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Topic: Wavelet compression


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In the News (Wed 3 Dec 08)

  
  Wavelets and Signal Processing
Wavelet transforms (of which there are, at least formally, an infinite number) allow the components of a non-stationary signal to be analyzed.
This means that the result consists of a wavelet scaling function value (also known as a smooth value or a low pass filter value), followed by bands of wavelet function values (sometimes called wavelet coefficients), in increasing frequency.
Wavelet compression can be used to estimate the amount of determinism in a particular region of a time series (or, looked at another way, the amount of noise).
www.bearcave.com /misl/misl_tech/wavelets   (2632 words)

  
 Lossless Wavelet Compression
Predictive compression yields good results for image compression, where the change from pixel to pixel is not an entirely random process (assuming that the image is of something other than random noise).
Rather than applying a classic compression coding scheme to estimate the number of bits needed to represent the wavelet result, a simple total for the number of bits is calculated.
Although the wavelet packet function is not without its extra cost, it is a better choice for estimating the determinism in a time series, since it provides a close fit for the data.
www.bearcave.com /misl/misl_tech/wavelets/compression   (3163 words)

  
 Wavelet-based Image and Video Compression   (Site not responding. Last check: 2007-10-09)
The wavelet transform is similar to the STFT in that the signal is multiplied by a function similar to windows function in STFT, but the transform is done separately for different segments of the signal.
For a given mother wavelet, the dimensions of the boxes can be changed, while keeping the area the same, and this is where the power of the wavelets lie.
Wavelet decomposition can be operated either on the original video samples before the motion compensation or on the residual video samples after motion compensation.
www.seas.upenn.edu /~ksl/Classes/TCOM502/Wavelets   (2566 words)

  
 JPEG2000 wavelet compression spec approved: Digital Photography Review   (Site not responding. Last check: 2007-10-09)
The best way to represent a signal using wavelets is to scan the entire image for a "mother wave" that best represents that particular image.
Compression ratios of 200:1 can be achieved with the 9/7 wavelet and 2:1 compression with the lossless 5/3 wavelet.
Instead, the images are compressed on the fly in real-time using the same wavelets now specified for JPEG2000-namely, the universal 9:7 wavelet.
www.dpreview.com /news/9912/99122901jpeg2000.asp   (1013 words)

  
 Optimizing Web Graphics: Compression - webreference.com
The potential of improved compression ratios using one of the wavelet flavors is showing scientific promise but will depend on the open standards issue for widespread acceptance.
Compression and decompression times are symmetric, although the International JPEG Group's (IJG) decoder is more optimized and noticeably faster than their encoder.
Wavelets are a transformation of an image into its component parts as a frequency representation (i.e., how fast things change in certain repetitive patterns: waves).
www.webreference.com /dev/graphics/compress.html   (3910 words)

  
 TASI :: Advice | Creating Digital Images | What is wavelet compression?
The common JPEG's compression (known as the DCT - Discrete Cosine Transform) cuts the pixels into blocks of 64 (8x8) and processes each block independently, shifting and simplifying the colours so there is less information to encode.
Consequently, when high compression (maximum simplification) is used, the block boundaries become obvious, causing the 'blockiness' or 'blocking artefact' frequently observed in the common JPEG.
JPEG 2000's wavelet compression is superior to the common JPEG's compression because it is able to treat larger areas of the image at once, and in a more discriminating way.
www.tasi.ac.uk /advice/creating/wavelet.html   (1248 words)

  
 About wavelet compression   (Site not responding. Last check: 2007-10-09)
Wavelet compression is one of the most effective methods of image compression.
Most of the wavelet coefficients of a typical image are nearly zero, and the image thus is well-approximated with a small number of large wavelet coefficients
The advantage of wavelet compression is that, in contrast to JPEG, wavelet algorithm does not divide image into blocks, but analyze the whole image.
www.barrt.ru /parshukov/about.htm   (123 words)

  
 [72] What is wavelet theory?
A wavelet transform coder construction kit is available at http://www.cs.dartmouth.edu/~gdavis/wavelet/wavelet.html Contact: Geoff Davis A matlab toolbox for constructing multi-scale image representations, including Laplacian pyramids, QMFs, wavelets, and steerable pyramids, is available at ftp://ftp.cis.upenn.edu/pub/eero/ Contact: Eero Simoncelli .
For back issues and other information, check the Wavelet Digest home page at http://www.wavelet.org/ A tutorial by M. Hilton, B. Jawerth, and A. Sengupta, entitled "Compressing Still and Moving Images with Wavelets" is available in ftp://ftp.math.sc.edu/pub/wavelet/papers/varia/tutorial/.
These wavelet functions have been likened to the edge detecting functions believed to be present in the human retina.
www.faqs.org /faqs/compression-faq/part2/section-3.html   (778 words)

  
 MOTION WAVELET COMPRESSION
In 2-1/2 D wavelet schemes, motion information either in the time or wavelet domain is combined with the 2 D wavelet transform.
In this case, previous and current images are wavelet transformed and in that domain motion estimation and difference is employed.
Entropy of wavelet domain motion estimation is greater than time domain motion vectors, but this is due to the increase in the number of vectors.
www.eee.metu.edu.tr /~bozdagi/mwc.html   (645 words)

  
 Evolving Better Wavelet Compression Schemes (ResearchIndex)   (Site not responding. Last check: 2007-10-09)
Abstract: Wavelet based compression schemes belong to the general class of transform coding schemes.
The results of optimized wavelet based compression schemes are compared with the JPEG compression standard.
Wavelets and Waves in Optical Signal Preprocessing - Beth, Klappenecker, Schmid,..
citeseer.ist.psu.edu /334994.html   (378 words)

  
 data compression
Compression pointers: http://www.internz.com/compression-pointers.html A large list of links organized by research topic -- fractals, wavelets, snippets (?), audio compression, a list of free software organizations and source code, and a huge list of people interested in compression.
Compression with Reversible Embedded Wavelets (CREW) http://www.crc.ricoh.com/CREW/CREW.html "CREW is a new form of still image compression that is lossy and lossless, bi-level and continuous-tone, progressive by resolution and pixel depth, and can preserve the source image at encode and quantize for the target device at decode or transmission."
Using the ``semi-functional compression'' techniques, plus an extra line or 2 at the end of the decompressor to run the program just decompressed, then after that program has finished, delete the temporary file (or just leave in the system /tmp/ directory to be automatically deleted later).
www.rdrop.com /~cary/html/data_compression.html   (12385 words)

  
 DataCompression.info - Image Compression   (Site not responding. Last check: 2007-10-09)
Compression is one of them, and there is certainly a great deal to learn about compression and media formats at this conference.
This appears to be an overview of various data compression methods applied to image compression, both lossy and lossless.
By using data compression techniques, it is possible to remove some of the redundant information contained in images, requiring less storage space and less time to transmit.
datacompression.info /ImageCompression.shtml   (7441 words)

  
 The Wavelet Digest :: Index
The free and non-commercial electronic newsletter since 1992, linking together the multi-disciplinary wavelet community.
The discussion forum enables rapid communication between members of the wavelet community.
The calendar includes the most interesting conferences, meetings, and workshops for wavelet researchers.
www.wavelet.org   (114 words)

  
 DataCompression.info - Wavelets   (Site not responding. Last check: 2007-10-09)
WSQ is a wavelet transform-based compression standard, developed by the FBI for compression of digital fingerprint images.
The Medical Compression Toolkit is a set of libraries for various image compression methods which have been adapted for medical use.
Some of his publications are relevant to compression techniques including a white paper on image compression by wavelets.
datacompression.info /Wavelets.shtml   (4309 words)

  
 Wavelet Image Compression Construction Kit
They will work with a whole variety of transforms, including DCT's, wavelet packets, local trig bases, etc. Moreover, they have been designed with the expectation that other features such as zerotrees or perceptual weighting will be added later.
The current transform routine should be fairly straightforward to extend to perfom wavelet packet decompositions.
The wavelet transform implements symmetrized boundaries and works for images of (more or less) arbitrary sizes, as long as the aspect ratio is less than 2:1 (the aspect ratio limitation should be straightforward to eliminate, but I haven't gotten around to it).
www.geoffdavis.net /dartmouth/wavelet/wavelet.html   (1180 words)

  
 The Wavelet Seismic Inversion Lab   (Site not responding. Last check: 2007-10-09)
One dimensional ladder inversion of wave equation by wavelet representation by L. Yang & Z.
Wavelet Compression of Seismic Data by E. Magani, et al.
Seismic Data Compression With Wavelets (in Chinese) by Z.
timna.mines.edu /~zmeng/waveletlab/waveletlab.html   (386 words)

  
 Aware, Inc. - Imaging & Biometrics Software Products   (Site not responding. Last check: 2007-10-09)
Our software enables standard-compliant compression and formatting of fingerprint and facial images, with products such as WSQ by Aware for fingerprint image compression, and NISTPack for compliant submission to government databases.
Aware's wavelet-based image Compression Software products are designed for use in a broad variety of applications where high quality and storage efficiency are of paramount importance.
Available as callable libraries and Web browser plugins, Aware's compression solutions can be quickly and seamlessly integrated into existing applications and systems.
www.aware.com /products/compression/compression.html   (297 words)

  
 Mitsuharu ARIMURA's Bookmarks on Source Coding/Data Compression
Ross Arnold and Tim Bell, "A Corpus for the Evaluation of Lossless Compression Algorithms", Proc.
Peter Fenwick, "Improvements to the Block-Sorting Text Compression Algorithm," The University of Auckland, Department of Computer Science, Technical Report 120, July 1995.
Mark Nelson, "Data Compression with the Burrows-Wheeler Transform," Dr.Dobb's Journal, Sep. 1996.
www.hn.is.uec.ac.jp /~arimura/compression_links.html   (996 words)

  
 Wavelet Compression - LEADTOOLS CMW Plug-In for Developers   (Site not responding. Last check: 2007-10-09)
In other words, if you need the best quality images while using the least amount of disk space, then the LEADTOOLS CMW plug-in is just what you need.
CMW is a new advanced compression that is better than JPEG2000 in quality, speed and compression ratios.
You can even specify to use lossless compression so that when the compressed image is decompressed it will be exactly the same as the original image.
www.leadtools.com /SDK/Raster/Raster-Addon-CMW.htm   (376 words)

  
 Wavelet NetCare
Most papers (with abstracts) are on wavelets, as well as the Wavelet Packet Lab 3.03 software.
Wavelets and Signal Processing by Man Kwong of Math and CS Division at Argonne National Lab
Wavelet Seismic Inversion Lab by Zhaobo Meng at the Center for Wave Phenomena in the Colorado School of Mines.
www.math.wustl.edu /wavelet   (1008 words)

  
 Wavelets
Page on the book "The World According to Wavelets: The Story of a Mathematical Technique in the Making" by Barbara Burke Hubbard, 1996, A K Peters, Ltd., ISBN 1-56881-047-4.
Wavelet related image compression papers by Z. Xiong, Princeton.
Wavelet based image and video compression at FHTW Berlin.
www.mat.sbg.ac.at /~uhl/wav.html   (229 words)

  
 What is wavelet compression? - A Word Definition From the Webopedia Computer Dictionary
The lossy compression of an image by converting it into a set of mathematical expressions.
MTS Insight: Metal Compression Testers - Offers high-performance metal compression testing solutions required to evaluate the mechanical properties, strength and durability.
ATP: Compression Molded Rubber - Provides unique custom tooling and compression molding capabilities to meet the wide range of customer requirements.
www.webopedia.com /TERM/W/wavelet_compression.html   (189 words)

  
 EETimes.com - JPEG2000 wavelet compression spec approved
That data will determine the order and speed at which separate JPEG2000 frames are to be displayed to create motion.
JPEG2000 image (middle) shows almost no quality loss from current JPEG, even at 158:1 compression.
JPEG2000 promises to compress images 200 times with better resulting quality than current JPEG images compressed fivefold.
www.eetimes.com /story/OEG19991228S0028   (1131 words)

  
 Dartmouth Wavelet Warriors' Home Page
Nerf Warrior in Training, Assistant Professor, Math & CS Image Compression, Joint Source/Channel Coding, Signal Processing
Wavelet Vassal, Graduate student, CS Signal Processing, Parallel Algorithms, Medical Imaging
Davis, "A Wavelet-based Analysis of Fractal Image Compression, " submitted to IEEE Transactions on Image Processing, 1996.
www.geoffdavis.net /dartmouth/warriors.html   (290 words)

  
 comp.compression Frequently Asked Questions (part 2/3)
If you have corrections or suggestions for this FAQ, send them to Jean-loup Gailly .
Contents ======== Part 2: (Long) introductions to data compression techniques [70] Introduction to data compression (long) Huffman and Related Compression Techniques Arithmetic Coding Substitutional Compressors The LZ78 family of compressors The LZ77 family of compressors [71] Introduction to MPEG (long) What is MPEG?
[77] Introduction to Fractal compression [78] The Burrows-Wheeler block sorting algorithm (long) Part 3: (Long) list of image compression hardware [85] Image compression hardware [99] Acknowledgments Search for "Subject: [#]" to get to question number # quickly.
www.faqs.org /faqs/compression-faq/part2/preamble.html   (227 words)

  
 LuraTech: JPEG2000, data compression, image compression, document compression
JPEG2000/Part6, JPM-style PDF and JBIG2: ISO standard-compliant document compression is available now
LuraTech is a leading developer of JPEG2000 implementations and technology for the color compression of images, data and scanned documents.
LuraTech makes color compression a reality for public and private sector organizations by delivering easy-to-implement, open-standard imaging products, coupled with enterprise-class support.
www.luratech.com   (62 words)

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