Message-ID: Pine.GSO.4.10.9912010938560.29279-100000@sun06.ams.org
To: Andy <apex@calpha.com>
Subject: ZIP compression [was: libtiff 3.5.3 release.]
From: Tom Kacvinsky <tjk@ams.org>
Date: Wed, 01 Dec 1999 09:42:56 -0500 (EST)
Cc: tiff@olympiakos.com
In-reply-to: <384531D3.DE4F8EB6@calpha.com>
Sender: owner-tiff@olympiakos.com


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 */
> 


