drewsxpa@portland.intel.com (Paul Drews) (02/07/91)
I'm looking for specifications of the group3 and group4 image compression standards. Can anyone e-mail me copies of these or give me an anonymous ftp reference? What I would really like is: Group3: "Standardization of Group 3 facsimile apparatus for document transmission," Recommendation T.4, Volume VII, Fascicle VII.3, Terminal Equipment and Protocols for Telematic Services, The International Telegraph and Telephone Consultative Committee (CCITT), Geneva, 1985, pages 16 through 31. Group 4: "Facsimile Coding Schemes and Coding Control Functions for Group 4 Facsimile Apparatus," Recommendation T.6, Volume VII, Fascicle VII.3, Terminal Equipment and Protocols for Telematic Services, The International Telegraph and Telephone Consultative Committee (CCITT), Geneva, 1985, pages 40 through 48. I've ordered this document, but it's taking a long time to arrive. By the way, I know about the T.4 _DRAFT_ that lives on titan.rice.edu (128.42.1.30) in directory public/graphics.formats. Unfortunately, this is only a _DRAFT_. It describes only the 1-dimensional encoding for Group 3, not the 2-dimensional encoding. I'm also aware of Jef Poskanzer's pbmplus utilities and Sam Leffler's tiff library. Both of these are limited to 1-dimensional Group 3 compression. A reference to implementations of Group3 and Group4 compression and decompression would be helpful, too. Please reply to me by electronic mail at the address drewsxpa@ashland.intel.com if possible. (Note, NOT the reply address of this article) I will summarize replies to the newsgroup. - Thanks, PauL Drews