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| | Lossless data compression -- Facts, Info, and Encyclopedia article |
 | | Good compression algorithms are those that achieve shorter output on input distributions that occur in real-world data. | | | Whilst, in principle, any general-purpose lossless compression algorithm (general-purpose means that they can handle all binary input) can be used on any type of data, many are unable to achieve significant compression on data that is not of the form that they are designed to deal with. | | | Most lossless compression programs use two different kinds of algorithm: One which generates a statistical model for the input data, and another which maps the input data to bit strings using this model in such a way that "probable" (e.g. |
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http://www.absoluteastronomy.com/encyclopedia/l/lo/lossless_data_compression.htm
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| | [1.0] Introduction / Lossless Data Compression |
| | Compression software can scan through the file, find these redundant strings of characters, and then store them using an escape character (ASCII 27), followed by the character and a binary count of the number of times it is repeated. | | | * A more sophisticated and efficient lossless compression technique is known as "Huffman coding", in which the characters in a data file are converted to a binary code, where the most common characters in the file have the shortest binary codes, and the least common have the longest. | | | In this specific case, the data compression software reduces the size of the data file by a factor of two, or results in a "compression ratio" of 2:1. |
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http://www.vectorsite.net/ttdcmp1.html
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| | Lossless Compression Algorithms (Entropy Encoding) |
| | Lossless compression frequently involves some form of entropy encoding and are based in information theoretic techniques, Shannon is father of information theory and we briefly summarise information theory below before looking at specific entropy encoding methods. |
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http://www.cs.cf.ac.uk/Dave/Multimedia/node207.html
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| | Maximum Compression (lossless data compression software) |
| | On the Compression Programs page added two columns to indicate if a compressor has a build in (or external) GUI and the algorithms used (if known) by that program. | | | The problem with different compression sizes in GUI and command-line is caused by a bug in the beta 2 version of the program. | | | This is *much* higher then current compression software is capable of. |
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http://www.maximumcompression.com
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| | Lossless Data Compression |
| | Unix compress and uncompress, gzip and gunzip, and Windows WinZip) are based on the Lempel-Ziv algorithm. | | | The main objective of this page is to introduce two important lossless compression algorithms: Huffman Coding and Lempel-Ziv Coding. | | | Huffman codes are optimal in the sense that no other lossless fixed-to-variable length code has a lower average rate. |
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http://www.data-compression.com/lossless.html
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| | Lossless Data Compression Program: Hybrid LZ77 RLE |
| | Some other data compression algorithms use a value (using variable-length code) that indicates the number of literal bytes that follow, but this is really analogous to a prefix bit, because 1-byte uncompressed data is very common for modestly compressible files. | | | It may be advantageous to compress a string as two shorter matches instead of one long match and a bunch of literal bytes, and it can be better to compress a string as a literal byte and a long match instead of two shorter matches. | | | This code also copies the compressed data forward in memory so that it won't be overwritten by the decompressed data before we have had a change to read it. |
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http://www.cs.tut.fi/~albert/Dev/pucrunch
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| | DataCompression.info - Lossless Compression |
| | DCG Framework is a object oriented framework for lossless data compression. | | | Not sure what algorithm they are using, it is described as "GEMAC's data compression algorithm." This algorithm was first published at DCC '95, and is described as a hybrid of ZL1 and ZL2, created with the goal of maximizing compression rate. |
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http://datacompression.info/Lossless.shtml
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| | LPAC - Lossless Predictive Audio Compression |
| | The new PAC file format (v5) has a CRC checksum to indicate lossless processing, and there are some compression enhancements associated with this new file format. | | | The LPAC file format (*.PAC) is designed to be compatible and lossless across different platforms and processors. | | | There are versions of LPAC for Windows, Linux and Solaris, which are compatible with each other, so you can exchange your compressed files between different systems. |
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http://www.nue.tu-berlin.de/wer/liebchen/lpac.html
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| | Digital Systems Research Center: Report 124 |
| | We describe a block-sorting, lossless data compression algorithm, and our implementation of that algorithm. | | | The transformation does not itself compress the data, but reorders it to make it easy to compress with simple algorithms such as move-to-front coding. | | | The algorithm works by applying a reversible transformation to a block of input text. |
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http://gatekeeper.dec.com/pub/DEC/SRC/research-reports/abstracts/src-rr-124.html
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| | lossless and lossy compression - a Whatis.com definition - see also: lossy, lossless, lossy compression, lossless ... |
| | This is generally the technique of choice for text or spreadsheet files, where losing words or financial data could pose a problem. | | | The JPEG image file, commonly used for photographs and other complex still images on the Web, is an image that has lossy compression. | | | On the other hand, lossy compression reduces a file by permanently eliminating certain information, especially redundant information. |
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http://whatis.techtarget.com/definition/0,,sid9_gci214453,00.html
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| | [16] What is the state of the art in lossless image compression? |
| | In particular, JPEG-LS significantly outperforms FELICS and lossless JPEG Huffman at similar levels of complexity (it also outperforms lossless JPEG arithmetic, which is of significantly higher complexity). | | | From the MG README file: The MG system is a suite of programs for compressing and indexing text and images. | | | Most of the functionality implemented in the suite is as described in the book ``Managing Gigabytes: Compressing and Indexing Documents and Images'', I.H. Witten, A. Moffat, and T.C. Bell; Van Nostrand Reinhold, New York, 1994, ISBN 0-442-01863-0; US $54.95; call 1 (800) 544-0550 to order. |
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http://www.faqs.org/faqs/compression-faq/part1/section-14.html
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| | JBIG-KIT lossless image compression library |
| | Even much better competitive compression results on computer generated images, which are free of scanning distortions. | | | About 1.1 to 1.5 times better compression ratio on typical scanned documents compared to G4 fax compression (ITU-T T.6), which has been the best compression algorithm for scanned documents available prior to JBIG1. | | | JBIG-KIT implements a highly effective data compression algorithm for bi-level high-resolution images such as fax pages or scanned documents. |
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http://www.cl.cam.ac.uk/~mgk25/jbigkit
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| | BitJazz: SheerVideo |
| | But for those occasions when material needs to be converted to a different format whether for input, output, or transport to different applications or devices, every Sheer codec can input and output images in any pixel format, so that the user can always decide which specific Sheer codec to use. | | | SheerVideo for Mac includes versions of each direct lossless image codec optimized for G3, G4 (AltiVec), and G5, and the decoders are multiprocessor-enabled, so it can make the most of whatever processors are available. | | | A version optimized for MMX is currently in the works as well. |
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http://www.bitjazz.com
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| | Tech Report: HPL-1999-144: Lossless Compression of Digital |
| | This new lossless compression algorithm uses only a small number of integer arithmetic operations and performs as well, or better than most state-of-the-art lossless compression algorithms. | | | The main operations of the algorithm are prediction with integer coefficients and Golomb-Rice coding. | | | This study finds that these algorithms appear to have reached a limit in compression that is very modest compared to what can be achieved with lossy audio coding technology. |
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http://www.hpl.hp.com/techreports/1999/HPL-1999-144.html
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| | FLAC - Free Lossless Audio Codec |
| | For developers there are also a few additions and changes to the metadata API to make working with tags easier. | | | See the features page for a complete list of features, or the comparison page to see how FLAC compares with other lossless codecs. | | | Visit the download page for links to the source code or pre-built binaries. |
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http://flac.sourceforge.net
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| | bzip2 : Home |
| | If you are trying to restore compressed data from a backup tape or disk, and that data contains some errors, bzip2 may still be able to decompress those parts of the file which are undamaged. | | | You can use the library in your own programs, to directly read and write.bz2 files, or even just to compress data in memory using the bzip2 algorithms. | | | The bzip2 program itself is a client of the library. |
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http://sources.redhat.com/bzip2
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| | hp labs : research : information theory |
| | The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories. | | | Weinberger, G. Seroussi, G. Sapiro, "LOCO-I: A Low Complexity, Context-Based, Lossless Image Compression Algorithm," Proc. | | | Get HP Labs' software implementation of JPEG-LS JPEG-LS DLL and Plug-in for Adobe Photoshop |
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http://www.hpl.hp.com/loco
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| | The Art Of Lossless Data Compression http://go.to/artest |
| | These 24 images, compressed with ERI to 8,891,702 bytes, are here and here. | | | 24 Kodak images are used to compare performance of lossless image compression algorithms since 1995, | | | PNG compresses them to 15,328,841 bytes; JPEG-LS to 15,404,818 (that's about 172%). |
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http://geocities.com/eri32/kodak.html
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| | WavPack Audio Compression |
| | Although the technology is loosely based on previous versions of WavPack, the new version 4 format has been designed from the ground up to offer unparalleled performance and functionality. | | | Instead of creating a single file, this mode creates both a relatively small, high-quality lossy file that can be used all by itself, and a "correction" file that (when combined with the lossy file) provides full lossless restoration. | | | The compression ratio depends on the source material, but generally is between 30% and 70%. |
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http://www.wavpack.com
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| | Lossless Image Compression |
| | Elements of information theory related to the evaluation of data compression algorithms are introduced. | | | Lossless image compression model is defined, serving as a framework for classification of lossless image compression techniques. | | | The goals of the lossless image data compression are presented. |
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http://www.cs.technion.ac.il/Labs/Isl/Project/Projects_done/VisionClasses/DIP/Lossless_Compression/lossless.html
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| | SoftSound Ltd. |
| | lossless: The decompressed file is exactly the same as the original. | | | Shorten for Windows is available for personal use: | | | It is fast and has low memory usage and thus is suitable for stand alone or embedded operation for a wide range of audio-like signals. |
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http://www.softsound.com/Shorten.html
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| | The Canterbury Corpus |
| | The Canterbury Corpus is a benchmark to enable researchers to evaluate lossless compression methods. | | | This site includes test files and compression test results for many research compression methods. | | | Research on the corpus and compression in general (includes papers and reports in PDF format) |
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http://corpus.canterbury.ac.nz
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| | Pegasus Imaging Imaging Toolkits and SDKs Image Compression and Editing JPEG |
| | A full suite of document imaging toolkits, medical image compression SDKs, color / photo editing and compression libraries, and video codecs provide advanced technology designed to enhance imaging software solutions. | | | Pegasus Imaging offers superior imaging technology, powerful digital imaging components and optimized image compression SDKs for application development. | | | Fully functional trial downloads and customer-acclaimed support allow you to be certain your requirements will be met before purchase. |
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http://www.pegasusimaging.com
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| | Nvidia rolls out GeForce 6800 The Register |
| | The new chips can handle GDDR 3 SDRAM across a 256-bit memory interface. | | | "Non-power of two textures" are supported, along with the sRGB texture format and both DirectX and S3TC texture compression algorithms. | | | Version 3.0 of Nvidia's own Intellisample system provides 16x anisotropic filtering and lossless compression for colour, texture and z-buffer data to speed it through the pipeline. |
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http://www.theregister.co.uk/2004/04/14/nvidia_6800
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| | Monkey's Audio - a fast and powerful lossless audio compressor |
| | Efficient (fast and great compression) — Monkey's Audio is highly optimized and highly efficient | | | Monkey’s Audio is a fast and easy way to compress digital music. | | | Freely available source code, simple SDK and non-restrictive licensing - other developers can easily use Monkey's Audio in their own programs -- and there are no evil restrictive licensing agreements |
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http://www.monkeysaudio.com
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| | Archive Comparison Test and PBZIP2 (by Jeff Gilchrist) |
| | Parallel BZIP2 (PBZIP2) is an open-source parallel implementation of the bzip2 block-sorting file compressor that uses pthreads and achieves near-linear speedup on SMP machines. | | | The output of this version is fully compatible with bzip2 v1.0.2 (ie: anything compressed with pbzip2 can be decompressed with bzip2). | | | est (ACT) is a set of benchmarks designed to show the state of the art in lossless data compression. |
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http://compression.ca
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| | Library Papers |
| | This paper was in turn a subset of the landmark paper 'Coding Methods for High-Resolution Recording Systems' presented at AES, New York in 1997 - copies of which can be obtained from AES as preprint #4639. | | | MLP Lossless Compression by Bob Stuart et al. | | | This previously unpublished overview was a superset of the shorter paper presented to AES Japan 9th in 1999. |
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http://www.meridian-audio.com/lib_pap.htm
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| | BBC NEWS Technology Online music lovers 'frustrated' |
| | Restrictive DRM needs to be addressed whereby a standard system can be implemented amongst different sites. | | | As faster broadband becomes more widely available there is no reason not to do this and once lossless downloads are available the quality will be the same as CDs. | | | Look at Metallica's live music store - you can choose to download an MP3 or lossless FLAC format, which of course means no loss of sound quality compared to the original source. |
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http://news.bbc.co.uk/go/newsFeedXML/moreover/-/1/hi/technology/4474143.stm
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| | Websites: Lossless Compression |
| | IEEE Data Compression Conference, Snowbird, Utah, March 1995, pages 202-211. |
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http://www.ganesh.org/related/loss.html
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