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More PKWare DCL Decompression Code
C++ code posted to comp.compression that describes extraction from PKWare’s Data Compression Library.
Update: The author posted this correction to comp.compression:
There’s a bug in the code posted 2001-10-07 19:36:38 PST. To fix:
In the
void tcDecoder::Decode(char *apBuffer, unsigned int *apSize, unsigned int anBufferSize)
function after both
if (lnIndex == mnCurrentPos) lnIndex = lnStartIndex;
add
if (lnIndex == mnDictionarySize) lnIndex = 0;
http://groups.google.com/groups?hl=en&threadm=93e3bf38.0110071836.3bfc02d3%40posting.google.com&rnum=1Aurora Borealis - a new way of compression
This document describes the Aurora Borealis algorithm, which combines statistical analysis with a back end using an unknown type of coding. Author Michael Asse seems to have high hopes for this technique.
DataCompression.info reader Viktor F. had this to say: This compression method is inefficient. LZW can beat this easily. The author should read some books […]
read more from " Aurora Borealis - a new way of compression "
FreeImage
The Free, Quality Image library for Windows. This library decodes quite a number of image formats, but don’t expect to see GIF in there anytime soon. Perhaps after the patent expires…
http://www.6ixsoft.com/Doom9’s MPEG Forum
This site is mostly oriented towards capturing and storing DVD - good advice on how to use various tools, codecs, hardware, etc. Very active site.
http://forum.doom9.org/Real-Time Imaging
An academic journal focusing on imaging and compression. It appears that all the papers published in this journal are available on line in PDF format!
http://www.academicpress.com/rtiWeb Graphics
A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
http://www.psychology.nottingham.ac.uk/staff/cr1/graphics.htmlHP Labs LOCO-I/JPEG-LS Home Page
JPEG-LS is the new lossless/near-lossless compression standard for continuous-tone images developed by ISO/IEC JTC1/SC29/WG1 (final draft international standard FDIS14495-1 as of Novembr 1998). The standard is based on the LOCO-I algorithm (LOw COmplexity LOssless COmpression for Images) developed at Hewlett-Packard Laboratories
Update: The HP site has just added a JPEG-LS plugin for Photoshop, in addition to […]
http://www.hpl.hp.com/loco/Proseminar Datenkompression - Arithmetische Kodierung
This page gives an introduction to Arithmetic Coding and shows how to implement it using floats or integers. There is also a proof of the efficiency of the algorithms, along with visualization and Win32 binaries. This page is in English and includes links to material in both German and English.
DataCompression.info user Juergen Abel found the […]
http://www.bodden.de/studies/ac/read more from " Proseminar Datenkompression - Arithmetische Kodierung "
Markov Predictive Coders : PPMZ
This directory contains source and executable for Charles Bloom’s PPMZ encoder, as well as a paper on PPMZ and some benchmark results. There are also links to a few other pages containing PPM information.
News: Charles Bloom has now released the source code to PPMZ2. He says it is both cleaner and faster than the […]
Huffman Coding with Priority Queues
This article is really about using the priority queue containers that are part of the standard C++ library. The example program implements a Huffman Encoder using the queues, showing how they can do a fairly complex piece of work without too much coding on your part.
http://www.dogma.net/markn/articles/pq_stl/priority.htm3DCompression.com
A directory of links and resources on compressing the 3D models used for computer graphics and other large geometric datasets. This is a replacement for the site at http://www.cc.gatech.edu/~kingd/3Dcompression.html.
http://www.3dcompression.com/Digging Deep Into Compression
An article in Wired that talks about the use of compression for patten recognition. Tools as simple as Zip are able to accurately determine the language of a given text. More complex algorithms are being used to determine matches of DNA sequences.
http://www.wired.com/news/technology/0,1282,50192,00.htmlBasics about MPEG Perceptual Audio Coding
The folks at Fraunhofer give a brief tutorial of some of the basic concepts behind MP3 encoding.
http://www.iis.fhg.de/amm/techinf/basics.htmlread more from " Basics about MPEG Perceptual Audio Coding "
MPEG-4 foe calls for antitrust probe
On2 Technologies is asking the US Department of Justice to take action against the coalition of MPEG-4 patent holders, arguing that the coalition is anti-competitive. Maybe not just a coincidence, On2 is presently pushing their own streaming format with industry standards groups.
http://zdnet.com.com/2100-1105-879439.htmlFELICS - Fast and Efficient Lossless Image Compression
P. G. Howard and J. S. Vitter. “Fast and Efficient Lossless Image Compression,” Proceedings of the 1993 IEEE Data Compression Conference (DCC ‘93), Snowbird, UT, April 1993. The abstract describes this as a lossless compression algorithm that provides results as good as JPEG in lossless mode with five times the speed.
http://www.cs.duke.edu/~jsv/Papers/catalog/node69.htmlread more from " FELICS - Fast and Efficient Lossless Image Compression "
Fast Progressive Lossless Image Compression
P. G. Howard and J. S. Vitter. “Fast Progressive Lossless Image Compression,” Proceedings of the 1994 IST/SPIE International Symposium on Electronic Imaging Science and Technology, San Jose, CA, February 1994. This paper describes a technique that combines the author’s previously published FELICS algorithm with the progressivity of the MLP method.
http://www.cs.duke.edu/~jsv/Papers/catalog/node70.htmlread more from " Fast Progressive Lossless Image Compression "
Arithmetic Coding for Data Compression
by P. G. Howard and J. S. Vitter. “Arithmetic Coding for Data Compression,” Proceedings of the IEEE, 82(6), June 1994, 857-865. This paper describes arithmetic coding, and introduces a technique that uses table lookups to make the process more efficient.
http://www.cs.duke.edu/~jsv/Papers/catalog/node71.htmlDictionary Selection using Partial Matching
D. T. Hoang, P. M. Long and J. S. Vitter. “Dictionary Selection using Partial Matching,” Information Sciences, 119(1-2), 57-72, 1999. This paper describes an attempt to squeeze improved compression out of existing dictionary-based schemes by using multiple context-based dictionaries for encoding.
http://www.cs.duke.edu/~jsv/Papers/catalog/node73.htmlread more from " Dictionary Selection using Partial Matching "
Compressed Suffix Arrays and Suffix Trees, with Applications to Text Indexing and String Matching
R. Grossi and J. S. Vitter. “Compressed Suffix Arrays and Suffix Trees, with Applications to Text Indexing and String Matching,” Proceedings of the 32nd Annual ACM Symposium on Theory of Computing (STOC ‘00), Portland, OR, May 2000, 397-406.
http://www.cs.duke.edu/~jsv/Papers/catalog/node79.htmlHuffman Coding: A CS2 Assignment
Some good introductory explanation here.
http://www.cs.duke.edu/csed/poop/huff/info/Technical Overview of Cartesian Perceptual Compression
This is a bi-level image compression scheme designed to be used for scanned images of books, faxes, etc. It is a non-degrading scheme, but not lossless. The company reports that their current customer list includes GetThePatent.com, FIS|Online, JSTOR, and Kurzweil. More information about clients and partners can be found
here.
read more from " Technical Overview of Cartesian Perceptual Compression "
The Video Quality Experts Group
A growing concern for video researchers and broadcasters alike, is the assurance and maintenance of an acceptable service quality level for the distribution of video programming. The Video Quality Experts Group (VQEG) was created to deal with video quality issues, specifically, objective methods for predicting video image quality.
http://www.its.bldrdoc.gov/vqeg/zlib information
Some information and assorted links regarding zlib.
http://gatekeep.cs.utah.edu/hppd/hpux/Misc/zlib-1.1.4/Relational Differentiation Encoding Patent App from Zeosync
The folks at Zeosync have been making some pretty bold claims regarding their yet-to-be-shown compressin tools. This patent application might open the door a bit.
http://l2.espacenet.com/dips/viewer?PN=WO0219536&CY=ep&LG=en&DB=EPDread more from " Relational Differentiation Encoding Patent App from Zeosync "
JPEG Compression - Interactive Demo
This page has a Java applet that lets you experiment a bit with different quantization schemes for JPEG. There is lots of information here, I highly recommend that you follow the Help link to see what’s going on.
http://www.cs.sfu.ca/CourseCentral/365/li/interactive-jpeg/Ijpeg.htmlJPEG Compression Example
An opportunity to look at a file when compressed with various JPEG quality factors.
http://www.cs.sfu.ca/CourseCentral/365/li/material/cgi-bin/whichjpeg.cgiWavelet Compression Example
This example shows the effects of wavelet compression at various levels of quality and compares the wavelet compression result to the JPEG compression result.
http://www.cs.sfu.ca/CourseCentral/365/li/material/misc/wavelet.htmlThe maths behind MP3
Dr. Keith Devlin writes an article in the UK Guardian explaining a bit about the technology behing the MP3 format.
http://www.guardian.co.uk/internetnews/story/0,7369,678607,00.htmlFree Compression and Archiving Libraries and Source Code
This web site keeps links to free libraries and source code. If you like this, you might want to browse around in some of their other areas as well.
DataCompression.info user Andrew S. was not too impressed with this site: I tried one half of their links and they were all dead or directed to content […]
http://www.thefreecountry.com/developercity/compression.shtmlread more from " Free Compression and Archiving Libraries and Source Code "
A Data Compression Primer
A short tutorial on a few basic data compression concepts.
http://www.gnosis.cx/publish/programming/compression_primer.html