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November 1999
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1999.12.02 11:42 "Re: ZIP compression [was: libtiff 3.5.3 release.]", by Ivo Penzar
Which value for the ZIP compression does Adobe use? Where on the Net is possible (if it is) to find Rev. 7? Thanks, Ivo ----- Original Message ----- From: Bryan H. Maret <homefront@acm.org> To: Tom Kacvinsky <tjk@ams.org>; Andy <apex@calpha.com> Cc: <tiff@olympiakos.com> Sent: Wednesday, December 01, 1999 6:39 PM Subject: Re: ZIP compression [was: libtiff 3.5.3 release.] > Libtiff uses a Compression value from the private range for ZIP compression - that's all that Sam could do without Adobe's official blessing. The actual TIFF 7 spec uses a Compression value from the "official" range for Deflate compression. Adobe's ImageReady uses the official value, since its developers had the benefit of the real spec. > > regards- > -Bryan Maret (formerly Adobe's TIFF person) > homefront@acm.org > > At 09:42 AM 12/1/99 -0500, Tom Kacvinsky wrote: > >Hi, > > > >As you may or may not know, Adobe's Image Ready support ZIP compressed > >TIFFs (reading and writing), but they use a different tag for the > >compression scheme. ZIP compressed TIFFs as built by tiffcp cannot be > >opened in Image Ready, and vice versa. So it lloks like Adobe is > >already heading torwards adding ZIP compression to the TIFF > >specification, but is using a different tag scheme. I belive that > >Leonard Rosenthal (of Adobe) is on this list and could answer this > >question. > > > >Regards, > > > >Tom > > > >> > >> What is the compression tag TIFFTAG_COMPRESSION assigned to Zip? The file > >> tiff.h says > >> #define COMPRESSION_DEFLATE 32946 /* Deflate compression */ > >> An associated tag is Zip quality: > >> /* Note: quality level is on the ZLIB 1-9 scale. Default value is -1 */ > >> #define TIFFTAG_ZIPQUALITY 65557 /* compression quality level */ > >> > > >