A guide on using AviSynth with AVSEdit -- the official script editor for AviSynth. It provides an easy interface to write and preview scripts, making AviSynth more accessible to beginners and advanced users alike.
Created: 18/01/2008
by Maxim SmirnovMore...
From the intro:
"This guide assumes you're already familiar with AVISynth and how to write scripts. In it, I will attempt to give a rundown of some of the most popular and useful AVISynth filters for filtering anime music video."
Created: 18/01/2008
by Maxim SmirnovMore...
This web site was founded as an independent non-commercial resource for industry participants to learn about the world of digital video technology. Besides some tutorial texts, it has a nice list of vendors, including links on vendors of hardware (IP cores, chips) and software video compression products.
Created: 14/05/2006
by Maxim SmirnovMore...
It is a very good site to know about audio technology and ask your questions. The site is organized as a forum, it has comprehensive FAQ.
Created: 11/02/2006
by Maxim SmirnovMore...
By Karl-Heinz Brandenburg from Fraunhofer Institute for Integrated Circuits. The paper gives an introduction to audio compression for music file exchange. Beyond the basics the focus is on quality issues and the compression ratio /
audio bandwidth / artifacts tradeoffs.
Created: 31/01/2006
by Maxim SmirnovMore...
The unofficial MPEG Audio page at University of Hannover. The page has news about MPEG Audio, overviews, a set of usefull links, MPEG Audio FAQ, MPEG-4 Audio standard drafts, some reference software.
Created: 31/01/2006
by Maxim SmirnovMore...
It's a nice explanation of advanced audio coding. Besides other things, it contains overview of MPEG-4 Low Delay Audio Coder (AAC-LD), comprehensible list of AAC's improvements over MP3, external links.
Created: 31/01/2006
by Maxim SmirnovMore...
Short definition and description of G.729 -- Coding of speech at 8 kbit/s using conjugate-structure algebraic-code-excited linear-prediction (CS-ACELP). G.729 is mostly used in Voice over IP (VoIP) applications.
Created: 30/01/2006
by Maxim SmirnovMore...
Short definition and explanation of G.711 -- Pulse Code Modulation (PCM) of Voice Frequencies on an 64 kbps channel.
Created: 30/01/2006
by Maxim SmirnovMore...
Most compression programs need to be able to do bit-oriented input and output. This is a problem, since most file systems are set up to do byte oriented I/O. Arturo Campos looks at ways to do an effective implementation of this neglected part of compression programming.
Created: 17/11/1999
by Mark NelsonMore...
How much can a given piece of data be compressed? This FAQ addresses that question, including some necessary critiques of the question itself. Graham Fyffe apparently spends some time thinking about complexity.
Created: 29/07/2000
by Mark NelsonMore...
Arturo Campos provides an easy-to-read explanation of the BWT transformation algorithm. This algorithm achieves very good compression ratios at relatively high speeds.
Created: 17/11/1999
by Mark NelsonMore...
An article Mark Nelson wrote that describes how to take advantage of the zip classes included in Java's 1.1 JDK. This includes some very simple programs that can create, view, and extract from zip files.
Created: 01/12/1999
by Mark NelsonMore...
A Practical Introduction To Data Compression by Alexander Ratushnyak. A Data Compression mini-FAQ with a good set of links.
Created: 21/09/2000
by Mark NelsonMore...
An article by Arturo Campos that describes and discusses Finite Context Modeling. This modeling technique is uses by PPM compressors, although Campos makes the point that the ideas in this article can be used in other compressors as well.
Created: 18/12/1999
by Mark NelsonMore...
GSM provides telephone quality speech at a compressed rate of 13 Kbps. Compare this to the 64 KBps required by standard u-law and A-law codes. This site gives lots of info about the GSM format, along with free source code.
Created: 21/11/1999
by Mark NelsonMore...
The MTF algorithm is not very exciting, but it does a really nice job of compressing streams that have been put through the BWT transform. Arturo Campos gives an explanation of how to implement it in this paper.
Created: 17/11/1999
by Mark NelsonMore...
An overview of the field by Debra A. Lelewer and Daniel S. Hirschberg. Lots of informative text. This appears to be a survey paper that was adapted for presentation on the web. Lossless compression techniques only!
Created: 10/11/1999
by Mark NelsonMore...
Mark Nelson's magazine articles, including articles on LZW coding, arithmetic coding, BWT, Zlib, JavaZip and some other topics.
Created: 23/11/1999
by Mark NelsonMore...
This site contains the comp.speech FAQ, and also has links to their ftp site, which contains software for speech codecs.
Created: 21/11/1999
by Mark NelsonMore...
This includes a brief discussion of Huffman coding, then of LZ77 compression, and finally some of the coding oddities that are found in deflate.
Created: 23/08/2001
by Mark NelsonMore...
Comparison of 6 codecs with default parameters.
Three of them were kindly provided by the codecs developers.
Created: 18/07/2005
by Dmitriy KulikovMore...
An introductory paper. Includes information on Huffman coding, Info Theory, Coding, LZ77, LZ78, and more. This page also has a good set of links.
Created: 15/02/1999
by Mark NelsonMore...
Mark Nelson's zlib article, originally published in Dr. Dobb's Journal. The source code for the article includes an OCX that allows you to use zlib from many different languages under Win32
If you are attempting to use the zlib OCX with Visual Basic or Visual C++, please follow the links to my FAQ. The OCX that accompanies this article needed an upgrade to work with later versions of Microsoft's tools.
Created: 06/11/1999
by Mark NelsonMore...
Charles is the author of PPMZ and has a really great collection of software he has written on this page, much of it is indexed here in the appropriate pages. His home page also contains links to some interesting papers and descriptions on various algorithms, as well as some archived posts that explain some compression topics. It's well worth nosing around this site a bit for more information.
Created: 25/12/1998
by Mark NelsonMore...
An article by Mark Nelson that appeared in the September 1996 issue of Dr. Dobb's Journal. At the time it appeared, the BWT was relatively unknown among compression enthusiasts. This article includes source code that implements a simple test program that demonstrates BWT compression.
Created: 10/12/1998
by Mark NelsonMore...
An article pitched to the layman on how compression works.
If you download many programs and files off the Internet, you've probably encountered ZIP files before. This compression system is a very handy invention, especially for Web users, because it lets you reduce the overall number of bits and bytes in a file so it can be transmitted faster over slower Internet connections, or take up less space on a disk. Once you download the file, your computer uses a program such as WinZip or Stuffit to expand the file back to its original size. If everything works correctly, the expanded file is identical to the original file before it was compressed.
Created: 25/07/2001
by Mark NelsonMore...
A concise explanation of Arithmetic Coding by Arturo Campos. The easy to read article is accompanied by snippets of pseudo code.
Created: 17/11/1999
by Mark NelsonMore...
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.
Charles Bloom has now released the source code to PPMZ2. He says it is both cleaner and faster than the original PPMZ code.
Created: 14/04/2002
by Mark NelsonMore...
An article that explains arithmetic coding, plus a sample program that implements a limited sort of PPM.
Christable C. had these kind words: I have read some other articles, but not clearly known. When reading this article, I find that Arithmetic Coding is easy to know !
Created: 07/11/1999
by Mark NelsonMore...
Arturo Campos describes a version of arithmetic coding which renormalizes in bytes, thus achiving twice the speed of an standard implementation and 0.01% less compression.
Created: 17/11/1999
by Mark NelsonMore...
Arturo Campos describes a model for arithmetic coding which results in less compression than an adaptative one, but at much higher speeds.
Created: 17/11/1999
by Mark NelsonMore...
A nice explanation of LZW compression from the fine folks at the Data Compression Center.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 06/11/1999
by Mark NelsonMore...
In this comp.compression posting, Ben Rudia-Gould opens up the compression format used by the PKWare Data Compression Library. This is the only place I have ever seen this information disclosed; PKWare has certainly not done so.
Created: 22/09/2001
by Mark NelsonMore...
Arturo Campos has been doing quite a bit of research on the LZP algorithm (first described by Charles Bloom.) This paper presents all of his results to date.
Created: 17/11/1999
by Mark NelsonMore...
Another article about LZP by Arturo Campos. This piece describes a specific implementation technique using linked lists.
Created: 17/11/1999
by Mark NelsonMore...
Arturo Campos presents the LZP algorithm, first described by Charles Bloom. LZP is a hybrid of dictionary based coding and statistical modeling. This means it has some of the elements of popular LZSS encoders, but takes advantage of PPM style modeling as well. The combination of the two leads to very good compression ratios.
Created: 17/11/1999
by Mark NelsonMore...
Arturo Campos explains some of the basics about LZ77 compression and its popular descendant, LZSS. This is one of Arturo's longer articles, and it includes a hefty does of 80x86 code for illustration purposes.
Created: 17/11/1999
by Mark NelsonMore...
Arturo Campos explains how your implentation of an LZ77 compressor might benefit from an improved parsing algorithm. Instead of always using the longest match found at at the current position, Flexible Parsing attempts to find the optimal match which will lead to the best overall compresion.
Created: 17/11/1999
by Mark NelsonMore...
This article describes a relatively painless way to construct suffix trees. Once you have a suffix tree constructed, it is extremely easy to search for the longest match of a given string. This makes the suffix tree a nice data structure to use in macro replacement forms of data compression.
Created: 01/12/1999
by Mark NelsonMore...
Arturo Campos describes one of the simplest yet often effective compression algorithms. Believe it or not, Huffman coding with an order-0 model is nearly 50 years old!
Created: 17/11/1999
by Mark NelsonMore...
A page by Michael Schindler that describes Huffman coding in a fair amount of detail. Also includes links to other information resources. This page also has an explanation of the canonical huffman table storage algorithm.
Created: 27/11/1999
by Mark NelsonMore...
A very nice description of Huffman coding, as well as a few other types of coding. I believe this is part of a survey paper by Debra A. Lelewer and Daniel S. Hirschberg.
Created: 15/12/1999
by Mark NelsonMore...
Arturo Campos descrives Canonical Huffman Coding, the technique used in the deflate algorithm made popular by PKZip. This type of Huffman coding follows some specific rules regarding the structure of the Huffman tree that simplify the process of transmitting the tree.
Created: 17/11/1999
by Mark NelsonMore...
bwtzip is an ongoing project, distributed under the GNU General Public License, to implement a Burrows-Wheeler compressor in standard, portable C++. It is research-grade in that it is highly modularized and abstracted, so that it is simple to swap out parts of the compressor without affecting anything else. This makes it easy to experiment with different algorithms at different stages of compression.
Looks like Steven T. Lavavej released a new version of bwtzip in early February, 2003. A wide variety of improvements, most of them in implementation - not visible to the end user. A description of recent changes is found here
Created: 11/12/2002
by Mark NelsonMore...
This site discusses a characteristic of some compression algorithms that the author refers to as One to One (bijective) compression. In a nutshell, this property means that for any file X, F( F'( X ) ) == X. (F is either the compressor or decompressor, and F' is its opposite number.) This is definitely not the case for most conventional compression algorithms.
This page has a some Huffman compression code that has been adapted to implement a bijective property.
Created: 17/12/1999
by Mark NelsonMore...
This page is designed made to teach people about Lossless compression algorithms through the use of text graphics and Java Applets! Dominik Szopa has created pages that demonstrate Huffman, Adaptive Huffman, and LZW compression.
DCL reader SF has this to say: While the site itself is rather quick, it's disorganized...the Java applets really don't show what's going on at all. They show only the external effects...This site has definate potential, and I do recommend people see it. However, it's also got a ways to go yet. .
Created: 24/12/1998
by Mark NelsonMore...
A nice description of Adaptive Huffman Coding, as seen through a couple of different algorithms. I believe this is part of a survey paper by Debra A. Lelewer and Daniel S. Hirschberg.
Created: 10/11/1999
by Mark NelsonMore...
A sample chapter from The Scientist and Engineer's Guide to Digital Signal Processing, which just happens to be on Data Compression. You can download this entire book for free from the web site.
Created: 13/01/2000
by Mark NelsonMore...
Reputedly an excellent set of resources for using libpng - but don't take my word for it - my Japanese is non-existent.
Created: 10/07/2004
by Mark NelsonMore...
An article on the CodeProject detailing a user's troubles with GDI+. In particular, he found that he was unable to load JPG or PNG files stored as resources with GDI+. This article presents a way to make it happen.
This article was updated June 17, 204.
Created: 27/06/2004
by Mark NelsonMore...
An article by Eric Uner talks a bit about generating reandom numbers, something we all want to do from time to time.
Created: 20/06/2004
by Mark NelsonMore...
An updated and translated version of our German paper "Proseminar Datenkompression - Arithmetische Kodierung" from 2001. To the best of our knowledge, it is the first comprehensive paper that describes the whole way from the basic principles of AC up to a simple implementation, fully documented with C++ source code.
Created: 06/06/2004
by Mark NelsonMore...
PDF documents are commonly used and their content is usually compressed. This article shows a simple C code that can be used to extract plain text from the PDF file.
Created: 31/05/2004
by Mark NelsonMore...
Advanced Image Coding (AIC) is an experimental still image compression system
that combines algorithms from the H.264 and JPEG standards. More specifically,
it combines intra frame block prediction from H.264 with a JPEG-style discrete
cosine transform, followed by context adaptive binary arithmetic coding as used
in H.264. The result is a compression scheme that performs much better than JPEG
and close to JPEG-2000.
Created: 15/05/2004
by Mark NelsonMore...
Microsoft's implemention of J# includes the standard Java zip classes, and CodeProject contributor Valeri has figured out how to use them from a C# program.
Created: 10/05/2004
by Mark NelsonMore...
A list of the various types of image compression that Accusoft supports, along with a little detail on each type.
Created: 10/05/2004
by Mark NelsonMore...
Compressing Web content can produce a much faster site for users. Here's how to set it up and measure your success.l
Created: 10/05/2004
by Mark NelsonMore...
The third in Michael's collection of pages explaining lossless compression algorithms. A nice tutorial accompanied by ANSI C source.
Created: 02/05/2004
by Mark NelsonMore...
In this article I describe a translation of most of the WMF SDK interfaces, data structures, constants, functions into C#. NOTE: Digital Rights Management (DRM) support is not included in this translation.
Created: 25/04/2004
by Mark NelsonMore...
APT (Adaptive Prediction Trees) image coding supersedes BTPC (Binary Tree Predictive Coding). It is a general-purpose compression scheme for all types of still image. It does both lossless and lossy compression of monochrome and color images from 1 to 16 bits per component. Its performance on all image types is often close to that of the best alternative.
Created: 27/03/2004
by Mark NelsonMore...
In this article, I examine an indexing method that lets you find any character sequence in the source text in time only proportional to the sequence length using a structure that can compress the entire source text and index into less space than the text alone. This technique is exceptionally fast at detecting and counting occurrences of any string in the source text.
Created: 20/03/2004
by Mark NelsonMore...
Course notes of a JPEG 2000 short course given at the International
Conference in Image Processing (ICIP). By Dr. Majid Rabbani and Diego Santa-Cruz. The course covers image coding principles, a review of JPEG and all the main elements of JPEG 2000: wavelet transform, entropy coding, bitstream structure, error resilience, functionality, performance evaluation, etc.
Created: 07/03/2004
by Mark NelsonMore...
This article in Streamingmedia.com breaks down the family tree
of the MPEG standards, starting with MPEG-1 and working up to the
current and inscrutable MPEG-21. Written for the layman, this can
get you up to speed quick without burning up too many brain cells.
Created: 22/02/2004
by Mark NelsonMore...
This is a nice article posted on Codeguru.com by Sjaak Priester. In this article Sjaak uses octree color quantization to reduce a JPEG image with millions of colors down to a GIF with 256, as
well as giving you a look or two at Microsoft's nice GDI+ API.
Created: 08/02/2004
by Mark NelsonMore...
Microsoft thinks Windows Media Video can be a big part of the HD scene. This web page is dedicated to that proposition.
Created: 18/01/2004
by Mark NelsonMore...
Star Encoding performs some preprocessing on text files, enabling standard compressors to do somewhat better on the files. This article explains the transform and provides some sample code.
Created: 06/12/2003
by Mark NelsonMore...
Michael Dipperstein describes his personal quest for understanding and implementation of LZSS coding. Full source included.
Created: 03/12/2003
by Mark NelsonMore...
A good description of LZW, along with some specific information about TIFF's implemenation of this compression algorithm.
Created: 09/11/2003
by Mark NelsonMore...
This reference page breaks down the structure of an MP3 file quite nicely. Covers all the stuff you've wanted to know in detail.
Created: 27/10/2003
by Mark NelsonMore...
Michael Dipperstein describes his personal quest for understanding an implementation of Huffman coding. Full source included.
The page was updated with new source December, 2002.
Created: 18/10/2003
by Mark NelsonMore...
Brian Livingston's short article on HTTP compression provides some pointers detailing how to configure your server to serve compressed content.
Created: 01/09/2003
by Mark NelsonMore...
A CodeProject article which includes working code. Compression here consists of removal of comments, extra line feeds, white space, etc.
Created: 04/08/2003
by Mark NelsonMore...
An article that gets into the details you need to know about in order to use the MMX instruction set found on Intel processors. The author uses image processing as a demo app.
Created: 15/07/2003
by Mark NelsonMore...
This site is dedicated to discussion and explanation of HTTP compression with the Apache web server. Looks to me like the first place to go for information.
Created: 29/06/2003
by Mark NelsonMore...
This article on the Codeguru site by Michael Chourdakis demonstrates how to use the Windows IPicture interface to quickly load a JPEG, GIF, or BMP file into an easy to use HBITMAP. This is of course assuming you are using C on the Win32 platform.
Created: 17/06/2003
by Mark NelsonMore...
This article on The Code Project web site shows you how to calculate a CRC, but even better it shows you how to create a file that will have a given CRC value.
Created: 07/06/2003
by Mark NelsonMore...
This CodeProject article describes the development of a PATRICIA trie in the .NET framework. The actual code is written in C#, but naturally, it can be used with any of the .NET languages.
Created: 30/05/2003
by Mark NelsonMore...
This MSDN article describes how to use the java.utl.zip package with a C# program. Includes a sample GUI Zip application.
Created: 17/05/2003
by Mark NelsonMore...
This Code Project article is pretty much summed up by its descriptive title. It appears to use the .NET framework to store images in PNG format.
Created: 11/05/2003
by Mark NelsonMore...
Gzip encoding is a great way to serve up your web pages, because all modern browsers can render this format. If you're creating pages with PHP4, it turns out to be really easy to compress your pages this way and get a bit of speedup.
Created: 05/05/2003
by Mark NelsonMore...
An article by John Pliam. Needs a better summary, but I don't quite get it, other than the fact that there is some cryptographic thinking going on here.
Created: 04/05/2003
by Mark NelsonMore...
Marco Schmidt has assembled a nice page of links and information on the Zip archive format. A few good links, but this isn't the comprehensive guide you need to answer any question about the format.
Created: 17/04/2003
by Mark NelsonMore...
This FAQ provides good information about various audio file formats, which naturally includes quite a few compressed formats. It also has a few links to other relevant pages.
Created: 14/04/2003
by Mark NelsonMore...
This document describes a lossless audio compressor that does some straightforward prediction in combination with a Rice coder. This is credited to Matt Ashland, author of the Monkey's Audio codec.
Created: 14/04/2003
by Mark NelsonMore...
BitMagic is a C++ library that deals with dynamic bit vectors. It supports a couple of different ways to compress these bit vectors. This page discusses D-Gap Compression.
Created: 14/04/2003
by Mark NelsonMore...
BitMagic is a C++ library that deals with dynamic bit vectors. It supports a couple of different ways to compress these bit vectors. This page explains how to perform common operations on bit vectors while they are compressed in memory.
Created: 14/04/2003
by Mark NelsonMore...
The How Stuff Works web site tackles the question of just how Data Compression works, pitched to the general audience. All in all not a bad stab at it, with links to may other How Stuff Works pages for the curious.
Created: 07/04/2003
by Mark NelsonMore...
A tutorial by P.N. Tudor on the BBC web site. Gets right down into the nitty-gritty, stay away if you have math-phobia.
Created: 03/04/2003
by Mark NelsonMore...
A great example of an incredible compression claim. There's just a teeny tiny bit good thinking in here, and a huge amount of tangential speculation attempting to walk upright on two legs. Read it and just be glad the author doesn't seem to be raising funds.
Created: 01/04/2003
by Mark NelsonMore...
Researchers looking for signs of life have decided that complexity might be a good indicator. What better to measure complexity than gzip?
Created: 31/03/2003
by Mark NelsonMore...
Matt Woodward has written an article for Ars Technica that gives a good rundown on capturing and compressing video. There's a great deal of detail here, which you should be able to use to walk through the process, even if you are a rank beginner.
Created: 31/03/2003
by Mark NelsonMore...
A definition from searchStorage.com. MrSID is an image compression format used primarily in mapping/GIS applications.
Created: 30/03/2003
by Mark NelsonMore...
An article on the Mozilla web site that talks about improving perceived performance via HTTP compression. This article looks at implementation on the Apache server.
Created: 27/03/2003
by Mark NelsonMore...
The American Mathematical Society runs a monthly column called 'What's New In Math," featuring topics of general interest to their readers. In October 2002, the topic was data compression, which led to a fairly lengthy column with many, many references. Good reading!
Created: 23/03/2003
by Mark NelsonMore...
Back in 1998 I heard from a poor soul who was being encouraged to put some money into the Premier America, makers of the MINC Compression System. Seeing that MINC promised an iterative compression system that guaranteed any ratio you cared to dial in, I encouraged him to run, not walk, away from this opportunity. This led to an email conversation with someone from the company, assuring me that they would have a real product on the market quite soon now.
I haven't heard a peep out of Premier America since then, so hopefully they have stopped raising funds for their unlikely system. Fortunately, a good soul named Chez DuLac has preserved MINC's manifesto on his web site, along with his reasoned rebuttal.
Created: 21/03/2003
by Mark NelsonMore...
Aleks Jakulin has created a tutorial that will walk you through the necessary steps to compress images using a wavelet transform. The steps in the process are illustrated using Mathematica code. This page goes beyond a basic tutorial in that it shows a proposal to improve image rendering by adding noise.
Created: 21/03/2003
by Mark NelsonMore...
This document clarifies aspects of colour specification and image coding that are important to computer graphics, image processing, video, and the transfer of digital images to print.
Created: 20/03/2003
by Mark NelsonMore...
MrSID is a wavelet-based image format that seems to be pretty popular for people creating mapping databases (which tend to be huge.) This page has a nice little explanation, provided for you courtesy of the state of Massachusetts. MrSID is a proprietary format owned by LizardTech.
Created: 18/03/2003
by Mark NelsonMore...
An article from Microsoft giving you the lowdown on the best way to use all the tools shipping with Windows Media 9. This includes basic guidelines on setting up a streaming media system, comparison to Media Services 4.1, locations of bottlenecks, performance evaluation, and advanced tuning tips.
Created: 17/03/2003
by Mark NelsonMore...
Digital media needs metadata to be supremely useful. For example, wouldn't it be nice if your CD player showed you artist, album, and track information while it was playing a song? MP3 tracks have ID3 tags to supply this information, but naturally, Microsoft has created an extensive set of APIs for embedding metadata in all types of media. This article will bring you up to speed on metadata support for media encoding, playback, and more.
Created: 17/03/2003
by Mark NelsonMore...
John Robinson's page on BTPC, which includes documentation, samples, links, and source. BTPC is designed to do both lossy and lossless compression of images.
John updated this package to version 5 in March, 2003.
Created: 13/03/2003
by Mark NelsonMore...
Coding integers of an arbitrary length is an interesting problem. Steven Pigeon discusses a way to code integers in a very efficient manner, which approaches the optimal Log2(n) value.
Created: 07/03/2003
by Mark NelsonMore...
T. Strutz offers up an overview and taxonomy of Data Compression. If you're looking for the big picture, this might be a good place to start. A PowerPoint presentation is available for download as well - might be just the thing if you only have an hour left to prepare that lecture!
Created: 18/02/2003
by Mark NelsonMore...
A Q/A column in JavaWorld magazine from 12/2002. The article answers a couple of questions regarding how a Java programmer can zip up data resident in memory, as opposed to files. The second Q/A was particularly interesting as it addresses a quest to zip up data being passed through RMI in particular app.
Created: 17/02/2003
by Mark NelsonMore...
This article gives a good look at how to use the java.util.zip classes that showed up in JDK 1.1. Todd Sunsted includes java source that shows you how to easily compress files using standard library functions.
Created: 17/02/2003
by Mark NelsonMore...
This step-by-step guide has links to the appropriate software along with specific instructions on how to perform the encoding process. (No help on how to rip content of your DVDs, but that information can be found on the net.)
Created: 15/02/2003
by Mark NelsonMore...
David describes his work creating a bijective LZW compressor. (See this and other pages of David for details on what he means by bijective.) The page includes C++ source.
Created: 27/12/2002
by Mark NelsonMore...
A nice set of links to AudioCoding information. Since this is a Wiki site, it is highly collaborative - registered users can provide updates and modifications to the site at will. (I think.)
Created: 13/12/2002
by Mark NelsonMore...
A Technical Documentation bulleting from TI that answers the question "What is a Compressed Postscript (.psz) File?"
Created: 13/12/2002
by Mark NelsonMore...
Bob Carpenter has created a nice Java package that implements a PPM/arithmetic coding compression system. This page includes links to the source code, javadocs, and a fair amount of tutorial material. Very complete!
Created: 11/12/2002
by Mark NelsonMore...
David Scott presents an implementation of Vitter's dynamic Huffman compressor, adapted so that it is bijective. Don't know what bijective means? Check out David's home page for more details.
Created: 09/12/2002
by Mark NelsonMore...
A nice set of lecture notes by Iain Richardson. The notes have a good level of detail, so there is value here even without the lecture.
Created: 17/11/2002
by Mark NelsonMore...
Andy McFadden was nice enough to post a series of a dozen lessons on Data Compression. It looks as though these were posts to the now-forgotten GEnie information service, once a pretender to the CompuServe popularity crown.
Created: 30/10/2002
by Mark NelsonMore...
This site collects information, links, and review on Windows Media 9. Includes some detailed information on the codecs that are part of the new package.
Created: 12/10/2002
by Mark NelsonMore...
This Microsoft Security Bulletin details a bug in the code that implements compressed folders in the Windows 9X product line.
Created: 12/10/2002
by Mark NelsonMore...
Roman Zaritski explains the arduous processes he went through learning how to convert his simulation data to MPEG format. Short and simple, and if you have a Linux system you can probably recreate this work pretty easily.
Created: 28/09/2002
by Mark NelsonMore...
No documentation or hint of how this page was created, but it purports to give you some stats on the frequency of characters in English text.
Created: 28/09/2002
by Mark NelsonMore...
Nice detailed documentation on the structure of an LHA file. If you're going to attempt to support LHA files, you need a pointer to this doc.
Created: 15/09/2002
by Mark NelsonMore...
Ian Kaplan's Wavelet and Signal Processing page has lots of articles and C++/Java source code implementing wavelet transform via the lifting scheme, the integer-to-integer wavelet transform and the best basis wavelet packet transform
Created: 03/09/2002
by Mark NelsonMore...
This page gives a short introduction to the DICOM standard, commonly used for medical imaging. It has a lengthy set of links to DICOM viewers, images, and other resources.
Created: 18/08/2002
by Mark NelsonMore...
VcDemo is an interactive image and video compression (freeware) software package for Windows. It is intended as a tool for learning about compression techniques: from basic sampling and PCM to today's most advanced scalable embedded zerotree wavelet image compression technique and the MPEG video compression standard. VcDemo is an ideal tool for students to explore the possibilities of compression theory using textbook algorithms on real images. The package is also very suitable for on-line demonstrations in lectures. A user manual is available, as well as a set of exercises that can serve as home work.
Created: 01/08/2002
by Mark NelsonMore...
An article by Stephane Rodriguez on the CodeProject web site. Stephane describes his article as Revealing XML best practices with a utility tool and a framework. Yes, that means there is some sample code here as well.
Created: 21/07/2002
by Mark NelsonMore...
An overview of the basics, including Shannon-Fano, Huffman, Arithmetic coding, and a section on LZW for good measure.
Created: 20/07/2002
by Mark NelsonMore...
A senior project whose goal was to design a hardware compressor for continuous tone images. Contains a description of the algorithm, Matlab implementations, chip designs, and more.
Created: 15/07/2002
by Mark NelsonMore...
This article from Microsoft's Knowledge Base talks about the role of the codec in Microsoft's Media Technologies.
Created: 09/07/2002
by Mark NelsonMore...
What appears to be a comprehensive FAQ on PPM programming. Russian language, and fairly slow loading, but no reason not to try Google or BabelFish for a translation.
Created: 06/06/2002
by Mark NelsonMore...
A good resource for anyone using compression or writing compression code for the Amiga platform. Includes tutorial and background information as well as links to code.
Created: 06/06/2002
by Mark NelsonMore...
Supporting material for a Wavelet course at Rowan University. There's quite a bit of detail here. I don't know if it stands on its own or whether it only works in conjunction with the course. Please check it out and provide feedback!
Created: 05/06/2002
by Mark NelsonMore...
An overview and explanation about MP3 from the folks at Fraunhofer. If you want to get a good overview in a single web page, this might be the spot for you.
Created: 04/06/2002
by Mark NelsonMore...
A guy named Steve Blackstock takes a shot at making this all clear to you. Gives some details on the LZW variation used in GIF files.
Created: 04/06/2002
by Mark NelsonMore...
Nine slides that provide some description of the Nancy codec. You will have to ask Acrobat Reader to rotate the slides if you are trying to view them on the screen.
Created: 02/06/2002
by Mark NelsonMore...
I'll have to take the word of the submitter on this site - it is entirely written in Japanese. Any DataCompression.info user who is fluent in the language is invited to provide a more detailed description. There are a couple of zip files on the site that perhaps contain demo programs?
Created: 15/05/2002
by Mark NelsonMore...
by Subhasis Saha. A typical overview article, devoted to image compression, concentrates on JPEG and Wavelet-based methods. I don't know where this article appeared, but it looks to be peer-reviewed quality.
Created: 01/05/2002
by Mark NelsonMore...
This is billed as an introductory article with illustrations. I haven't seen it - it requires free registration with this game development site. If you're interested, please check it out and send me your thoughts.
Created: 01/05/2002
by Mark NelsonMore...
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 about compression.
Created: 22/04/2002
by Mark NelsonMore...
A tutorial page discussing the various image formats currently in use on the web. Nice comparisons and a good set of links.
Created: 17/04/2002
by Mark NelsonMore...
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 site quite good: Clear description, especially the explanation of the renormalisation part, full source code.
Created: 15/04/2002
by Mark NelsonMore...
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.
Created: 12/04/2002
by Mark NelsonMore...
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.
Created: 11/04/2002
by Mark NelsonMore...
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.
Created: 08/04/2002
by Mark NelsonMore...
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.
Created: 07/04/2002
by Mark NelsonMore...
This example shows the effects of wavelet compression at various levels of quality and compares the wavelet compression result to the JPEG compression result.
Created: 07/04/2002
by Mark NelsonMore...
Dr. Keith Devlin writes an article in the UK Guardian explaining a bit about the technology behing the MP3 format.
Created: 07/04/2002
by Mark NelsonMore...
The author of this code created this visualization executable for a seminar.
DCL reader Drew D. downloaded the code, executed it, and had this to say about it: The program is an executable for windows with a dll and some gif's. The program seems to require a screen size greater than 800x600 to view the fixed size window. The program is a bit cryptic to me since I only have a basic understanding of Arithmetic encoding but it offers nice step by step encoding with some statistical information. It also allows for the modifying of input types and reading from a file..
Created: 01/04/2002
by Mark NelsonMore...
A program to compress images, plus a write up from author Doug Houghton. Doug says its simple and fast, and does pretty well on 24 bit color images. New release from Doug as of 3/2002
Created: 19/03/2002
by Mark NelsonMore...
Yes, it is possible to create GIF images with far more than 256 colors. This page will show you exactly how that is done, or at least prove to you that it is possible. It links to a GIF library called ANGIF that purports to be able to pull this trick off.
Created: 19/03/2002
by Mark NelsonMore...
Bob talks about new codes that use more bits to compress the stuff you're looking at, and fewer bits for things on the sidelines.
Created: 02/03/2002
by Mark NelsonMore...
A decoder for images compressed by the JPEG algorithm is stated in the pure functional programming language Gofer. The program can be regarded as a mathematical specification of the decompression algorithm; the concise description (which is included in full) is very suitable for learning about the algorithm. At the same time the `specification' is an executable program, which shows the usefulness of a functional programming language as a prototyping tool for graphics algorithms
Created: 28/02/2002
by Mark NelsonMore...
Course notes on audio compression. Discusses simple compression methods, then psychoacoustics and MPEG Audio.
Created: 26/02/2002
by Mark NelsonMore...
A short description of how one goes about using zlib in Kylix.
Reader Michael wasn't too happy with what he found here: The article is unclear and does not explain the reason or logic behind anything the creator has done. I see no point in linking back to the zlib unit under Kylix/Linux if that is the file you are trying to cross-compatify.
Created: 25/02/2002
by Mark NelsonMore...
Cheok Yan Cheng decided to write up a short tutorial on LZW compression. It is presented here, along with some source code.
Created: 25/02/2002
by Mark NelsonMore...
An article describing the way compression can speed up the web, along with a nifty demo. Unfortunately, links to the demo seem to be broken.
Created: 25/02/2002
by Mark NelsonMore...
UCSB research activities, including speech coding, audio compression, video coding. Lots of links to demos and publications.
Created: 22/02/2002
by Mark NelsonMore...
A presentation by Michael J. Gormish & Michael W. Marcellin, which was given at the DCC in 2000. Lots of information and figures, but as always, the slides without the talk leaves one wanting more.
Created: 30/01/2002
by Mark NelsonMore...
The Wikipedia entry for Algorithmic Information Theory. Explains the field of study that includes such interesting things as Kolmogorov complexity.
Created: 27/01/2002
by Mark NelsonMore...
The Wikipedia entry for the topic of Data Compression. Many links to other Wikipedia entries on this page, including MP3, JPEG, Fractal compression, etc.
Created: 27/01/2002
by Mark NelsonMore...
This Wikipedia entry describes the deflate compression algorithm. Very terse, could use an update from a DCL reader!
Created: 27/01/2002
by Mark NelsonMore...
This Wikipedia entry describes lossy data compression. In addition to a nice overview, includes links to many lossy compressors for still image, moving image, music and sound.
Created: 27/01/2002
by Mark NelsonMore...
This Wikipedia entry describes the Vorbis codec, used in the open music codec Ogg Vorbis. Overview, a few interesting links, not much detail.
Created: 27/01/2002
by Mark NelsonMore...
This Wikipedia entry describes the MPEG-2 standard, the version of MPEG used to encode movies on DVD. Not too much information here, although it does enumerate the standards documents that collectively define MPEG-2.
Created: 27/01/2002
by Mark NelsonMore...
This Wikipedia entry describes the MPEG-4 standard, the version of MPEG designed for lower bit-rate applications. Light on detail.
Created: 27/01/2002
by Mark NelsonMore...
This Wikipedia entry describes the H.263 video compression standard. A short entry but it has a few valuable outside links.
Created: 27/01/2002
by Mark NelsonMore...
Al Williams wrote an excellent article on using the Info-Zip DLLs to manipulate Zip files. There are lots of commercial libraries that let you access Zip files, but your choices in free software are few and far between. So if you need a free solution, Al's article is a must-read. Many thanks to Al for getting this back on line after Visual Developer's web site disappeared.
Created: 04/01/2002
by Mark NelsonMore...
The Usenet newsgroup sci.fractals and the listserv forum frac-l are devoted to discussions on fractals. This FAQ (Frequently Asked Questions) is an electronic serial compiled from questions and answers contributed by many participants in those discussions. This FAQ also lists various archives of programs, images, and papers that can be accessed through the global computer networks (WWW/Internet/BITNET) by using email, anonymous ftp, gophers, and World Wide Web browsers. This FAQ is not intended as a general introduction to fractals, or a set of rigorous definitions, but rather a useful summary of ideas, sources, and references.
DCL user feedback:The links on that particular page are extremely outdated, as well as a lot of the information. It's still useful, but there's gotta be
a more up-to-date alternative
Created: 30/12/2001
by Mark NelsonMore...
This article from EE Times talks about the changes made to the Advanced Audio Coding portion of the standard during the change from MPEG-2 to MPEG-4.
Created: 27/12/2001
by Mark NelsonMore...
A technical report giving an overview of various video streaming formats used in today's Internt. Includes low-level details such as transport formats, and high-level info such as providers of application servers.
Created: 24/12/2001
by Mark NelsonMore...
Mohamed Qasem's page dealing with VQ. A nice overview of what it's all about, plus links to other sites and people in the VQ world.
Created: 15/12/2001
by Mark NelsonMore...
Jim Mischel's article from Visual Developer discussing the use of Microsoft's CABINET.DLL to work with CAB files.
Created: 05/12/2001
by Mark NelsonMore...
The Video and Image Processing Laboratory at Purdue has a tutorial page on JPEG. Good place to start when looking for introductory material.
Created: 10/11/2001
by Mark NelsonMore...
Chitaranjan P.S., Arun Shankar, and Niyant .K posted a description of a new coding scheme called LBE on the web. It's interesting, but I'm not sure that it appears to have any serious advantages over current state of the art.
Created: 06/10/2001
by Mark NelsonMore...
This article describes a variant on BWT that doesn't use the cyclical rotations of strings used for BWT, but a different scheme. DCL reader points to a Burrows paper showing that this scheme is suboptimal.
Created: 03/09/2001
by Mark NelsonMore...
A short description of the MPEG-2 standard from the official site. Brief, but includes some nice pictures an words.
Created: 25/08/2001
by Mark NelsonMore...
An overview of the MPEG-7 standard from the official site. There is quite a bit of detail on this page, making it a combination of a standard, FAQ, and overview.
Created: 25/08/2001
by Mark NelsonMore...
This page contains a description of the emerging MPEG-21 standard, which is a multimedia wrapper specification.
Created: 25/08/2001
by Mark NelsonMore...
A set of links to the FAQs maintained by the MPEG committee. This includes information on the emerging MPEG-21 standard, plus oldies like MPEG-1 and MPEG-2. MPEG-4 and MPEG-7 are represented as well.
Created: 25/08/2001
by Mark NelsonMore...
HEI seems to be a company that consults with broadcasters. They have this page which gives a little tutorial that talks about forward error correction and other things of interest to broadcasters.
Created: 16/07/2001
by Mark NelsonMore...
This issue of the Data Compression Newsletter from Dr. Dobb's looks into the MPEG-4 codec now available for use with Microsoft's Media Player. Included are pointers to tools allowing you to create your own MPEG-4 streams.
Created: 05/07/2001
by Mark NelsonMore...
This issue of the Data Compression Newsletter from Dr. Dobb's Journal looks at an idea for compression that doesn't quite pan out.
Created: 05/07/2001
by Mark NelsonMore...
This issue of the Data Compression Newsletter from Dr. Dobb's has some sample code showing how one might use Intel's JPEG library to display JPEG files under Win32.
Created: 05/07/2001
by Mark NelsonMore...
An attempt to catalog archive types based on the first few bytes of a file. This list was created for Amiga users, but might help on other platforms as well.
Created: 11/01/2001
by Mark NelsonMore...
The Data Compression Center gives an explanation of LZSS coding.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 02/12/2000
by Mark NelsonMore...
Issue #11 of the DDJ Compression Newsletter contains some sample code that uses the Zip library from The CodeProject to create a little unzip program. A very simple program that uses a free library to get a lot done.
Created: 17/11/2000
by Mark NelsonMore...
Tutorial by Rich Holowczak from Rutgers U. A set of slides that would probably be really useful if you had the lecture to go with it. Without the lecture, not so hot.
Created: 17/11/2000
by Mark NelsonMore...
A short description of JPEG baseline compression from the folks at DAKX, who offer a competing method of compressing analog data of all types.
Created: 12/11/2000
by Mark NelsonMore...
Guy has a set of slides here that must illustrate a comprehensive set of links about data compression. Includes a link to a PS file containing a sample chapter on algorithms that Guy is writing.
Created: 23/10/2000
by Mark NelsonMore...
The Data Compression Research Center has an overview of arithmetic coding on this page.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 04/10/2000
by Mark NelsonMore...
The Data Compression Reference Center wants to teach you about Run Length Encoding. A tutorial here, plus some links.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 03/10/2000
by Mark NelsonMore...
A good explanation on color perception. This isn't truly a data compression topic, but it actually plays a very important role in lossy image compression schemes, so I though the library ought to have at least one or two points.
Created: 21/09/2000
by Mark NelsonMore...
An overview of Shannon Fano coding from the folks at the DataCompression Reference Center.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 30/08/2000
by Mark NelsonMore...
This page has links to a bunch of algorithm descriptions, courtesy of the Data Compression Reference Center.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 30/08/2000
by Mark NelsonMore...
by Jeffrey N. Ladino. His description of the page: This page is a research project in the field of data compression algorithms. It is intended to be an informative overview for a beginner in the field of computer science. Mostly talks about lossless compression, with an explanation of Huffman coding.
Created: 01/08/2000
by Mark NelsonMore...
A nice overview of the field by Nam Phamdo, slanted a bit towards the academic view but at a very accessible level. Links to important and influential papers.
Created: 29/07/2000
by Mark NelsonMore...
An overview of the topic by Nam Phamdo, with some basic definitions, plus a look at Huffman coding and LZ78/LZW coding.
Created: 29/07/2000
by Mark NelsonMore...
A short description of VQ by Nam Phamdo. Contains an animation which provides a nice picture of what actually happens in VQ.
Created: 29/07/2000
by Mark NelsonMore...
A straightforward discussion of Huffman compression. Written at a level so that it can be understood without much experience in data compression or programming.
Created: 14/07/2000
by Mark NelsonMore...
This is a recurring theme in comp.compression, which I call "The Magic Function Theory." It sounds like a good idea, but analysis shows that it won't work.
Created: 13/07/2000
by Mark NelsonMore...
Paper by C. Valens describing this algorithm which is frequently used in wavelet based data compression algorithms.
Created: 04/05/2000
by Mark NelsonMore...
A short article with some code that illustrates how one would unzip archives using built-in java classes. Registration required to view the page.
Created: 12/04/2000
by Mark NelsonMore...
The Data Compression Reference Center talks about Huffman coding. A short but fairly succint explanation.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 15/12/1999
by Mark NelsonMore...
MPEG-4 is an ISO/IEC standard being developed by MPEG (Moving Picture Experts Group), the committee which also developed the Emmy Award winning standards known as MPEG-1 and MPEG-2.
This document appears to be an overview of the standard as it existed in approximately 10/99
Created: 23/11/1999
by Mark NelsonMore...
The purpose of this applet is to help develop intuition about maximum entropy distributions. A central advantage of the maximum entropy framework is its ability to model overlapping events without increasing the number of parameters or fragmenting the training data. Using maximum entropy techniques, it is possible to model a probability distribution on 2n elements using only n free parameters.
Created: 22/11/1999
by Mark NelsonMore...
A page with a brief description of LZW compression by Dominik Szopa. This page includes a Java applet that helps show how LZW looks in action.
Created: 22/11/1999
by Mark NelsonMore...
Just what the title says. IDL appears to be a product from Kodak that is designed for programming tasks requiring data analysis and visualization. You can read the full pitch at the
Research Systems web site. It gets a little breathless at times, but I suppose that's to be expected.
Created: 21/11/1999
by Mark NelsonMore...
A discussion of LZSS in Croatian.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 19/11/1999
by Mark NelsonMore...
A look at lossless compression techniques, including LZ77, LZSS, LZ78, and LZW. Croatian language.
The original of this page is now missing, any help locating it would be greatly appreciated. You can find an archived copy at the link.
Created: 19/11/1999
by Mark NelsonMore...
This page discusses the various compression schemes used by EGI, Shannon-Fano, BWT, and RLE. EGI is a player of animation sequences.
Created: 14/11/1999
by Mark NelsonMore...
This contains pointers to some of the frequently asked questions that I receive. Many are related to data compression.
Created: 07/11/1999
by Mark NelsonMore...
A site that provides some good pages discussing various fundamental aspects of Data Compression. Although the site appears to be a university project in Croatia, all of the pages are writen in English.
This link points to an archived site, as the original has disappeared. Links on the archived page may or may not work properly.
Created: 06/11/1999
by Mark NelsonMore...
Clemen has some pages here that discuss Wavelet theory in general, as well as specifics on the Fast Lifting Wavelet Transfrom and Embedded Zerotree Wavelet Encoding.
Created: 05/11/1999
by Mark NelsonMore...
Greg Roelofs' home page. Greg has invested many years of his life towards good works such as PNG, zlib, and Info-ZIP. You might know him as Cave Newt.
Created: 21/09/1999
by Mark NelsonMore...
After MPEG-1 and MPEG-2, the next phase of compression work in ISO/IEC JTC1/SC29/WG11 is called MPEG-4 and is planned to be available by end of 1998 in a first version. The MPEG-4 format is meant to become the universal language between broadcasting, movie and multimedia applications. While former MPEG standards were only concerned about compression, MPEG-4 will provide additional functionality (e.g. bitrate scalability, object-based representation, intellectual property management & protection etc.) and is based on a rich tool set starting at bitrates as low as 2 kbit/s for a channel.
Created: 17/02/1999
by Mark NelsonMore...
A set of Markov compressors by Charles Bloom, including source code. This includes links to a wide variety of his programs, including Context Coders, List LRU, and DefSum, along with a link to an early paper of his.
Created: 14/02/1999
by Mark NelsonMore...
This article contains the answers to some Frequently Asked Questions (FAQ) often seen in the USENET newsgroup comp.dcom.fax relating to facsimile standards, software, and hardware. Most importantly, contains an explanation of FAX encoding.
Created: 30/01/1999
by Mark NelsonMore...
By Ross Williams, 1991. A description of a lossless algorithm invented by Ross Williams. The algorithm is based on LZW compression with the addition of a Markov-like prediction engine. Maybe.
Created: 24/12/1998
by Mark NelsonMore...
By David G. Green, Environmental and Information Sciences, Charles Sturt University. A short tutorial that provides an introduction to just what fractals are all about.
Created: 23/12/1998
by Mark NelsonMore...
The site bills itself as an animation, but in fact it is just a couple of screen captures that demonstrate an animation.
Created: 22/12/1998
by Mark NelsonMore...
On these web pages I try to give an idea of the principles involved in speech coding, and details of commonly used coders. Also links are given to other related pages, and the source code of some common speech codecs.
Created: 01/01/1970
by Mark NelsonMore...
PKWare issued a slightly self-serving press release trumpeting the fact that they've updated their App Note that describes the Zip format. While it's true that they have updated the document, I can't find any description of the two new compression formats that are added to their version of the Zip standard. They're using a new version of deflate called Deflate64, and have added support for the PKWare Data Compression Library. Neither of the two formats is documented.
Created: 01/01/1970
by Mark NelsonMore...
This Wikipedia entry describes lossless data compression, includes a short explanation of the famous counting argument, which proves that any compressor cannot losslessly compress all files.
Created: 01/01/1970
by Mark NelsonMore...
This article on Microsoft's web site goes into many of the interesting
features included in WM9 codec, such as fold-down from multiple channels to stereo, high resolution multichannel content, and more. Highly technical.
Created: 01/01/1970
by Mark NelsonMore...
