plane array is contained within an evacuated cryostat, which incorporates detector front-end electronics and thermal control. The cryostat lens serves as an entrance window and vacuum seal for the cryostat. Similarly, the camera body lens serves as an entrance window and gas seal for the camera housing, which is filled with a suitable gas to provide the operating environment for the shutter and filter change mechanisms. The filter carousel can accommodate 5 filters, each 75 cm in diameter, for rapid exchange without external intervention.

  20. Jack & the Video Camera

    ERIC Educational Resources Information Center

    Charlan, Nathan

    2010-01-01

    This article narrates how the use of video camera has transformed the life of Jack Williams, a 10-year-old boy from Colorado Springs, Colorado, who has autism. The way autism affected Jack was unique. For the first nine years of his life, Jack remained in his world, alone. Functionally non-verbal and with motor skill problems that affected his…

  1. Anger Camera Firmware

    Energy Science and Technology Software Center (ESTSC)

    2010-11-19

    The firmware is responsible for the operation of Anger Camera Electronics, calculation of position, time of flight and digital communications. It provides a first stage analysis of 48 signals from 48 analog signals that have been converted to digital values using A/D convertors.

  2. Make a Pinhole Camera

    ERIC Educational Resources Information Center

    Fisher, Diane K.; Novati, Alexander

    2009-01-01

    On Earth, using ordinary visible light, one can create a single image of light recorded over time. Of course a movie or video is light recorded over time, but it is a series of instantaneous snapshots, rather than light and time both recorded on the same medium. A pinhole camera, which is simple to make out of ordinary materials and using ordinary…

  3. Iterative procedure for camera parameters estimation using extrinsic matrix decomposition

    NASA Astrophysics Data System (ADS)

    Goshin, Yegor V.; Fursov, Vladimir A.

    2016-03-01

    This paper addresses the problem of 3D scene reconstruction in cases when the extrinsic parameters (rotation and translation) of the camera are unknown. This problem is both important and urgent because the accuracy of the camera parameters significantly influences the resulting 3D model. A common approach is to determine the fundamental matrix from corresponding points on two views of a scene and then to use singular value decomposition for camera projection matrix estimation. However, this common approach is very sensitive to fundamental matrix errors. In this paper we propose a novel approach in which camera parameters are determined directly from the equations of the projective transformation by using corresponding points on the views. The proposed decomposition allows us to use an iterative procedure for determining the parameters of the camera. This procedure is implemented in two steps: the translation determination and the rotation determination. The experimental results of the camera parameters estimation and 3D scene reconstruction demonstrate the reliability of the proposed approach.

  4. Computer-generated hologram calculation for real scenes using a commercial portable plenoptic camera

    NASA Astrophysics Data System (ADS)

    Endo, Yutaka; Wakunami, Koki; Shimobaba, Tomoyoshi; Kakue, Takashi; Arai, Daisuke; Ichihashi, Yasuyuki; Yamamoto, Kenji; Ito, Tomoyoshi

    2015-12-01

    This paper shows the process used to calculate a computer-generated hologram (CGH) for real scenes under natural light using a commercial portable plenoptic camera. In the CGH calculation, a light field captured with the commercial plenoptic camera is converted into a complex amplitude distribution. Then the converted complex amplitude is propagated to a CGH plane. We tested both numerical and optical reconstructions of the CGH and showed that the CGH calculation from captured data with the commercial plenoptic camera was successful.

  5. Reconstructing Glaciers on Mars

    NASA Astrophysics Data System (ADS)

    Hubbard, A., II; Brough, S.; Hubbard, B. P.

    2015-12-01

    Mars' mid-latitudes host a substantial volume of ice, equivalent to a ~1 - 2.5 m-thick global layer or the sum of Earth's glaciers and ice caps outside of Antarctica and Greenland. These deposits are the remnants of what is believed to have been a once far larger 'ice age', culminating in a last martian glacial maximum. Despite the identification of >1,300 glacier-like forms (GLFs) - the first order component of Mars' glacial landsystem - in Mars' mid-latitudes, little is known about their composition, dynamics or former extent. Here, we reconstruct the former 3D extent of a well-studied GLF located in eastern Hellas Planitia. We combine high-resolution geomorphic and topographic data, obtained from the High-Resolution Imaging Science Experiment (HiRISE) camera, to reconstruct the GLF's former limits. We then apply a perfect plasticity rheological model, to generate multiple flow-parallel ice-surface transects. These are combined with the GLF's boundary to guide interpolation using ArcGIS' 'Topo to Raster' function to produce a continuous 3D surface for the reconstructed former GLF. Our results indicate that, since its reconstructed 'recent maximum' extent, the GLF's volume has reduced by 0.31 km3 and its area by 6.85 km2, or 70%. On-going research is addressing the degree to which this change is typical of Mars' full GLF population.

  6. Depth estimation and camera calibration of a focused plenoptic camera for visual odometry

    NASA Astrophysics Data System (ADS)

    Zeller, Niclas; Quint, Franz; Stilla, Uwe

    2016-08-01

    This paper presents new and improved methods of depth estimation and camera calibration for visual odometry with a focused plenoptic camera. For depth estimation we adapt an algorithm previously used in structure-from-motion approaches to work with images of a focused plenoptic camera. In the raw image of a plenoptic camera, scene patches are recorded in several micro-images under slightly different angles. This leads to a multi-view stereo-problem. To reduce the complexity, we divide this into multiple binocular stereo problems. For each pixel with sufficient gradient we estimate a virtual (uncalibrated) depth based on local intensity error minimization. The estimated depth is characterized by the variance of the estimate and is subsequently updated with the estimates from other micro-images. Updating is performed in a Kalman-like fashion. The result of depth estimation in a single image of the plenoptic camera is a probabilistic depth map, where each depth pixel consists of an estimated virtual depth and a corresponding variance. Since the resulting image of the plenoptic camera contains two plains: the optical image and the depth map, camera calibration is divided into two separate sub-problems. The optical path is calibrated based on a traditional calibration method. For calibrating the depth map we introduce two novel model based methods, which define the relation of the virtual depth, which has been estimated based on the light-field image, and the metric object distance. These two methods are compared to a well known curve fitting approach. Both model based methods show significant advantages compared to the curve fitting method. For visual odometry we fuse the probabilistic depth map gained from one shot of the plenoptic camera with the depth data gained by finding stereo correspondences between subsequent synthesized intensity images of the plenoptic camera. These images can be synthesized totally focused and thus finding stereo correspondences is enhanced

  7. Image Sensors Enhance Camera Technologies

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In the 1990s, a Jet Propulsion Laboratory team led by Eric Fossum researched ways of improving complementary metal-oxide semiconductor (CMOS) image sensors in order to miniaturize cameras on spacecraft while maintaining scientific image quality. Fossum s team founded a company to commercialize the resulting CMOS active pixel sensor. Now called the Aptina Imaging Corporation, based in San Jose, California, the company has shipped over 1 billion sensors for use in applications such as digital cameras, camera phones, Web cameras, and automotive cameras. Today, one of every three cell phone cameras on the planet feature Aptina s sensor technology.

  8. The absolute path command

    Energy Science and Technology Software Center (ESTSC)

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the absolute path to a relative directory from the current working directory.« less

  9. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the absolute path to a relative directory from the current working directory.

  10. Photogrammetric Applications of Immersive Video Cameras

    NASA Astrophysics Data System (ADS)

    Kwiatek, K.; Tokarczyk, R.

    2014-05-01

    The paper investigates immersive videography and its application in close-range photogrammetry. Immersive video involves the capture of a live-action scene that presents a 360° field of view. It is recorded simultaneously by multiple cameras or microlenses, where the principal point of each camera is offset from the rotating axis of the device. This issue causes problems when stitching together individual frames of video separated from particular cameras, however there are ways to overcome it and applying immersive cameras in photogrammetry provides a new potential. The paper presents two applications of immersive video in photogrammetry. At first, the creation of a low-cost mobile mapping system based on Ladybug®3 and GPS device is discussed. The amount of panoramas is much too high for photogrammetric purposes as the base line between spherical panoramas is around 1 metre. More than 92 000 panoramas were recorded in one Polish region of Czarny Dunajec and the measurements from panoramas enable the user to measure the area of outdoors (adverting structures) and billboards. A new law is being created in order to limit the number of illegal advertising structures in the Polish landscape and immersive video recorded in a short period of time is a candidate for economical and flexible measurements off-site. The second approach is a generation of 3d video-based reconstructions of heritage sites based on immersive video (structure from immersive video). A mobile camera mounted on a tripod dolly was used to record the interior scene and immersive video, separated into thousands of still panoramas, was converted from video into 3d objects using Agisoft Photoscan Professional. The findings from these experiments demonstrated that immersive photogrammetry seems to be a flexible and prompt method of 3d modelling and provides promising features for mobile mapping systems.

  11. 15. ELEVATED CAMERA STAND, SHOWING LINE OF CAMERA STANDS PARALLEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. ELEVATED CAMERA STAND, SHOWING LINE OF CAMERA STANDS PARALLEL TO SLED TRACK. Looking west southwest down Camera Road. - Edwards Air Force Base, South Base Sled Track, Edwards Air Force Base, North of Avenue B, between 100th & 140th Streets East, Lancaster, Los Angeles County, CA

  12. Camera calibration based on the back projection process

    NASA Astrophysics Data System (ADS)

    Gu, Feifei; Zhao, Hong; Ma, Yueyang; Bu, Penghui

    2015-12-01

    Camera calibration plays a crucial role in 3D measurement tasks of machine vision. In typical calibration processes, camera parameters are iteratively optimized in the forward imaging process (FIP). However, the results can only guarantee the minimum of 2D projection errors on the image plane, but not the minimum of 3D reconstruction errors. In this paper, we propose a universal method for camera calibration, which uses the back projection process (BPP). In our method, a forward projection model is used to obtain initial intrinsic and extrinsic parameters with a popular planar checkerboard pattern. Then, the extracted image points are projected back into 3D space and compared with the ideal point coordinates. Finally, the estimation of the camera parameters is refined by a non-linear function minimization process. The proposed method can obtain a more accurate calibration result, which is more physically useful. Simulation and practical data are given to demonstrate the accuracy of the proposed method.

  13. Epipolar rectification method for a stereovision system with telecentric cameras

    NASA Astrophysics Data System (ADS)

    Liu, Haibo; Zhu, Zhaokun; Yao, Linshen; Dong, Jin; Chen, Shengyi; Zhang, Xiaohu; Shang, Yang

    2016-08-01

    3D metrology of a stereovision system requires epipolar rectification to be performed before dense stereo matching. In this study, we propose an epipolar rectification method for a stereovision system with two telecentric lens-based cameras. Given the orthographic projection matrices of each camera, the new projection matrices are computed by determining the new camera coordinates system in affine space and imposing some constraints on the intrinsic parameters. Then, the transformation that maps the old image planes on to the new image planes is achieved. Experiments are performed to validate the performance of the proposed rectification method. The test results show that the perpendicular distance and 3D reconstructed deviation obtained from the rectified images is not significantly higher than the corresponding values obtained from the original images. Considering the roughness of the extracted corner points and calibrated camera parameters, we can conclude that the proposed method can provide sufficiently accurate rectification results.

  14. Face Liveness Detection Using a Light Field Camera

    PubMed Central

    Kim, Sooyeon; Ban, Yuseok; Lee, Sangyoun

    2014-01-01

    A light field camera is a sensor that can record the directions as well as the colors of incident rays. This camera is widely utilized from 3D reconstruction to face and iris recognition. In this paper, we suggest a novel approach for defending spoofing face attacks, like printed 2D facial photos (hereinafter 2D photos) and HD tablet images, using the light field camera. By viewing the raw light field photograph from a different standpoint, we extract two special features which cannot be obtained from the conventional camera. To verify the performance, we compose light field photograph databases and conduct experiments. Our proposed method achieves at least 94.78% accuracy or up to 99.36% accuracy under different types of spoofing attacks. PMID:25436651

  15. Face liveness detection using a light field camera.

    PubMed

    Kim, Sooyeon; Ban, Yuseok; Lee, Sangyoun

    2014-01-01

    A light field camera is a sensor that can record the directions as well as the colors of incident rays. This camera is widely utilized from 3D reconstruction to face and iris recognition. In this paper, we suggest a novel approach for defending spoofing face attacks, like printed 2D facial photos (hereinafter 2D photos) and HD tablet images, using the light field camera. By viewing the raw light field photograph from a different standpoint, we extract two special features which cannot be obtained from the conventional camera. To verify the performance, we compose light field photograph databases and conduct experiments. Our proposed method achieves at least 94.78% accuracy or up to 99.36% accuracy under different types of spoofing attacks. PMID:25436651

  16. Penile Reconstruction

    PubMed Central

    Salgado, Christopher J.; Chim, Harvey; Tang, Jennifer C.; Monstrey, Stan J.; Mardini, Samir

    2011-01-01

    A variety of surgical options exists for penile reconstruction. The key to success of therapy is holistic management of the patient, with attention to the psychological aspects of treatment. In this article, we review reconstructive modalities for various types of penile defects inclusive of partial and total defects as well as the buried penis, and also describe recent basic science advances, which may promise new options for penile reconstruction. PMID:22851914

  17. Dual cameras acquisition and display system of retina-like sensor camera and rectangular sensor camera

    NASA Astrophysics Data System (ADS)

    Cao, Nan; Cao, Fengmei; Lin, Yabin; Bai, Tingzhu; Song, Shengyu

    2015-04-01

    For a new kind of retina-like senor camera and a traditional rectangular sensor camera, dual cameras acquisition and display system need to be built. We introduce the principle and the development of retina-like senor. Image coordinates transformation and interpolation based on sub-pixel interpolation need to be realized for our retina-like sensor's special pixels distribution. The hardware platform is composed of retina-like senor camera, rectangular sensor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes two cameras' acquisition and display.

  18. Camera Trajectory fromWide Baseline Images

    NASA Astrophysics Data System (ADS)

    Havlena, M.; Torii, A.; Pajdla, T.

    2008-09-01

    Camera trajectory estimation, which is closely related to the structure from motion computation, is one of the fundamental tasks in computer vision. Reliable camera trajectory estimation plays an important role in 3D reconstruction, self localization, and object recognition. There are essential issues for a reliable camera trajectory estimation, for instance, choice of the camera and its geometric projection model, camera calibration, image feature detection and description, and robust 3D structure computation. Most of approaches rely on classical perspective cameras because of the simplicity of their projection models and ease of their calibration. However, classical perspective cameras offer only a limited field of view, and thus occlusions and sharp camera turns may cause that consecutive frames look completely different when the baseline becomes longer. This makes the image feature matching very difficult (or impossible) and the camera trajectory estimation fails under such conditions. These problems can be avoided if omnidirectional cameras, e.g. a fish-eye lens convertor, are used. The hardware which we are using in practice is a combination of Nikon FC-E9 mounted via a mechanical adaptor onto a Kyocera Finecam M410R digital camera. Nikon FC-E9 is a megapixel omnidirectional addon convertor with 180° view angle which provides images of photographic quality. Kyocera Finecam M410R delivers 2272×1704 images at 3 frames per second. The resulting combination yields a circular view of diameter 1600 pixels in the image. Since consecutive frames of the omnidirectional camera often share a common region in 3D space, the image feature matching is often feasible. On the other hand, the calibration of these cameras is non-trivial and is crucial for the accuracy of the resulting 3D reconstruction. We calibrate omnidirectional cameras off-line using the state-of-the-art technique and Mičušík's two-parameter model, that links the radius of the image point r to the

  19. Porcelain three-dimensional shape reconstruction and its color reconstruction

    NASA Astrophysics Data System (ADS)

    Yu, Xiaoyang; Wu, Haibin; Yang, Xue; Yu, Shuang; Wang, Beiyi; Chen, Deyun

    2013-01-01

    In this paper, structured light three-dimensional measurement technology was used to reconstruct the porcelain shape, and further more the porcelain color was reconstructed. So the accurate reconstruction of the shape and color of porcelain was realized. Our shape measurement installation drawing is given. Because the porcelain surface is color complex and highly reflective, the binary Gray code encoding is used to reduce the influence of the porcelain surface. The color camera was employed to obtain the color of the porcelain surface. Then, the comprehensive reconstruction of the shape and color was realized in Java3D runtime environment. In the reconstruction process, the space point by point coloration method is proposed and achieved. Our coloration method ensures the pixel corresponding accuracy in both of shape and color aspects. The porcelain surface shape and color reconstruction experimental results completed by proposed method and our installation, show that: the depth range is 860 ˜ 980mm, the relative error of the shape measurement is less than 0.1%, the reconstructed color of the porcelain surface is real, refined and subtle, and has the same visual effect as the measured surface.

  20. Combustion pinhole camera system

    DOEpatents

    Witte, Arvel B.

    1984-02-21

    A pinhole camera system utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

  1. Combustion pinhole camera system

    DOEpatents

    Witte, A.B.

    1984-02-21

    A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor. 2 figs.

  2. The NEAT Camera Project

    NASA Technical Reports Server (NTRS)

    Jr., Ray L. Newburn

    1995-01-01

    The NEAT (Near Earth Asteroid Tracking) camera system consists of a camera head with a 6.3 cm square 4096 x 4096 pixel CCD, fast electronics, and a Sun Sparc 20 data and control computer with dual CPUs, 256 Mbytes of memory, and 36 Gbytes of hard disk. The system was designed for optimum use with an Air Force GEODSS (Ground-based Electro-Optical Deep Space Surveillance) telescope. The GEODSS telescopes have 1 m f/2.15 objectives of the Ritchey-Chretian type, designed originally for satellite tracking. Installation of NEAT began July 25 at the Air Force Facility on Haleakala, a 3000 m peak on Maui in Hawaii.

  3. LSST Camera Optics

    SciTech Connect

    Olivier, S S; Seppala, L; Gilmore, K; Hale, L; Whistler, W

    2006-06-05

    The Large Synoptic Survey Telescope (LSST) is a unique, three-mirror, modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary feeding a camera system that includes corrector optics to produce a 3.5 degree field of view with excellent image quality (<0.3 arcsecond 80% encircled diffracted energy) over the entire field from blue to near infra-red wavelengths. We describe the design of the LSST camera optics, consisting of three refractive lenses with diameters of 1.6m, 1.0m and 0.7m, along with a set of interchangeable, broad-band, interference filters with diameters of 0.75m. We also describe current plans for fabricating, coating, mounting and testing these lenses and filters.

  4. Streak camera receiver definition study

    NASA Technical Reports Server (NTRS)

    Johnson, C. B.; Hunkler, L. T., Sr.; Letzring, S. A.; Jaanimagi, P.

    1990-01-01

    Detailed streak camera definition studies were made as a first step toward full flight qualification of a dual channel picosecond resolution streak camera receiver for the Geoscience Laser Altimeter and Ranging System (GLRS). The streak camera receiver requirements are discussed as they pertain specifically to the GLRS system, and estimates of the characteristics of the streak camera are given, based upon existing and near-term technological capabilities. Important problem areas are highlighted, and possible corresponding solutions are discussed.

  5. Automated Camera Array Fine Calibration

    NASA Technical Reports Server (NTRS)

    Clouse, Daniel; Padgett, Curtis; Ansar, Adnan; Cheng, Yang

    2008-01-01

    Using aerial imagery, the JPL FineCalibration (JPL FineCal) software automatically tunes a set of existing CAHVOR camera models for an array of cameras. The software finds matching features in the overlap region between images from adjacent cameras, and uses these features to refine the camera models. It is not necessary to take special imagery of a known target and no surveying is required. JPL FineCal was developed for use with an aerial, persistent surveillance platform.

  6. 3-D Flow Visualization with a Light-field Camera

    NASA Astrophysics Data System (ADS)

    Thurow, B.

    2012-12-01

    Light-field cameras have received attention recently due to their ability to acquire photographs that can be computationally refocused after they have been acquired. In this work, we describe the development of a light-field camera system for 3D visualization of turbulent flows. The camera developed in our lab, also known as a plenoptic camera, uses an array of microlenses mounted next to an image sensor to resolve both the position and angle of light rays incident upon the camera. For flow visualization, the flow field is seeded with small particles that follow the fluid's motion and are imaged using the camera and a pulsed light source. The tomographic MART algorithm is then applied to the light-field data in order to reconstruct a 3D volume of the instantaneous particle field. 3D, 3C velocity vectors are then determined from a pair of 3D particle fields using conventional cross-correlation algorithms. As an illustration of the concept, 3D/3C velocity measurements of a turbulent boundary layer produced on the wall of a conventional wind tunnel are presented. Future experiments are planned to use the camera to study the influence of wall permeability on the 3-D structure of the turbulent boundary layer.Schematic illustrating the concept of a plenoptic camera where each pixel represents both the position and angle of light rays entering the camera. This information can be used to computationally refocus an image after it has been acquired. Instantaneous 3D velocity field of a turbulent boundary layer determined using light-field data captured by a plenoptic camera.

  7. Orbiter Camera Payload System

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Components for an orbiting camera payload system (OCPS) include the large format camera (LFC), a gas supply assembly, and ground test, handling, and calibration hardware. The LFC, a high resolution large format photogrammetric camera for use in the cargo bay of the space transport system, is also adaptable to use on an RB-57 aircraft or on a free flyer satellite. Carrying 4000 feet of film, the LFC is usable over the visible to near IR, at V/h rates of from 11 to 41 milliradians per second, overlap of 10, 60, 70 or 80 percent and exposure times of from 4 to 32 milliseconds. With a 12 inch focal length it produces a 9 by 18 inch format (long dimension in line of flight) with full format low contrast resolution of 88 lines per millimeter (AWAR), full format distortion of less than 14 microns and a complement of 45 Reseau marks and 12 fiducial marks. Weight of the OCPS as supplied, fully loaded is 944 pounds and power dissipation is 273 watts average when in operation, 95 watts in standby. The LFC contains an internal exposure sensor, or will respond to external command. It is able to photograph starfields for inflight calibration upon command.

  8. Hemispherical Laue camera

    DOEpatents

    Li, James C. M.; Chu, Sungnee G.

    1980-01-01

    A hemispherical Laue camera comprises a crystal sample mount for positioning a sample to be analyzed at the center of sphere of a hemispherical, X-radiation sensitive film cassette, a collimator, a stationary or rotating sample mount and a set of standard spherical projection spheres. X-radiation generated from an external source is directed through the collimator to impinge onto the single crystal sample on the stationary mount. The diffracted beam is recorded on the hemispherical X-radiation sensitive film mounted inside the hemispherical film cassette in either transmission or back-reflection geometry. The distances travelled by X-radiation diffracted from the crystal to the hemispherical film are the same for all crystal planes which satisfy Bragg's Law. The recorded diffraction spots or Laue spots on the film thereby preserve both the symmetry information of the crystal structure and the relative intensities which are directly related to the relative structure factors of the crystal orientations. The diffraction pattern on the exposed film is compared with the known diffraction pattern on one of the standard spherical projection spheres for a specific crystal structure to determine the orientation of the crystal sample. By replacing the stationary sample support with a rotating sample mount, the hemispherical Laue camera can be used for crystal structure determination in a manner previously provided in conventional Debye-Scherrer cameras.

  9. Gamma ray camera

    DOEpatents

    Perez-Mendez, V.

    1997-01-21

    A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

  10. Gamma ray camera

    DOEpatents

    Perez-Mendez, Victor

    1997-01-01

    A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

  11. Stochastic reconstruction of sandstones

    PubMed

    Manwart; Torquato; Hilfer

    2000-07-01

    A simulated annealing algorithm is employed to generate a stochastic model for a Berea sandstone and a Fontainebleau sandstone, with each a prescribed two-point probability function, lineal-path function, and "pore size" distribution function, respectively. We find that the temperature decrease of the annealing has to be rather quick to yield isotropic and percolating configurations. A comparison of simple morphological quantities indicates good agreement between the reconstructions and the original sandstones. Also, the mean survival time of a random walker in the pore space is reproduced with good accuracy. However, a more detailed investigation by means of local porosity theory shows that there may be significant differences of the geometrical connectivity between the reconstructed and the experimental samples. PMID:11088546

  12. Lights, Camera, Reflection!

    ERIC Educational Resources Information Center

    Mourlam, Daniel

    2013-01-01

    There are many ways to critique teaching, but few are more effective than video. Personal reflection through the use of video allows one to see what really happens in the classrooms--good and bad--and provides a visual path forward for improvement, whether it be in one's teaching, work with a particular student, or learning environment. This…

  13. Camera calibration method of binocular stereo vision based on OpenCV

    NASA Astrophysics Data System (ADS)

    Zhong, Wanzhen; Dong, Xiaona

    2015-10-01

    Camera calibration, an important part of the binocular stereo vision research, is the essential foundation of 3D reconstruction of the spatial object. In this paper, the camera calibration method based on OpenCV (open source computer vision library) is submitted to make the process better as a result of obtaining higher precision and efficiency. First, the camera model in OpenCV and an algorithm of camera calibration are presented, especially considering the influence of camera lens radial distortion and decentering distortion. Then, camera calibration procedure is designed to compute those parameters of camera and calculate calibration errors. High-accurate profile extraction algorithm and a checkboard with 48 corners have also been used in this part. Finally, results of calibration program are presented, demonstrating the high efficiency and accuracy of the proposed approach. The results can reach the requirement of robot binocular stereo vision.

  14. Penile reconstruction

    PubMed Central

    Garaffa, Giulio; Sansalone, Salvatore; Ralph, David J

    2013-01-01

    During the most recent years, a variety of new techniques of penile reconstruction have been described in the literature. This paper focuses on the most recent advances in male genital reconstruction after trauma, excision of benign and malignant disease, in gender reassignment surgery and aphallia with emphasis on surgical technique, cosmetic and functional outcome. PMID:22426595

  15. Image reconstruction

    SciTech Connect

    Defrise, Michel; Gullberg, Grant T.

    2006-04-05

    We give an overview of the role of Physics in Medicine andBiology in development of tomographic reconstruction algorithms. We focuson imaging modalities involving ionizing radiation, CT, PET and SPECT,and cover a wide spectrum of reconstruction problems, starting withclassical 2D tomogra tomography in the 1970s up to 4D and 5D problemsinvolving dynamic imaging of moving organs.

  16. Blob-enhanced reconstruction technique

    NASA Astrophysics Data System (ADS)

    Castrillo, Giusy; Cafiero, Gioacchino; Discetti, Stefano; Astarita, Tommaso

    2016-09-01

    A method to enhance the quality of the tomographic reconstruction and, consequently, the 3D velocity measurement accuracy, is presented. The technique is based on integrating information on the objects to be reconstructed within the algebraic reconstruction process. A first guess intensity distribution is produced with a standard algebraic method, then the distribution is rebuilt as a sum of Gaussian blobs, based on location, intensity and size of agglomerates of light intensity surrounding local maxima. The blobs substitution regularizes the particle shape allowing a reduction of the particles discretization errors and of their elongation in the depth direction. The performances of the blob-enhanced reconstruction technique (BERT) are assessed with a 3D synthetic experiment. The results have been compared with those obtained by applying the standard camera simultaneous multiplicative reconstruction technique (CSMART) to the same volume. Several blob-enhanced reconstruction processes, both substituting the blobs at the end of the CSMART algorithm and during the iterations (i.e. using the blob-enhanced reconstruction as predictor for the following iterations), have been tested. The results confirm the enhancement in the velocity measurements accuracy, demonstrating a reduction of the bias error due to the ghost particles. The improvement is more remarkable at the largest tested seeding densities. Additionally, using the blobs distributions as a predictor enables further improvement of the convergence of the reconstruction algorithm, with the improvement being more considerable when substituting the blobs more than once during the process. The BERT process is also applied to multi resolution (MR) CSMART reconstructions, permitting simultaneously to achieve remarkable improvements in the flow field measurements and to benefit from the reduction in computational time due to the MR approach. Finally, BERT is also tested on experimental data, obtaining an increase of the

  17. Photorealistic image synthesis and camera validation from 2D images

    NASA Astrophysics Data System (ADS)

    Santos Ferrer, Juan C.; González Chévere, David; Manian, Vidya

    2014-06-01

    This paper presents a new 3D scene reconstruction technique using the Unity 3D game engine. The method presented here allow us to reconstruct the shape of simple objects and more complex ones from multiple 2D images, including infrared and digital images from indoor scenes and only digital images from outdoor scenes and then add the reconstructed object to the simulated scene created in Unity 3D, these scenes are then validated with real world scenes. The method used different cameras settings and explores different properties in the reconstructions of the scenes including light, color, texture, shapes and different views. To achieve the highest possible resolution, it was necessary the extraction of partial textures from visible surfaces. To recover the 3D shapes and the depth of simple objects that can be represented by the geometric bodies, there geometric characteristics were used. To estimate the depth of more complex objects the triangulation method was used, for this the intrinsic and extrinsic parameters were calculated using geometric camera calibration. To implement the methods mentioned above the Matlab tool was used. The technique presented here also let's us to simulate small simple videos, by reconstructing a sequence of multiple scenes of the video separated by small margins of time. To measure the quality of the reconstructed images and video scenes the Fast Low Band Model (FLBM) metric from the Video Quality Measurement (VQM) software was used. Low bandwidth perception based features include edges and motion.

  18. Measuring SO2 ship emissions with an ultraviolet imaging camera

    NASA Astrophysics Data System (ADS)

    Prata, A. J.

    2014-05-01

    Over the last few years fast-sampling ultraviolet (UV) imaging cameras have been developed for use in measuring SO2 emissions from industrial sources (e.g. power plants; typical emission rates ~ 1-10 kg s-1) and natural sources (e.g. volcanoes; typical emission rates ~ 10-100 kg s-1). Generally, measurements have been made from sources rich in SO2 with high concentrations and emission rates. In this work, for the first time, a UV camera has been used to measure the much lower concentrations and emission rates of SO2 (typical emission rates ~ 0.01-0.1 kg s-1) in the plumes from moving and stationary ships. Some innovations and trade-offs have been made so that estimates of the emission rates and path concentrations can be retrieved in real time. Field experiments were conducted at Kongsfjord in Ny Ålesund, Svalbard, where SO2 emissions from cruise ships were made, and at the port of Rotterdam, Netherlands, measuring emissions from more than 10 different container and cargo ships. In all cases SO2 path concentrations could be estimated and emission rates determined by measuring ship plume speeds simultaneously using the camera, or by using surface wind speed data from an independent source. Accuracies were compromised in some cases because of the presence of particulates in some ship emissions and the restriction of single-filter UV imagery, a requirement for fast-sampling (> 10 Hz) from a single camera. Despite the ease of use and ability to determine SO2 emission rates from the UV camera system, the limitation in accuracy and precision suggest that the system may only be used under rather ideal circumstances and that currently the technology needs further development to serve as a method to monitor ship emissions for regulatory purposes. A dual-camera system or a single, dual-filter camera is required in order to properly correct for the effects of particulates in ship plumes.

  19. A comparison of select image-compression algorithms for an electronic still camera

    NASA Technical Reports Server (NTRS)

    Nerheim, Rosalee

    1989-01-01

    This effort is a study of image-compression algorithms for an electronic still camera. An electronic still camera can record and transmit high-quality images without the use of film, because images are stored digitally in computer memory. However, high-resolution images contain an enormous amount of information, and will strain the camera's data-storage system. Image compression will allow more images to be stored in the camera's memory. For the electronic still camera, a compression algorithm that produces a reconstructed image of high fidelity is most important. Efficiency of the algorithm is the second priority. High fidelity and efficiency are more important than a high compression ratio. Several algorithms were chosen for this study and judged on fidelity, efficiency and compression ratio. The transform method appears to be the best choice. At present, the method is compressing images to a ratio of 5.3:1 and producing high-fidelity reconstructed images.

  20. DEVICE CONTROLLER, CAMERA CONTROL

    Energy Science and Technology Software Center (ESTSC)

    1998-07-20

    This is a C++ application that is the server for the cameral control system. Devserv drives serial devices, such as cameras and videoswitchers used in a videoconference, upon request from a client such as the camxfgbfbx ccint program. cc Deverv listens on UPD ports for clients to make network contractions. After a client connects and sends a request to control a device (such as to pan,tilt, or zooma camera or do picture-in-picture with a videoswitcher),more » devserv formats the request into an RS232 message appropriate for the device and sends this message over the serial port to which the device is connected. Devserv then reads the reply from the device from the serial port to which the device is connected. Devserv then reads the reply from the device from the serial port and then formats and sends via multicast a status message. In addition, devserv periodically multicasts status or description messages so that all clients connected to the multicast channel know what devices are supported and their ranges of motion and the current position. The software design employs a class hierarchy such that an abstract base class for devices can be subclassed into classes for various device categories(e.g. sonyevid30, cononvco4, panasonicwjmx50, etc.). which are further subclassed into classes for various device categories. The devices currently supported are the Sony evi-D30, Canon, VCC1, Canon VCC3, and Canon VCC4 cameras and the Panasonic WJ-MX50 videoswitcher. However, developers can extend the class hierarchy to support other devices.« less

  1. Adaptive compressive sensing camera

    NASA Astrophysics Data System (ADS)

    Hsu, Charles; Hsu, Ming K.; Cha, Jae; Iwamura, Tomo; Landa, Joseph; Nguyen, Charles; Szu, Harold

    2013-05-01

    We have embedded Adaptive Compressive Sensing (ACS) algorithm on Charge-Coupled-Device (CCD) camera based on the simplest concept that each pixel is a charge bucket, and the charges comes from Einstein photoelectric conversion effect. Applying the manufactory design principle, we only allow altering each working component at a minimum one step. We then simulated what would be such a camera can do for real world persistent surveillance taking into account of diurnal, all weather, and seasonal variations. The data storage has saved immensely, and the order of magnitude of saving is inversely proportional to target angular speed. We did design two new components of CCD camera. Due to the matured CMOS (Complementary metal-oxide-semiconductor) technology, the on-chip Sample and Hold (SAH) circuitry can be designed for a dual Photon Detector (PD) analog circuitry for changedetection that predicts skipping or going forward at a sufficient sampling frame rate. For an admitted frame, there is a purely random sparse matrix [Φ] which is implemented at each bucket pixel level the charge transport bias voltage toward its neighborhood buckets or not, and if not, it goes to the ground drainage. Since the snapshot image is not a video, we could not apply the usual MPEG video compression and Hoffman entropy codec as well as powerful WaveNet Wrapper on sensor level. We shall compare (i) Pre-Processing FFT and a threshold of significant Fourier mode components and inverse FFT to check PSNR; (ii) Post-Processing image recovery will be selectively done by CDT&D adaptive version of linear programming at L1 minimization and L2 similarity. For (ii) we need to determine in new frames selection by SAH circuitry (i) the degree of information (d.o.i) K(t) dictates the purely random linear sparse combination of measurement data a la [Φ]M,N M(t) = K(t) Log N(t).

  2. Phoenix Robotic Arm Camera

    NASA Astrophysics Data System (ADS)

    Keller, H. U.; Goetz, W.; Hartwig, H.; Hviid, S. F.; Kramm, R.; Markiewicz, W. J.; Reynolds, R.; Shinohara, C.; Smith, P.; Tanner, R.; Woida, P.; Woida, R.; Bos, B. J.; Lemmon, M. T.

    2008-10-01

    The Phoenix Robotic Arm Camera (RAC) is a variable-focus color camera mounted to the Robotic Arm (RA) of the Phoenix Mars Lander. It is designed to acquire both close-up images of the Martian surface and microscopic images (down to a scale of 23 μm/pixel) of material collected in the RA scoop. The mounting position at the end of the Robotic Arm allows the RAC to be actively positioned for imaging of targets not easily seen by the Stereo Surface Imager (SSI), such as excavated trench walls and targets under the Lander structure. Color information is acquired by illuminating the target with red, green, and blue light-emitting diodes. Digital terrain models (DTM) can be generated from RAC images acquired from different view points. This can provide high-resolution stereo information about fine details of the trench walls. The large stereo baseline possible with the arm can also provide a far-field DTM. The primary science objectives of the RAC are the search for subsurface soil/ice layering at the landing site and the characterization of scoop samples prior to delivery to other instruments on board Phoenix. The RAC shall also provide low-resolution panoramas in support of SSI activities and acquire images of the Lander deck for instrument and Lander check out. The camera design was inherited from the unsuccessful Mars Polar Lander mission (1999) and further developed for the (canceled) Mars Surveyor 2001 Lander (MSL01). Extensive testing and partial recalibration qualified the MSL01 RAC flight model for integration into the Phoenix science payload.

  3. DEVICE CONTROLLER, CAMERA CONTROL

    SciTech Connect

    Perry, Marcia

    1998-07-20

    This is a C++ application that is the server for the cameral control system. Devserv drives serial devices, such as cameras and videoswitchers used in a videoconference, upon request from a client such as the camxfgbfbx ccint program. cc Deverv listens on UPD ports for clients to make network contractions. After a client connects and sends a request to control a device (such as to pan,tilt, or zooma camera or do picture-in-picture with a videoswitcher), devserv formats the request into an RS232 message appropriate for the device and sends this message over the serial port to which the device is connected. Devserv then reads the reply from the device from the serial port to which the device is connected. Devserv then reads the reply from the device from the serial port and then formats and sends via multicast a status message. In addition, devserv periodically multicasts status or description messages so that all clients connected to the multicast channel know what devices are supported and their ranges of motion and the current position. The software design employs a class hierarchy such that an abstract base class for devices can be subclassed into classes for various device categories(e.g. sonyevid30, cononvco4, panasonicwjmx50, etc.). which are further subclassed into classes for various device categories. The devices currently supported are the Sony evi-D30, Canon, VCC1, Canon VCC3, and Canon VCC4 cameras and the Panasonic WJ-MX50 videoswitcher. However, developers can extend the class hierarchy to support other devices.

  4. Breast reconstruction.

    PubMed

    DellaCroce, Frank J; Wolfe, Emily T

    2013-04-01

    As diagnostic technology has progressed and the understanding of the disease process has evolved, the number of mastectomies performed in the United States has increased. Breast reconstructive techniques have commensurately become more sophisticated along the same timeline. The result is that those facing mastectomy have the potential to simultaneously retain physical beauty and wholeness. Only 33% of women who are otherwise candidates for immediate reconstruction at the time of mastectomy choose reconstruction. Patients generally have a high level of satisfaction with the option they choose, contributing to a feeling of overall recovery and physical and emotional wholeness. PMID:23464695

  5. Aircraft path planning for optimal imaging using dynamic cost functions

    NASA Astrophysics Data System (ADS)

    Christie, Gordon; Chaudhry, Haseeb; Kochersberger, Kevin

    2015-05-01

    Unmanned aircraft development has accelerated with recent technological improvements in sensing and communications, which has resulted in an "applications lag" for how these aircraft can best be utilized. The aircraft are becoming smaller, more maneuverable and have longer endurance to perform sensing and sampling missions, but operating them aggressively to exploit these capabilities has not been a primary focus in unmanned systems development. This paper addresses a means of aerial vehicle path planning to provide a realistic optimal path in acquiring imagery for structure from motion (SfM) reconstructions and performing radiation surveys. This method will allow SfM reconstructions to occur accurately and with minimal flight time so that the reconstructions can be executed efficiently. An assumption is made that we have 3D point cloud data available prior to the flight. A discrete set of scan lines are proposed for the given area that are scored based on visibility of the scene. Our approach finds a time-efficient path and calculates trajectories between scan lines and over obstacles encountered along those scan lines. Aircraft dynamics are incorporated into the path planning algorithm as dynamic cost functions to create optimal imaging paths in minimum time. Simulations of the path planning algorithm are shown for an urban environment. We also present our approach for image-based terrain mapping, which is able to efficiently perform a 3D reconstruction of a large area without the use of GPS data.

  6. Oblique along path toward structures at rear of parcel. Original ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Oblique along path toward structures at rear of parcel. Original skinny mosaic path along edge of structures was altered (delineation can be seen in concrete) path was widened with a newer mosaic to make access to the site safer. Structures (from right) edge of Round House (with "Spring Garden"), Pencil house, Shell House, School House, wood lattice is attached to chain-link fence along north (rear) property line. These structures were all damaged by the 1994 Northridge earthquake. Camera facing northeast. - Grandma Prisbrey's Bottle Village, 4595 Cochran Street, Simi Valley, Ventura County, CA

  7. Mars Science Laboratory Engineering Cameras

    NASA Technical Reports Server (NTRS)

    Maki, Justin N.; Thiessen, David L.; Pourangi, Ali M.; Kobzeff, Peter A.; Lee, Steven W.; Dingizian, Arsham; Schwochert, Mark A.

    2012-01-01

    NASA's Mars Science Laboratory (MSL) Rover, which launched to Mars in 2011, is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover (MER) cameras, which were sent to Mars in 2003. The engineering cameras weigh less than 300 grams each and use less than 3 W of power. Images returned from the engineering cameras are used to navigate the rover on the Martian surface, deploy the rover robotic arm, and ingest samples into the rover sample processing system. The navigation cameras (Navcams) are mounted to a pan/tilt mast and have a 45-degree square field of view (FOV) with a pixel scale of 0.82 mrad/pixel. The hazard avoidance cameras (Haz - cams) are body-mounted to the rover chassis in the front and rear of the vehicle and have a 124-degree square FOV with a pixel scale of 2.1 mrad/pixel. All of the cameras utilize a frame-transfer CCD (charge-coupled device) with a 1024x1024 imaging region and red/near IR bandpass filters centered at 650 nm. The MSL engineering cameras are grouped into two sets of six: one set of cameras is connected to rover computer A and the other set is connected to rover computer B. The MSL rover carries 8 Hazcams and 4 Navcams.

  8. Stereoscopic camera design

    NASA Astrophysics Data System (ADS)

    Montgomery, David J.; Jones, Christopher K.; Stewart, James N.; Smith, Alan

    2002-05-01

    It is clear from the literature that the majority of work in stereoscopic imaging is directed towards the development of modern stereoscopic displays. As costs come down, wider public interest in this technology is expected to increase. This new technology would require new methods of image formation. Advances in stereo computer graphics will of course lead to the creation of new stereo computer games, graphics in films etc. However, the consumer would also like to see real-world stereoscopic images, pictures of family, holiday snaps etc. Such scenery would have wide ranges of depth to accommodate and would need also to cope with moving objects, such as cars, and in particular other people. Thus, the consumer acceptance of auto/stereoscopic displays and 3D in general would be greatly enhanced by the existence of a quality stereoscopic camera. This paper will cover an analysis of existing stereoscopic camera designs and show that they can be categorized into four different types, with inherent advantages and disadvantages. A recommendation is then made with regard to 3D consumer still and video photography. The paper will go on to discuss this recommendation and describe its advantages and how it can be realized in practice.

  9. NFC - Narrow Field Camera

    NASA Astrophysics Data System (ADS)

    Koukal, J.; Srba, J.; Gorková, S.

    2015-01-01

    We have been introducing a low-cost CCTV video system for faint meteor monitoring and here we describe the first results from 5 months of two-station operations. Our system called NFC (Narrow Field Camera) with a meteor limiting magnitude around +6.5mag allows research on trajectories of less massive meteoroids within individual parent meteor showers and the sporadic background. At present 4 stations (2 pairs with coordinated fields of view) of NFC system are operated in the frame of CEMeNt (Central European Meteor Network). The heart of each NFC station is a sensitive CCTV camera Watec 902 H2 and a fast cinematographic lens Meopta Meostigmat 1/50 - 52.5 mm (50 mm focal length and fixed aperture f/1.0). In this paper we present the first results based on 1595 individual meteors, 368 of which were recorded from two stations simultaneously. This data set allows the first empirical verification of theoretical assumptions for NFC system capabilities (stellar and meteor magnitude limit, meteor apparent brightness distribution and accuracy of single station measurements) and the first low mass meteoroid trajectory calculations. Our experimental data clearly showed the capabilities of the proposed system for low mass meteor registration and for calculations based on NFC data to lead to a significant refinement in the orbital elements for low mass meteoroids.

  10. Investigation of a consumer-grade digital stereo camera

    NASA Astrophysics Data System (ADS)

    Menna, Fabio; Nocerino, Erica; Remondino, Fabio; Shortis, Mark

    2013-04-01

    The paper presents a metric investigation of the Fuji FinePix Real 3D W1 stereo photo-camera. The stereo-camera uses a synchronized Twin Lens-CCD System to acquire simultaneously two images using two Fujinon 3x optical zoom lenses arranged in an aluminum die-cast frame integrated in a very compact body. The nominal baseline is 77 mm and the resolution of the each CCD is 10 megapixels. Given the short baseline and the presence of two optical paths, the investigation aims to evaluate the accuracy of the 3D data that can be produced and the stability of the camera. From a photogrammetric point of view, the interest in this camera is its capability to acquire synchronized image pairs that contain important 3D metric information for many close-range applications (human body parts measurement, rapid prototyping, surveying of archeological artifacts, etc.). Calibration values - for the left and right cameras - at different focal lengths, derived with an in-house software application, are reported together with accuracy analyses. The object coordinates obtained from the bundle adjustment computation for each focal length were compared to reference coordinates of a test range by means of a similarity transformation. Additionally, the article reports on the investigation of the asymmetrical relative orientation between the left and right camera.

  11. ACL reconstruction

    MedlinePlus

    ... Tissue taken from a donor is called an allograft. The procedure is usually performed with the help ... This increases the chance you may have a meniscus tear. ACL reconstruction may be used for these ...

  12. The universal path integral

    NASA Astrophysics Data System (ADS)

    Lloyd, Seth; Dreyer, Olaf

    2016-02-01

    Path integrals calculate probabilities by summing over classical configurations of variables such as fields, assigning each configuration a phase equal to the action of that configuration. This paper defines a universal path integral, which sums over all computable structures. This path integral contains as sub-integrals all possible computable path integrals, including those of field theory, the standard model of elementary particles, discrete models of quantum gravity, string theory, etc. The universal path integral possesses a well-defined measure that guarantees its finiteness. The probabilities for events corresponding to sub-integrals can be calculated using the method of decoherent histories. The universal path integral supports a quantum theory of the universe in which the world that we see around us arises out of the interference between all computable structures.

  13. [Eyebrow reconstruction].

    PubMed

    Baraër, F; Darsonval, V; Lejeune, F; Bochot-Hermouet, B; Rousseau, P

    2013-10-01

    The eyebrow is an essential anatomical area, from a social point of view, so its reconstruction, in case of skin defect, must be as meticulous as possible, with the less residual sequela. Capillary density extremely varies from one person to another and the different methods of restoration of this area should absolutely take this into consideration. We are going to review the various techniques of reconstruction, according to the sex and the surface to cover. PMID:23896574

  14. Characterizing the Evolutionary Path(s) to Early Homo

    PubMed Central

    Schroeder, Lauren; Roseman, Charles C.; Cheverud, James M.; Ackermann, Rebecca R.

    2014-01-01

    Numerous studies suggest that the transition from Australopithecus to Homo was characterized by evolutionary innovation, resulting in the emergence and coexistence of a diversity of forms. However, the evolutionary processes necessary to drive such a transition have not been examined. Here, we apply statistical tests developed from quantitative evolutionary theory to assess whether morphological differences among late australopith and early Homo species in Africa have been shaped by natural selection. Where selection is demonstrated, we identify aspects of morphology that were most likely under selective pressure, and determine the nature (type, rate) of that selection. Results demonstrate that selection must be invoked to explain an Au. africanus—Au. sediba—Homo transition, while transitions from late australopiths to various early Homo species that exclude Au. sediba can be achieved through drift alone. Rate tests indicate that selection is largely directional, acting to rapidly differentiate these taxa. Reconstructions of patterns of directional selection needed to drive the Au. africanus—Au. sediba—Homo transition suggest that selection would have affected all regions of the skull. These results may indicate that an evolutionary path to Homo without Au. sediba is the simpler path and/or provide evidence that this pathway involved more reliance on cultural adaptations to cope with environmental change. PMID:25470780

  15. Transmission electron microscope CCD camera

    DOEpatents

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  16. Collision-related Early Paleozoic evolution of a crustal fragment from the northern Gondwana margin (Slavonian Mountains, Tisia Mega-Unit, Croatia): Reconstruction of the P-T path, timing and paleotectonic implications

    NASA Astrophysics Data System (ADS)

    Balen, D.; Massonne, H.-J.; Petrinec, Z.

    2015-09-01

    An orthogneiss from the oldest metamorphic complex at Mt. Papuk (Tisia Mega-Unit, Croatia) enables the quantification of the P-T evolution of Early Paleozoic rocks of the Panonian Basin basement in contrast to neighboring peri-Gondwanan terrains which are significantly overprinted by pre-Variscan, Variscan, and Alpine events. Two different groups of Ce-rich monazite within oval-shaped corona microstructures have been observed. Age dating of the corona cores yielded two populations with average ages of 528 ± 7 (2σ) Ma and 465 ± 7 Ma, respectively. Furthermore, an Y-rich group, found inside garnet cores, was dated at 616 ± 23 Ma. Th-rich monazite included in garnet rims yielded an age of 491 ± 6 Ma. The youngest monazite group at 417 ± 20 Ma is located inside mica. The orthogneiss precursor was a calc-alkaline to high-K calc-alkaline igneous peraluminous crustal rock (diorite) from an active continental marginal setting. The calculated P-T pseudosection in the MnNCKFMASHTO system in combination with assemblage characteristics and mineral chemistry data provides good constraints on the P-T evolution: for stage I peak P-T conditions of 13 kbar and 670 °C were derived followed by stage II, which was characterized by moderate cooling accompanied by uplift to mid-crustal levels (5.2 kbar and 610 °C). Subsequently, the system cooled to 480 °C at ~ 4.4 kbar (stage III). Formation of titanite rims on ilmenite suggests further cooling to 4 kbar and 400 °C (stage IV). The clockwise P-T path implies exhumation from a tectonically thickened crustal setting (ca. 45 km depth at a geothermal gradient of ~ 15 °C/km) to mid-crustal levels (ca. 18 km) followed by cooling at depths < 14 km. Crustal thickening was due to the collision of a continental plate (Gondwana) with a smaller plate, which was underthrust.

  17. Fast frame scanning camera system for light-sheet microscopy.

    PubMed

    Wu, Di; Zhou, Xing; Yao, Baoli; Li, Runze; Yang, Yanlong; Peng, Tong; Lei, Ming; Dan, Dan; Ye, Tong

    2015-10-10

    In the interest of improving the temporal resolution for light-sheet microscopy, we designed a fast frame scanning camera system that incorporated a galvanometer scanning mirror into the imaging path of a home-built light-sheet microscope. This system transformed a temporal image sequence to a spatial one so that multiple images could be acquired during one exposure period. The improvement factor of the frame rate was dependent on the number of sub-images that could be tiled on the sensor without overlapping each other and was therefore a trade-off with the image size. As a demonstration, we achieved 960 frames/s (fps) on a CCD camera that was originally capable of recording images at only 30 fps (full frame). This allowed us to observe millisecond or sub-millisecond events with ordinary CCD cameras. PMID:26479797

  18. Spherical vision cameras in a semi-autonomous wheelchair system.

    PubMed

    Nguyen, Jordan S; Su, Steven W; Nguyen, Hung T

    2010-01-01

    This paper is concerned with the methods developed for extending the capabilities of a spherical vision camera system to allow detection of surrounding objects and whether or not they pose a danger for movement in that direction during autonomous navigation of a power wheelchair. A Point Grey Research (PGR) Ladybug2 spherical vision camera system was attached to the power wheelchair for surrounding vision. The objective is to use this Ladybug2 system to provide information about obstacles all around the wheelchair and aid the automated decision-making process involved during navigation. Through instantaneous neural network classification of individual camera images to determine whether obstacles are present, detection of obstacles have been successfully achieved with accuracies reaching 96%. This assistive technology has the purpose of automated obstacle detection, navigational path planning and decision-making, and collision avoidance during navigation. PMID:21097098

  19. A Motionless Camera

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Omniview, a motionless, noiseless, exceptionally versatile camera was developed for NASA as a receiving device for guiding space robots. The system can see in one direction and provide as many as four views simultaneously. Developed by Omniview, Inc. (formerly TRI) under a NASA Small Business Innovation Research (SBIR) grant, the system's image transformation electronics produce a real-time image from anywhere within a hemispherical field. Lens distortion is removed, and a corrected "flat" view appears on a monitor. Key elements are a high resolution charge coupled device (CCD), image correction circuitry and a microcomputer for image processing. The system can be adapted to existing installations. Applications include security and surveillance, teleconferencing, imaging, virtual reality, broadcast video and military operations. Omniview technology is now called IPIX. The company was founded in 1986 as TeleRobotics International, became Omniview in 1995, and changed its name to Interactive Pictures Corporation in 1997.

  20. Remote removal of an obstruction from FFTF (Fast Flux Test Facility) in-service inspection camera track

    SciTech Connect

    Gibbons, P.W.

    1990-11-01

    Remote techniques and special equipment were used to clear the path of a closed-circuit television camera system that travels on a monorail track around the reactor vessel support arm structure. A tangle of wire-wrapped instrumentation tubing had been inadvertently inserted through a dislocated guide-tube expansion joint and into the camera track area. An externally driven auger device, mounted on the track ahead of the camera to view the procedure, was used to retrieve the tubing. 6 figs.

  1. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Cannon, S.D.; Finch, S.M.

    1992-10-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  2. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-01-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  3. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1991-01-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms; environmental transport environmental monitoring data; demographics, agriculture, food habits; environmental pathways and dose estimates.

  4. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-02-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

  5. A novel SPECT camera for molecular imaging of the prostate

    NASA Astrophysics Data System (ADS)

    Cebula, Alan; Gilland, David; Su, Li-Ming; Wagenaar, Douglas; Bahadori, Amir

    2011-10-01

    The objective of this work is to develop an improved SPECT camera for dedicated prostate imaging. Complementing the recent advancements in agents for molecular prostate imaging, this device has the potential to assist in distinguishing benign from aggressive cancers, to improve site-specific localization of cancer, to improve accuracy of needle-guided prostate biopsy of cancer sites, and to aid in focal therapy procedures such as cryotherapy and radiation. Theoretical calculations show that the spatial resolution/detection sensitivity of the proposed SPECT camera can rival or exceed 3D PET and further signal-to-noise advantage is attained with the better energy resolution of the CZT modules. Based on photon transport simulation studies, the system has a reconstructed spatial resolution of 4.8 mm with a sensitivity of 0.0001. Reconstruction of a simulated prostate distribution demonstrates the focal imaging capability of the system.

  6. Dynamic Human Body Modeling Using a Single RGB Camera

    PubMed Central

    Zhu, Haiyu; Yu, Yao; Zhou, Yu; Du, Sidan

    2016-01-01

    In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones. PMID:26999159

  7. Dynamic Human Body Modeling Using a Single RGB Camera.

    PubMed

    Zhu, Haiyu; Yu, Yao; Zhou, Yu; Du, Sidan

    2016-01-01

    In this paper, we present a novel automatic pipeline to build personalized parametric models of dynamic people using a single RGB camera. Compared to previous approaches that use monocular RGB images, our system can model a 3D human body automatically and incrementally, taking advantage of human motion. Based on coarse 2D and 3D poses estimated from image sequences, we first perform a kinematic classification of human body parts to refine the poses and obtain reconstructed body parts. Next, a personalized parametric human model is generated by driving a general template to fit the body parts and calculating the non-rigid deformation. Experimental results show that our shape estimation method achieves comparable accuracy with reconstructed models using depth cameras, yet requires neither user interaction nor any dedicated devices, leading to the feasibility of using this method on widely available smart phones. PMID:26999159

  8. Light field reconstruction robust to signal dependent noise

    NASA Astrophysics Data System (ADS)

    Ren, Kun; Bian, Liheng; Suo, Jinli; Dai, Qionghai

    2014-11-01

    Capturing four dimensional light field data sequentially using a coded aperture camera is an effective approach but suffers from low signal noise ratio. Although multiplexing can help raise the acquisition quality, noise is still a big issue especially for fast acquisition. To address this problem, this paper proposes a noise robust light field reconstruction method. Firstly, scene dependent noise model is studied and incorporated into the light field reconstruction framework. Then, we derive an optimization algorithm for the final reconstruction. We build a prototype by hacking an off-the-shelf camera for data capturing and prove the concept. The effectiveness of this method is validated with experiments on the real captured data.

  9. Versatility of the CFR algorithm for limited angle reconstruction

    SciTech Connect

    Fujieda, I.; Heiskanen, K.; Perez-Mendez, V. )

    1990-04-01

    The constrained Fourier reconstruction (CFR) algorithm and the iterative reconstruction-reprojection (IRR) algorithm are evaluated based on their accuracy for three types of limited angle reconstruction problems. The cFR algorithm performs better for problems such as Xray CT imaging of a nuclear reactor core with one large data gap due to structural blocking of the source and detector pair. For gated heart imaging by Xray CT, radioisotope distribution imaging by PET or SPECT, using a polygonal array of gamma cameras with insensitive gaps between camera boundaries, the IRR algorithm has a slight advantage over the CFR algorithm but the difference is not significant.

  10. Applying image quality in cell phone cameras: lens distortion

    NASA Astrophysics Data System (ADS)

    Baxter, Donald; Goma, Sergio R.; Aleksic, Milivoje

    2009-01-01

    This paper describes the framework used in one of the pilot studies run under the I3A CPIQ initiative to quantify overall image quality in cell-phone cameras. The framework is based on a multivariate formalism which tries to predict overall image quality from individual image quality attributes and was validated in a CPIQ pilot program. The pilot study focuses on image quality distortions introduced in the optical path of a cell-phone camera, which may or may not be corrected in the image processing path. The assumption is that the captured image used is JPEG compressed and the cellphone camera is set to 'auto' mode. As the used framework requires that the individual attributes to be relatively perceptually orthogonal, in the pilot study, the attributes used are lens geometric distortion (LGD) and lateral chromatic aberrations (LCA). The goal of this paper is to present the framework of this pilot project starting with the definition of the individual attributes, up to their quantification in JNDs of quality, a requirement of the multivariate formalism, therefore both objective and subjective evaluations were used. A major distinction in the objective part from the 'DSC imaging world' is that the LCA/LGD distortions found in cell-phone cameras, rarely exhibit radial behavior, therefore a radial mapping/modeling cannot be used in this case.

  11. Camera Calibration for Uav Application Using Sensor of Mobile Camera

    NASA Astrophysics Data System (ADS)

    Takahashi, Y.; Chikatsu, H.

    2015-05-01

    Recently, 3D measurements using small unmanned aerial vehicles (UAVs) have increased in Japan, because small type UAVs is easily available at low cost and the analysis software can be created the easily 3D models. However, small type UAVs have a problem: they have very short flight times and a small payload. In particular, as the payload of a small type UAV increases, its flight time decreases. Therefore, it is advantageous to use lightweight sensors in small type UAVs. A mobile camera is lightweight and has many sensors such as an accelerometer, a magnetic field, and a gyroscope. Moreover, these sensors can be used simultaneously. Therefore, the authors think that the problems of small UAVs can be solved using the mobile camera. The authors executed camera calibration using a test target for evaluating sensor values measured using a mobile camera. Consequently, the authors confirmed the same accuracy with normal camera calibration.

  12. Single-camera, three-dimensional particle tracking velocimetry.

    PubMed

    Peterson, Kevin; Regaard, Boris; Heinemann, Stefan; Sick, Volker

    2012-04-01

    This paper introduces single-camera, three-dimensional particle tracking velocimetry (SC3D-PTV), an image-based, single-camera technique for measuring 3-component, volumetric velocity fields in environments with limited optical access, in particular, optically accessible internal combustion engines. The optical components used for SC3D-PTV are similar to those used for two-camera stereoscopic-µPIV, but are adapted to project two simultaneous images onto a single image sensor. A novel PTV algorithm relying on the similarity of the particle images corresponding to a single, physical particle produces 3-component, volumetric velocity fields, rather than the 3-component, planar results obtained with stereoscopic PIV, and without the reconstruction of an instantaneous 3D particle field. The hardware and software used for SC3D-PTV are described, and experimental results are presented. PMID:22513613

  13. Observation of Marine Animals Using Underwater Acoustic Camera

    NASA Astrophysics Data System (ADS)

    Iida, Kohji; Takahashi, Rika; Tang, Yong; Mukai, Tohru; Sato, Masanori

    2006-05-01

    An underwater acoustic camera enclosed in a pressure-resistant case was constructed to observe underwater marine animals. This enabled the measurement of the size, shape, and behavior of living marine animals in the detection range up to 240 cm. The transducer array of the acoustic camera was driven by 3.5 MHz ultrasonic signals, and B-mode acoustic images were obtained. Observations were conducted for captive animals in a water tank and for natural animals in a field. The captive animals, including fish, squid and jellyfish, were observed, and a three-dimensional internal structure of animals was reconstructed using multiple acoustical images. The most important contributors of acoustic scattering were the swimbladder and vertebra of bladdered fish, and the liver and reproductive organs of invertebrate animals. In a field experiment, the shape, size, and swimming behavior of wild animals were observed. The possibilities and limitations of the underwater acoustic camera for fishery applications were discussed.

  14. Using television cameras to measure emittance

    SciTech Connect

    Ross, M.

    1984-09-25

    Since the luminosity in a linear collider depends on the horizontal and vertical emittance (epsilon/sub x/, epsilon/sub y/) as 1/..sqrt..(epsilon/sub x/epsilon/sub y/) a possible method for improving the performance would be to decrease one or both of these numbers. Once this has been done in a damping ring for example, great care must be taken to avoid effective emittance growth in the remainder of the collider. Therefore an effort should be made to measure epsilon, (x and y), as accurately as possible, both during machine development and operationally. One technique used for measuring epsilon is to insert a luminescent screen in the path of the beam and measure the size of the spot of light made as the beam passes with a television camera and some associated electronics. This has advantages over sampling type techniques (such as wire scanners) because it provides full pulse to pulse two-dimensional information.

  15. Auto-preview camera orientation for environment perception on a mobile robot

    NASA Astrophysics Data System (ADS)

    Radovnikovich, Micho; Vempaty, Pavan K.; Cheok, Ka C.

    2010-01-01

    Using wide-angle or omnidirectional camera lenses to increase a mobile robot's field of view introduces nonlinearity in the image due to the 'fish-eye' effect. This complicates distance perception, and increases image processing overhead. Using multiple cameras avoids the fish-eye complications, but involves using more electrical and processing power to interface them to a computer. Being able to control the orientation of a single camera, both of these disadvantages are minimized while still allowing the robot to preview a wider area. In addition, controlling the orientation allows the robot to optimize its environment perception by only looking where the most useful information can be discovered. In this paper, a technique is presented that creates a two dimensional map of objects of interest surrounding a mobile robot equipped with a panning camera on a telescoping shaft. Before attempting to negotiate a difficult path planning situation, the robot takes snapshots at different camera heights and pan angles and then produces a single map of the surrounding area. Distance perception is performed by making calibration measurements of the camera and applying coordinate transformations to project the camera's findings into the vehicle's coordinate frame. To test the system, obstacles and lines were placed to form a chicane. Several snapshots were taken with different camera orientations, and the information from each were stitched together to yield a very useful map of the surrounding area for the robot to use to plan a path through the chicane.

  16. Spectral image reconstruction through the PCA transform

    NASA Astrophysics Data System (ADS)

    Ma, Long; Qiu, Xuewei; Cong, Yangming

    2015-12-01

    Digital color image reproduction based on spectral information has become a field of much interest and practical importance in recent years. The representation of color in digital form with multi-band images is not very accurate, hence the use of spectral image is justified. Reconstructing high-dimensional spectral reflectance images from relatively low-dimensional camera signals is generally an ill-posed problem. The aim of this study is to use the Principal component analysis (PCA) transform in spectral reflectance images reconstruction. The performance is evaluated by the mean, median and standard deviation of color difference values. The values of mean, median and standard deviation of root mean square (GFC) errors between the reconstructed and the actual spectral image were also calculated. Simulation experiments conducted on a six-channel camera system and on spectral test images show the performance of the suggested method.

  17. The effect of acquisition interval and spatial resolution on dynamic cardiac imaging with a stationary SPECT camera.

    PubMed

    Roberts, J; Maddula, R; Clackdoyle, R; DiBella, E; Fu, Z

    2007-08-01

    The current SPECT scanning paradigm that acquires images by slow rotation of multiple detectors in body-contoured orbits around the patient is not suited to the rapid collection of tomographically complete data. During rapid image acquisition, mechanical and patient safety constraints limit the detector orbit to circular paths at increased distances from the patient, resulting in decreased spatial resolution. We consider a novel dynamic rotating slant-hole (DyRoSH) SPECT camera that can collect full tomographic data every 2 s, employing three stationary detectors mounted with slant-hole collimators that rotate at 30 rpm. Because the detectors are stationary, they can be placed much closer to the patient than is possible with conventional SPECT systems. We propose that the decoupling of the detector position from the mechanics of rapid image acquisition offers an additional degree of freedom which can be used to improve accuracy in measured kinetic parameter estimates. With simulations and list-mode reconstructions, we consider the effects of different acquisition intervals on dynamic cardiac imaging, comparing a conventional three detector SPECT system with the proposed DyRoSH SPECT system. Kinetic parameters of a two-compartment model of myocardial perfusion for technetium-99m-teboroxime were estimated. When compared to a conventional SPECT scanner for the same acquisition periods, the proposed DyRoSH system shows equivalent or reduced bias or standard deviation values for the kinetic parameter estimates. The DyRoSH camera with a 2 s acquisition period does not show any improvement compared to a DyRoSH camera with a 10 s acquisition period. PMID:17634648

  18. Stability Analysis for a Multi-Camera Photogrammetric System

    PubMed Central

    Habib, Ayman; Detchev, Ivan; Kwak, Eunju

    2014-01-01

    Consumer-grade digital cameras suffer from geometrical instability that may cause problems when used in photogrammetric applications. This paper provides a comprehensive review of this issue of interior orientation parameter variation over time, it explains the common ways used for coping with the issue, and describes the existing methods for performing stability analysis for a single camera. The paper then points out the lack of coverage of stability analysis for multi-camera systems, suggests a modification of the collinearity model to be used for the calibration of an entire photogrammetric system, and proposes three methods for system stability analysis. The proposed methods explore the impact of the changes in interior orientation and relative orientation/mounting parameters on the reconstruction process. Rather than relying on ground truth in real datasets to check the system calibration stability, the proposed methods are simulation-based. Experiment results are shown, where a multi-camera photogrammetric system was calibrated three times, and stability analysis was performed on the system calibration parameters from the three sessions. The proposed simulation-based methods provided results that were compatible with a real-data based approach for evaluating the impact of changes in the system calibration parameters on the three-dimensional reconstruction. PMID:25196012

  19. Digital Cameras for Student Use.

    ERIC Educational Resources Information Center

    Simpson, Carol

    1997-01-01

    Describes the features, equipment and operations of digital cameras and compares three different digital cameras for use in education. Price, technology requirements, features, transfer software, and accessories for the Kodak DC25, Olympus D-200L and Casio QV-100 are presented in a comparison table. (AEF)

  20. The "All Sky Camera Network"

    ERIC Educational Resources Information Center

    Caldwell, Andy

    2005-01-01

    In 2001, the "All Sky Camera Network" came to life as an outreach program to connect the Denver Museum of Nature and Science (DMNS) exhibit "Space Odyssey" with Colorado schools. The network is comprised of cameras placed strategically at schools throughout Colorado to capture fireballs--rare events that produce meteorites. Meteorites have great…

  1. An Educational PET Camera Model

    ERIC Educational Resources Information Center

    Johansson, K. E.; Nilsson, Ch.; Tegner, P. E.

    2006-01-01

    Positron emission tomography (PET) cameras are now in widespread use in hospitals. A model of a PET camera has been installed in Stockholm House of Science and is used to explain the principles of PET to school pupils as described here.

  2. Radiation camera motion correction system

    DOEpatents

    Hoffer, P.B.

    1973-12-18

    The device determines the ratio of the intensity of radiation received by a radiation camera from two separate portions of the object. A correction signal is developed to maintain this ratio at a substantially constant value and this correction signal is combined with the camera signal to correct for object motion. (Official Gazette)

  3. SEOS frame camera applications study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A research and development satellite is discussed which will provide opportunities for observation of transient phenomena that fall within the fixed viewing circle of the spacecraft. The evaluation of possible applications for frame cameras, for SEOS, are studied. The computed lens characteristics for each camera are listed.

  4. Airborne ballistic camera tracking systems

    NASA Technical Reports Server (NTRS)

    Redish, W. L.

    1976-01-01

    An operational airborne ballistic camera tracking system was tested for operational and data reduction feasibility. The acquisition and data processing requirements of the system are discussed. Suggestions for future improvements are also noted. A description of the data reduction mathematics is outlined. Results from a successful reentry test mission are tabulated. The test mission indicated that airborne ballistic camera tracking systems are feasible.

  5. Multi-PSPMT scintillation camera

    SciTech Connect

    Pani, R.; Pellegrini, R.; Trotta, G.; Scopinaro, F.; Soluri, A.; Vincentis, G. de; Scafe, R.; Pergola, A.

    1999-06-01

    Gamma ray imaging is usually accomplished by the use of a relatively large scintillating crystal coupled to either a number of photomultipliers (PMTs) (Anger Camera) or to a single large Position Sensitive PMT (PSPMT). Recently the development of new diagnostic techniques, such as scintimammography and radio-guided surgery, have highlighted a number of significant limitations of the Anger camera in such imaging procedures. In this paper a dedicated gamma camera is proposed for clinical applications with the aim of improving image quality by utilizing detectors with an appropriate size and shape for the part of the body under examination. This novel scintillation camera is based upon an array of PSPMTs (Hamamatsu R5900-C8). The basic concept of this camera is identical to the Anger Camera with the exception of the substitution of PSPMTs for the PMTs. In this configuration it is possible to use the high resolution of the PSPMTs and still correctly position events lying between PSPMTs. In this work the test configuration is a 2 by 2 array of PSPMTs. Some advantages of this camera are: spatial resolution less than 2 mm FWHM, good linearity, thickness less than 3 cm, light weight, lower cost than equivalent area PSPMT, large detection area when coupled to scintillating arrays, small dead boundary zone (< 3 mm) and flexibility in the shape of the camera.

  6. Mars Exploration Rover engineering cameras

    USGS Publications Warehouse

    Maki, J.N.; Bell, J.F., III; Herkenhoff, K. E.; Squyres, S. W.; Kiely, A.; Klimesh, M.; Schwochert, M.; Litwin, T.; Willson, R.; Johnson, Aaron H.; Maimone, M.; Baumgartner, E.; Collins, A.; Wadsworth, M.; Elliot, S.T.; Dingizian, A.; Brown, D.; Hagerott, E.C.; Scherr, L.; Deen, R.; Alexander, D.; Lorre, J.

    2003-01-01

    NASA's Mars Exploration Rover (MER) Mission will place a total of 20 cameras (10 per rover) onto the surface of Mars in early 2004. Fourteen of the 20 cameras are designated as engineering cameras and will support the operation of the vehicles on the Martian surface. Images returned from the engineering cameras will also be of significant importance to the scientific community for investigative studies of rock and soil morphology. The Navigation cameras (Navcams, two per rover) are a mast-mounted stereo pair each with a 45?? square field of view (FOV) and an angular resolution of 0.82 milliradians per pixel (mrad/pixel). The Hazard Avoidance cameras (Hazcams, four per rover) are a body-mounted, front- and rear-facing set of stereo pairs, each with a 124?? square FOV and an angular resolution of 2.1 mrad/pixel. The Descent camera (one per rover), mounted to the lander, has a 45?? square FOV and will return images with spatial resolutions of ???4 m/pixel. All of the engineering cameras utilize broadband visible filters and 1024 x 1024 pixel detectors. Copyright 2003 by the American Geophysical Union.

  7. Computational photography with plenoptic camera and light field capture: tutorial.

    PubMed

    Lam, Edmund Y

    2015-11-01

    Photography is a cornerstone of imaging. Ever since cameras became consumer products more than a century ago, we have witnessed great technological progress in optics and recording mediums, with digital sensors replacing photographic films in most instances. The latest revolution is computational photography, which seeks to make image reconstruction computation an integral part of the image formation process; in this way, there can be new capabilities or better performance in the overall imaging system. A leading effort in this area is called the plenoptic camera, which aims at capturing the light field of an object; proper reconstruction algorithms can then adjust the focus after the image capture. In this tutorial paper, we first illustrate the concept of plenoptic function and light field from the perspective of geometric optics. This is followed by a discussion on early attempts and recent advances in the construction of the plenoptic camera. We will then describe the imaging model and computational algorithms that can reconstruct images at different focus points, using mathematical tools from ray optics and Fourier optics. Last, but not least, we will consider the trade-off in spatial resolution and highlight some research work to increase the spatial resolution of the resulting images. PMID:26560916

  8. LISS-4 camera for Resourcesat

    NASA Astrophysics Data System (ADS)

    Paul, Sandip; Dave, Himanshu; Dewan, Chirag; Kumar, Pradeep; Sansowa, Satwinder Singh; Dave, Amit; Sharma, B. N.; Verma, Anurag

    2006-12-01

    The Indian Remote Sensing Satellites use indigenously developed high resolution cameras for generating data related to vegetation, landform /geomorphic and geological boundaries. This data from this camera is used for working out maps at 1:12500 scale for national level policy development for town planning, vegetation etc. The LISS-4 Camera was launched onboard Resourcesat-1 satellite by ISRO in 2003. LISS-4 is a high-resolution multi-spectral camera with three spectral bands and having a resolution of 5.8m and swath of 23Km from 817 Km altitude. The panchromatic mode provides a swath of 70Km and 5-day revisit. This paper briefly discusses the configuration of LISS-4 Camera of Resourcesat-1, its onboard performance and also the changes in the Camera being developed for Resourcesat-2. LISS-4 camera images the earth in push-broom mode. It is designed around a three mirror un-obscured telescope, three linear 12-K CCDs and associated electronics for each band. Three spectral bands are realized by splitting the focal plane in along track direction using an isosceles prism. High-speed Camera Electronics is designed for each detector with 12- bit digitization and digital double sampling of video. Seven bit data selected from 10 MSBs data by Telecommand is transmitted. The total dynamic range of the sensor covers up to 100% albedo. The camera structure has heritage of IRS- 1C/D. The optical elements are precisely glued to specially designed flexure mounts. The camera is assembled onto a rotating deck on spacecraft to facilitate +/- 26° steering in Pitch-Yaw plane. The camera is held on spacecraft in a stowed condition before deployment. The excellent imageries from LISS-4 Camera onboard Resourcesat-1 are routinely used worldwide. Such second Camera is being developed for Resourcesat-2 launch in 2007 with similar performance. The Camera electronics is optimized and miniaturized. The size and weight are reduced to one third and the power to half of the values in Resourcesat

  9. Improving image quality in compressed ultrafast photography with a space- and intensity-constrained reconstruction algorithm

    NASA Astrophysics Data System (ADS)

    Zhu, Liren; Chen, Yujia; Liang, Jinyang; Gao, Liang; Ma, Cheng; Wang, Lihong V.

    2016-03-01

    The single-shot compressed ultrafast photography (CUP) camera is the fastest receive-only camera in the world. In this work, we introduce an external CCD camera and a space- and intensity-constrained (SIC) reconstruction algorithm to improve the image quality of CUP. The CCD camera takes a time-unsheared image of the dynamic scene. Unlike the previously used unconstrained algorithm, the proposed algorithm incorporates both spatial and intensity constraints, based on the additional prior information provided by the external CCD camera. First, a spatial mask is extracted from the time-unsheared image to define the zone of action. Second, an intensity threshold constraint is determined based on the similarity between the temporally projected image of the reconstructed datacube and the time-unsheared image taken by the external CCD. Both simulation and experimental studies showed that the SIC reconstruction improves the spatial resolution, contrast, and general quality of the reconstructed image.

  10. Camera array based light field microscopy.

    PubMed

    Lin, Xing; Wu, Jiamin; Zheng, Guoan; Dai, Qionghai

    2015-09-01

    This paper proposes a novel approach for high-resolution light field microscopy imaging by using a camera array. In this approach, we apply a two-stage relay system for expanding the aperture plane of the microscope into the size of an imaging lens array, and utilize a sensor array for acquiring different sub-apertures images formed by corresponding imaging lenses. By combining the rectified and synchronized images from 5 × 5 viewpoints with our prototype system, we successfully recovered color light field videos for various fast-moving microscopic specimens with a spatial resolution of 0.79 megapixels at 30 frames per second, corresponding to an unprecedented data throughput of 562.5 MB/s for light field microscopy. We also demonstrated the use of the reported platform for different applications, including post-capture refocusing, phase reconstruction, 3D imaging, and optical metrology. PMID:26417490

  11. Camera array based light field microscopy

    PubMed Central

    Lin, Xing; Wu, Jiamin; Zheng, Guoan; Dai, Qionghai

    2015-01-01

    This paper proposes a novel approach for high-resolution light field microscopy imaging by using a camera array. In this approach, we apply a two-stage relay system for expanding the aperture plane of the microscope into the size of an imaging lens array, and utilize a sensor array for acquiring different sub-apertures images formed by corresponding imaging lenses. By combining the rectified and synchronized images from 5 × 5 viewpoints with our prototype system, we successfully recovered color light field videos for various fast-moving microscopic specimens with a spatial resolution of 0.79 megapixels at 30 frames per second, corresponding to an unprecedented data throughput of 562.5 MB/s for light field microscopy. We also demonstrated the use of the reported platform for different applications, including post-capture refocusing, phase reconstruction, 3D imaging, and optical metrology. PMID:26417490

  12. A method for measuring aircraft height and velocity using dual television cameras

    NASA Technical Reports Server (NTRS)

    Young, W. R.

    1977-01-01

    A unique electronic optical technique, consisting of two closed circuit television cameras and timing electronics, was devised to measure an aircraft's horizontal velocity and height above ground without the need for airborne cooperative devices. The system is intended to be used where the aircraft has a predictable flight path and a height of less than 660 meters (2,000 feet) at or near the end of an air terminal runway, but is suitable for greater aircraft altitudes whenever the aircraft remains visible. Two television cameras, pointed at zenith, are placed in line with the expected path of travel of the aircraft. Velocity is determined by measuring the time it takes the aircraft to travel the measured distance between cameras. Height is determined by correlating this speed with the time required to cross the field of view of either camera. Preliminary tests with a breadboard version of the system and a small model aircraft indicate the technique is feasible.

  13. Time-of-Flight Microwave Camera

    NASA Astrophysics Data System (ADS)

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-10-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable “stealth” regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows “camera-like” behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum.

  14. Time-of-Flight Microwave Camera

    PubMed Central

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-01-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable “stealth” regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz–12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows “camera-like” behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum. PMID:26434598

  15. Time-of-Flight Microwave Camera.

    PubMed

    Charvat, Gregory; Temme, Andrew; Feigin, Micha; Raskar, Ramesh

    2015-01-01

    Microwaves can penetrate many obstructions that are opaque at visible wavelengths, however microwave imaging is challenging due to resolution limits associated with relatively small apertures and unrecoverable "stealth" regions due to the specularity of most objects at microwave frequencies. We demonstrate a multispectral time-of-flight microwave imaging system which overcomes these challenges with a large passive aperture to improve lateral resolution, multiple illumination points with a data fusion method to reduce stealth regions, and a frequency modulated continuous wave (FMCW) receiver to achieve depth resolution. The camera captures images with a resolution of 1.5 degrees, multispectral images across the X frequency band (8 GHz-12 GHz), and a time resolution of 200 ps (6 cm optical path in free space). Images are taken of objects in free space as well as behind drywall and plywood. This architecture allows "camera-like" behavior from a microwave imaging system and is practical for imaging everyday objects in the microwave spectrum. PMID:26434598

  16. IMAX camera (12-IML-1)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The IMAX camera system is used to record on-orbit activities of interest to the public. Because of the extremely high resolution of the IMAX camera, projector, and audio systems, the audience is afforded a motion picture experience unlike any other. IMAX and OMNIMAX motion picture systems were designed to create motion picture images of superior quality and audience impact. The IMAX camera is a 65 mm, single lens, reflex viewing design with a 15 perforation per frame horizontal pull across. The frame size is 2.06 x 2.77 inches. Film travels through the camera at a rate of 336 feet per minute when the camera is running at the standard 24 frames/sec.

  17. Coherent infrared imaging camera (CIRIC)

    SciTech Connect

    Hutchinson, D.P.; Simpson, M.L.; Bennett, C.A.; Richards, R.K.; Emery, M.S.; Crutcher, R.I.; Sitter, D.N. Jr.; Wachter, E.A.; Huston, M.A.

    1995-07-01

    New developments in 2-D, wide-bandwidth HgCdTe (MCT) and GaAs quantum-well infrared photodetectors (QWIP) coupled with Monolithic Microwave Integrated Circuit (MMIC) technology are now making focal plane array coherent infrared (IR) cameras viable. Unlike conventional IR cameras which provide only thermal data about a scene or target, a coherent camera based on optical heterodyne interferometry will also provide spectral and range information. Each pixel of the camera, consisting of a single photo-sensitive heterodyne mixer followed by an intermediate frequency amplifier and illuminated by a separate local oscillator beam, constitutes a complete optical heterodyne receiver. Applications of coherent IR cameras are numerous and include target surveillance, range detection, chemical plume evolution, monitoring stack plume emissions, and wind shear detection.

  18. CCD Camera Observations

    NASA Astrophysics Data System (ADS)

    Buchheim, Bob; Argyle, R. W.

    One night late in 1918, astronomer William Milburn, observing the region of Cassiopeia from Reverend T.H.E.C. Espin's observatory in Tow Law (England), discovered a hitherto unrecorded double star (Wright 1993). He reported it to Rev. Espin, who measured the pair using his 24-in. reflector: the fainter star was 6.0 arcsec from the primary, at position angle 162.4 ^{circ } (i.e. the fainter star was south-by-southeast from the primary) (Espin 1919). Some time later, it was recognized that the astrograph of the Vatican Observatory had taken an image of the same star-field a dozen years earlier, in late 1906. At that earlier epoch, the fainter star had been separated from the brighter one by only 4.8 arcsec, at position angle 186.2 ^{circ } (i.e. almost due south). Were these stars a binary pair, or were they just two unrelated stars sailing past each other? Some additional measurements might have begun to answer this question. If the secondary star was following a curved path, that would be a clue of orbital motion; if it followed a straight-line path, that would be a clue that these are just two stars passing in the night. Unfortunately, nobody took the trouble to re-examine this pair for almost a century, until the 2MASS astrometric/photometric survey recorded it in late 1998. After almost another decade, this amateur astronomer took some CCD images of the field in 2007, and added another data point on the star's trajectory, as shown in Fig. 15.1.

  19. Proportional counter radiation camera

    DOEpatents

    Borkowski, C.J.; Kopp, M.K.

    1974-01-15

    A gas-filled proportional counter camera that images photon emitting sources is described. A two-dimensional, positionsensitive proportional multiwire counter is provided as the detector. The counter consists of a high- voltage anode screen sandwiched between orthogonally disposed planar arrays of multiple parallel strung, resistively coupled cathode wires. Two terminals from each of the cathode arrays are connected to separate timing circuitry to obtain separate X and Y coordinate signal values from pulse shape measurements to define the position of an event within the counter arrays which may be recorded by various means for data display. The counter is further provided with a linear drift field which effectively enlarges the active gas volume of the counter and constrains the recoil electrons produced from ionizing radiation entering the counter to drift perpendicularly toward the planar detection arrays. A collimator is interposed between a subject to be imaged and the counter to transmit only the radiation from the subject which has a perpendicular trajectory with respect to the planar cathode arrays of the detector. (Official Gazette)

  20. Cameras for digital microscopy.

    PubMed

    Spring, Kenneth R

    2013-01-01

    This chapter reviews the fundamental characteristics of charge-coupled devices (CCDs) and related detectors, outlines the relevant parameters for their use in microscopy, and considers promising recent developments in the technology of detectors. Electronic imaging with a CCD involves three stages--interaction of a photon with the photosensitive surface, storage of the liberated charge, and readout or measurement of the stored charge. The most demanding applications in fluorescence microscopy may require as much as four orders of greater magnitude sensitivity. The image in the present-day light microscope is usually acquired with a CCD camera. The CCD is composed of a large matrix of photosensitive elements (often referred to as "pixels" shorthand for picture elements, which simultaneously capture an image over the entire detector surface. The light-intensity information for each pixel is stored as electronic charge and is converted to an analog voltage by a readout amplifier. This analog voltage is subsequently converted to a numerical value by a digitizer situated on the CCD chip, or very close to it. Several (three to six) amplifiers are required for each pixel, and to date, uniform images with a homogeneous background have been a problem because of the inherent difficulties of balancing the gain in all of the amplifiers. Complementary metal oxide semiconductor sensors also exhibit relatively high noise associated with the requisite high-speed switching. Both of these deficiencies are being addressed, and sensor performance is nearing that required for scientific imaging. PMID:23931507

  1. Lights, Camera, Courtroom? Should Trials Be Televised?

    ERIC Educational Resources Information Center

    Kirtley, Jane E.; Brothers, Thomas W.; Veal, Harlan K.

    1999-01-01

    Presents three differing perspectives from American Bar Association members on whether television cameras should be allowed in the courtroom. Contends that cameras should be allowed with differing degrees of certainty: cameras truly open the courts to the public; cameras must be strategically placed; and cameras should be used only with the…

  2. The infrared camera onboard JEM-EUSO

    NASA Astrophysics Data System (ADS)

    Adams, J. H.; Ahmad, S.; Albert, J.-N.; Allard, D.; Anchordoqui, L.; Andreev, V.; Anzalone, A.; Arai, Y.; Asano, K.; Ave Pernas, M.; Baragatti, P.; Barrillon, P.; Batsch, T.; Bayer, J.; Bechini, R.; Belenguer, T.; Bellotti, R.; Belov, K.; Berlind, A. A.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Blaksley, C.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Blümer, J.; Bobik, P.; Bogomilov, M.; Bonamente, M.; Briggs, M. S.; Briz, S.; Bruno, A.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellinic, G.; Catalano, C.; Catalano, G.; Cellino, A.; Chikawa, M.; Christl, M. J.; Cline, D.; Connaughton, V.; Conti, L.; Cordero, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Dagoret-Campagne, S.; de Castro, A. J.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Dell'Oro, A.; De Simone, N.; Di Martino, M.; Distratis, G.; Dulucq, F.; Dupieux, M.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Falk, S.; Fang, K.; Fenu, F.; Fernández-Gómez, I.; Ferrarese, S.; Finco, D.; Flamini, M.; Fornaro, C.; Franceschi, A.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; Garipov, G.; Geary, J.; Gelmini, G.; Giraudo, G.; Gonchar, M.; González Alvarado, C.; Gorodetzky, P.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Higashide, K.; Ikeda, D.; Ikeda, H.; Inoue, N.; Inoue, S.; Insolia, A.; Isgrò, F.; Itow, Y.; Joven, E.; Judd, E. G.; Jung, A.; Kajino, F.; Kajino, T.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Karus, M.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Keilhauer, B.; Khrenov, B. A.; Kim, J.-S.; Kim, S.-W.; Kim, S.-W.; Kleifges, M.; Klimov, P. A.; Kolev, D.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; Lacombe, M.; Lachaud, C.; Lee, J.; Licandro, J.; Lim, H.; López, F.; Maccarone, M. C.; Mannheim, K.; Maravilla, D.; Marcelli, L.; Marini, A.; Martinez, O.; Masciantonio, G.; Mase, K.; Matev, R.; Medina-Tanco, G.; Mernik, T.; Miyamoto, H.; Miyazaki, Y.; Mizumoto, Y.; Modestino, G.; Monaco, A.; Monnier-Ragaigne, D.; Morales de los Ríos, J. A.; Moretto, C.; Morozenko, V. S.; Mot, B.; Murakami, T.; Murakami, M. Nagano; Nagata, M.; Nagataki, S.; Nakamura, T.; Napolitano, T.; Naumov, D.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Panasyuk, M. I.; Parizot, E.; Park, I. H.; Park, H. W.; Pastircak, B.; Patzak, T.; Paul, T.; Pennypacker, C.; Perez Cano, S.; Peter, T.; Picozza, P.; Pierog, T.; Piotrowski, L. W.; Piraino, S.; Plebaniak, Z.; Pollini, A.; Prat, P.; Prévôt, G.; Prieto, H.; Putis, M.; Reardon, P.; Reyes, M.; Ricci, M.; Rodríguez, I.; Rodríguez Frías, M. D.; Ronga, F.; Roth, M.; Rothkaehl, H.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez-Cano, G.; Sagawa, H.; Saito, A.; Sakaki, N.; Sakata, M.; Salazar, H.; Sánchez, S.; Santangelo, A.; Santiago Crúz, L.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, H.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Segreto, A.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shibata, T.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Siemieniec-Oziȩbło, G.; Silva López, H. H.; Sledd, J.; Słomińska, K.; Sobey, A.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, F.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Tenzer, C.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Trillaud, F.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tymieniecka, T.; Uchihori, Y.; Unger, M.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Valore, L.; Vankova, G.; Vigorito, C.; Villaseñor, L.; von Ballmoos, P.; Wada, S.; Watanabe, J.; Watanabe, S.; Watts, J.; Weber, M.; Weiler, T. J.; Wibig, T.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yamamoto, Y.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, K.; Yoshida, S.; Young, R.; Zotov, M. Yu.; Zuccaro Marchi, A.

    2015-11-01

    The Extreme Universe Space Observatory on the Japanese Experiment Module (JEM-EUSO) on board the International Space Station (ISS) is the first space-based mission worldwide in the field of Ultra High-Energy Cosmic Rays (UHECR). For UHECR experiments, the atmosphere is not only the showering calorimeter for the primary cosmic rays, it is an essential part of the readout system, as well. Moreover, the atmosphere must be calibrated and has to be considered as input for the analysis of the fluorescence signals. Therefore, the JEM-EUSO Space Observatory is implementing an Atmospheric Monitoring System (AMS) that will include an IR-Camera and a LIDAR. The AMS Infrared Camera is an infrared, wide FoV, imaging system designed to provide the cloud coverage along the JEM-EUSO track and the cloud top height to properly achieve the UHECR reconstruction in cloudy conditions. In this paper, an updated preliminary design status, the results from the calibration tests of the first prototype, the simulation of the instrument, and preliminary cloud top height retrieval algorithms are presented.

  3. Process simulation in digital camera system

    NASA Astrophysics Data System (ADS)

    Toadere, Florin

    2012-06-01

    The goal of this paper is to simulate the functionality of a digital camera system. The simulations cover the conversion from light to numerical signal and the color processing and rendering. We consider the image acquisition system to be linear shift invariant and axial. The light propagation is orthogonal to the system. We use a spectral image processing algorithm in order to simulate the radiometric properties of a digital camera. In the algorithm we take into consideration the transmittances of the: light source, lenses, filters and the quantum efficiency of a CMOS (complementary metal oxide semiconductor) sensor. The optical part is characterized by a multiple convolution between the different points spread functions of the optical components. We use a Cooke triplet, the aperture, the light fall off and the optical part of the CMOS sensor. The electrical part consists of the: Bayer sampling, interpolation, signal to noise ratio, dynamic range, analog to digital conversion and JPG compression. We reconstruct the noisy blurred image by blending different light exposed images in order to reduce the photon shot noise, also we filter the fixed pattern noise and we sharpen the image. Then we have the color processing blocks: white balancing, color correction, gamma correction, and conversion from XYZ color space to RGB color space. For the reproduction of color we use an OLED (organic light emitting diode) monitor. The analysis can be useful to assist students and engineers in image quality evaluation and imaging system design. Many other configurations of blocks can be used in our analysis.

  4. Reconstructing Validity

    ERIC Educational Resources Information Center

    Moss, Pamela A.

    2007-01-01

    In response to Lissitz and Samuelsen (2007), the author reconstructs the historical arguments for the more comprehensive unitary concept of validity and the principles of scientific inquiry underlying it. Her response is organized in terms of four questions: (a) How did validity in educational measurement come to be conceptualized as unitary, and…

  5. Vaginal reconstruction

    SciTech Connect

    Lesavoy, M.A.

    1985-05-01

    Vaginal reconstruction can be an uncomplicated and straightforward procedure when attention to detail is maintained. The Abbe-McIndoe procedure of lining the neovaginal canal with split-thickness skin grafts has become standard. The use of the inflatable Heyer-Schulte vaginal stent provides comfort to the patient and ease to the surgeon in maintaining approximation of the skin graft. For large vaginal and perineal defects, myocutaneous flaps such as the gracilis island have been extremely useful for correction of radiation-damaged tissue of the perineum or for the reconstruction of large ablative defects. Minimal morbidity and scarring ensue because the donor site can be closed primarily. With all vaginal reconstruction, a compliant patient is a necessity. The patient must wear a vaginal obturator for a minimum of 3 to 6 months postoperatively and is encouraged to use intercourse as an excellent obturator. In general, vaginal reconstruction can be an extremely gratifying procedure for both the functional and emotional well-being of patients.

  6. Project Reconstruct.

    ERIC Educational Resources Information Center

    Helisek, Harriet; Pratt, Donald

    1994-01-01

    Presents a project in which students monitor their use of trash, input and analyze information via a database and computerized graphs, and "reconstruct" extinct or endangered animals from recyclable materials. The activity was done with second-grade students over a period of three to four weeks. (PR)

  7. Hi-G electronic gated camera for precision trajectory analysis

    NASA Astrophysics Data System (ADS)

    Snyder, Donald R.; Payne, Scott; Keller, Ed; Longo, Salvatore; Caudle, Dennis E.; Walker, Dennis C.; Sartor, Mark A.; Keeler, Joe E.; Kerr, David A.; Fail, R. Wallace; Gannon, Jim; Carrol, Ernie; Jamison, Todd A.

    1997-12-01

    trajectory, timing, and advanced sensor development. This system will be used for ground tracking data reduction in support of small air vehicle and munition testing. It will provide a means of integrating the imagery and telemetry data from the item with ground based photographic support. The technique we have designed will exploit off-the-shelf software and analysis components. A differential GPS survey instrument will establish a photogrammetric calibration grid throughout the range and reference targets along the flight path. Images from the on-board sensor will be used to calibrate the ortho- rectification model in the analysis software. The projectile images will be transmitted and recorded on several tape recorders to insure complete capture of each video field. The images will be combined with a non-linear video editor into a time-correlated record. Each correlated video field will be written to video disk. The files will be converted to DMA compatible format and then analyzed for determination of the projectile altitude, attitude and position in space. The resulting data file will be used to create a photomosaic of the ground the projectile flew over and the targets it saw. The data will be then transformed to a trajectory file and used to generate a graphic overlay that will merge digital photo data of the range with actual images captured. The plan is to superimpose the flight path of the projectile, the path of the weapons aimpoint, and annotation of each internal sequence event. With tools used to produce state-of-the-art computer graphics, we now think it will be possible to reconstruct the test event from the viewpoint of the warhead, the target, and a 'God's-Eye' view looking over the shoulder of the projectile.

  8. Detection of the optimal region of interest for camera oximetry.

    PubMed

    Karlen, Walter; Ansermino, J Mark; Dumont, Guy A; Scheffer, Cornie

    2013-01-01

    The estimation of heart rate and blood oxygen saturation with an imaging array on a mobile phone (camera oximetry) has great potential for mobile health applications as no additional hardware other than a camera and LED flash enabled phone are required. However, this approach is challenging as the configuration of the camera can negatively influence the estimation quality. Further, the number of photons recorded with the photo detector is largely dependent on the optical path length, resulting in a non-homogeneous image. In this paper we describe a novel method to automatically detect the optimal region of interest (ROI) for the captured image to extract a pulse waveform. We also present a study to select the optimal camera settings, notably the white balance. The experiments show that the incandescent white balance mode is the preferable setting for camera oximetry applications on the tested mobile phone (Samsung Galaxy Ace). Also, the ROI algorithm successfully identifies the frame regions which provide waveforms with the largest amplitudes. PMID:24110175

  9. Thermal design and flight validation for high precision camera

    NASA Astrophysics Data System (ADS)

    Meng, Henghui; Sun, Lixia; Zhang, Chuanqiang; Geng, Liyin

    2015-10-01

    High precision camera, designed for advanced optical system, with a wide field of vision, high resolution and fast response, has a wild range of applications. As the main payload for spacecraft, the optical remote sensor is mounted exposed to the space, which means it should have a reliable optical performance in harsh space environment during lifetime. Because of the special optical characteristic, imaging path should be accurate, and less thermal deformation for the optical parts is required in the working process, so the high precision camera has a high level requirement for temperature. High resolution space camera is generally required to own the capability of adapting to space thermal environments. The flexible satellite's change of rolling attitude affects the temperature distribution of the camera and makes a difference to optical performance. The thermal control design of space camera is presented, and analysis the temperature data in orbit to prove the thermal design correct. It is proved that the rolling attitude has more influence on outer parts and less influence on inner parts, and active thermal control can weaken the influence of rolling attitude.

  10. ACL reconstruction - discharge

    MedlinePlus

    Anterior cruciate ligament reconstruction - discharge; ACL reconstruction - discharge ... had surgery to reconstruct your anterior cruciate ligament (ACL). The surgeon drilled holes in the bones of ...

  11. Cryogenic wafer-level MWIR camera: laboratory demonstration

    NASA Astrophysics Data System (ADS)

    Druart, G.; De La Barrière, F.; Chambon, M.; Guérineau, N.; Lasfargues, G.; Fendler, M.

    2013-06-01

    We present a compact infrared cryogenic multichannel camera with a wide field of view equal to 120°. By merging the optics with the detector, the concept has to be compatible with both cryogenic constraints and wafer-level fabrication. For this, we take advantage of the progress in micro-optics to design a multichannel optical architecture directly integrated on the detector. This wafer-level camera uses state of art microlenses with a high sag height. The additional mass of the optics is sufficiently small to be compatible with the cryogenic environment of the Dewar. The performance of this camera will be discussed. Its characterization has been carried out in terms of modulation transfer function and noise equivalent temperature difference (NETD). The optical system is limited by the diffraction. By cooling the optics, we achieve a very low NETD equal to 15 mK compared with traditional infrared cameras. A postprocessing algorithm that aims at reconstructing a well-sampled image from the set of undersampled raw subimages produced by the camera is proposed and validated on experimental images.

  12. A Path to Discovery

    ERIC Educational Resources Information Center

    Stegemoller, William; Stegemoller, Rebecca

    2004-01-01

    The path taken and the turns made as a turtle traces a polygon are examined to discover an important theorem in geometry. A unique tool, the Angle Adder, is implemented in the investigation. (Contains 9 figures.)

  13. Tortuous path chemical preconcentrator

    DOEpatents

    Manginell, Ronald P.; Lewis, Patrick R.; Adkins, Douglas R.; Wheeler, David R.; Simonson, Robert J.

    2010-09-21

    A non-planar, tortuous path chemical preconcentrator has a high internal surface area having a heatable sorptive coating that can be used to selectively collect and concentrate one or more chemical species of interest from a fluid stream that can be rapidly released as a concentrated plug into an analytical or microanalytical chain for separation and detection. The non-planar chemical preconcentrator comprises a sorptive support structure having a tortuous flow path. The tortuosity provides repeated twists, turns, and bends to the flow, thereby increasing the interfacial contact between sample fluid stream and the sorptive material. The tortuous path also provides more opportunities for desorption and readsorption of volatile species. Further, the thermal efficiency of the tortuous path chemical preconcentrator is comparable or superior to the prior non-planar chemical preconcentrator. Finally, the tortuosity can be varied in different directions to optimize flow rates during the adsorption and desorption phases of operation of the preconcentrator.

  14. Vision Sensors and Cameras

    NASA Astrophysics Data System (ADS)

    Hoefflinger, Bernd

    Silicon charge-coupled-device (CCD) imagers have been and are a specialty market ruled by a few companies for decades. Based on CMOS technologies, active-pixel sensors (APS) began to appear in 1990 at the 1 μm technology node. These pixels allow random access, global shutters, and they are compatible with focal-plane imaging systems combining sensing and first-level image processing. The progress towards smaller features and towards ultra-low leakage currents has provided reduced dark currents and μm-size pixels. All chips offer Mega-pixel resolution, and many have very high sensitivities equivalent to ASA 12.800. As a result, HDTV video cameras will become a commodity. Because charge-integration sensors suffer from a limited dynamic range, significant processing effort is spent on multiple exposure and piece-wise analog-digital conversion to reach ranges >10,000:1. The fundamental alternative is log-converting pixels with an eye-like response. This offers a range of almost a million to 1, constant contrast sensitivity and constant colors, important features in professional, technical and medical applications. 3D retino-morphic stacking of sensing and processing on top of each other is being revisited with sub-100 nm CMOS circuits and with TSV technology. With sensor outputs directly on top of neurons, neural focal-plane processing will regain momentum, and new levels of intelligent vision will be achieved. The industry push towards thinned wafers and TSV enables backside-illuminated and other pixels with a 100% fill-factor. 3D vision, which relies on stereo or on time-of-flight, high-speed circuitry, will also benefit from scaled-down CMOS technologies both because of their size as well as their higher speed.

  15. A liquid xenon radioisotope camera.

    NASA Technical Reports Server (NTRS)

    Zaklad, H.; Derenzo, S. E.; Muller, R. A.; Smadja, G.; Smits, R. G.; Alvarez, L. W.

    1972-01-01

    A new type of gamma-ray camera is discussed that makes use of electron avalanches in liquid xenon and is currently under development. It is shown that such a radioisotope camera promises many advantages over any other existing gamma-ray cameras. Spatial resolution better than 1 mm and counting rates higher than one million C/sec are possible. An energy resolution of 11% FWHM has recently been achieved with a collimated Hg-203 source using a parallel-plate ionization chamber containing a Frisch grid.

  16. Dark energy survey and camera

    SciTech Connect

    William Wester

    2004-08-16

    The authors describe the Dark Energy Survey and Camera. The survey will image 5000 sq. deg. in the southern sky to collect 300 million galaxies, 30,000 galaxy clusters and 2000 Type Ia supernovae. They expect to derive a value for the dark energy equation of state parameters, w, to a precision of 5% by combining four distinct measurement techniques. They describe the mosaic camera that will consist of CCDs with enhanced sensitivity in the near infrared. The camera will be mounted at the prime focus of the 4m Blanco telescope.

  17. Three-dimensional Camera Phone

    NASA Astrophysics Data System (ADS)

    Iizuka, Keigo

    2004-12-01

    An inexpensive technique for realizing a three-dimensional (3D) camera phone display is presented. Light from the liquid-crystal screen of a camera phone is linearly polarized, and its direction of polarization is easily manipulated by a cellophane sheet used as a half-waveplate. The novel 3D camera phone display is made possible solely by optical components without resorting to computation, so that the 3D image is displayed in real time. Quality of the original image is not sacrificed in the process of converting it into a 3D image.

  18. Photogrammetric Accuracy and Modeling of Rolling Shutter Cameras

    NASA Astrophysics Data System (ADS)

    Vautherin, Jonas; Rutishauser, Simon; Schneider-Zapp, Klaus; Choi, Hon Fai; Chovancova, Venera; Glass, Alexis; Strecha, Christoph

    2016-06-01

    Unmanned aerial vehicles (UAVs) are becoming increasingly popular in professional mapping for stockpile analysis, construction site monitoring, and many other applications. Due to their robustness and competitive pricing, consumer UAVs are used more and more for these applications, but they are usually equipped with rolling shutter cameras. This is a significant obstacle when it comes to extracting high accuracy measurements using available photogrammetry software packages. In this paper, we evaluate the impact of the rolling shutter cameras of typical consumer UAVs on the accuracy of a 3D reconstruction. Hereto, we use a beta-version of the Pix4Dmapper 2.1 software to compare traditional (non rolling shutter) camera models against a newly implemented rolling shutter model with respect to both the accuracy of geo-referenced validation points and to the quality of the motion estimation. Multiple datasets have been acquired using popular quadrocopters (DJI Phantom 2 Vision+, DJI Inspire 1 and 3DR Solo) following a grid flight plan. For comparison, we acquired a dataset using a professional mapping drone (senseFly eBee) equipped with a global shutter camera. The bundle block adjustment of each dataset shows a significant accuracy improvement on validation ground control points when applying the new rolling shutter camera model for flights at higher speed (8m=s). Competitive accuracies can be obtained by using the rolling shutter model, although global shutter cameras are still superior. Furthermore, we are able to show that the speed of the drone (and its direction) can be solely estimated from the rolling shutter effect of the camera.

  19. Speckle Camera Imaging of the Planet Pluto

    NASA Astrophysics Data System (ADS)

    Howell, Steve B.; Horch, Elliott P.; Everett, Mark E.; Ciardi, David R.

    2012-10-01

    We have obtained optical wavelength (692 nm and 880 nm) speckle imaging of the planet Pluto and its largest moon Charon. Using our DSSI speckle camera attached to the Gemini North 8 m telescope, we collected high resolution imaging with an angular resolution of ~20 mas, a value at the Gemini-N telescope diffraction limit. We have produced for this binary system the first speckle reconstructed images, from which we can measure not only the orbital separation and position angle for Charon, but also the diameters of the two bodies. Our measurements of these parameters agree, within the uncertainties, with the current best values for Pluto and Charon. The Gemini-N speckle observations of Pluto are presented to illustrate the capabilities of our instrument and the robust production of high accuracy, high spatial resolution reconstructed images. We hope our results will suggest additional applications of high resolution speckle imaging for other objects within our solar system and beyond. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the National Science Foundation on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  20. Extrinsic calibration of a non-overlapping camera network based on close-range photogrammetry.

    PubMed

    Dong, Shuai; Shao, Xinxing; Kang, Xin; Yang, Fujun; He, Xiaoyuan

    2016-08-10

    In this paper, an extrinsic calibration method for a non-overlapping camera network is presented based on close-range photogrammetry. The method does not require calibration targets or the cameras to be moved. The visual sensors are relatively motionless and do not see the same area at the same time. The proposed method combines the multiple cameras using some arbitrarily distributed encoded targets. The calibration procedure consists of three steps: reconstructing the three-dimensional (3D) coordinates of the encoded targets using a hand-held digital camera, performing the intrinsic calibration of the camera network, and calibrating the extrinsic parameters of each camera with only one image. A series of experiments, including 3D reconstruction, rotation, and translation, are employed to validate the proposed approach. The results show that the relative error for the 3D reconstruction is smaller than 0.003%, the relative errors of both rotation and translation are less than 0.066%, and the re-projection error is only 0.09 pixels. PMID:27534480

  1. Breast Reconstruction After Mastectomy

    MedlinePlus

    ... around the cancer removed (lumpectomy or breast-conserving surgery) might not need reconstruction, but sometimes they do. Breast reconstruction is done by a plastic surgeon. Should I have breast reconstruction? Breast reconstruction ...

  2. Trajectory Generation and Path Planning for Autonomous Aerobots

    NASA Technical Reports Server (NTRS)

    Sharma, Shivanjli; Kulczycki, Eric A.; Elfes, Alberto

    2007-01-01

    This paper presents global path planning algorithms for the Titan aerobot based on user defined waypoints in 2D and 3D space. The algorithms were implemented using information obtained through a planner user interface. The trajectory planning algorithms were designed to accurately represent the aerobot's characteristics, such as minimum turning radius. Additionally, trajectory planning techniques were implemented to allow for surveying of a planar area based solely on camera fields of view, airship altitude, and the location of the planar area's perimeter. The developed paths allow for planar navigation and three-dimensional path planning. These calculated trajectories are optimized to produce the shortest possible path while still remaining within realistic bounds of airship dynamics.

  3. An Inexpensive Digital Infrared Camera

    ERIC Educational Resources Information Center

    Mills, Allan

    2012-01-01

    Details are given for the conversion of an inexpensive webcam to a camera specifically sensitive to the near infrared (700-1000 nm). Some experiments and practical applications are suggested and illustrated. (Contains 9 figures.)

  4. A protocol and calibration method for accurate multi-camera field videography.

    PubMed

    Theriault, Diane H; Fuller, Nathan W; Jackson, Brandon E; Bluhm, Evan; Evangelista, Dennis; Wu, Zheng; Betke, Margrit; Hedrick, Tyson L

    2014-06-01

    Stereo videography is a powerful technique for quantifying the kinematics and behavior of animals, but it can be challenging to use in an outdoor field setting. We here present a workflow and associated software for performing calibration of cameras placed in a field setting and estimating the accuracy of the resulting stereoscopic reconstructions. We demonstrate the workflow through example stereoscopic reconstructions of bat and bird flight. We provide software tools for planning experiments and processing the resulting calibrations that other researchers may use to calibrate their own cameras. Our field protocol can be deployed in a single afternoon, requiring only short video clips of light, portable calibration objects. PMID:24577444

  5. Clinical applications with the HIDAC positron camera

    NASA Astrophysics Data System (ADS)

    Frey, P.; Schaller, G.; Christin, A.; Townsend, D.; Tochon-Danguy, H.; Wensveen, M.; Donath, A.

    1988-06-01

    , and more detailed data on a larger number of clinical and experimental PET scans will be necessary for definitive evaluation. Nevertheless, the HIDAC positron camera may be used for clinical PET imaging in well-defined patient cases, particularly in situations where both high spatial resolution is desired in the reconstructed image of the examined pathological condition and at the same time "static" PET imaging may be adequate, as is the case in thyroid-, ENT- and liver tomographic imaging using the HIDAC positron camera.

  6. The future of consumer cameras

    NASA Astrophysics Data System (ADS)

    Battiato, Sebastiano; Moltisanti, Marco

    2015-03-01

    In the last two decades multimedia, and in particular imaging devices (camcorders, tablets, mobile phones, etc.) have been dramatically diffused. Moreover the increasing of their computational performances, combined with an higher storage capability, allows them to process large amount of data. In this paper an overview of the current trends of consumer cameras market and technology will be given, providing also some details about the recent past (from Digital Still Camera up today) and forthcoming key issues.

  7. Solid State Television Camera (CID)

    NASA Technical Reports Server (NTRS)

    Steele, D. W.; Green, W. T.

    1976-01-01

    The design, development and test are described of a charge injection device (CID) camera using a 244x248 element array. A number of video signal processing functions are included which maximize the output video dynamic range while retaining the inherently good resolution response of the CID. Some of the unique features of the camera are: low light level performance, high S/N ratio, antiblooming, geometric distortion, sequential scanning and AGC.

  8. Fundus Camera Guided Photoacoustic Ophthalmoscopy

    PubMed Central

    Liu, Tan; Li, Hao; Song, Wei; Jiao, Shuliang; Zhang, Hao F.

    2014-01-01

    Purpose To demonstrate the feasibility of fundus camera guided photoacoustic ophthalmoscopy (PAOM) system and its multimodal imaging capabilities. Methods We integrated PAOM and a fundus camera consisting of a white-light illuminator and a high-sensitivity, high-speed CCD. The fundus camera captures both retinal anatomy and PAOM illumination at the same time to provide a real-time feedback when we position the PAOM illuminating light. We applied the integrated system to image rat eyes in vivo and used full-spectrum, visible (VIS), and near infrared (NIR) illuminations in fundus photography. Results Both albino and pigmented rat eyes were imaged in vivo. During alignment, different trajectories of PAOM laser scanning were successfully visualized by the fundus camera, which reduced the PAOM alignment time from several minutes to 30 s. In albino eyes, in addition to retinal vessels, main choroidal vessels were observed using VIS-illumination, which is similar to PAOM images. In pigmented eyes, the radial striations of retinal nerve fiber layer were visualized by fundus photography using full-spectrum illumination; meanwhile, PAOM imaged both retinal vessels and the retinal pigmented epithelium melanin distribution. Conclusions The results demonstrated that PAOM can be well-integrated with fundus camera without affecting its functionality. The fundus camera guidance is faster and easier comparing with our previous work. The integrated system also set the stage for the next-step verification between oximetry methods based on PAOM and fundus photography. PMID:24131226

  9. Streak camera dynamic range optimization

    SciTech Connect

    Wiedwald, J.D.; Lerche, R.A.

    1987-09-01

    The LLNL optical streak camera is used by the Laser Fusion Program in a wide range of applications. Many of these applications require a large recorded dynamic range. Recent work has focused on maximizing the dynamic range of the streak camera recording system. For our streak cameras, image intensifier saturation limits the upper end of the dynamic range. We have developed procedures to set the image intensifier gain such that the system dynamic range is maximized. Specifically, the gain is set such that a single streak tube photoelectron is recorded with an exposure of about five times the recording system noise. This ensures detection of single photoelectrons, while not consuming intensifier or recording system dynamic range through excessive intensifier gain. The optimum intensifier gain has been determined for two types of film and for a lens-coupled CCD camera. We have determined that by recording the streak camera image with a CCD camera, the system is shot-noise limited up to the onset of image intensifier nonlinearity. When recording on film, the film determines the noise at high exposure levels. There is discussion of the effects of slit width and image intensifier saturation on dynamic range. 8 refs.

  10. Wide Dynamic Range CCD Camera

    NASA Astrophysics Data System (ADS)

    Younse, J. M.; Gove, R. J.; Penz, P. A.; Russell, D. E.

    1984-11-01

    A liquid crystal attenuator (LCA) operated as a variable neutral density filter has been attached to a charge-coupled device (CCD) imager to extend the dynamic range of a solid-state TV camera by an order of magnitude. Many applications are best served by a camera with a dynamic range of several thousand. For example, outside security systems must operate unattended with "dawn-to-dusk" lighting conditions. Although this can be achieved with available auto-iris lens assemblies, more elegant solutions which provide the small size, low power, high reliability advantages of solid state technology are now available. This paper will describe one such unique way of achieving these dynamic ranges using standard optics by making the CCD imager's glass cover a controllable neutral density filter. The liquid crystal attenuator's structure and theoretical properties for this application will be described along with measured transmittance. A small integrated TV camera which utilizes a "virtual-phase" CCD sensor coupled to a LCA will be described and test results for a number of the camera's optical and electrical parameters will be given. These include the following camera parameters: dynamic range, Modulation Transfer Function (MTF), spectral response, and uniformity. Also described will be circuitry which senses the ambient scene illuminance and automatically provides feedback signals to appropriately adjust the transmittance of the LCA. Finally, image photographs using this camera, under various scene illuminations, will be shown.

  11. The virtual gamma camera room.

    PubMed

    Penrose, J M; Trowbridge, E A; Tindale, W B

    1996-05-01

    The installation of a gamma camera is time-consuming and costly and, once installed, the camera position is unlikely to be altered during its working life. Poor choice of camera position therefore has long-term consequences. Additional equipment such as collimators and carts, the operator's workstation and wall-mounted display monitors must also be situated to maximize access and ease of use. The layout of a gamma camera room can be optimized prior to installation by creating a virtual environment. Super-Scape VRT software running on an upgraded 486 PC microprocessor was used to create a 'virtual camera room'. The simulation included an operator's viewpoint and a controlled tour of the room. Equipment could be repositioned as required, allowing potential problems to be identified at the design stage. Access for bed-ridden patients, operator ergonomics, operator and patient visibility were addressed. The display can also be used for patient education. Creation of a virtual environment is a valuable tool which allows different camera systems to be compared interactively in terms of dimensions, extent of movement and use of a defined space. Such a system also has applications in radiopharmacy design and simulation. PMID:8736511

  12. Rapid 360 degree imaging and stitching of 3D objects using multiple precision 3D cameras

    NASA Astrophysics Data System (ADS)

    Lu, Thomas; Yin, Stuart; Zhang, Jianzhong; Li, Jiangan; Wu, Frank

    2008-02-01

    In this paper, we present the system architecture of a 360 degree view 3D imaging system. The system consists of multiple 3D sensors synchronized to take 3D images around the object. Each 3D camera employs a single high-resolution digital camera and a color-coded light projector. The cameras are synchronized to rapidly capture the 3D and color information of a static object or a live person. The color encoded structure lighting ensures the precise reconstruction of the depth of the object. A 3D imaging system architecture is presented. The architecture employs the displacement of the camera and the projector to triangulate the depth information. The 3D camera system has achieved high depth resolution down to 0.1mm on a human head sized object and 360 degree imaging capability.

  13. Sampling diffusive transition paths

    SciTech Connect

    F. Miller III, Thomas; Predescu, Cristian

    2006-10-12

    We address the problem of sampling double-ended diffusive paths. The ensemble of paths is expressed using a symmetric version of the Onsager-Machlup formula, which only requires evaluation of the force field and which, upon direct time discretization, gives rise to a symmetric integrator that is accurate to second order. Efficiently sampling this ensemble requires avoiding the well-known stiffness problem associated with sampling infinitesimal Brownian increments of the path, as well as a different type of stiffness associated with sampling the coarse features of long paths. The fine-features sampling stiffness is eliminated with the use of the fast sampling algorithm (FSA), and the coarse-feature sampling stiffness is avoided by introducing the sliding and sampling (S&S) algorithm. A key feature of the S&S algorithm is that it enables massively parallel computers to sample diffusive trajectories that are long in time. We use the algorithm to sample the transition path ensemble for the structural interconversion of the 38-atom Lennard-Jones cluster at low temperature.

  14. Sampling diffusive transition paths.

    PubMed

    Miller, Thomas F; Predescu, Cristian

    2007-04-14

    The authors address the problem of sampling double-ended diffusive paths. The ensemble of paths is expressed using a symmetric version of the Onsager-Machlup formula, which only requires evaluation of the force field and which, upon direct time discretization, gives rise to a symmetric integrator that is accurate to second order. Efficiently sampling this ensemble requires avoiding the well-known stiffness problem associated with the sampling of infinitesimal Brownian increments of the path, as well as a different type of stiffness associated with the sampling of the coarse features of long paths. The fine-feature sampling stiffness is eliminated with the use of the fast sampling algorithm, and the coarse-feature sampling stiffness is avoided by introducing the sliding and sampling (S&S) algorithm. A key feature of the S&S algorithm is that it enables massively parallel computers to sample diffusive trajectories that are long in time. The authors use the algorithm to sample the transition path ensemble for the structural interconversion of the 38-atom Lennard-Jones cluster at low temperature. PMID:17444696

  15. The MC and LFC cameras. [metric camera (MC); large format camera (LFC)

    NASA Technical Reports Server (NTRS)

    Norton, Clarice L.; Schroeder, Manfried; Mollberg, Bernard

    1986-01-01

    The characteristics of the shuttle-borne Large Format Camera are listed. The LFC focal plane format was 23 by 46 cm, double the usual size, thereby acquiring approximately double the ground area. Forward motion compensation was employed. With the stable platform (shuttle) it was possible to use the slow exposure, high resolution, Kodak aerial films; 3414 and 3412 black and white, SO-242 color, and SO-131 aerochrome infrared. The camera was designed to maintain stability during varying temperature extremes of space.

  16. Paths correlation matrix.

    PubMed

    Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang

    2015-09-15

    Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions. PMID:26371930

  17. Combined Intra- and Extra-articular Reconstruction of the Anterior Cruciate Ligament: The Reconstruction of the Knee Anterolateral Ligament

    PubMed Central

    Helito, Camilo Partezani; Bonadio, Marcelo Batista; Gobbi, Riccardo Gomes; da Mota e Albuquerque, Roberto Freire; Pécora, José Ricardo; Camanho, Gilberto Luis; Demange, Marco Kawamura

    2015-01-01

    We present a new technique for the combined intra- and extra-articular reconstruction of the anterior cruciate ligament. Intra-articular reconstruction is performed in an outside-in manner according to the precepts of the anatomic femoral tunnel technique. Extra-articular reconstruction is performed with the gracilis tendon while respecting the anatomic parameters of the origin and insertion points and the path described for the knee anterolateral ligament. PMID:26258037

  18. Pose Estimation and Mapping Using Catadioptric Cameras with Spherical Mirrors

    NASA Astrophysics Data System (ADS)

    Ilizirov, Grigory; Filin, Sagi

    2016-06-01

    Catadioptric cameras have the advantage of broadening the field of view and revealing otherwise occluded object parts. However, they differ geometrically from standard central perspective cameras because of light reflection from the mirror surface which alters the collinearity relation and introduces severe non-linear distortions of the imaged scene. Accommodating for these features, we present in this paper a novel modeling for pose estimation and reconstruction while imaging through spherical mirrors. We derive a closed-form equivalent to the collinearity principle via which we estimate the system's parameters. Our model yields a resection-like solution which can be developed into a linear one. We show that accurate estimates can be derived with only a small set of control points. Analysis shows that control configuration in the orientation scheme is rather flexible and that high levels of accuracy can be reached in both pose estimation and mapping. Clearly, the ability to model objects which fall outside of the immediate camera field-of-view offers an appealing means to supplement 3-D reconstruction and modeling.

  19. Mobile transporter path planning

    NASA Technical Reports Server (NTRS)

    Baffes, Paul; Wang, Lui

    1990-01-01

    The use of a genetic algorithm (GA) for solving the mobile transporter path planning problem is investigated. The mobile transporter is a traveling robotic vehicle proposed for the space station which must be able to reach any point of the structure autonomously. Elements of the genetic algorithm are explored in both a theoretical and experimental sense. Specifically, double crossover, greedy crossover, and tournament selection techniques are examined. Additionally, the use of local optimization techniques working in concert with the GA are also explored. Recent developments in genetic algorithm theory are shown to be particularly effective in a path planning problem domain, though problem areas can be cited which require more research.

  20. Sub-Camera Calibration of a Penta-Camera

    NASA Astrophysics Data System (ADS)

    Jacobsen, K.; Gerke, M.

    2016-03-01

    Penta cameras consisting of a nadir and four inclined cameras are becoming more and more popular, having the advantage of imaging also facades in built up areas from four directions. Such system cameras require a boresight calibration of the geometric relation of the cameras to each other, but also a calibration of the sub-cameras. Based on data sets of the ISPRS/EuroSDR benchmark for multi platform photogrammetry the inner orientation of the used IGI Penta DigiCAM has been analyzed. The required image coordinates of the blocks Dortmund and Zeche Zollern have been determined by Pix4Dmapper and have been independently adjusted and analyzed by program system BLUH. With 4.1 million image points in 314 images respectively 3.9 million image points in 248 images a dense matching was provided by Pix4Dmapper. With up to 19 respectively 29 images per object point the images are well connected, nevertheless the high number of images per object point are concentrated to the block centres while the inclined images outside the block centre are satisfying but not very strongly connected. This leads to very high values for the Student test (T-test) of the finally used additional parameters or in other words, additional parameters are highly significant. The estimated radial symmetric distortion of the nadir sub-camera corresponds to the laboratory calibration of IGI, but there are still radial symmetric distortions also for the inclined cameras with a size exceeding 5μm even if mentioned as negligible based on the laboratory calibration. Radial and tangential effects of the image corners are limited but still available. Remarkable angular affine systematic image errors can be seen especially in the block Zeche Zollern. Such deformations are unusual for digital matrix cameras, but it can be caused by the correlation between inner and exterior orientation if only parallel flight lines are used. With exception of the angular affinity the systematic image errors for corresponding

  1. A testbed for wide-field, high-resolution, gigapixel-class cameras

    NASA Astrophysics Data System (ADS)

    Kittle, David S.; Marks, Daniel L.; Son, Hui S.; Kim, Jungsang; Brady, David J.

    2013-05-01

    The high resolution and wide field of view (FOV) of the AWARE (Advanced Wide FOV Architectures for Image Reconstruction and Exploitation) gigapixel class cameras present new challenges in calibration, mechanical testing, and optical performance evaluation. The AWARE system integrates an array of micro-cameras in a multiscale design to achieve gigapixel sampling at video rates. Alignment and optical testing of the micro-cameras is vital in compositing engines, which require pixel-level accurate mappings over the entire array of cameras. A testbed has been developed to automatically calibrate and measure the optical performance of the entire camera array. This testbed utilizes translation and rotation stages to project a ray into any micro-camera of the AWARE system. A spatial light modulator is projected through a telescope to form an arbitrary object space pattern at infinity. This collimated source is then reflected by an elevation stage mirror for pointing through the aperture of the objective into the micro-optics and eventually the detector of the micro-camera. Different targets can be projected with the spatial light modulator for measuring the modulation transfer function (MTF) of the system, fiducials in the overlap regions for registration and compositing, distortion mapping, illumination profiles, thermal stability, and focus calibration. The mathematics of the testbed mechanics are derived for finding the positions of the stages to achieve a particular incident angle into the camera, along with calibration steps for alignment of the camera and testbed coordinate axes. Measurement results for the AWARE-2 gigapixel camera are presented for MTF, focus calibration, illumination profile, fiducial mapping across the micro-camera for registration and distortion correction, thermal stability, and alignment of the camera on the testbed.

  2. A testbed for wide-field, high-resolution, gigapixel-class cameras.

    PubMed

    Kittle, David S; Marks, Daniel L; Son, Hui S; Kim, Jungsang; Brady, David J

    2013-05-01

    The high resolution and wide field of view (FOV) of the AWARE (Advanced Wide FOV Architectures for Image Reconstruction and Exploitation) gigapixel class cameras present new challenges in calibration, mechanical testing, and optical performance evaluation. The AWARE system integrates an array of micro-cameras in a multiscale design to achieve gigapixel sampling at video rates. Alignment and optical testing of the micro-cameras is vital in compositing engines, which require pixel-level accurate mappings over the entire array of cameras. A testbed has been developed to automatically calibrate and measure the optical performance of the entire camera array. This testbed utilizes translation and rotation stages to project a ray into any micro-camera of the AWARE system. A spatial light modulator is projected through a telescope to form an arbitrary object space pattern at infinity. This collimated source is then reflected by an elevation stage mirror for pointing through the aperture of the objective into the micro-optics and eventually the detector of the micro-camera. Different targets can be projected with the spatial light modulator for measuring the modulation transfer function (MTF) of the system, fiducials in the overlap regions for registration and compositing, distortion mapping, illumination profiles, thermal stability, and focus calibration. The mathematics of the testbed mechanics are derived for finding the positions of the stages to achieve a particular incident angle into the camera, along with calibration steps for alignment of the camera and testbed coordinate axes. Measurement results for the AWARE-2 gigapixel camera are presented for MTF, focus calibration, illumination profile, fiducial mapping across the micro-camera for registration and distortion correction, thermal stability, and alignment of the camera on the testbed. PMID:23742532

  3. Accurate three-dimensional virtual reconstruction of surgical field using calibrated trajectories of an image-guided medical robot

    PubMed Central

    Gong, Yuanzheng; Hu, Danying; Hannaford, Blake; Seibel, Eric J.

    2014-01-01

    Abstract. Brain tumor margin removal is challenging because diseased tissue is often visually indistinguishable from healthy tissue. Leaving residual tumor leads to decreased survival, and removing normal tissue causes life-long neurological deficits. Thus, a surgical robotics system with a high degree of dexterity, accurate navigation, and highly precise resection is an ideal candidate for image-guided removal of fluorescently labeled brain tumor cells. To image, we developed a scanning fiber endoscope (SFE) which acquires concurrent reflectance and fluorescence wide-field images at a high resolution. This miniature flexible endoscope was affixed to the arm of a RAVEN II surgical robot providing programmable motion with feedback control using stereo-pair surveillance cameras. To verify the accuracy of the three-dimensional (3-D) reconstructed surgical field, a multimodal physical-sized model of debulked brain tumor was used to obtain the 3-D locations of residual tumor for robotic path planning to remove fluorescent cells. Such reconstruction is repeated intraoperatively during margin clean-up so the algorithm efficiency and accuracy are important to the robotically assisted surgery. Experimental results indicate that the time for creating this 3-D surface can be reduced to one-third by using known trajectories of a robot arm, and the error from the reconstructed phantom is within 0.67 mm in average compared to the model design. PMID:26158071

  4. Accurate three-dimensional virtual reconstruction of surgical field using calibrated trajectories of an image-guided medical robot.

    PubMed

    Gong, Yuanzheng; Hu, Danying; Hannaford, Blake; Seibel, Eric J

    2014-10-01

    Brain tumor margin removal is challenging because diseased tissue is often visually indistinguishable from healthy tissue. Leaving residual tumor leads to decreased survival, and removing normal tissue causes life-long neurological deficits. Thus, a surgical robotics system with a high degree of dexterity, accurate navigation, and highly precise resection is an ideal candidate for image-guided removal of fluorescently labeled brain tumor cells. To image, we developed a scanning fiber endoscope (SFE) which acquires concurrent reflectance and fluorescence wide-field images at a high resolution. This miniature flexible endoscope was affixed to the arm of a RAVEN II surgical robot providing programmable motion with feedback control using stereo-pair surveillance cameras. To verify the accuracy of the three-dimensional (3-D) reconstructed surgical field, a multimodal physical-sized model of debulked brain tumor was used to obtain the 3-D locations of residual tumor for robotic path planning to remove fluorescent cells. Such reconstruction is repeated intraoperatively during margin clean-up so the algorithm efficiency and accuracy are important to the robotically assisted surgery. Experimental results indicate that the time for creating this 3-D surface can be reduced to one-third by using known trajectories of a robot arm, and the error from the reconstructed phantom is within 0.67 mm in average compared to the model design. PMID:26158071

  5. Reconstructing the temporal progression of HIV-1 immune response pathways

    PubMed Central

    Jain, Siddhartha; Arrais, Joel; Venkatachari, Narasimhan J.; Ayyavoo, Velpandi; Bar-Joseph, Ziv

    2016-01-01

    Motivation: Most methods for reconstructing response networks from high throughput data generate static models which cannot distinguish between early and late response stages. Results: We present TimePath, a new method that integrates time series and static datasets to reconstruct dynamic models of host response to stimulus. TimePath uses an Integer Programming formulation to select a subset of pathways that, together, explain the observed dynamic responses. Applying TimePath to study human response to HIV-1 led to accurate reconstruction of several known regulatory and signaling pathways and to novel mechanistic insights. We experimentally validated several of TimePaths’ predictions highlighting the usefulness of temporal models. Availability and Implementation: Data, Supplementary text and the TimePath software are available from http://sb.cs.cmu.edu/timepath Contact: zivbj@cs.cmu.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27307624

  6. Paved Path for Opportunity

    NASA Technical Reports Server (NTRS)

    2006-01-01

    As NASA's Mars Exploration Rover Opportunity continues a southward trek from 'Erebus Crater' toward 'Victoria Crater,' the terrain consists of large sand ripples and patches of flat-lying rock outcrops, as shown in this image. Whenever possible, rover planners keep Opportunity on the 'pavement' for best mobility.

    This false-color image mosaic was assembled using images acquired by the panoramic camera on Opportunity's 784th sol (April 8, 2006) at about 11:45 a.m. local solar time. The camera used its 753-nanometer, 535-nanometer and 432-nanometer filters. This view shows a portion of the outcrop named 'Bosque,' including rover wheel tracks, fractured and finely-layered outcrop rocks and smaller, dark cobbles littered across the surface.

  7. Distributed consensus on camera pose.

    PubMed

    Jorstad, Anne; DeMenthon, Daniel; Wang, I-Jeng; Burlina, Philippe

    2010-09-01

    Our work addresses pose estimation in a distributed camera framework. We examine how processing cameras can best reach a consensus about the pose of an object when they are each given a model of the object, defined by a set of point coordinates in the object frame of reference. The cameras can only see a subset of the object feature points in the midst of background clutter points, not knowing which image points match with which object points, nor which points are object points or background points. The cameras individually recover a prediction of the object's pose using their knowledge of the model, and then exchange information with their neighbors, performing consensus updates locally to obtain a single estimate consistent across all cameras, without requiring a common centralized processor. Our main contributions are: 1) we present a novel algorithm performing consensus updates in 3-D world coordinates penalized by a 3-D model, and 2) we perform a thorough comparison of our method with other current consensus methods. Our method is consistently the most accurate, and we confirm that the existing consensus method based upon calculating the Karcher mean of rotations is also reliable and fast. Experiments on simulated and real imagery are reported. PMID:20363678

  8. The Clementine longwave infrared camera

    SciTech Connect

    Priest, R.E.; Lewis, I.T.; Sewall, N.R.; Park, H.S.; Shannon, M.J.; Ledebuhr, A.G.; Pleasance, L.D.; Massie, M.A.; Metschuleit, K.

    1995-04-01

    The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. The longwave-infrared (LWIR) camera supplemented the UV/Visible and near-infrared mapping cameras providing limited strip coverage of the moon, giving insight to the thermal properties of the soils. This camera provided {approximately}100 m spatial resolution at 400 km periselene, and a 7 km across-track swath. This 2.1 kg camera using a 128 x 128 Mercury-Cadmium-Telluride (MCT) FPA viewed thermal emission of the lunar surface and lunar horizon in the 8.0 to 9.5 {micro}m wavelength region. A description of this light-weight, low power LWIR camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

  9. CARTOGAM: a portable gamma camera

    NASA Astrophysics Data System (ADS)

    Gal, O.; Izac, C.; Lainé, F.; Nguyen, A.

    1997-02-01

    The gamma camera is devised to establish the cartography of radioactive sources against a visible background in quasi real time. This device is designed to spot sources from a distance during the preparation of interventions on active areas of nuclear installations. This implement will permit to optimize interventions especially on the dosimetric level. The camera consists of a double cone collimator, a scintillator and an intensified CCD camera. This chain of detection provides the formation of both gamma images and visible images. Even though it is wrapped in a denal shield, the camera is still portable (mass < 15 kg) and compact (external diameter = 8 cm). The angular resolution is of the order of one degree for gamma rays of 1 MeV. In a few minutes, the device is able to measure a dose rate of 10 μGy/h delivered for instance by a source of 60Co of 90 mCi located at 10 m from the detector. The first images recorded in the laboratory will be presented and will illustrate the performances obtained with this camera.

  10. Traditional gamma cameras are preferred.

    PubMed

    DePuey, E Gordon

    2016-08-01

    Although the new solid-state dedicated cardiac cameras provide excellent spatial and energy resolution and allow for markedly reduced SPECT acquisition times and/or injected radiopharmaceutical activity, they have some distinct disadvantages compared to traditional sodium iodide SPECT cameras. They are expensive. Attenuation correction is not available. Cardio-focused collimation, advantageous to increase depth-dependent resolution and myocardial count density, accentuates diaphragmatic attenuation and scatter from subdiaphragmatic structures. Although supplemental prone imaging is therefore routinely advised, many patients cannot tolerate it. Moreover, very large patients cannot be accommodated in the solid-state camera gantries. Since data are acquired simultaneously with an arc of solid-state detectors around the chest, no temporally dependent "rotating" projection images are obtained. Therefore, patient motion can be neither detected nor corrected. In contrast, traditional sodium iodide SPECT cameras provide rotating projection images to allow technologists and physicians to detect and correct patient motion and to accurately detect the position of soft tissue attenuators and to anticipate associated artifacts. Very large patients are easily accommodated. Low-dose x-ray attenuation correction is widely available. Also, relatively inexpensive low-count density software is provided by many vendors, allowing shorter SPECT acquisition times and reduced injected activity approaching that achievable with solid-state cameras. PMID:27072004

  11. Strategic options towards an affordable high-performance infrared camera

    NASA Astrophysics Data System (ADS)

    Oduor, Patrick; Mizuno, Genki; Dutta, Achyut K.; Lewis, Jay; Dhar, Nibir K.

    2016-05-01

    The promise of infrared (IR) imaging attaining low-cost akin to CMOS sensors success has been hampered by the inability to achieve cost advantages that are necessary for crossover from military and industrial applications into the consumer and mass-scale commercial realm despite well documented advantages. Banpil Photonics is developing affordable IR cameras by adopting new strategies to speed-up the decline of the IR camera cost curve. We present a new short-wave IR (SWIR) camera; 640x512 pixel InGaAs uncooled system that is high sensitivity low noise (<50e-), high dynamic range (100 dB), high-frame rates (> 500 frames per second (FPS)) at full resolution, and low power consumption (< 1 W) in a compact system. This camera paves the way towards mass market adoption by not only demonstrating high-performance IR imaging capability value add demanded by military and industrial application, but also illuminates a path towards justifiable price points essential for consumer facing application industries such as automotive, medical, and security imaging adoption. Among the strategic options presented include new sensor manufacturing technologies that scale favorably towards automation, multi-focal plane array compatible readout electronics, and dense or ultra-small pixel pitch devices.

  12. Characterization of a C-QWIP LWIR camera

    NASA Astrophysics Data System (ADS)

    Forrai, David P.; Sempsrott, Mark; Fischer, Robert; Choi, Kwong-Kit; Devitt, John W.

    2007-04-01

    Large format corrugated quantum well infrared photodetector (C-QWIP) focal plane arrays (FPAs) have been developed over the past two years. The results of this development have demonstrated the potential for this technology to satisfy requirements for very large format high performance long-wave infrared (LWIR) imaging systems. One particular C-QWIP design has focused on developing an FPA that operates in the 8 to 10 μm spectrum with integration times in the millisecond regime when used against warm backgrounds. This FPA is very suitable for many LWIR applications and has been integrated into a camera system. The specifications of that camera are described in this paper. The characterization of this camera system includes standard electro-optical tests and compares the results of those tests to theoretical models for the FPA. This paper concludes by describing the ongoing effort to tailor the system specifically for the C-QWIP. This includes design features of the read-out integrated circuit (ROIC), dewar-cooler design and interfacing electronics, and video processing. This thorough characterization of the camera has demonstrated the utility of the C-QWIP FPA for LWIR imaging and has established a path forward to further improve the performance of imaging systems implementing this technology.

  13. Video camera use at nuclear power plants

    SciTech Connect

    Estabrook, M.L.; Langan, M.O.; Owen, D.E. )

    1990-08-01

    A survey of US nuclear power plants was conducted to evaluate video camera use in plant operations, and determine equipment used and the benefits realized. Basic closed circuit television camera (CCTV) systems are described and video camera operation principles are reviewed. Plant approaches for implementing video camera use are discussed, as are equipment selection issues such as setting task objectives, radiation effects on cameras, and the use of disposal cameras. Specific plant applications are presented and the video equipment used is described. The benefits of video camera use --- mainly reduced radiation exposure and increased productivity --- are discussed and quantified. 15 refs., 6 figs.

  14. Fuzzy Visual Path Following by a Mobile Robot

    NASA Astrophysics Data System (ADS)

    Hamissi, A.; Bazoula, A.

    2008-06-01

    We present in this work a variant of a visual navigation method developed for path following by a nonholonomic mobile robot moving in an environment free of obstacles. Only an embedded CCD camera is used for perception. The integration of perception and action leads us to develop firstly a method of extraction of the useful information from each acquired image, secondly a control approach using fuzzy logic.

  15. Tracheal reconstructions.

    PubMed

    Srikrishna, S V; Shekar, P S; Shetty, N

    1998-12-01

    Surgical reconstruction of the trachea is a relatively complex procedure. We had 20 cases of tracheal stenosis. We have a modest experience of 16 tracheal reconstructions for acquired tracheal stenosis. Two patients underwent laser treatment while another two died before any intervention. The majority of these cases were a result of prolonged ventilation (14 cases), following organophosphorous poisoning (11 cases), Guillain-Barré syndrome, bullet injury, fat embolism and surprisingly only one tumor, a case of mucoepidermoid carcinoma, who had a very unusual presentation. There were 12 males and 4 females in this series, age ranging from 12-35 years. The duration of ventilation ranged from 1-21 days and the interval from decannulation to development of stridor was between 5-34 days. Six of them were approached by the cervical route, 5 by thoracotomy and cervical approach, 2 via median sternotomy and 3 by thoracotomy alone. Five of them required an additional laryngeal drop and 1 required pericardiotomy and release of pulmonary veins to gain additional length. The excised segments of trachea measured 3 to 5 cms in length. All were end to end anastomosis with interrupted Vicryl sutures. We have had no experience with stents or prosthetic tubes. Three patients developed anastomotic leaks which were controlled conservatively. Almost all of them required postoperative tracheo-bronchial suctioning with fibreoptic bronchoscope. We had one death in this series due to sepsis. PMID:9914459

  16. Coherence-path duality relations for N paths

    NASA Astrophysics Data System (ADS)

    Hillery, Mark; Bagan, Emilio; Bergou, Janos; Cottrell, Seth

    2016-05-01

    For an interferometer with two paths, there is a relation between the information about which path the particle took and the visibility of the interference pattern at the output. The more path information we have, the smaller the visibility, and vice versa. We generalize this relation to a multi-path interferometer, and we substitute two recently defined measures of quantum coherence for the visibility, which results in two duality relations. The path information is provided by attaching a detector to each path. In the first relation, which uses an l1 measure of coherence, the path information is obtained by applying the minimum-error state discrimination procedure to the detector states. In the second, which employs an entropic measure of coherence, the path information is the mutual information between the detector states and the result of measuring them. Both approaches are quantitative versions of complementarity for N-path interferometers. Support provided by the John Templeton Foundation.

  17. 94. ARAIV. Aerial view of ML1 area. Camera facing north. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    94. ARA-IV. Aerial view of ML-1 area. Camera facing north. Reactor test building is in center of view. Walking path and utility lines connect test building. Berm lies between. Road curves to left and continues to GCRE complex. Ineel photo no. 79-4707. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

  18. System Architecture of the Dark Energy Survey Camera Readout Electronics

    SciTech Connect

    Shaw, Theresa; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Chappa, Steve; de Vicente, Juan; Holm, Scott; Huffman, Dave; Kozlovsky, Mark; Martinez, Gustavo; Moore, Todd; /Madrid, CIEMAT /Fermilab /Illinois U., Urbana /Fermilab

    2010-05-27

    The Dark Energy Survey makes use of a new camera, the Dark Energy Camera (DECam). DECam will be installed in the Blanco 4M telescope at Cerro Tololo Inter-American Observatory (CTIO). DECam is presently under construction and is expected to be ready for observations in the fall of 2011. The focal plane will make use of 62 2Kx4K and 12 2kx2k fully depleted Charge-Coupled Devices (CCDs) for guiding, alignment and focus. This paper will describe design considerations of the system; including, the entire signal path used to read out the CCDs, the development of a custom crate and backplane, the overall grounding scheme and early results of system tests.

  19. Following the Path

    ERIC Educational Resources Information Center

    Rodia, Becky

    2004-01-01

    This article profiles Diane Stanley, an author and illustrator of children's books. Although she was studying to be a medical illustrator in graduate school, Stanley's path changed when she got married and had children. As she was raising her children, she became increasingly enamored of the colorful children's books she would check out of the…

  20. An Unplanned Path

    ERIC Educational Resources Information Center

    McGarvey, Lynn M.; Sterenberg, Gladys Y.; Long, Julie S.

    2013-01-01

    The authors elucidate what they saw as three important challenges to overcome along the path to becoming elementary school mathematics teacher leaders: marginal interest in math, low self-confidence, and teaching in isolation. To illustrate how these challenges were mitigated, they focus on the stories of two elementary school teachers--Laura and…

  1. Cameras for semiconductor process control

    NASA Technical Reports Server (NTRS)

    Porter, W. A.; Parker, D. L.

    1977-01-01

    The application of X-ray topography to semiconductor process control is described, considering the novel features of the high speed camera and the difficulties associated with this technique. The most significant results on the effects of material defects on device performance are presented, including results obtained using wafers processed entirely within this institute. Defects were identified using the X-ray camera and correlations made with probe data. Also included are temperature dependent effects of material defects. Recent applications and improvements of X-ray topographs of silicon-on-sapphire and gallium arsenide are presented with a description of a real time TV system prototype and of the most recent vacuum chuck design. Discussion is included of our promotion of the use of the camera by various semiconductor manufacturers.

  2. Camera-on-a-Chip

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Jet Propulsion Laboratory's research on a second generation, solid-state image sensor technology has resulted in the Complementary Metal- Oxide Semiconductor Active Pixel Sensor (CMOS), establishing an alternative to the Charged Coupled Device (CCD). Photobit Corporation, the leading supplier of CMOS image sensors, has commercialized two products of their own based on this technology: the PB-100 and PB-300. These devices are cameras on a chip, combining all camera functions. CMOS "active-pixel" digital image sensors offer several advantages over CCDs, a technology used in video and still-camera applications for 30 years. The CMOS sensors draw less energy, they use the same manufacturing platform as most microprocessors and memory chips, and they allow on-chip programming of frame size, exposure, and other parameters.

  3. Aerial camera auto focusing system

    NASA Astrophysics Data System (ADS)

    Wang, Xuan; Lan, Gongpu; Gao, Xiaodong; Liang, Wei

    2012-10-01

    Before the aerial photographic task, the cameras focusing work should be performed at first to compensate the defocus caused by the changes of the temperature, pressure etc. A new method of aerial camera auto focusing is proposed through traditional photoelectric self-collimation combined with image processing method. Firstly, the basic principles of optical self-collimation and image processing are introduced. Secondly, the limitations of the two are illustrated and the benefits of the new method are detailed. Then the basic principle, the system composition and the implementation of this new method are presented. Finally, the data collection platform is set up reasonably and the focus evaluation function curve is draw. The results showed that: the method can be used in the Aerial camera focusing field, adapt to the aviation equipment trends of miniaturization and lightweight .This paper is helpful to the further work of accurate and automatic focusing.

  4. Dark Energy Camera for Blanco

    SciTech Connect

    Binder, Gary A.; /Caltech /SLAC

    2010-08-25

    In order to make accurate measurements of dark energy, a system is needed to monitor the focus and alignment of the Dark Energy Camera (DECam) to be located on the Blanco 4m Telescope for the upcoming Dark Energy Survey. One new approach under development is to fit out-of-focus star images to a point spread function from which information about the focus and tilt of the camera can be obtained. As a first test of a new algorithm using this idea, simulated star images produced from a model of DECam in the optics software Zemax were fitted. Then, real images from the Mosaic II imager currently installed on the Blanco telescope were used to investigate the algorithm's capabilities. A number of problems with the algorithm were found, and more work is needed to understand its limitations and improve its capabilities so it can reliably predict camera alignment and focus.

  5. Perceptual Color Characterization of Cameras

    PubMed Central

    Vazquez-Corral, Javier; Connah, David; Bertalmío, Marcelo

    2014-01-01

    Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as XY Z, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a 3 × 3 matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson et al., to perform a perceptual color characterization. In particular, we search for the 3 × 3 matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE ΔE error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3% for the ΔE error, 7% for the S-CIELAB error and 13% for the CID error measures. PMID:25490586

  6. The GISMO-2 Bolometer Camera

    NASA Technical Reports Server (NTRS)

    Staguhn, Johannes G.; Benford, Dominic J.; Fixsen, Dale J.; Hilton, Gene; Irwin, Kent D.; Jhabvala, Christine A.; Kovacs, Attila; Leclercq, Samuel; Maher, Stephen F.; Miller, Timothy M.; Moseley, Samuel H.; Sharp, Elemer H.; Wollack, Edward J.

    2012-01-01

    We present the concept for the GISMO-2 bolometer camera) which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISM0-2 will operate Simultaneously in the 1 mm and 2 mm atmospherical windows. The 1 mm channel uses a 32 x 40 TES-based Backshort Under Grid (BUG) bolometer array, the 2 mm channel operates with a 16 x 16 BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISM0-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera which is successfully operating at the 30m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals.

  7. Slant path range gated imaging of static and moving targets

    NASA Astrophysics Data System (ADS)

    Steinvall, Ove; Elmqvist, Magnus; Karlsson, Kjell; Gustafsson, Ove; Chevalier, Tomas

    2012-06-01

    This paper will report experiments and analysis of slant path imaging using 1.5 μm and 0.8 μm gated imaging. The investigation is a follow up on the measurement reported last year at the laser radar conference at SPIE Orlando. The sensor, a SWIR camera was collecting both passive and active images along a 2 km long path over an airfield. The sensor was elevated by a lift in steps from 1.6-13.5 meters. Targets were resolution charts and also human targets. The human target was holding various items and also performing certain tasks some of high of relevance in defence and security. One of the main purposes with this investigation was to compare the recognition of these human targets and their activities with the resolution information obtained from conventional resolution charts. The data collection of human targets was also made from out roof top laboratory at about 13 m height above ground. The turbulence was measured along the path with anemometers and scintillometers. The camera was collecting both passive and active images in the SWIR region. We also included the Obzerv camera working at 0.8 μm in some tests. The paper will present images for both passive and active modes obtained at different elevations and discuss the results from both technical and system perspectives.

  8. Characterization of a PET Camera Optimized for ProstateImaging

    SciTech Connect

    Huber, Jennifer S.; Choong, Woon-Seng; Moses, William W.; Qi,Jinyi; Hu, Jicun; Wang, G.C.; Wilson, David; Oh, Sang; Huesman, RonaldH.; Derenzo, Stephen E.

    2005-11-11

    We present the characterization of a positron emission tomograph for prostate imaging that centers a patient between a pair of external curved detector banks (ellipse: 45 cm minor, 70 cm major axis). The distance between detector banks adjusts to allow patient access and to position the detectors as closely as possible for maximum sensitivity with patients of various sizes. Each bank is composed of two axial rows of 20 HR+ block detectors for a total of 80 detectors in the camera. The individual detectors are angled in the transaxial plane to point towards the prostate to reduce resolution degradation in that region. The detectors are read out by modified HRRT data acquisition electronics. Compared to a standard whole-body PET camera, our dedicated-prostate camera has the same sensitivity and resolution, less background (less randoms and lower scatter fraction) and a lower cost. We have completed construction of the camera. Characterization data and reconstructed images of several phantoms are shown. Sensitivity of a point source in the center is 946 cps/mu Ci. Spatial resolution is 4 mm FWHM in the central region.

  9. a Method for Self-Calibration in Satellite with High Precision of Space Linear Array Camera

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Qian, Fangming; Miao, Yuzhe; Wang, Rongjian

    2016-06-01

    At present, the on-orbit calibration of the geometric parameters of a space surveying camera is usually processed by data from a ground calibration field after capturing the images. The entire process is very complicated and lengthy and cannot monitor and calibrate the geometric parameters in real time. On the basis of a large number of on-orbit calibrations, we found that owing to the influence of many factors, e.g., weather, it is often difficult to capture images of the ground calibration field. Thus, regular calibration using field data cannot be ensured. This article proposes a real time self-calibration method for a space linear array camera on a satellite using the optical auto collimation principle. A collimating light source and small matrix array CCD devices are installed inside the load system of the satellite; these use the same light path as the linear array camera. We can extract the location changes of the cross marks in the matrix array CCD to determine the real-time variations in the focal length and angle parameters of the linear array camera. The on-orbit status of the camera is rapidly obtained using this method. On one hand, the camera's change regulation can be mastered accurately and the camera's attitude can be adjusted in a timely manner to ensure optimal photography; in contrast, self-calibration of the camera aboard the satellite can be realized quickly, which improves the efficiency and reliability of photogrammetric processing.

  10. Geiger-mode ladar cameras

    NASA Astrophysics Data System (ADS)

    Yuan, Ping; Sudharsanan, Rengarajan; Bai, Xiaogang; Boisvert, Joseph; McDonald, Paul; Labios, Eduardo; Morris, Bryan; Nicholson, John P.; Stuart, Gary M.; Danny, Harrison; Van Duyne, Stephen; Pauls, Greg; Gaalema, Stephen

    2011-06-01

    The performance of Geiger-mode LAser Detection and Ranging (LADAR) cameras is primarily defined by individual pixel attributes, such as dark count rate (DCR), photon detection efficiency (PDE), jitter, and crosstalk. However, for the expanding LADAR imaging applications, other factors, such as image uniformity, component tolerance, manufacturability, reliability, and operational features, have to be considered. Recently we have developed new 32×32 and 32×128 Read-Out Integrated Circuits (ROIC) for LADAR applications. With multiple filter and absorber structures, the 50-μm-pitch arrays demonstrate pixel crosstalk less than 100 ppm level, while maintaining a PDE greater than 40% at 4 V overbias. Besides the improved epitaxial and process uniformity of the APD arrays, the new ROICs implement a Non-uniform Bias (NUB) circuit providing 4-bit bias voltage tunability over a 2.5 V range to individually bias each pixel. All these features greatly increase the performance uniformity of the LADAR camera. Cameras based on these ROICs were integrated with a data acquisition system developed by Boeing DES. The 32×32 version has a range gate of up to 7 μs and can cover a range window of about 1 km with 14-bit and 0.5 ns timing resolution. The 32×128 camera can be operated at a frame rate of up to 20 kHz with 0.3 ns and 14-bit time resolution through a full CameraLink. The performance of the 32×32 LADAR camera has been demonstrated in a series of field tests on various vehicles.

  11. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.

    1990-09-01

    This monthly report summarizes the technical progress and project status for the Hanford Environmental Dose Reconstruction (HEDR) Project being conducted at the Pacific Northwest Laboratory (PNL) under the direction of a Technical Steering Panel (TSP). The TSP is composed of experts in numerous technical fields related to this project and represents the interests of the public. The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms, environmental transport, environmental monitoring data, demographics, agriculture, food habits, environmental pathways and dose estimates. 3 figs.

  12. Photometric Calibration of Consumer Video Cameras

    NASA Technical Reports Server (NTRS)

    Suggs, Robert; Swift, Wesley, Jr.

    2007-01-01

    analyze. The light source used to generate the calibration images is an artificial variable star comprising a Newtonian collimator illuminated by a light source modulated by a rotating variable neutral- density filter. This source acts as a point source, the brightness of which varies at a known rate. A video camera to be calibrated is aimed at this source. Fixed neutral-density filters are inserted in or removed from the light path as needed to make the video image of the source appear to fluctuate between dark and saturated bright. The resulting video-image data are analyzed by use of custom software that determines the integrated signal in each video frame and determines the system response curve (measured output signal versus input brightness). These determinations constitute the calibration, which is thereafter used in automatic, frame-by-frame processing of the data from the video images to be analyzed.

  13. Hanford Environmental Dose Reconstruction Project

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-06-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is being managed and conducted by the Battelle Pacific Northwest Laboratories under contract with the Centers for Disease Control. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

  14. Reconstruction of the anterior cruciate ligament.

    PubMed

    Seedhom, B B

    1992-01-01

    Ligaments are strong collagenous structures that act as constraints on joint motion, thus confining the articular surfaces to more or less the same paths. In so doing they prevent arbitrary apposition of these surfaces from occurring and resulting in abnormal stresses which may damage the joint surfaces. Ligaments rupture due to excessive loads, particularly those resulting from trauma occurring during sporting events or motor vehicle accidents. Knee and ankle joints have the highest frequency of ligamentous injuries. This paper is a brief review of the current approaches to the reconstruction of the knee ligaments with specific reference to the anterior cruciate ligament (ACL) being the most frequently reconstructed. This is not only because it is frequently injured but also because of the debilitating consequences of such an injury. Approaches ranging from the conservative to those that advocate the use of frank prosthetic replacement have been adopted by surgeons at both ends of the spectrum. Following a discussion of the rationale for reconstruction of the ACL, the mechanical and biological considerations of the reconstructive procedure are discussed. The different methods of ACL reconstruction are reviewed. These include: (a) primary repair, (b) reconstruction with different tissues, including autogenous allografts and xenografts, (c) reconstruction employing different synthetic devices. A brief discussion of the procedures used for reconstruction with different types of tissue and of the surviving examples of the synthetic devices will follow. PMID:1418190

  15. Pedestrian Counting with Occlusion Handling Using Stereo Thermal Cameras.

    PubMed

    Kristoffersen, Miklas S; Dueholm, Jacob V; Gade, Rikke; Moeslund, Thomas B

    2016-01-01

    The number of pedestrians walking the streets or gathered in public spaces is a valuable piece of information for shop owners, city governments, event organizers and many others. However, automatic counting that takes place day and night is challenging due to changing lighting conditions and the complexity of scenes with many people occluding one another. To address these challenges, this paper introduces the use of a stereo thermal camera setup for pedestrian counting. We investigate the reconstruction of 3D points in a pedestrian street with two thermal cameras and propose an algorithm for pedestrian counting based on clustering and tracking of the 3D point clouds. The method is tested on two five-minute video sequences captured at a public event with a moderate density of pedestrians and heavy occlusions. The counting performance is compared to the manually annotated ground truth and shows success rates of 95.4% and 99.1% for the two sequences. PMID:26742047

  16. Design and fabrication of endoscope-type Compton camera

    NASA Astrophysics Data System (ADS)

    Nakamura, Y.; Shimazoe, K.; Takahashi, H.

    2013-12-01

    We are constructing an endoscope coupled with a Compton camera to intra-operatively inspect early stage cancer and metastatic lymph node (5 mm-10 mm). The radiation imaging system is composed of pixelated semiconductor detectors, which are Si array and CdTe array, whose sizes are less than 10 mm×10 mm, and a digital signal-processing unit with ASIC and FPGA and reconstruction algorithm using spherical harmonics that can compute in real time. In this paper, we show some simulation results on the performance of the proposed prototype detector using EGS5, Monte Carlo simulation code. The FWHM of 1 mm spatial resolution for an object located 10 mm away from the detector surface and the intrinsic efficiency of 0.05% were observed. Imaging and data acquisition time to take fine images are just 1 min. It therefore can be considered that the endoscopic Compton camera is useful for intra-operative inspection.

  17. Positron camera using position-sensitive detectors: PENN-PET

    SciTech Connect

    Muehllehner, G.; Karp, J.S.

    1986-01-01

    A single-slice positron camera has been developed with good spatial resolution and high count rate capability. The camera uses a hexagonal arrangement of six position-sensitive NaI(Tl) detectors. The count rate capability of NaI(Tl) was extended to 800k cps through the use of pulse shortening. In order to keep the detectors stationary, an iterative reconstruction algorithm was modified which ignores the missing data in the gaps between the six detectors and gives artifact-free images. The spatial resolution, as determined from the image of point sources in air, is 6.5 mm full width at half maximum. We have also imaged a brain phantom and dog hearts.

  18. Pedestrian Counting with Occlusion Handling Using Stereo Thermal Cameras

    PubMed Central

    Kristoffersen, Miklas S.; Dueholm, Jacob V.; Gade, Rikke; Moeslund, Thomas B.

    2016-01-01

    The number of pedestrians walking the streets or gathered in public spaces is a valuable piece of information for shop owners, city governments, event organizers and many others. However, automatic counting that takes place day and night is challenging due to changing lighting conditions and the complexity of scenes with many people occluding one another. To address these challenges, this paper introduces the use of a stereo thermal camera setup for pedestrian counting. We investigate the reconstruction of 3D points in a pedestrian street with two thermal cameras and propose an algorithm for pedestrian counting based on clustering and tracking of the 3D point clouds. The method is tested on two five-minute video sequences captured at a public event with a moderate density of pedestrians and heavy occlusions. The counting performance is compared to the manually annotated ground truth and shows success rates of 95.4% and 99.1% for the two sequences. PMID:26742047

  19. Oblique Multi-Camera Systems - Orientation and Dense Matching Issues

    NASA Astrophysics Data System (ADS)

    Rupnik, E.; Nex, F.; Remondino, F.

    2014-03-01

    The use of oblique imagery has become a standard for many civil and mapping applications, thanks to the development of airborne digital multi-camera systems, as proposed by many companies (Blomoblique, IGI, Leica, Midas, Pictometry, Vexcel/Microsoft, VisionMap, etc.). The indisputable virtue of oblique photography lies in its simplicity of interpretation and understanding for inexperienced users allowing their use of oblique images in very different applications, such as building detection and reconstruction, building structural damage classification, road land updating and administration services, etc. The paper reports an overview of the actual oblique commercial systems and presents a workflow for the automated orientation and dense matching of large image blocks. Perspectives, potentialities, pitfalls and suggestions for achieving satisfactory results are given. Tests performed on two datasets acquired with two multi-camera systems over urban areas are also reported.

  20. Angular sensitivity of gated microchannel plate framing cameras

    SciTech Connect

    Landen, O. L.; Lobban, A.; Tutt, T.; Bell, P. M.; Costa, R.; Hargrove, D. R.; Ze, F.

    2001-01-01

    Gated, microchannel-plate-based (MCP) framing cameras have been deployed worldwide for 0.2--9 keV x-ray imaging and spectroscopy of transient plasma phenomena. For a variety of spectroscopic and imaging applications, the angular sensitivity of MCPs must be known for correctly interpreting the data. We present systematic measurements of angular sensitivity at discrete relevant photon energies and arbitrary MCP gain. The results can been accurately predicted by using a simple two-dimensional approximation to the three-dimensional MCP geometry and by averaging over all possible photon ray paths.

  1. Angular Sensitivity of Gated Micro-Channel Plate Framing Cameras

    SciTech Connect

    Landen, O L; Lobban, A; Tutt, T; Bell, P M; Costa, R; Ze, F

    2000-07-24

    Gated, microchannel-plate-based (MCP) framing cameras have been deployed worldwide for 0.2 - 9 keV x-ray imaging and spectroscopy of transient plasma phenomena. For a variety of spectroscopic and imaging applications, the angular sensitivity of MCPs must be known for correctly interpreting the data. We present systematic measurements of angular sensitivity at discrete relevant photon energies and arbitrary MCP gain. The results can been accurately predicted by using a simple 2D approximation to the 3D MCP geometry and by averaging over all possible photon ray paths.

  2. Linearisation of RGB Camera Responses for Quantitative Image Analysis of Visible and UV Photography: A Comparison of Two Techniques

    PubMed Central

    Garcia, Jair E.; Dyer, Adrian G.; Greentree, Andrew D.; Spring, Gale; Wilksch, Philip A.

    2013-01-01

    Linear camera responses are required for recovering the total amount of incident irradiance, quantitative image analysis, spectral reconstruction from camera responses and characterisation of spectral sensitivity curves. Two commercially-available digital cameras equipped with Bayer filter arrays and sensitive to visible and near-UV radiation were characterised using biexponential and Bézier curves. Both methods successfully fitted the entire characteristic curve of the tested devices, allowing for an accurate recovery of linear camera responses, particularly those corresponding to the middle of the exposure range. Nevertheless the two methods differ in the nature of the required input parameters and the uncertainty associated with the recovered linear camera responses obtained at the extreme ends of the exposure range. Here we demonstrate the use of both methods for retrieving information about scene irradiance, describing and quantifying the uncertainty involved in the estimation of linear camera responses. PMID:24260244

  3. Compact large FoV gamma camera for breast molecular imaging

    NASA Astrophysics Data System (ADS)

    Pani, R.; Cinti, M. N.; Pellegrini, R.; Betti, M.; Devincentis, G.; Bennati, P.; Ridolfi, S.; Iurlaro, G.; Montani, L.; Scafè, R.; Marini, M.; Porfiri, L. M.; Giachetti, G.; Baglini, F.; Salvadori, G.; Madesani, M.; Pieracci, M.; Catarsi, F.; Bigongiari, A.

    2006-12-01

    The very low sensitivity of scintimammography for tumours under 1 cm in diameter, with current nuclear medicine cameras, is the major limitation in recommending this test modality for screening purposes. To improve this diagnostic technique,a new concept of scintillation gamma camera, which fits the best requirements for functional breast imaging has been developed under "Integrated Mammographic Imaging" (IMI) project. This camera consists of a large detection head (6″×7″),very compact sized and with light weight to be easily positioned in the same X-ray geometry. The detection head consists of matrix of 42 photodetector Hamamatsu 1 in 2 square H8520-C12 PSPMTs, which are closely packed and coupled to a NaI(Tl) scintillating array, with individual crystal pixel 2×2×6 mm 3 size. Large FoV camera shows a very good pixel identification in the detection dead zones between tubes allowing an accurate LUT correction of the final image reconstruction. Electronic read-out was especially designed to optimize the intrinsic spatial resolution and camera compactness. With respect to Anger camera, the overall spatial resolution is improved up to 40% while the overall energy resolution values is ˜16% at 140 keV. Large FoV dedicated camera was characterized and tested by phantom studies; and clinical trials are currently performed. For all patients, compression views have been acquiring for both breasts in craniocaudal projections, and are compared with standard gamma camera images.

  4. Tree STEM Reconstruction Using Vertical Fisheye Images: a Preliminary Study

    NASA Astrophysics Data System (ADS)

    Berveglieri, A.; Tommaselli, A. M. G.

    2016-06-01

    A preliminary study was conducted to assess a tree stem reconstruction technique with panoramic images taken with fisheye lenses. The concept is similar to the Structure from Motion (SfM) technique, but the acquisition and data preparation rely on fisheye cameras to generate a vertical image sequence with height variations of the camera station. Each vertical image is rectified to four vertical planes, producing horizontal lateral views. The stems in the lateral view are rectified to the same scale in the image sequence to facilitate image matching. Using bundle adjustment, the stems are reconstructed, enabling later measurement and extraction of several attributes. The 3D reconstruction was performed with the proposed technique and compared with SfM. The preliminary results showed that the stems were correctly reconstructed by using the lateral virtual images generated from the vertical fisheye images and with the advantage of using fewer images and taken from one single station.

  5. Image Intensifier Modules For Use With Commercially Available Solid State Cameras

    NASA Astrophysics Data System (ADS)

    Murphy, Howard; Tyler, Al; Lake, Donald W.

    1989-04-01

    A modular approach to design has contributed greatly to the success of the family of machine vision video equipment produced by EG&G Reticon during the past several years. Internal modularity allows high-performance area (matrix) and line scan cameras to be assembled with two or three electronic subassemblies with very low labor costs, and permits camera control and interface circuitry to be realized by assemblages of various modules suiting the needs of specific applications. Product modularity benefits equipment users in several ways. Modular matrix and line scan cameras are available in identical enclosures (Fig. 1), which allows enclosure components to be purchased in volume for economies of scale and allows field replacement or exchange of cameras within a customer-designed system to be easily accomplished. The cameras are optically aligned (boresighted) at final test; modularity permits optical adjustments to be made with the same precise test equipment for all camera varieties. The modular cameras contain two, or sometimes three, hybrid microelectronic packages (Fig. 2). These rugged and reliable "submodules" perform all of the electronic operations internal to the camera except for the job of image acquisition performed by the monolithic image sensor. Heat produced by electrical power dissipation in the electronic modules is conducted through low resistance paths to the camera case by the metal plates, which results in a thermally efficient and environmentally tolerant camera with low manufacturing costs. A modular approach has also been followed in design of the camera control, video processor, and computer interface accessory called the Formatter (Fig. 3). This unit can be attached directly onto either a line scan or matrix modular camera to form a self-contained units, or connected via a cable to retain the advantages inherent to a small, light weight, and rugged image sensing component. Available modules permit the bus-structured Formatter to be

  6. Hyperspectral imaging using a color camera and its application for pathogen detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper reports the results of a feasibility study for the development of a hyperspectral image recovery (reconstruction) technique using a RGB color camera and regression analysis in order to detect and classify colonies of foodborne pathogens. The target bacterial pathogens were the six represe...

  7. Reconstruction of missing cells in fluorescent microscopy.

    PubMed

    Leung, Nat; Wan, Justin W L

    2012-01-01

    Fluorescent microscopy is one of the several types of imaging techniques used by biologists to study cell activities. One challenge of tracking cells from fluorescence microscopy is that cells in fluorescent images frequently disappear and reappear. The situation is further complicated by cell divisions, which also occur frequently in an image sequence. In this paper, we apply a level set method to reconstruct cells that disappear in an image sequence and in particular, cells that are undergoing cell division. The image frames are stacked together to form a 3D image volume. The disappearance of a cell leads to a broken cell path. We reconstruct the incomplete cell paths by a level set segmentation of the 3D image volume. If the disappearance happens during cell division, the level set method segments the visible cell paths before and after cell division, and then joins them together by extending the cell paths into the missing gap. We also propose a simple and cost-efficient method similar to inpainting techniques to capture the cell appearance when it disappears by making use of the level set function obtained from the segmentation. The idea is that the intensities of a visible cell on a level set contour are copied to the corresponding contours of a disappeared cell. We will present results for reconstruction of cells undergoing cell division for C2C12 cells in fluorescent images to illustrate the effectiveness of our method. PMID:23367131

  8. Multi-camera synchronization core implemented on USB3 based FPGA platform

    NASA Astrophysics Data System (ADS)

    Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Dias, Morgado

    2015-03-01

    Centered on Awaiba's NanEye CMOS image sensor family and a FPGA platform with USB3 interface, the aim of this paper is to demonstrate a new technique to synchronize up to 8 individual self-timed cameras with minimal error. Small form factor self-timed camera modules of 1 mm x 1 mm or smaller do not normally allow external synchronization. However, for stereo vision or 3D reconstruction with multiple cameras as well as for applications requiring pulsed illumination it is required to synchronize multiple cameras. In this work, the challenge of synchronizing multiple selftimed cameras with only 4 wire interface has been solved by adaptively regulating the power supply for each of the cameras. To that effect, a control core was created to constantly monitor the operating frequency of each camera by measuring the line period in each frame based on a well-defined sampling signal. The frequency is adjusted by varying the voltage level applied to the sensor based on the error between the measured line period and the desired line period. To ensure phase synchronization between frames, a Master-Slave interface was implemented. A single camera is defined as the Master, with its operating frequency being controlled directly through a PC based interface. The remaining cameras are setup in Slave mode and are interfaced directly with the Master camera control module. This enables the remaining cameras to monitor its line and frame period and adjust their own to achieve phase and frequency synchronization. The result of this work will allow the implementation of smaller than 3mm diameter 3D stereo vision equipment in medical endoscopic context, such as endoscopic surgical robotic or micro invasive surgery.

  9. Measuring Distances Using Digital Cameras

    ERIC Educational Resources Information Center

    Kendal, Dave

    2007-01-01

    This paper presents a generic method of calculating accurate horizontal and vertical object distances from digital images taken with any digital camera and lens combination, where the object plane is parallel to the image plane or tilted in the vertical plane. This method was developed for a project investigating the size, density and spatial…

  10. Gamma-ray camera flyby

    SciTech Connect

    2010-01-01

    Animation based on an actual classroom demonstration of the prototype CCI-2 gamma-ray camera's ability to image a hidden radioactive source, a cesium-137 line source, in three dimensions. For more information see http://newscenter.lbl.gov/feature-stories/2010/06/02/applied-nuclear-physics/.

  11. Camera assisted multimodal user interaction

    NASA Astrophysics Data System (ADS)

    Hannuksela, Jari; Silvén, Olli; Ronkainen, Sami; Alenius, Sakari; Vehviläinen, Markku

    2010-01-01

    Since more processing power, new sensing and display technologies are already available in mobile devices, there has been increased interest in building systems to communicate via different modalities such as speech, gesture, expression, and touch. In context identification based user interfaces, these independent modalities are combined to create new ways how the users interact with hand-helds. While these are unlikely to completely replace traditional interfaces, they will considerably enrich and improve the user experience and task performance. We demonstrate a set of novel user interface concepts that rely on built-in multiple sensors of modern mobile devices for recognizing the context and sequences of actions. In particular, we use the camera to detect whether the user is watching the device, for instance, to make the decision to turn on the display backlight. In our approach the motion sensors are first employed for detecting the handling of the device. Then, based on ambient illumination information provided by a light sensor, the cameras are turned on. The frontal camera is used for face detection, while the back camera provides for supplemental contextual information. The subsequent applications triggered by the context can be, for example, image capturing, or bar code reading.

  12. Television Camera Operator. Student's Manual.

    ERIC Educational Resources Information Center

    Grimes, L. A., Jr.

    This student manual is one in a series of individualized instructional materials for use under the supervision of an instructor. The self-contained manual was developed for persons training to become television camera operators. Each assignment has all the information needed, including a list of objectives that should be met and exercise questions…

  13. The Camera Comes to Court.

    ERIC Educational Resources Information Center

    Floren, Leola

    After the Lindbergh kidnapping trial in 1935, the American Bar Association sought to eliminate electronic equipment from courtroom proceedings. Eventually, all but two states adopted regulations applying that ban to some extent, and a 1965 Supreme Court decision encouraged the banning of television cameras at trials as well. Currently, some states…

  14. Camera lens adapter magnifies image

    NASA Technical Reports Server (NTRS)

    Moffitt, F. L.

    1967-01-01

    Polaroid Land camera with an illuminated 7-power magnifier adapted to the lens, photographs weld flaws. The flaws are located by inspection with a 10-power magnifying glass and then photographed with this device, thus providing immediate pictorial data for use in remedial procedures.

  15. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1991-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occuring during the readout window.

  16. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1989-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occurring during the readout window.

  17. Full Stokes polarization imaging camera

    NASA Astrophysics Data System (ADS)

    Vedel, M.; Breugnot, S.; Lechocinski, N.

    2011-10-01

    Objective and background: We present a new version of Bossa Nova Technologies' passive polarization imaging camera. The previous version was performing live measurement of the Linear Stokes parameters (S0, S1, S2), and its derivatives. This new version presented in this paper performs live measurement of Full Stokes parameters, i.e. including the fourth parameter S3 related to the amount of circular polarization. Dedicated software was developed to provide live images of any Stokes related parameters such as the Degree Of Linear Polarization (DOLP), the Degree Of Circular Polarization (DOCP), the Angle Of Polarization (AOP). Results: We first we give a brief description of the camera and its technology. It is a Division Of Time Polarimeter using a custom ferroelectric liquid crystal cell. A description of the method used to calculate Data Reduction Matrix (DRM)5,9 linking intensity measurements and the Stokes parameters is given. The calibration was developed in order to maximize the condition number of the DRM. It also allows very efficient post processing of the images acquired. Complete evaluation of the precision of standard polarization parameters is described. We further present the standard features of the dedicated software that was developed to operate the camera. It provides live images of the Stokes vector components and the usual associated parameters. Finally some tests already conducted are presented. It includes indoor laboratory and outdoor measurements. This new camera will be a useful tool for many applications such as biomedical, remote sensing, metrology, material studies, and others.

  18. Making Films without a Camera.

    ERIC Educational Resources Information Center

    Cox, Carole

    1980-01-01

    Describes draw-on filmmaking as an exciting way to introduce children to the plastic, fluid nature of the film medium, to develop their appreciation and understanding of divergent cinematic techniques and themes, and to invite them into the dream world of filmmaking without the need for a camera. (AEA)

  19. Stratoscope 2 integrating television camera

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The development, construction, test and delivery of an integrating television camera for use as the primary data sensor on Flight 9 of Stratoscope 2 is described. The system block diagrams are presented along with the performance data, and definition of the interface of the telescope with the power, telemetry, and communication system.

  20. Kinect v2 and RGB Stereo Cameras Integration for Depth Map Enhancement

    NASA Astrophysics Data System (ADS)

    Ravanelli, R.; Nascetti, A.; Crespi, M.

    2016-06-01

    Today range cameras are widespread low-cost sensors based on two different principles of operation: we can distinguish between Structured Light (SL) range cameras (Kinect v1, Structure Sensor, ...) and Time Of Flight (ToF) range cameras (Kinect v2, ...). Both the types are easy to use 3D scanners, able to reconstruct dense point clouds at high frame rate. However the depth maps obtained are often noisy and not enough accurate, therefore it is generally essential to improve their quality. Standard RGB cameras can be a valuable solution to solve such issue. The aim of this paper is therefore to evaluate the integration feasibility of these two different 3D modelling techniques, characterized by complementary features and based on standard low-cost sensors. For this purpose, a 3D model of a DUPLOTM bricks construction was reconstructed both with the Kinect v2 range camera and by processing one stereo pair acquired with a Canon Eos 1200D DSLR camera. The scale of the photgrammetric model was retrieved from the coordinates measured by Kinect v2. The preliminary results are encouraging and show that the foreseen integration could lead to an higher metric accuracy and a major level of completeness with respect to that obtained by using only separated techniques.

  1. Nonadiabatic transition path sampling

    NASA Astrophysics Data System (ADS)

    Sherman, M. C.; Corcelli, S. A.

    2016-07-01

    Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase.

  2. Nonadiabatic transition path sampling.

    PubMed

    Sherman, M C; Corcelli, S A

    2016-07-21

    Fewest-switches surface hopping (FSSH) is combined with transition path sampling (TPS) to produce a new method called nonadiabatic path sampling (NAPS). The NAPS method is validated on a model electron transfer system coupled to a Langevin bath. Numerically exact rate constants are computed using the reactive flux (RF) method over a broad range of solvent frictions that span from the energy diffusion (low friction) regime to the spatial diffusion (high friction) regime. The NAPS method is shown to quantitatively reproduce the RF benchmark rate constants over the full range of solvent friction. Integrating FSSH within the TPS framework expands the applicability of both approaches and creates a new method that will be helpful in determining detailed mechanisms for nonadiabatic reactions in the condensed-phase. PMID:27448877

  3. Four paths of competition

    SciTech Connect

    Studness, C.M.

    1995-05-01

    The financial community`s focus on utility competition has been riveted on the proceedings now in progress at state regulatory commissions. The fear that something immediately damaging will come out of these proceedings seems to have diminished in recent months, and the stock market has reacted favorably. However, regulatory developments are only one of four paths leading to competition; the others are the marketplace, the legislatures, and the courts. Each could play a critical role in the emergence of competition.

  4. An investigation of photosensor aperture shaping in facsimile cameras

    NASA Technical Reports Server (NTRS)

    Katzberg, S. J.; Huck, F. O.; Wall, S. D.

    1972-01-01

    Optical-mechanical scanning techniques are generally employed in instruments specifically designed to spectrally or radiometrically characterize variations in scene brightness. The effect of aliasing, which can be caused by line scan sampling, on the spatial detail of the reconstructed image has, therefore, been of little concern. Emphasis of some recent applications of optical-mechanical scanning techniques in facsimile cameras is, however, on the spatial characterization of the scene which, as is shown, can be severely degraded by aliasing. The characteristics of aliasing are analyzed to establish quantitative bounds, and photosensor aperture shaping and line scan spacing are investigated as a means for reducing this degradation.

  5. Proton shadow camera using CR-39 track detectors

    SciTech Connect

    Stone, G.F.; Ceglio, N.M.

    1983-09-01

    We have developed a capability for imaging proton sources of moderate energy (6 MeV), with moderate spatial resolution (approx. = 9 ..mu..m), as a diagnostic for laser fusion research. Our technique involves the use of Fresnel zone plate coded imaging coupled with nuclear track detectors (CR-39). We report on a series of test experiments in which a zone plate shadow camera successfully produced images of a proton source distribution. The zone plate shadow patterns were optically reconstructed in higher order producing diffraction-limited point response images with FWHM values of approx. = 9 ..mu..m for a 6 MeV proton source.

  6. PATHS groundwater hydrologic model

    SciTech Connect

    Nelson, R.W.; Schur, J.A.

    1980-04-01

    A preliminary evaluation capability for two-dimensional groundwater pollution problems was developed as part of the Transport Modeling Task for the Waste Isolation Safety Assessment Program (WISAP). Our approach was to use the data limitations as a guide in setting the level of modeling detail. PATHS Groundwater Hydrologic Model is the first level (simplest) idealized hybrid analytical/numerical model for two-dimensional, saturated groundwater flow and single component transport; homogeneous geology. This document consists of the description of the PATHS groundwater hydrologic model. The preliminary evaluation capability prepared for WISAP, including the enhancements that were made because of the authors' experience using the earlier capability is described. Appendixes A through D supplement the report as follows: complete derivations of the background equations are provided in Appendix A. Appendix B is a comprehensive set of instructions for users of PATHS. It is written for users who have little or no experience with computers. Appendix C is for the programmer. It contains information on how input parameters are passed between programs in the system. It also contains program listings and test case listing. Appendix D is a definition of terms.

  7. Recent advances in digital camera optics

    NASA Astrophysics Data System (ADS)

    Ishiguro, Keizo

    2012-10-01

    The digital camera market has extremely expanded in the last ten years. The zoom lens for digital camera is especially the key determining factor of the camera body size and image quality. Its technologies have been based on several analog technological progresses including the method of aspherical lens manufacturing and the mechanism of image stabilization. Panasonic is one of the pioneers of both technologies. I will introduce the previous trend in optics of zoom lens as well as original optical technologies of Panasonic digital camera "LUMIX", and in addition optics in 3D camera system. Besides, I would like to suppose the future trend in digital cameras.

  8. Photogrammetric Reconstruction with Bayesian Information

    NASA Astrophysics Data System (ADS)

    Masiero, A.; Fissore, F.; Guarnieri, A.; Pirotti, F.; Vettore, A.

    2016-06-01

    Nowadays photogrammetry and laser scanning methods are the most wide spread surveying techniques. Laser scanning methods usually allow to obtain more accurate results with respect to photogrammetry, but their use have some issues, e.g. related to the high cost of the instrumentation and the typical need of high qualified personnel to acquire experimental data on the field. Differently, photogrammetric reconstruction can be achieved by means of low cost devices and by persons without specific training. Furthermore, the recent diffusion of smart devices (e.g. smartphones) embedded with imaging and positioning sensors (i.e. standard camera, GNSS receiver, inertial measurement unit) is opening the possibility of integrating more information in the photogrammetric reconstruction procedure, in order to increase its computational efficiency, its robustness and accuracy. In accordance with the above observations, this paper examines and validates new possibilities for the integration of information provided by the inertial measurement unit (IMU) into the photogrammetric reconstruction procedure, and, to be more specific, into the procedure for solving the feature matching and the bundle adjustment problems.

  9. New Reconstruction Accuracy Metric for 3D PIV

    NASA Astrophysics Data System (ADS)

    Bajpayee, Abhishek; Techet, Alexandra

    2015-11-01

    Reconstruction for 3D PIV typically relies on recombining images captured from different viewpoints via multiple cameras/apertures. Ideally, the quality of reconstruction dictates the accuracy of the derived velocity field. A reconstruction quality parameter Q is commonly used as a measure of the accuracy of reconstruction algorithms. By definition, a high Q value requires intensity peak levels and shapes in the reconstructed and reference volumes to be matched. We show that accurate velocity fields rely only on the peak locations in the volumes and not on intensity peak levels and shapes. In synthetic aperture (SA) PIV reconstructions, the intensity peak shapes and heights vary with the number of cameras and due to spatial/temporal particle intensity variation respectively. This lowers Q but not the accuracy of the derived velocity field. We introduce a new velocity vector correlation factor Qv as a metric to assess the accuracy of 3D PIV techniques, which provides a better indication of algorithm accuracy. For SAPIV, the number of cameras required for a high Qv are lower than that for a high Q. We discuss Qv in the context of 3D PIV and also present a preliminary comparison of the performance of TomoPIV and SAPIV based on Qv.

  10. Performance simulation model for a new MWIR camera for missile plume detection

    NASA Astrophysics Data System (ADS)

    Yoon, Jeeyeon; Ryu, Dongok; Kim, Sangmin; Seong, Sehyun; Kim, Jieun; Kim, Sug-Whan; Yoon, Woongsup

    2013-10-01

    We report realistic performance simulation results for a new MWIR camera. It is designed for early detection of long distance missile plumes over few hundreds kilometer in the distance range. The camera design uses a number of refractive optical element and a IR detector. Both imaging and radiometric performance of the camera are investigated by using large scale ray tracing including targets and background scene models. Missile plume radiance was calculated from using CFD type radiative transfer algorithm and used as the light source for ray tracing computation. The atmospheric background was estimated using MODTRAN utilizing path thermal radiance, single/multiple scattered radiance and transmittance. The ray tracing simulation results demonstrate that the camera would satisfy the imaging and radiometric performance requirements in field operation at the target MWIR band.

  11. Feasibility study of transmission of OTV camera control information in the video vertical blanking interval

    NASA Technical Reports Server (NTRS)

    White, Preston A., III

    1994-01-01

    The Operational Television system at Kennedy Space Center operates hundreds of video cameras, many remotely controllable, in support of the operations at the center. This study was undertaken to determine if commercial NABTS (North American Basic Teletext System) teletext transmission in the vertical blanking interval of the genlock signals distributed to the cameras could be used to send remote control commands to the cameras and the associated pan and tilt platforms. Wavelength division multiplexed fiberoptic links are being installed in the OTV system to obtain RS-250 short-haul quality. It was demonstrated that the NABTS transmission could be sent over the fiberoptic cable plant without excessive video quality degradation and that video cameras could be controlled using NABTS transmissions over multimode fiberoptic paths as long as 1.2 km.

  12. Replacing 16-mm film cameras with high-definition digital cameras

    NASA Astrophysics Data System (ADS)

    Balch, Kris S.

    1995-09-01

    For many years 16 mm film cameras have been used in severe environments. These film cameras are used on Hy-G automotive sleds, airborne gun cameras, range tracking and other hazardous environments. The companies and government agencies using these cameras are in need of replacing them with a more cost effective solution. Film-based cameras still produce the best resolving capability, however, film development time, chemical disposal, recurring media cost, and faster digital analysis are factors influencing the desire for a 16 mm film camera replacement. This paper will describe a new camera from Kodak that has been designed to replace 16 mm high speed film cameras.

  13. Action Sport Cameras as an Instrument to Perform a 3D Underwater Motion Analysis.

    PubMed

    Bernardina, Gustavo R D; Cerveri, Pietro; Barros, Ricardo M L; Marins, João C B; Silvatti, Amanda P

    2016-01-01

    Action sport cameras (ASC) are currently adopted mainly for entertainment purposes but their uninterrupted technical improvements, in correspondence of cost decreases, are going to disclose them for three-dimensional (3D) motion analysis in sport gesture study and athletic performance evaluation quantitatively. Extending this technology to sport analysis however still requires a methodologic step-forward to making ASC a metric system, encompassing ad-hoc camera setup, image processing, feature tracking, calibration and 3D reconstruction. Despite traditional laboratory analysis, such requirements become an issue when coping with both indoor and outdoor motion acquisitions of athletes. In swimming analysis for example, the camera setup and the calibration protocol are particularly demanding since land and underwater cameras are mandatory. In particular, the underwater camera calibration can be an issue affecting the reconstruction accuracy. In this paper, the aim is to evaluate the feasibility of ASC for 3D underwater analysis by focusing on camera setup and data acquisition protocols. Two GoPro Hero3+ Black (frequency: 60Hz; image resolutions: 1280×720/1920×1080 pixels) were located underwater into a swimming pool, surveying a working volume of about 6m3. A two-step custom calibration procedure, consisting in the acquisition of one static triad and one moving wand, carrying nine and one spherical passive markers, respectively, was implemented. After assessing camera parameters, a rigid bar, carrying two markers at known distance, was acquired in several positions within the working volume. The average error upon the reconstructed inter-marker distances was less than 2.5mm (1280×720) and 1.5mm (1920×1080). The results of this study demonstrate that the calibration of underwater ASC is feasible enabling quantitative kinematic measurements with accuracy comparable to traditional motion capture systems. PMID:27513846

  14. Action Sport Cameras as an Instrument to Perform a 3D Underwater Motion Analysis

    PubMed Central

    Cerveri, Pietro; Barros, Ricardo M. L.; Marins, João C. B.; Silvatti, Amanda P.

    2016-01-01

    Action sport cameras (ASC) are currently adopted mainly for entertainment purposes but their uninterrupted technical improvements, in correspondence of cost decreases, are going to disclose them for three-dimensional (3D) motion analysis in sport gesture study and athletic performance evaluation quantitatively. Extending this technology to sport analysis however still requires a methodologic step-forward to making ASC a metric system, encompassing ad-hoc camera setup, image processing, feature tracking, calibration and 3D reconstruction. Despite traditional laboratory analysis, such requirements become an issue when coping with both indoor and outdoor motion acquisitions of athletes. In swimming analysis for example, the camera setup and the calibration protocol are particularly demanding since land and underwater cameras are mandatory. In particular, the underwater camera calibration can be an issue affecting the reconstruction accuracy. In this paper, the aim is to evaluate the feasibility of ASC for 3D underwater analysis by focusing on camera setup and data acquisition protocols. Two GoPro Hero3+ Black (frequency: 60Hz; image resolutions: 1280×720/1920×1080 pixels) were located underwater into a swimming pool, surveying a working volume of about 6m3. A two-step custom calibration procedure, consisting in the acquisition of one static triad and one moving wand, carrying nine and one spherical passive markers, respectively, was implemented. After assessing camera parameters, a rigid bar, carrying two markers at known distance, was acquired in several positions within the working volume. The average error upon the reconstructed inter-marker distances was less than 2.5mm (1280×720) and 1.5mm (1920×1080). The results of this study demonstrate that the calibration of underwater ASC is feasible enabling quantitative kinematic measurements with accuracy comparable to traditional motion capture systems. PMID:27513846

  15. Noise evaluation of Compton camera imaging for proton therapy.

    PubMed

    Ortega, P G; Torres-Espallardo, I; Cerutti, F; Ferrari, A; Gillam, J E; Lacasta, C; Llosá, G; Oliver, J F; Sala, P R; Solevi, P; Rafecas, M

    2015-03-01

    Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming γ energy is considered as a variable in the reconstruction inverse problem. Jointly with prompt gamma, secondary neutrons and scattered photons, not strongly correlated with the dose map, can also reach the imaging detector and produce false events. These events deteriorate the image quality. Also, high intensity beams can produce particle accumulation in the camera, which lead to an increase of random coincidences, meaning events which gather measurements from different incoming particles. The noise scenario is expected to be different if double or triple events are used, and consequently, the reconstructed images can be affected differently by spurious data. The aim of the present work is to study the effect of false events in the reconstructed image, evaluating their impact in the determination of the beam particle ranges. A simulation study that includes misidentified events (neutrons and random coincidences) in the final image of a Compton Telescope for PT monitoring is presented. The complete chain of

  16. Noise evaluation of Compton camera imaging for proton therapy

    NASA Astrophysics Data System (ADS)

    Ortega, P. G.; Torres-Espallardo, I.; Cerutti, F.; Ferrari, A.; Gillam, J. E.; Lacasta, C.; Llosá, G.; Oliver, J. F.; Sala, P. R.; Solevi, P.; Rafecas, M.

    2015-02-01

    Compton Cameras emerged as an alternative for real-time dose monitoring techniques for Particle Therapy (PT), based on the detection of prompt-gammas. As a consequence of the Compton scattering process, the gamma origin point can be restricted onto the surface of a cone (Compton cone). Through image reconstruction techniques, the distribution of the gamma emitters can be estimated, using cone-surfaces backprojections of the Compton cones through the image space, along with more sophisticated statistical methods to improve the image quality. To calculate the Compton cone required for image reconstruction, either two interactions, the last being photoelectric absorption, or three scatter interactions are needed. Because of the high energy of the photons in PT the first option might not be adequate, as the photon is not absorbed in general. However, the second option is less efficient. That is the reason to resort to spectral reconstructions, where the incoming γ energy is considered as a variable in the reconstruction inverse problem. Jointly with prompt gamma, secondary neutrons and scattered photons, not strongly correlated with the dose map, can also reach the imaging detector and produce false events. These events deteriorate the image quality. Also, high intensity beams can produce particle accumulation in the camera, which lead to an increase of random coincidences, meaning events which gather measurements from different incoming particles. The noise scenario is expected to be different if double or triple events are used, and consequently, the reconstructed images can be affected differently by spurious data. The aim of the present work is to study the effect of false events in the reconstructed image, evaluating their impact in the determination of the beam particle ranges. A simulation study that includes misidentified events (neutrons and random coincidences) in the final image of a Compton Telescope for PT monitoring is presented. The complete chain of

  17. 3D puzzle reconstruction for archeological fragments

    NASA Astrophysics Data System (ADS)

    Jampy, F.; Hostein, A.; Fauvet, E.; Laligant, O.; Truchetet, F.

    2015-03-01

    The reconstruction of broken artifacts is a common task in archeology domain; it can be supported now by 3D data acquisition device and computer processing. Many works have been dedicated in the past to reconstructing 2D puzzles but very few propose a true 3D approach. We present here a complete solution including a dedicated transportable 3D acquisition set-up and a virtual tool with a graphic interface allowing the archeologists to manipulate the fragments and to, interactively, reconstruct the puzzle. The whole lateral part is acquired by rotating the fragment around an axis chosen within a light sheet thanks to a step-motor synchronized with the camera frame clock. Another camera provides a top view of the fragment under scanning. A scanning accuracy of 100μm is attained. The iterative automatic processing algorithm is based on segmentation into facets of the lateral part of the fragments followed by a 3D matching providing the user with a ranked short list of possible assemblies. The device has been applied to the reconstruction of a set of 1200 fragments from broken tablets supporting a Latin inscription dating from the first century AD.

  18. Error control in the set-up of stereo camera systems for 3d animal tracking

    NASA Astrophysics Data System (ADS)

    Cavagna, A.; Creato, C.; Del Castello, L.; Giardina, I.; Melillo, S.; Parisi, L.; Viale, M.

    2015-12-01

    Three-dimensional tracking of animal systems is the key to the comprehension of collective behavior. Experimental data collected via a stereo camera system allow the reconstruction of the 3d trajectories of each individual in the group. Trajectories can then be used to compute some quantities of interest to better understand collective motion, such as velocities, distances between individuals and correlation functions. The reliability of the retrieved trajectories is strictly related to the accuracy of the 3d reconstruction. In this paper, we perform a careful analysis of the most significant errors affecting 3d reconstruction, showing how the accuracy depends on the camera system set-up and on the precision of the calibration parameters.

  19. Compact infrared cryogenic wafer-level camera: design and experimental validation.

    PubMed

    de la Barrière, Florence; Druart, Guillaume; Guérineau, Nicolas; Lasfargues, Gilles; Fendler, Manuel; Lhermet, Nicolas; Taboury, Jean

    2012-03-10

    We present a compact infrared cryogenic multichannel camera with a wide field of view equal to 120°. By merging the optics with the detector, the concept is compatible with both cryogenic constraints and wafer-level fabrication. The design strategy of such a camera is described, as well as its fabrication and integration process. Its characterization has been carried out in terms of the modulation transfer function and the noise equivalent temperature difference (NETD). The optical system is limited by the diffraction. By cooling the optics, we achieve a very low NETD equal to 15 mK compared with traditional infrared cameras. A postprocessing algorithm that aims at reconstructing a well-sampled image from the set of undersampled raw subimages produced by the camera is proposed and validated on experimental images. PMID:22410982

  20. Robust real time extraction of plane segments from time-of-flight camera images

    NASA Astrophysics Data System (ADS)

    Dalbah, Yosef; Koltermann, Dirk; Wahl, Friedrich M.

    2014-04-01

    We present a method that extracts plane segments from images of a time-of-flight camera. Future driver assistance systems rely on an accurate description of the vehicle's environment. Time-of-flight cameras can be used for environment perception and for the reconstruction of the environment. Since most structures in urban environments are planar, extracted plane segments from single camera images can be used for the creation of a global map. We present a method for real time detection of planar surface structures from time-of-flight camera data. The concept is based on a planar surface segmentation that serves as the fundament for a subsequent global planar surface extraction. The evaluation demonstrates the ability of the described algorithm to detect planar surfaces form depth data of complex scenarios in real time. We compare our methods to state of the art planar surface extraction algorithms.

  1. The wide field/planetary camera

    NASA Technical Reports Server (NTRS)

    Westphal, J. A.; Baum, W. A.; Code, A. D.; Currie, D. G.; Danielson, G. E.; Gunn, J. E.; Kelsall, T. F.; Kristian, J. A.; Lynds, C. R.; Seidelmann, P. K.

    1982-01-01

    A wide site of potential astronomical and solar system scientific studies using the wide field planetary camera on space telescope are described. The expected performance of the camera as it approaches final assembly and testing is also detailed.

  2. Lytro camera technology: theory, algorithms, performance analysis

    NASA Astrophysics Data System (ADS)

    Georgiev, Todor; Yu, Zhan; Lumsdaine, Andrew; Goma, Sergio

    2013-03-01

    The Lytro camera is the first implementation of a plenoptic camera for the consumer market. We consider it a successful example of the miniaturization aided by the increase in computational power characterizing mobile computational photography. The plenoptic camera approach to radiance capture uses a microlens array as an imaging system focused on the focal plane of the main camera lens. This paper analyzes the performance of Lytro camera from a system level perspective, considering the Lytro camera as a black box, and uses our interpretation of Lytro image data saved by the camera. We present our findings based on our interpretation of Lytro camera file structure, image calibration and image rendering; in this context, artifacts and final image resolution are discussed.

  3. Critical Path Web Site

    NASA Technical Reports Server (NTRS)

    Robinson, Judith L.; Charles, John B.; Rummel, John A. (Technical Monitor)

    2000-01-01

    Approximately three years ago, the Agency's lead center for the human elements of spaceflight (the Johnson Space Center), along with the National Biomedical Research Institute (NSBRI) (which has the lead role in developing countermeasures) initiated an activity to identify the most critical risks confronting extended human spaceflight. Two salient factors influenced this activity: first, what information is needed to enable a "go/no go" decision to embark on extended human spaceflight missions; and second, what knowledge and capabilities are needed to address known and potential health, safety and performance risks associated with such missions. A unique approach was used to first define and assess those risks, and then to prioritize them. This activity was called the Critical Path Roadmap (CPR) and it represents an opportunity to develop and implement a focused and evolving program of research and technology designed from a "risk reduction" perspective to prevent or minimize the risks to humans exposed to the space environment. The Critical Path Roadmap provides the foundation needed to ensure that human spaceflight, now and in the future, is as safe, productive and healthy as possible (within the constraints imposed on any particular mission) regardless of mission duration or destination. As a tool, the Critical Path Roadmap enables the decisionmaker to select from among the demonstrated or potential risks those that are to be mitigated, and the completeness of that mitigation. The primary audience for the CPR Web Site is the members of the scientific community who are interested in the research and technology efforts required for ensuring safe and productive human spaceflight. They may already be informed about the various space life sciences research programs or they may be newcomers. Providing the CPR content to potential investigators increases the probability of their delivering effective risk mitigations. Others who will use the CPR Web Site and its content

  4. Critical Path Web Site

    NASA Technical Reports Server (NTRS)

    Robinson, Judith L.; Charles, John B.; Rummel, John A. (Technical Monitor)

    2000-01-01

    Approximately three years ago, the Agency's lead center for the human elements of spaceflight (the Johnson Space Center), along with the National Biomedical Research Institute (NSBRI) (which has the lead role in developing countermeasures) initiated an activity to identify the most critical risks confronting extended human spaceflight. Two salient factors influenced this activity: first, what information is needed to enable a "go/no go" decision to embark on extended human spaceflight missions; and second, what knowledge and capabilities are needed to address known and potential health, safety and performance risks associated with such missions. A unique approach was used to first define and assess those risks, and then to prioritize them. This activity was called the Critical Path Roadmap (CPR) and it represents an opportunity to develop and implement a focused and evolving program of research and technology designed from a "risk reduction" perspective to prevent or minimize the risks to humans exposed to the space environment. The Critical Path Roadmap provides the foundation needed to ensure that human spaceflight, now and in the future, is as safe, productive and healthy as possible (within the constraints imposed on any particular mission) regardless of mission duration or destination. As a tool, the Critical Path Roadmap enables the decision maker to select from among the demonstrated or potential risks those that are to be mitigated, and the completeness of that mitigation. The primary audience for the CPR Web Site is the members of the scientific community who are interested in the research and technology efforts required for ensuring safe and productive human spaceflight. They may already be informed about the various space life sciences research programs or they may be newcomers. Providing the CPR content to potential investigators increases the probability of their delivering effective risk mitigations. Others who will use the CPR Web Site and its

  5. Electronographic cameras for space astronomy.

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.; Opal, C. B.

    1972-01-01

    Magnetically-focused electronographic cameras have been under development at the Naval Research Laboratory for use in far-ultraviolet imagery and spectrography, primarily in astronomical and optical-geophysical observations from sounding rockets and space vehicles. Most of this work has been with cameras incorporating internal optics of the Schmidt or wide-field all-reflecting types. More recently, we have begun development of electronographic spectrographs incorporating an internal concave grating, operating at normal or grazing incidence. We also are developing electronographic image tubes of the conventional end-window-photo-cathode type, for far-ultraviolet imagery at the focus of a large space telescope, with image formats up to 120 mm in diameter.

  6. Combustion pinhole-camera system

    DOEpatents

    Witte, A.B.

    1982-05-19

    A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

  7. The Dark Energy Survey Camera

    NASA Astrophysics Data System (ADS)

    Flaugher, Brenna

    2012-03-01

    The Dark Energy Survey Collaboration has built the Dark Energy Camera (DECam), a 3 square degree, 520 Megapixel CCD camera which is being mounted on the Blanco 4-meter telescope at CTIO. DECam will be used to carry out the 5000 sq. deg. Dark Energy Survey, using 30% of the telescope time over a 5 year period. During the remainder of the time, and after the survey, DECam will be available as a community instrument. Construction of DECam is complete. The final components were shipped to Chile in Dec. 2011 and post-shipping checkout is in progress in Dec-Jan. Installation and commissioning on the telescope are taking place in 2012. A summary of lessons learned and an update of the performance of DECam and the status of the DECam installation and commissioning will be presented.

  8. A 10-microm infrared camera.

    PubMed

    Arens, J F; Jernigan, J G; Peck, M C; Dobson, C A; Kilk, E; Lacy, J; Gaalema, S

    1987-09-15

    An IR camera has been built at the University of California at Berkeley for astronomical observations. The camera has been used primarily for high angular resolution imaging at mid-IR wavelengths. It has been tested at the University of Arizona 61- and 90-in. telescopes near Tucson and the NASA Infrared Telescope Facility on Mauna Kea, HI. In the observations the system has been used as an imager with interference coated and Fabry-Perot filters. These measurements have demonstrated a sensitivity consistent with photon shot noise, showing that the system is limited by the radiation from the telescope and atmosphere. Measurements of read noise, crosstalk, and hysteresis have been made in our laboratory. PMID:20490151

  9. Thermoalgebras and path integral

    NASA Astrophysics Data System (ADS)

    Khanna, F. C.; Malbouisson, A. P. C.; Malbouisson, J. M. C.; Santana, A. E.

    2009-09-01

    Using a representation for Lie groups closely associated with thermal problems, we derive the algebraic rules of the real-time formalism for thermal quantum field theories, the so-called thermo-field dynamics (TFD), including the tilde conjugation rules for interacting fields. These thermo-group representations provide a unified view of different approaches for finite-temperature quantum fields in terms of a symmetry group. On these grounds, a path integral formalism is constructed, using Bogoliubov transformations, for bosons, fermions and non-abelian gauge fields. The generalization of the results for quantum fields in (S1)d×R topology is addressed.

  10. Path Integrals and Supersolids

    NASA Astrophysics Data System (ADS)

    Ceperley, D. M.

    2008-11-01

    Recent experiments by Kim and Chan on solid 4He have been interpreted as discovery of a supersolid phase of matter. Arguments based on wavefunctions have shown that such a phase exists, but do not necessarily apply to solid 4He. Imaginary time path integrals, implemented using Monte Carlo methods, provide a definitive answer; a clean system of solid 4He should be a normal quantum solid, not one with superfluid properties. The Kim-Chan phenomena must be due to defects introduced when the solid is formed.

  11. JAVA PathFinder

    NASA Technical Reports Server (NTRS)

    Mehhtz, Peter

    2005-01-01

    JPF is an explicit state software model checker for Java bytecode. Today, JPF is a swiss army knife for all sort of runtime based verification purposes. This basically means JPF is a Java virtual machine that executes your program not just once (like a normal VM), but theoretically in all possible ways, checking for property violations like deadlocks or unhandled exceptions along all potential execution paths. If it finds an error, JPF reports the whole execution that leads to it. Unlike a normal debugger, JPF keeps track of every step how it got to the defect.

  12. Portage and Path Dependence*

    PubMed Central

    Bleakley, Hoyt; Lin, Jeffrey

    2012-01-01

    We examine portage sites in the U.S. South, Mid-Atlantic, and Midwest, including those on the fall line, a geomorphological feature in the southeastern U.S. marking the final rapids on rivers before the ocean. Historically, waterborne transport of goods required portage around the falls at these points, while some falls provided water power during early industrialization. These factors attracted commerce and manufacturing. Although these original advantages have long since been made obsolete, we document the continuing importance of these portage sites over time. We interpret these results as path dependence and contrast explanations based on sunk costs interacting with decreasing versus increasing returns to scale. PMID:23935217

  13. Portage and Path Dependence.

    PubMed

    Bleakley, Hoyt; Lin, Jeffrey

    2012-05-01

    We examine portage sites in the U.S. South, Mid-Atlantic, and Midwest, including those on the fall line, a geomorphological feature in the southeastern U.S. marking the final rapids on rivers before the ocean. Historically, waterborne transport of goods required portage around the falls at these points, while some falls provided water power during early industrialization. These factors attracted commerce and manufacturing. Although these original advantages have long since been made obsolete, we document the continuing importance of these portage sites over time. We interpret these results as path dependence and contrast explanations based on sunk costs interacting with decreasing versus increasing returns to scale. PMID:23935217

  14. Corrective Optics For Camera On Telescope

    NASA Technical Reports Server (NTRS)

    Macenka, Steven A.; Meinel, Aden B.

    1994-01-01

    Assembly of tilted, aspherical circularly symmetric mirrors used as corrective optical subsystem for camera mounted on telescope exhibiting both large spherical wave-front error and inherent off-axis astigmatism. Subsystem provides unobscured camera aperture and diffraction-limited camera performance, despite large telescope aberrations. Generic configuration applied in other optical systems in which aberations deliberately introduced into telescopes and corrected in associated cameras. Concept of corrective optical subsystem provides designer with additional degrees of freedom used to optimize optical system.

  15. Optical boundary reconstruction of tokamak plasmas for feedback control of plasma position and shape

    SciTech Connect

    Hommen, G.; Baar, M. de; Nuij, P.; Steinbuch, M.; McArdle, G.; Akers, R.

    2010-11-15

    A new diagnostic is developed to reconstruct the plasma boundary using visible wavelength images. Exploiting the plasma's edge localized and toroidally symmetric emission profile, a new coordinate transform is presented to reconstruct the plasma boundary from a poloidal view image. The plasma boundary reconstruction is implemented in MATLAB and applied to camera images of Mega-Ampere Spherical Tokamak discharges. The optically reconstructed plasma boundaries are compared to magnetic reconstructions from the offline reconstruction code EFIT, showing very good qualitative and quantitative agreement. Average errors are within 2 cm and correlation is high. In the current software implementation, plasma boundary reconstruction from a single image takes 3 ms. The applicability and system requirements of the new optical boundary reconstruction, called OFIT, for use in both feedback control of plasma position and shape and in offline reconstruction tools are discussed.

  16. 3D Reconstruction of Human Motion from Monocular Image Sequences.

    PubMed

    Wandt, Bastian; Ackermann, Hanno; Rosenhahn, Bodo

    2016-08-01

    This article tackles the problem of estimating non-rigid human 3D shape and motion from image sequences taken by uncalibrated cameras. Similar to other state-of-the-art solutions we factorize 2D observations in camera parameters, base poses and mixing coefficients. Existing methods require sufficient camera motion during the sequence to achieve a correct 3D reconstruction. To obtain convincing 3D reconstructions from arbitrary camera motion, our method is based on a-priorly trained base poses. We show that strong periodic assumptions on the coefficients can be used to define an efficient and accurate algorithm for estimating periodic motion such as walking patterns. For the extension to non-periodic motion we propose a novel regularization term based on temporal bone length constancy. In contrast to other works, the proposed method does not use a predefined skeleton or anthropometric constraints and can handle arbitrary camera motion. We achieve convincing 3D reconstructions, even under the influence of noise and occlusions. Multiple experiments based on a 3D error metric demonstrate the stability of the proposed method. Compared to other state-of-the-art methods our algorithm shows a significant improvement. PMID:27093439

  17. Graphic design of pinhole cameras

    NASA Technical Reports Server (NTRS)

    Edwards, H. B.; Chu, W. P.

    1979-01-01

    The paper describes a graphic technique for the analysis and optimization of pinhole size and focal length. The technique is based on the use of the transfer function of optical elements described by Scott (1959) to construct the transfer function of a circular pinhole camera. This transfer function is the response of a component or system to a pattern of lines having a sinusoidally varying radiance at varying spatial frequencies. Some specific examples of graphic design are presented.

  18. Coaxial fundus camera for opthalmology

    NASA Astrophysics Data System (ADS)

    de Matos, Luciana; Castro, Guilherme; Castro Neto, Jarbas C.

    2015-09-01

    A Fundus Camera for ophthalmology is a high definition device which needs to meet low light illumination of the human retina, high resolution in the retina and reflection free image1. Those constraints make its optical design very sophisticated, but the most difficult to comply with is the reflection free illumination and the final alignment due to the high number of non coaxial optical components in the system. Reflection of the illumination, both in the objective and at the cornea, mask image quality, and a poor alignment make the sophisticated optical design useless. In this work we developed a totally axial optical system for a non-midriatic Fundus Camera. The illumination is performed by a LED ring, coaxial with the optical system and composed of IR of visible LEDs. The illumination ring is projected by the objective lens in the cornea. The Objective, LED illuminator, CCD lens are coaxial making the final alignment easily to perform. The CCD + capture lens module is a CCTV camera with autofocus and Zoom built in, added to a 175 mm focal length doublet corrected for infinity, making the system easily operated and very compact.

  19. Solid-state array cameras.

    PubMed

    Strull, G; List, W F; Irwin, E L; Farnsworth, D L

    1972-05-01

    Over the past few years there has been growing interest shown in the rapidly maturing technology of totally solid-state imaging. This paper presents a synopsis of developments made in this field at the Westinghouse ATL facilities with emphasis on row-column organized monolithic arrays of diffused junction phototransistors. The complete processing sequence applicable to the fabrication of modern highdensity arrays is described from wafer ingot preparation to final sensor testing. Special steps found necessary for high yield processing, such as surface etching prior to both sawing and lapping, are discussed along with the rationale behind their adoption. Camera systems built around matrix array photosensors are presented in a historical time-wise progression beginning with the first 50 x 50 element converter developed in 1965 and running through the most recent 400 x 500 element system delivered in 1972. The freedom of mechanical architecture made available to system designers by solid-state array cameras is noted from the description of a bare-chip packaged cubic inch camera. Hybrid scan systems employing one-dimensional line arrays are cited, and the basic tradeoffs to their use are listed. PMID:20119094

  20. Unassisted 3D camera calibration

    NASA Astrophysics Data System (ADS)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  1. 21 CFR 886.1120 - Ophthalmic camera.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic camera. 886.1120 Section 886.1120 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1120 Ophthalmic camera. (a) Identification. An ophthalmic camera is an AC-powered device intended to take photographs of the eye and the surrounding...

  2. 21 CFR 886.1120 - Opthalmic camera.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Opthalmic camera. 886.1120 Section 886.1120 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1120 Opthalmic camera. (a) Identification. An ophthalmic camera is an AC-powered device intended to take photographs of the eye and the surrounding...

  3. 21 CFR 886.1120 - Ophthalmic camera.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic camera. 886.1120 Section 886.1120 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1120 Ophthalmic camera. (a) Identification. An ophthalmic camera is an AC-powered device intended to take photographs of the eye and the surrounding...

  4. 21 CFR 886.1120 - Opthalmic camera.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Opthalmic camera. 886.1120 Section 886.1120 Food... DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1120 Opthalmic camera. (a) Identification. An ophthalmic camera is an AC-powered device intended to take photographs of the eye and the surrounding...

  5. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  6. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  7. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  8. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  9. 16 CFR 501.1 - Camera film.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Camera film. 501.1 Section 501.1 Commercial... 500 § 501.1 Camera film. Camera film packaged and labeled for retail sale is exempt from the net... should be expressed, provided: (a) The net quantity of contents on packages of movie film and bulk...

  10. 21 CFR 892.1110 - Positron camera.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Positron camera. 892.1110 Section 892.1110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1110 Positron camera. (a) Identification. A positron camera is a device intended to image...

  11. In vitro evaluation of stereoscopic liver surface reconstruction

    PubMed Central

    Karwan, Adam; Zylkowski, Jaroslaw; Wróblewski, Tadeusz

    2013-01-01

    Introduction Tracking abdominal motion of organs is an important factor in image-guided navigation systems. The paper presents the evaluation methodology of a practical approach to measure liver motion, both respiratory and laparoscopic, with a tool guided in the operating room. Aim Evaluation of the methodology of a practical approach to measure liver motion, both respiratory and laparoscopic, with a tool guided in the operating room. Material and methods The presented evaluation method is based on standard operating room equipment, i.e. laparoscopic cameras. We decided to use two rigid cameras to gain stereo in order to reconstruct characteristic points by triangulation. Our research aim was to survey the impact of three parameters on reconstruction accuracy: the number of calibration points, the imprecision of camera assembly, and the difference in resolution of images. Results Three calibration chessboard configurations were tested. The reconstructed landmark positions and residual mean square errors were presented in three phantom poses: the reference position, translated position and rotated position. Conclusions The presented approach is a development of the previous work. Our research proved the importance of a rigid stereo camera system and the use of high definition image resolution for both stages, namely calibration and reconstruction. PMID:23630559

  12. A calibration technology for multi-camera system with various focal lengths

    NASA Astrophysics Data System (ADS)

    Yang, Ruihua; Zhang, Jin; Deng, Huaxia; Yu, Liandong

    2016-01-01

    Calibration is the basis of three-dimensional (3D) reconstruction for machine vision technology. Nowadays, the most widely used calibration method among computer vision is the technique for binocular stereo measurement. However, binocular stereo vision has limited view field which is difficult to measure large-scale mechanical components synchronously. Thus, enlarging the view field is urgent in need for the large scale measurement. With the application of multi-camera system, the calibration for cameras with different focal lengths is required. In this paper, a method aiming at calibration problems for multi-camera system of different focal lengths is proposed. An imaging model for multi-camera system with various focal lengths is analyzed. The Harris corner detector is applied to determine the relationship between signal camera and checkerboard. Finally, the external parameters of different cameras can be obtained by the link with the checkerboard. The calibration results indicate that the calculation method used in this work can calibrate multi-camera with various focal lengths.

  13. Fringe projection profilometry for panoramic 3D reconstruction

    NASA Astrophysics Data System (ADS)

    Almaraz-Cabral, César-Cruz; Gonzalez-Barbosa, José-Joel; Villa, Jesús; Hurtado-Ramos, Juan-Bautista; Ornelas-Rodriguez, Francisco-Javier; Córdova-Esparza, Diana-Margarita

    2016-03-01

    In this paper, we introduce a panoramic profilometric system to reconstruct inner cylindrical environments. The system projects circular fringes and uses a temporal phase unwrapping technique. The recovered phase map is used to reconstruct objects placed on the inner cylindrical surface. We derived a phase to depth conversion formula for this system. The use of fringe projection allows dense reconstructions. The panoramic system is composed by a digital projector, two parabolic mirrors and a CCD camera. All these components share a common axis with a reference cylinder. This paper presents results for distinct objects.

  14. Mosad and Stream Vision For A Telerobotic, Flying Camera System

    NASA Technical Reports Server (NTRS)

    Mandl, William

    2002-01-01

    Two full custom camera systems using the Multiplexed OverSample Analog to Digital (MOSAD) conversion technology for visible light sensing were built and demonstrated. They include a photo gate sensor and a photo diode sensor. The system includes the camera assembly, driver interface assembly, a frame stabler board with integrated decimeter and Windows 2000 compatible software for real time image display. An array size of 320X240 with 16 micron pixel pitch was developed for compatibility with 0.3 inch CCTV optics. With 1.2 micron technology, a 73% fill factor was achieved. Noise measurements indicated 9 to 11 bits operating with 13.7 bits best case. Power measured under 10 milliwatts at 400 samples per second. Nonuniformity variation was below noise floor. Pictures were taken with different cameras during the characterization study to demonstrate the operable range. The successful conclusion of this program demonstrates the utility of the MOSAD for NASA missions, providing superior performance over CMOS and lower cost and power consumption over CCD. The MOSAD approach also provides a path to radiation hardening for space based applications.

  15. Internet's critical path horizon

    NASA Astrophysics Data System (ADS)

    Valverde, S.; Solé, R. V.

    2004-03-01

    Internet is known to display a highly heterogeneous structure and complex fluctuations in its traffic dynamics. Congestion seems to be an inevitable result of user's behavior coupled to the network dynamics and it effects should be minimized by choosing appropriate routing strategies. But what are the requirements of routing depth in order to optimize the traffic flow? In this paper we analyse the behavior of Internet traffic with a topologically realistic spatial structure as described in a previous study [S.-H. Yook et al., Proc. Natl Acad. Sci. USA 99, 13382 (2002)]. The model involves self-regulation of packet generation and different levels of routing depth. It is shown that it reproduces the relevant key, statistical features of Internet's traffic. Moreover, we also report the existence of a critical path horizon defining a transition from low-efficient traffic to highly efficient flow. This transition is actually a direct consequence of the web's small world architecture exploited by the routing algorithm. Once routing tables reach the network diameter, the traffic experiences a sudden transition from a low-efficient to a highly-efficient behavior. It is conjectured that routing policies might have spontaneously reached such a compromise in a distributed manner. Internet would thus be operating close to such critical path horizon.

  16. Generic MSFA mosaicking and demosaicking for multispectral cameras

    NASA Astrophysics Data System (ADS)

    Miao, Lidan; Qi, Hairong; Ramanath, Rajeev

    2006-02-01

    In this paper, we investigate the potential application of the multispectral filter array (MSFA) techniques in multispectral imaging for reasons like low cost, exact registration, and strong robustness. In both human and many animal visual systems, different types of photoreceptors are organized into mosaic patterns. This behavior has been emulated in the industry to develop the so-called color filter array (CFA) in the manufacture of digital color cameras. In this way, only one color component is measured at each pixel, and the sensed image is a mosaic of different color bands. We extend this idea to multispectral imaging by developing generic mosaicking and demosaicking algorithms. The binary tree-driven MSFA design process guarantees that the pixel distributions of different spectral bands are uniform and highly correlated. These spatial features facilitate the design of the generic demosaicking algorithm based on the same binary tree, which considers three interrelated issues: band selection, pixel selection and interpolation. We evaluate the reconstructed images from two aspects: better reconstruction and better target classification. The experimental results demonstrate that the mosaicking and demosaicking process preserves the image quality effectively, which further supports that the MSFA technique is a feasible solution for multispectral cameras.

  17. Environment reconstruction for robot navigation

    SciTech Connect

    Bohn, S.; Thornton, E.

    1994-04-01

    The United State Department of Energy (DOE) is facing a large task in characterizing and remediating waste tanks and their contents. Because of the hazardous materials inside the waste tanks, all of the work must be done remotely. The purpose of this paper is to show how to reconstruct an enclosed environment from various scans of a Laser Range Finder (LRF). The reconstructed environment can then be used by a robot for path planning, and by an operator to monitor the progress of the waste remediation process. Environment reconstruction consists of two tasks: image processing and laser sculpting. The image processing task focuses first on reducing the quantity of low-confidence data and on smoothing random fluctuations in the data. Then the processed range data must be converted into an XYZ Cartesian coordinate space, a process for which we examined two methods. The first method is a geometrical transform of the LRF data. The second uses an artificial neural network to transform the data to XYZ coordinates. Once an XYZ data set is computed, laser sculpting can be performed. Laser sculpting employs a hierarchical tree structure formally called an octree. The octree structure allows efficient storage of volumetric data and the ability to fuse multiple data sets. Our research has allowed us to examine the difficulties of fusing multiple LRF scans into an octree and to develop algorithms for converting an octree structure into a representation of polygon surfaces.

  18. Interface Reconstruction with Directional Walking

    SciTech Connect

    Yao, J

    2009-05-22

    Young's interface reconstruction with three-dimensional arbitrary mesh, in general, is rather tedious to implement compared to the case of a regular mesh. The main difficulty comes from the construction of a planar facet that bounds a certain volume inside a cell. Unlike the five basic configurations with a Cartesian mesh, there can be a great number of different configurations in the case of a general mesh. We represent a simple method that can derive the topology/geometry of the intersection of arbitrary planar objects in a uniform way. The method is based on a directional walking on the surface of objects, and links the intersection points with the paths of the walking naturally defining the intersection of objects. The method works in both two and three dimensions. The method does not take advantage of convexity, thus decomposition of an object is not necessary. Therefore, the solution with this method will have a reduced number of edges and less data storage, compared with methods that use shape decomposition. The treatment is general for arbitrary polyhedrons, and no look-up tables are needed. The same operation can easily be extended for curved geometry. The implementation of this new algorithm shall allow the interface reconstruction on an arbitrary mesh to be as simple as it is on a regular mesh. Furthermore, we exactly compute the integral of partial cell volume bounded by quadratic interface. Therefore, interface reconstruction with higher than second order accuracy can be achieved on an arbitrary mesh.

  19. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect

    Cannon, S.D.; Finch, S.M.

    1992-10-01

    The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The independent Technical Steering Panel (TSP) provides technical direction. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates):Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  20. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-04-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates.

  1. Hanford Environmental Dose Reconstruction Project monthly report

    SciTech Connect

    Finch, S.M.

    1991-10-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doeses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source terms; environmental transport; environmental monitoring data; demographics, agriculture, food habits; environmental pathways and dose estimates.

  2. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-03-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  3. Hanford Environmental Dose Reconstruction Project. Monthly report

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-02-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): source terms; environmental transport; environmental monitoring data; demography, food consumption, and agriculture; environmental pathways and dose estimates.

  4. Hanford Environmental Dose Reconstruction Project Monthly Report

    SciTech Connect

    Finch, S.M.; McMakin, A.H.

    1992-03-01

    The objective of the Hanford Environmental Dose Reconstruction Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed, from release to impact on humans (dose estimates): Source Terms, Environmental Transport, Environmental Monitoring Data, Demography, Food Consumption, and Agriculture, and Environmental Pathways and Dose Estimates.

  5. Mini gamma camera, camera system and method of use

    DOEpatents

    Majewski, Stanislaw; Weisenberger, Andrew G.; Wojcik, Randolph F.

    2001-01-01

    A gamma camera comprising essentially and in order from the front outer or gamma ray impinging surface: 1) a collimator, 2) a scintillator layer, 3) a light guide, 4) an array of position sensitive, high resolution photomultiplier tubes, and 5) printed circuitry for receipt of the output of the photomultipliers. There is also described, a system wherein the output supplied by the high resolution, position sensitive photomultipiler tubes is communicated to: a) a digitizer and b) a computer where it is processed using advanced image processing techniques and a specific algorithm to calculate the center of gravity of any abnormality observed during imaging, and c) optional image display and telecommunications ports.

  6. Restoration of TDI camera images with motion distortion and blur

    NASA Astrophysics Data System (ADS)

    Wu, Jiagu; Zheng, Zhenzhen; Feng, Huajun; Xu, Zhihai; Li, qi; Chen, Yueting

    2010-11-01

    Platform movement during exposure of imaging system severely degrades image quality. In the case of Time delay and integration (TDI) camera, abnormal movements cause not only image blur but also distortion, for image Point Spread Function (PSF) is space-variant. In this paper, we present a motion degradation model of TDI image, and provide a method to restore such degraded image. While a TDI camera is imaging, it outputs images row by row (or line by line) along the scanning axis, and our method processes in the same track. We firstly calculate the space-invariant PSF of each row using the movement information of the TDI camera. Then, we substitute pixels of the row and the ones of their neighbor rows together with the PSF into standard Richardson-Lucy algorithm. By deconvoluting we get the restored pixels of the row. The same operations are executed for all rows of the degraded TDI image. Finally, a restored image can be reconstructed from those restored rows. Both simulated and experimental results prove the effectiveness of our method.

  7. A simple data loss model for positron camera systems

    SciTech Connect

    Eriksson, L. . Dept. of Clinical Neurophysiology); Wienhard, K. ); Dahlbom, M. . School of Medicine)

    1994-08-01

    A simple model to describe data losses in PET cameras is presented. The model is not intended to be used primarily for dead time corrections in existing scanners, although this is possible. Instead the model is intended to be used for data simulations in order to determine the figures of merit of future camera systems, based on data handling state-of-art solutions. The model assumes the data loss to be factorized into two components, one describing the detector or block-detector performance and the other the remaining data handling such as coincidence determinations, data transfer and data storage. Two modern positron camera systems have been investigated in terms of this model. These are the Siemens-CTI ECAT EXACT and ECAT EXACT HR systems, which both have an axial field-of-view (FOV) of about 15 cm. They both have retractable septa and can acquire data from the whole volume within the FOV and can reconstruct volume image data. An example is given how to use the model for live time calculation in a futuristic large axial FOV cylindrical system.

  8. Demonstration of three-dimensional imaging based on handheld Compton camera

    NASA Astrophysics Data System (ADS)

    Kishimoto, A.; Kataoka, J.; Nishiyama, T.; Taya, T.; Kabuki, S.

    2015-11-01

    Compton cameras are potential detectors that are capable of performing measurements across a wide energy range for medical imaging applications, such as in nuclear medicine and ion beam therapy. In previous work, we developed a handheld Compton camera to identify environmental radiation hotspots. This camera consists of a 3D position-sensitive scintillator array and multi-pixel photon counter arrays. In this work, we reconstructed the 3D image of a source via list-mode maximum likelihood expectation maximization and demonstrated the imaging performance of the handheld Compton camera. Based on both the simulation and the experiments, we confirmed that multi-angle data acquisition of the imaging region significantly improved the spatial resolution of the reconstructed image in the direction vertical to the detector. The experimental spatial resolutions in the X, Y, and Z directions at the center of the imaging region were 6.81 mm ± 0.13 mm, 6.52 mm ± 0.07 mm and 6.71 mm ± 0.11 mm (FWHM), respectively. Results of multi-angle data acquisition show the potential of reconstructing 3D source images.

  9. Passive Millimeter Wave Camera (PMMWC) at TRW

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Engineers at TRW, Redondo Beach, California, inspect the Passive Millimeter Wave Camera, a weather-piercing camera designed to 'see' through fog, clouds, smoke and dust. Operating in the millimeter wave portion of the electromagnetic spectrum, the camera creates visual-like video images of objects, people, runways, obstacles and the horizon. A demonstration camera (shown in photo) has been completed and is scheduled for checkout tests and flight demonstration. Engineer (left) holds a compact, lightweight circuit board containing 40 complete radiometers, including antenna, monolithic millimeter wave integrated circuit (MMIC) receivers and signal processing and readout electronics that forms the basis for the camera's 1040-element focal plane array.

  10. Passive Millimeter Wave Camera (PMMWC) at TRW

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Engineers at TRW, Redondo Beach, California, inspect the Passive Millimeter Wave Camera, a weather-piercing camera designed to see through fog, clouds, smoke and dust. Operating in the millimeter wave portion of the electromagnetic spectrum, the camera creates visual-like video images of objects, people, runways, obstacles and the horizon. A demonstration camera (shown in photo) has been completed and is scheduled for checkout tests and flight demonstration. Engineer (left) holds a compact, lightweight circuit board containing 40 complete radiometers, including antenna, monolithic millimeter wave integrated circuit (MMIC) receivers and signal processing and readout electronics that forms the basis for the camera's 1040-element focal plane array.

  11. HHEBBES! All sky camera system: status update

    NASA Astrophysics Data System (ADS)

    Bettonvil, F.

    2015-01-01

    A status update is given of the HHEBBES! All sky camera system. HHEBBES!, an automatic camera for capturing bright meteor trails, is based on a DSLR camera and a Liquid Crystal chopper for measuring the angular velocity. Purpose of the system is to a) recover meteorites; b) identify origin/parental bodies. In 2015, two new cameras were rolled out: BINGO! -alike HHEBBES! also in The Netherlands-, and POgLED, in Serbia. BINGO! is a first camera equipped with a longer focal length fisheye lens, to further increase the accuracy. Several minor improvements have been done and the data reduction pipeline was used for processing two prominent Dutch fireballs.

  12. Reconstruction for proton computed tomography by tracing proton trajectories – A Monte Carlo study

    PubMed Central

    Li, Tianfang; Liang, Zhengrong; Singanallur, Jayalakshmi V.; Satogata, Todd J.; Williams, David C.; Schulte, Reinhard W.

    2006-01-01

    Proton computed tomography (pCT) has been explored in the past decades because of its unique imaging characteristics, low radiation dose, and its possible use for treatment planning and on-line target localization in proton therapy. However, reconstruction of pCT images is challenging because the proton path within the object to be imaged is statistically affected by multiple Coulomb scattering. In this paper, we employ GEANT4-based Monte Carlo simulations of the two-dimensional pCT reconstruction of an elliptical phantom to investigate the possible use of the Algebraic Reconstruction Technique (ART) with three different path-estimation methods for pCT reconstruction. The first method assumes a straight-line path (SLP) connecting the proton entry and exit positions, the second method adapts the most-likely path (MLP) theoretically determined for a uniform medium, and the third method employs a cubic spline path (CSP). The ART reconstructions showed progressive improvement of spatial resolution when going from the SLP (2 line pairs (lp) cm-1) to the curved CSP and MLP path estimates (5 lp cm-1). The MLP-based ART algorithm had the fastest convergence and smallest residual error of all three estimates. This work demonstrates the advantage of tracking curved proton paths in conjunction with the ART algorithm and curved path estimates. PMID:16878573

  13. Reconstruction for proton computed tomography by tracing proton trajectories: A Monte Carlo study

    SciTech Connect

    Li Tianfang; Liang Zhengrong; Singanallur, Jayalakshmi V.; Satogata, Todd J.; Williams, David C.; Schulte, Reinhard W.

    2006-03-15

    Proton computed tomography (pCT) has been explored in the past decades because of its unique imaging characteristics, low radiation dose, and its possible use for treatment planning and on-line target localization in proton therapy. However, reconstruction of pCT images is challenging because the proton path within the object to be imaged is statistically affected by multiple Coulomb scattering. In this paper, we employ GEANT4-based Monte Carlo simulations of the two-dimensional pCT reconstruction of an elliptical phantom to investigate the possible use of the algebraic reconstruction technique (ART) with three different path-estimation methods for pCT reconstruction. The first method assumes a straight-line path (SLP) connecting the proton entry and exit positions, the second method adapts the most-likely path (MLP) theoretically determined for a uniform medium, and the third method employs a cubic spline path (CSP). The ART reconstructions showed progressive improvement of spatial resolution when going from the SLP [2 line pairs (lp) cm{sup -1}] to the curved CSP and MLP path estimates (5 lp cm{sup -1}). The MLP-based ART algorithm had the fastest convergence and smallest residual error of all three estimates. This work demonstrates the advantage of tracking curved proton paths in conjunction with the ART algorithm and curved path estimates.

  14. Bragg peak prediction from quantitative proton computed tomography using different path estimates.

    PubMed

    Wang, Dongxu; Mackie, T Rockwell; Tomé, Wolfgang A

    2011-02-01

    This paper characterizes the performance of the straight-line path (SLP) and cubic spline path (CSP) as path estimates used in reconstruction of proton computed tomography (pCT). The GEANT4 Monte Carlo simulation toolkit is employed to simulate the imaging phantom and proton projections. SLP, CSP and the most-probable path (MPP) are constructed based on the entrance and exit information of each proton. The physical deviations of SLP, CSP and MPP from the real path are calculated. Using a conditional proton path probability map, the relative probability of SLP, CSP and MPP are calculated and compared. The depth dose and Bragg peak are predicted on the pCT images reconstructed using SLP, CSP, and MPP and compared with the simulation result. The root-mean-square physical deviations and the cumulative distribution of the physical deviations show that the performance of CSP is comparable to MPP while SLP is slightly inferior. About 90% of the SLP pixels and 99% of the CSP pixels lie in the 99% relative probability envelope of the MPP. Even at an imaging dose of ∼0.1 mGy the proton Bragg peak for a given incoming energy can be predicted on the pCT image reconstructed using SLP, CSP, or MPP with 1 mm accuracy. This study shows that SLP and CSP, like MPP, are adequate path estimates for pCT reconstruction, and therefore can be chosen as the path estimation method for pCT reconstruction, which can aid the treatment planning and range prediction of proton radiation therapy. PMID:21212472

  15. Initial laboratory evaluation of color video cameras

    SciTech Connect

    Terry, P L

    1991-01-01

    Sandia National Laboratories has considerable experience with monochrome video cameras used in alarm assessment video systems. Most of these systems, used for perimeter protection, were designed to classify rather than identify an intruder. Monochrome cameras are adequate for that application and were selected over color cameras because of their greater sensitivity and resolution. There is a growing interest in the identification function of security video systems for both access control and insider protection. Color information is useful for identification purposes, and color camera technology is rapidly changing. Thus, Sandia National Laboratories established an ongoing program to evaluate color solid-state cameras. Phase one resulted in the publishing of a report titled, Initial Laboratory Evaluation of Color Video Cameras (SAND--91-2579).'' It gave a brief discussion of imager chips and color cameras and monitors, described the camera selection, detailed traditional test parameters and procedures, and gave the results of the evaluation of twelve cameras. In phase two six additional cameras were tested by the traditional methods and all eighteen cameras were tested by newly developed methods. This report details both the traditional and newly developed test parameters and procedures, and gives the results of both evaluations.

  16. Initial laboratory evaluation of color video cameras

    NASA Astrophysics Data System (ADS)

    Terry, P. L.

    1991-12-01

    Sandia National Laboratories has considerable experience with monochrome video cameras used in alarm assessment video systems. Most of these systems, used for perimeter protection, were designed to classify rather than identify an intruder. Monochrome cameras are adequate for that application and were selected over color cameras because of their greater sensitivity and resolution. There is a growing interest in the identification function of security video systems for both access control and insider protection. Color information is useful for identification purposes, and color camera technology is rapidly changing. Thus, Sandia National Laboratories established an ongoing program to evaluate color solid-state cameras. Phase one resulted in the publishing of a report titled, 'Initial Laboratory Evaluation of Color Video Cameras (SAND--91-2579).' It gave a brief discussion of imager chips and color cameras and monitors, described the camera selection, detailed traditional test parameters and procedures, and gave the results of the evaluation of twelve cameras. In phase two, six additional cameras were tested by the traditional methods and all eighteen cameras were tested by newly developed methods. This report details both the traditional and newly developed test parameters and procedures, and gives the results of both evaluations.

  17. Phenology cameras observing boreal ecosystems of Finland

    NASA Astrophysics Data System (ADS)

    Peltoniemi, Mikko; Böttcher, Kristin; Aurela, Mika; Kolari, Pasi; Tanis, Cemal Melih; Linkosalmi, Maiju; Loehr, John; Metsämäki, Sari; Nadir Arslan, Ali

    2016-04-01

    Cameras have become useful tools for monitoring seasonality of ecosystems. Low-cost cameras facilitate validation of other measurements and allow extracting some key ecological features and moments from image time series. We installed a network of phenology cameras at selected ecosystem research sites in Finland. Cameras were installed above, on the level, or/and below the canopies. Current network hosts cameras taking time lapse images in coniferous and deciduous forests as well as at open wetlands offering thus possibilities to monitor various phenological and time-associated events and elements. In this poster, we present our camera network and give examples of image series use for research. We will show results about the stability of camera derived color signals, and based on that discuss about the applicability of cameras in monitoring time-dependent phenomena. We will also present results from comparisons between camera-derived color signal time series and daily satellite-derived time series (NVDI, NDWI, and fractional snow cover) from the Moderate Resolution Imaging Spectrometer (MODIS) at selected spruce and pine forests and in a wetland. We will discuss the applicability of cameras in supporting phenological observations derived from satellites, by considering the possibility of cameras to monitor both above and below canopy phenology and snow.

  18. Indoor Calibration for Stereoscopic Camera STC, A New Method

    NASA Astrophysics Data System (ADS)

    Simioni, E.; Re, C.; Da Deppo, V.; Naletto, G.; Borrelli, D.; Dami, M.; Ficai Veltroni, I.; Cremonese, G.

    2014-10-01

    In the framework of the ESA-JAXA BepiColombo mission to Mercury, the global mapping of the planet will be performed by the on-board Stereo Camera (STC), part of the SIMBIO-SYS suite [1]. In this paper we propose a new technique for the validation of the 3D reconstruction of planetary surface from images acquired with a stereo camera. STC will provide a three-dimensional reconstruction of Mercury surface. The generation of a DTM of the observed features is based on the processing of the acquired images and on the knowledge of the intrinsic and extrinsic parameters of the optical system. The new stereo concept developed for STC needs a pre-flight verification of the actual capabilities to obtain elevation information from stereo couples: for this, a stereo validation setup to get an indoor reproduction of the flight observing condition of the instrument would give a much greater confidence to the developed instrument design. STC is the first stereo satellite camera with two optical channels converging in a unique sensor. Its optical model is based on a brand new concept to minimize mass and volume and to allow push-frame imaging. This model imposed to define a new calibration pipeline to test the reconstruction method in a controlled ambient. An ad-hoc indoor set-up has been realized for validating the instrument designed to operate in deep space, i.e. in-flight STC will have to deal with source/target essentially placed at infinity. This auxiliary indoor setup permits on one side to rescale the stereo reconstruction problem from the operative distance in-flight of 400 km to almost 1 meter in lab; on the other side it allows to replicate different viewing angles for the considered targets. Neglecting for sake of simplicity the Mercury curvature, the STC observing geometry of the same portion of the planet surface at periherm corresponds to a rotation of the spacecraft (SC) around the observed target by twice the 20° separation of each channel with respect to nadir

  19. Automatic calibration method for plenoptic camera

    NASA Astrophysics Data System (ADS)

    Luan, Yinsen; He, Xing; Xu, Bing; Yang, Ping; Tang, Guomao

    2016-04-01

    An automatic calibration method is proposed for a microlens-based plenoptic camera. First, all microlens images on the white image are searched and recognized automatically based on digital morphology. Then, the center points of microlens images are rearranged according to their relative position relationships. Consequently, the microlens images are located, i.e., the plenoptic camera is calibrated without the prior knowledge of camera parameters. Furthermore, this method is appropriate for all types of microlens-based plenoptic cameras, even the multifocus plenoptic camera, the plenoptic camera with arbitrarily arranged microlenses, or the plenoptic camera with different sizes of microlenses. Finally, we verify our method by the raw data of Lytro. The experiments show that our method has higher intelligence than the methods published before.

  20. Characterization of the Series 1000 Camera System

    SciTech Connect

    Kimbrough, J; Moody, J; Bell, P; Landen, O

    2004-04-07

    The National Ignition Facility requires a compact network addressable scientific grade CCD camera for use in diagnostics ranging from streak cameras to gated x-ray imaging cameras. Due to the limited space inside the diagnostic, an analog and digital input/output option in the camera controller permits control of both the camera and the diagnostic by a single Ethernet link. The system consists of a Spectral Instruments Series 1000 camera, a PC104+ controller, and power supply. The 4k by 4k CCD camera has a dynamic range of 70 dB with less than 14 electron read noise at a 1MHz readout rate. The PC104+ controller includes 16 analog inputs, 4 analog outputs and 16 digital input/output lines for interfacing to diagnostic instrumentation. A description of the system and performance characterization is reported.