home *** CD-ROM | disk | FTP | other *** search
/ NetNews Usenet Archive 1993 #1 / NN_1993_1.iso / spool / comp / graphics / research / 415 < prev    next >
Encoding:
Internet Message Format  |  1993-01-07  |  1.2 KB

  1. Path: sparky!uunet!olivea!spool.mu.edu!darwin.sura.net!gatech!mailer.cc.fsu.edu!sun13!G.GP.CS.CMU.EDU!Tom_Lane
  2. From: Tom_Lane@G.GP.CS.CMU.EDU
  3. Newsgroups: comp.graphics.research
  4. Subject: Fast dithering techniques?
  5. Message-ID: <11626@sun13.scri.fsu.edu>
  6. Date: 7 Jan 93 19:17:20 GMT
  7. Sender: news@sun13.scri.fsu.edu
  8. Lines: 18
  9. Approved: murray@vs6.scri.fsu.edu
  10. X-Submissions-To: graphics@scri1.scri.fsu.edu
  11. X-Administrivia-To: graphics-request@scri1.scri.fsu.edu
  12.  
  13. The free JPEG image compression software currently uses traditional
  14. Floyd-Steinberg dithering when reducing the number of colors in its output.
  15.  
  16. Even with careful coding, F-S dithering is a remarkably expensive
  17. proposition... in our current release, dithering *alone* (not counting color
  18. selection) takes nearly as much time as JPEG decompression proper.
  19.  
  20. If anyone is aware of cheaper dithering techniques that give results as good
  21. as F-S, or of implementation tricks to speed up F-S, I'd appreciate hearing
  22. about them.
  23.  
  24.             thanks, tom lane
  25.             organizer, Independent JPEG Group
  26.             tgl@cs.cmu.edu
  27.  
  28. --
  29. Moderated by SCRI Vis <>           Submissions to: graphics@scri1.scri.fsu.edu
  30. Guy, John R. Murray   <> Administrivia to: graphics-request@scri1.scri.fsu.edu
  31.