Re: Image compression
Jon Watte <[email protected]>
| Newsgroups | gmane.games.devel.algorithms |
|---|---|
| Message-ID | <[email protected]> |
Richard Fabian wrote: > notable. I took the vertical gradient, horizontal gradient, and the > _saddle_ (diagonal difference / Determinant), and these were then the > values recorded for later use in the compression. This 2D approach > made a small but significant difference in the compressability of the > Isn't that basically a lifting process, based on a 2D predicted value? For previous approaches, I believe that the good-old lossless JPEG method used almost exactly that pre-process to determine deltas, and then used an entropy coder to code the deltas (instead of treating the deltas as something to separately compress using wavelets or whatever). What kind of compression ratios are you seeing now, btw? And have you tried the smaller/embedded profiles of JPEG 2000 for comparison? Sincerely, jw -- Revenge is the most pointless and damaging of human desires. ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ GDAlgorithms-list mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list Archives: http://sourceforge.net/mailarchive/forum.php?forum_name=gdalgorithms-list