Download or read book Lossy Compression of Weak Lensing Data written by and published by . This book was released on 2011 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Future orbiting observatories will survey large areas of sky in order to constrain the physics of dark matter and dark energy using weak gravitational lensing and other methods. Lossy compression of the resultant data will improve the cost and feasibility of transmitting the images through the space communication network. We evaluate the consequences of the lossy compression algorithm of Bernstein et al. (2010) for the high-precision measurement of weak-lensing galaxy ellipticities. This square-root algorithm compresses each pixel independently, and the information discarded is by construction less than the Poisson error from photon shot noise. For simulated space-based images (without cosmic rays) digitized to the typical 16 bits per pixel, application of the lossy compression followed by image-wise lossless compression yields images with only 2.4 bits per pixel, a factor of 6.7 compression. We demonstrate that this compression introduces no bias in the sky background. The compression introduces a small amount of additional digitization noise to the images, and we demonstrate a corresponding small increase in ellipticity measurement noise. The ellipticity measurement method is biased by the addition of noise, so the additional digitization noise is expected to induce a multiplicative bias on the galaxies measured ellipticities. After correcting for this known noise-induced bias, we find a residual multiplicative ellipticity bias of m ≈ -4 x 10−4. This bias is small when compared to the many other issues that precision weak lensing surveys must confront, and furthermore we expect it to be reduced further with better calibration of ellipticity measurement methods.

Download or read book Algorithms Advances in Research and Application 2012 Edition written by and published by ScholarlyEditions. This book was released on 2012-12-26 with total page 2152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Algorithms—Advances in Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Algorithms. The editors have built Algorithms—Advances in Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Algorithms in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Algorithms—Advances in Research and Application: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book A Lossy Compression Tolerant Data Hiding Method Based on JPEG and VQ written by Ren-junn Hwang and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Idealization and the Laws of Nature written by Billy Wheeler and published by Springer. This book was released on 2018-08-28 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new study provides a refreshing look at the issue of exceptions and shows that much of the problem stems from a failure to recognize at least two kinds of exception-ridden law: ceteris paribus laws and ideal laws. Billy Wheeler offers the first book-length discussion of ideal laws. The key difference between these two kinds of laws concerns the nature of the conditions that need to be satisfied and their epistemological role in the law’s formulation and discovery. He presents a Humean-inspired approach that draws heavily on concepts from the information and computing sciences. Specifically, Wheeler argues that laws are best seen as algorithms for compressing empirical data and that ideal laws are needed as 'lossy compressors' for complex data. Major figures in the metaphysics of science receive special attention such as Ronald Giere, Bas van Fraassen, Nancy Cartwright, David Lewis and Marc Lange. This book is essential reading for philosophers of science and will interest metaphysicians, epistemologists and others interested in applying concepts from computing to traditional philosophical problems.

Download or read book Space and Earth Science Data Compression Workshop written by and published by . This book was released on 1993 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Low Overhead Data Compression Algorithm for Converting Lossy Compression Processes to Lossless written by and published by . This book was released on 1993 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a hybrid lossless compression model is tested which employs a combination of both a lossy compression method and one or more lossless image compression methods to produce an overall lossless image compression. The hybrid model decomposes the original image into a browse and a residual image. The hybrid model is tested and evaluated using various combinations of lossy and lossless image compression methods. The lossy compression method used in the model is JPEG (Joint Photographic Experts (Group) . The lossless compression methods used are Huffman, Arithmetic, LZW, lossless JPEG. and Diagonal coding. The compression results achieved using the hybrid compression model are compared to the compression achieved using the corresponding direct lossless compression. Additionally, the hybrid model is evaluated as to the advantages that the decomposition of the image into browse and residual images provide to the user. Image compression, Data compression, Hybrid compression, Lossless, Lossy, Browse, Residual.

Download or read book Lossy Compression tolerant Data Hiding written by Chuan-Ho Kao and published by . This book was released on 2005 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Simple Low Overhead Data Compression Algorithm for Converting Lossy Processes to Lossless written by Walter D. Abbott and published by . This book was released on 1993 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, a hybrid lossless compression model is tested which employs a combination of both a lossy compression method and one or more lossless image compression methods to produce an overall lossless image compression. The hybrid model decomposes the original image into a browse and a residual image. The hybrid model is tested and evaluated using various combinations of lossy and lossless image compression methods. The lossy compression method used in the model is JPEG (Joint Photographic Experts (Group) . The lossless compression methods used are Huffman, Arithmetic, LZW, lossless JPEG. and Diagonal coding. The compression results achieved using the hybrid compression model are compared to the compression achieved using the corresponding direct lossless compression. Additionally, the hybrid model is evaluated as to the advantages that the decomposition of the image into browse and residual images provide to the user.

Download or read book Lossy Compression of Scientific Data Via Wavelets and Vector Quantization written by Jill R. Goldschneider and published by . This book was released on 1997 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hyperspectral Data Compression written by Giovanni Motta and published by Springer Science & Business Media. This book was released on 2006 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a survey of results in the field of compression of remote sensed 3D data, with a particular interest in hyperspectral imagery. This work covers topics such as compression architecture, lossless compression, lossy techniques, and more. It also describes a lossless algorithm based on vector quantization.

Download or read book The Application of Weak Lensing written by Yong-Seon Song and published by . This book was released on 2004 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rateless Lossy Compression Via the Extremes written by Albert No and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the era of Big Data, the volume of data grows rapidly, and compression is becoming an increasingly important issue. Information theory, in particular, approaches this problem mathematically to find optimum compression algorithms. Such works often focus more on optimality of compression rate but tacitly ignore the complexity of algorithms. On the other hand, in the real world, various compression algorithms are developed for each different application. These algorithms provide low complexity but cannot guarantee the optimum compression rate. In this work, we try to achieve both the low complexity and optimality of the rate. More precisely, a new technique using successive refinement is proposed to reduce the complexity of algorithms that achieve the optimum compression rate.

Download or read book Lossless and Lossy Raw Data Compression in CT Imaging written by Jochen Wilhelmy and published by . This book was released on 2012 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Image Processing Technique for Achieving Lossy Compression of Data at Ratios in Excess of 100 1 written by Michael G. Ellis and published by . This book was released on 1992 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Weak Lensing Analysis of the Canada France Imaging Survey written by Axel Guinot and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among the big questions cosmology faces today, the nature of dark matter and dark energy are at the center of upcoming surveys. The future stage IV missions Euclid and LSST will cover a surface on the sky never reached before to unveil structures at very large scales and different epochs. Weak gravitational lensing will be one of the cosmological probes used to trace dark matter. Gravitational lensing is a physical phenomenon which uses the distortion of light to trace the presence of mass in the Universe. The interesting point of weak lensing is its sensitivity to total mass, i.e. baryonic and non-baryonic. Due to gravitational lensing, distant galaxies will appear distorted on the observed images. The measurement of the distortions induced by gravitational shear requires a very accurate estimation of the shape of galaxies. This thesis will present the data reduction pipeline built for weak lensing studies, from the telescope to cosmological parameter inference. The work focuses on the analysis of the Canada-France Imaging Survey (CFIS), a u- and r-band survey covering 5,000 deg2 in the Northern hemisphere. The high resolution and depth of those data make it one the best survey candidates for weak lensing science to date. Among other things, accurate measurement of the shape galaxies requires a very good knowledge of the PSF for which a suite of validation tests have been developed. Due to the noise, and approximations used in the shape measurement, the results can be biased. The residual multiplicative and additive biases have been reduced to m

Download or read book A Lossy Data Compression Based on an Approximate Pattern Matching written by Purdue University. Dept. of Computer Sciences and published by . This book was released on 1994 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Lossy Data Compression Methods for Halftoned and Printed Images written by Rick A. Vander Kam and published by . This book was released on 1995 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: