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Showing 1 to 20 of 26 for “"Coded aperture"”.
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Multi-channel coded-aperture photography
This thesis describes the multi-channel coded-aperture photography, a modified camera system that can extract an all-focus image of the scene along with a depth estimate over the scene. The modification consists of inserting a set of patterned color filters into the aperture of the camera lens. …
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Coded Aperture Imaging: Digital Decoding and Tomographic Artifacts
Made available in DSpace on 2014-12-12T20:54:34Z (GMT). No. of bitstreams: 1 7709189.pdf: 4576715 bytes, checksum: a01295fbefe6961b97ab6b87b5d1330d (MD5) Previous issue date: 1976
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Coded aperture imaging for fast neautron activation analysis
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1996, and Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.
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Coded aperture imaging application in one-sided imaging of visually obscured objects
… signal is the coding and decoding provided by Coded Aperture Imaging (CAI). The purpose of this study was to create and test a coded aperture imaging system using backscattered x-rays. This would enable one-sided imaging of concealed objects and demonstrate whether a portable imaging system was …
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Coded aperture and coded exposure photography : an investigation into applications and methods
… recent research. Specific attention is given to coded aperture and coded exposure theory and methods, as these form the basis for the experiments performed.
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Long range x-ray imaging utilizing coded aperture techniques and dynamic reconstruction
… targets by analyzing their shape. Furthermore, a coded aperture used in conjunction with dynamic reconstruction algorithms offers high sensitivity and resolution even while the target is moving towards the detector. This paper describes a lab-based system that simulated a source-target-detector …
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Shape Dynamical Models for Activity Recognition and Coded Aperture Imaging for Light-Field Capture
… so that appropriate images with varying focus, aperture, blur and colorimetric settings may be rendered as required. In this regard, capturing the 4D light-field as opposed to a 2D image allows us to freely vary viewpoint and focus at the time of rendering an image. In this dissertation, we …
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Development of X-ray Fan Beam Coded Aperture Diffraction Imaging for Improving Breast Cancer Diagnostics
… XRD measurements in a single snapshot, while a coded aperture is placed between imaged objects and detector, enabling XRD spectra for individual pixels along the fan beam extent to be recovered from the multiplexed measurement. Simulations were used to identify a suitable geometry for the …
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Design of a near-field coded aperture cameras for high-resolution medical and industrial gamma-ray imaging
Coded Aperture Imaging is a technique originally developed for X-ray astronomy, where typical imaging problems are characterized by far-field geometry and an object made of point sources distributed over a mainly dark background. These conditions provide, respectively, the basis of artifact-free …
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The design and development of Prometheus 1: Rice University's coded aperture faint object gamma ray telescope
… gamma ray detections. The telescope uses a coded aperture approach yielding an overall geometrical spatial resolution of 2.6$\sp\circ$ x 2.6$\sp\circ$ FWHM. The energy resolution of the detector is expected to be 12% FWHM at 0.661 MeV. Simulations of the detector/shield assembly yield a …
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Design and Qualification of a Coded Aperture Cycloidal Mass Spectrometer to Detect Perfluorocarbon Tracer Molecules for Environmental Applications
… PFC detection method is required. A cycloidal coded aperture miniature mass spectrometers (C-CAMMS) could be such a method due to its integration of three core technologies that help to overcome the throughput versus resolution tradeoff that has historically hampered the miniaturization of mass …
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Near field three-dimensional coded aperture techniques : theoretical and experimental exploration for applications in imaging and detection systems
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering; and, Harvard-MIT Division of Health Sciences and Technology, 1998.
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MOBILE, HYBRID COMPTON/CODED APERTURE IMAGING FOR DETECTION, IDENTIFICATION AND LOCALIZATION OF GAMMA-RAY SOURCES AT STAND-OFF DISTANCES
… spectroscopy and two imaging modalities; coded aperture and Compton scatter imaging. The TMI consists of 35 NaI crystals (5x5x2 in each), arranged in a random coded aperture CA, followed by 30 position sensitive NaI bars (24x2.5x3 in each) called the DA. The CA array acts as both a coded …
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Detection of improvised explosive devices at long-range using coded aperture imaging of backscattered X-rays with dynamic reconstruction
… is to determine the feasibility of a large-area, Coded-Aperture Imaging (CAI) system using X-Ray backscatter as the source of radiation. A moving source-detector system required development of a new reconstruction technique, dynamic reconstruction (DR), which continually back-projects detected …
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Programmable Aperture Photography: An investigation into applications and methods
… photography are ever growing with new focuses on coded aperture imaging and its real-world applications. Research has shown that coded apertures are far superior to traditional circular apertures for various tasks. A variety of coded aperture patterns have been proposed and developed over the …
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Computational spectral microscopy and compressive millimeter-wave holography
… The first sensor is a scanning multi-spectral aperture-coded microscope containing a coded aperture spectrometer that is vertically scanned through a microscope intermediate image plane. The spectrometer aperture-code spatially encodes the object spectral data and nonnegative</p> <p>least …
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Computational Optical Imaging Systems for Spectroscopy and Wide Field-of-View Gigapixel Photography
… information at each instant of time. Using a coded aperture and dispersive element, the coded aperture snapshot spectral imagers (CASSI) here described leverage correlations between voxels in the spatial-spectral data cube to compressively sample the power spectral density with minimal loss in …
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Studies of intrinsic properties of gamma ray bursts detected by the HETE-II satellite
… source and background counts during a burst with coded aperture instruments such as the Wide-field X-ray Monitor (WXM) on HETE-II. A closely related photon-by-photon statistical bootstrap analysis is then described that can be used to compute the non-Gaussian error distribution of GRB temporal …
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GAMMA-RAY IMAGING OBSERVATIONS OF THE CRAB AND CYGNUS REGIONS
… keV to 9.3 MeV. It utilizes a technique known as coded aperture imaging in order to obtain spatially resolved images of the sky with an angular resolution of $3.8\sp\circ.$ This detector is the first flight-ready instrument of this type operating at energies above 160 keV. The first successful …
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