Data compression explained

[Matt Mahoney]

Thanks for the correction. http://mattmahoney.net/dc/dce.html#Section_6163

[Shelwien]

> and compression became noticeably better

Is it better than packjpg now?

[WAHa.06x36]

I tried it on the image used in http://www.maximumcompression.com/data/jpg.php, but I didn't manage to beat PackJPG although I did improve on the WinZip result.

I have no idea what other kinds of tweaks might be worth trying, so I just left it at that. If anyone else wants to try playing with it and see if they can improve it, the code is here: http://code.google.com/p/wilt-compre...imental%2FJPEG. Consider it public domain, do whatever you want with it. It's lacking some critical features like actually checking the JPEG file is valid which would need to be added to use it for anything real.

The parent directory has a little Perl script named "optimize.pl" which will just try all the settings for the shift parameters to see which gets the best result. Run it as "perl optimize.pl JPEG/SimpleCompress file.jpg 9".

It would be pretty neat if someone could turn this into an actually useful algorithm.