Download or read book Coded Aperture Imaging with a HURA Coded Aperture and a Discrete Pixel Detector written by Kevin Byard and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Imaging in High Energy Astronomy written by L. Bassani and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: An almost complete collection of the papers given at the International Workshop on Imaging in High Energy Astronomy (Anacapri, Italy, 1994). These proceedings, which concentrate on imaging above 10 keV, represent the state of the art in the field, resulting from the success of many missions (I.C. Granat and CGRO) carrying detectors for high energy astronomy with imaging capabilities. The main topics of the book are Bragg concentrators, coded mask-modulation collimators, double Compton telescopes, the occultation method, tracking chambers, and new experimental techniques. The book also contains some papers dealing with image reconstruction and processing, with an emphasis on the above techniques.

Download or read book Coded Aperture Design in Compressive Spectral Imaging written by Laura Galvis-Carreno and published by . This book was released on 2018 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compressive Spectral Imaging (CSI) systems sense 3D spatio-spectral data cubes through just few two dimensional (2D) projections by using a coded aperture, a dispersive element, and an FPA. The coded apertures in these systems, whose main function is the modulation of the data cube, are often implemented through photomasks attached to piezoelectric devices. The optimization of such coded aperture patterns is an actual area of research. Two remarkable improvements on this configuration have been recently proposed. First, the replacement of the photomask by digital micromirror devices (DMD) for block-unblock coding in order to facilitate the capture of multiple projections/snapshots or the capture of multiple shots at video rates without the displacement of the optical elements on the system. Secondly, the replacement of block-unblock coded apertures by patterned optical filter arrays, referred as “colored” coded apertures, which not only allow spatial modulation but spectral modulation as well. Despite the improvements, the design of the coded aperture patterns is still constrained by hardware considerations. This dissertation aims to overcome these hardware considerations by developing different coded aperture design strategies. ☐ When using the DMD for coding the data cube, the DMD resolution and the possibility to use multiple shots have to be considered. Usually, the pitch size of the DMD mirrors is different than the pitch size of the pixels in the detector. The mismatch of the DMD mirrors and the detector pixels is such that pixel-to-pixel correspondence is not achieved. The first proposed strategy is a mismatching coded aperture design to exploit the maximum resolution of the coding element and the detector. Additionally, the capture of multiple snapshots could be highly exploited to extract prior-information of the scenes, here a second strategy is proposed, the use of side information in CSI not only to improve the reconstructions but to design scenes-adaptive coded aperture patterns. ☐ On the other hand, when using “colored” coded apertures, its real implementation in terms of cost and complexity, directly depends on the number of filters to be used as well as the number of shots. A shifting color coded aperture optimization featuring these observations is proposed as the third strategy with the aim to improve the quality reconstruction and to generate an achievable optical implementation. ☐ The mathematical models of the different strategies of computational imaging to overcome the limitations of actual CSI systems will be presented along with testbed implementations. Simulations as well as experimental results will prove the accuracy and performance of the three proposed coding strategies.

Download or read book Coded Aperture Imaging written by R. G. Simpson and published by . This book was released on 1979* with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Astronomy and Astrophysics written by and published by . This book was released on 1994 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coded Aperture Imaging Application in One sided Imaging of Visually Obscured Objects written by William Scott and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The physical properties of visible light and its interaction with matter create obstructions the human eye cannot explore. High energy radiation has been used as an alternative to visible light to penetrate these concealed regions and reveal their contents. However, traditional imaging techniques require a two-sided apparatus with a radiation source and a detector on opposite sides of the concealed object. One-sided imaging of concealed objects is made possible by a technique called backscatter imaging, utilizing high energy radiation. However, the signal produced by backscatter imaging is inherently weak, which makes in- terpretation di cult. One of the most promising techniques for recovering the weak 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 feasible. The results obtained from conducting a computer simulation, visi- ble light experiments, and x-ray experiments proved that the process works, however, the x-ray ux levels required were too high for a portable system, based upon the current equipment available at UOIT.

Download or read book Collected Papers on Coded Aperture Imaging written by Edward E. Fenimore and published by . This book was released on 1990* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coded Aperture Imaging written by Manuel Martinello and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis studies the coded aperture camera, a device consisting of a conventional camera with a modified aperture mask, that enables the recovery of both depth map and all-in-focus image from a single 2D input image. Key contributions of this work are the modeling of the statistics of natural images and the design of efficient blur identification methods in a Bayesian framework. Two cases are distinguished: 1) when the aperture can be decomposed in a small set of identical holes, and 2) when the aperture has a more general configuration. In the first case, the formulation of the problem incorporates priors about the statistical variation of the texture to avoid ambiguities in the solution. This allows to bypass the recovery of the sharp image and concentrate only on estimating depth. In the second case, the depth reconstruction is addressed via convolutions with a bank of linear filters. Key advantages over competing methods are the higher numerical stability and the ability to deal with large blur. The all-in-focus image can then be recovered by using a deconvolution step with the estimated depth map. Furthermore, for the purpose of depth estimation alone, the proposed algorithm does not require information about the mask in use. The comparison with existing algorithms in the literature shows that the proposed methods achieve state-of-the-art performance. This solution is also extended for the first time to images affected by both defocus and motion blur and, finally, to video sequences with moving and deformable objects.

Download or read book CODED APERTURE IMAGING DIGITAL DECODING AND TOMOGRAPHIC ARTIFACTS written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1990 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Confocal Coded Aperture Imaging written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for imaging a target volume comprises the steps of: radiating a small bandwidth of energy toward the target volume; focusing the small bandwidth of energy into a beam; moving the target volume through a plurality of positions within the focused beam; collecting a beam of energy scattered from the target volume with a non-diffractive confocal coded aperture; generating a shadow image of said aperture from every point source of radiation in the target volume; and, reconstructing the shadow image into a 3-dimensional image of the every point source by mathematically correlating the shadow image with a digital or analog version of the coded aperture. The method can comprise the step of collecting the beam of energy scattered from the target volume with a Fresnel zone plate.

Download or read book Coded Aperture Imaging written by Matthew Selwood and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comparison of Coded Aperture Imaging Systems Containing Zone Plate and Random phase Code Functions written by Frank Roger Whitehead and published by . This book was released on 1976 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparisons of Coded Aperture Imaging Using Various Apertures and Decoding Methods gamma Camera Imaging of Radionuclides in Tissues written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The utility of coded aperture .gamma. camera imaging of radioisotope distributions in Nuclear Medicine is in its ability to give depth information about a three dimensional source. We have calculated imaging with Fresnel zone plate and multiple pinhole apertures to produce coded shadows and reconstruction of these shadows using correlation, Fresnel diffraction, and Fourier transform deconvolution. Comparisons of the coded apertures and decoding methods are made by evaluating their point response functions both for in-focus and out-of-focus image planes. Background averages and standard deviations were calculated. In some cases, background subtraction was made using combinations of two complementary apertures. Results using deconvolution reconstruction for finite numbers of events are also given.

Download or read book Comparison of Single Pinhole and Coded Aperture Imaging Systems and Study of Signal to Noise Ratio in Coded Aperture Imaging written by Dhinesh Babu Jayakumar and published by . This book was released on 2005 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 1991 with total page 1250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theses on any subject submitted by the academic libraries in the UK and Ireland.