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February 2003
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2003.02.14 01:24 "Obsolete JPEG encoding in TIFF files", by Chris Cox
At 7:48 PM -0500 2/13/03, Dwight Kelly wrote: > Today I discovered one of the leading producers of OldStyle JPEG > (COMPRESSION=6) - Pixel Translations (www.pixtran.com). When I contacted > them to ask why they continue to produce this stype of JPEG compressed > TIFF when Adobe had documented COMPRESSION=7 method almost a year ago, We just cleaned up the notes and updated it with suppliment 2 in 2002. The type 7 JPEG update came out a long time before that. (and appears to have been deleted since we posted the cleaned up version) http://partners.adobe.com/asn.developer/graphics/graphics.html > "Compression type 7 does not adhere to the latest TIFF specification > (version 6.0) for JPEG data. We support the JPEG compression format > type 6 from > that specification." Adobe has not supported compression type 6 for many years, and the documentation for compression type 7 is on Adobe's web site (as well as in several of the Adobe product SDKs). Even LIBTIFF has documented compression type 6 as being obsolete..... Chris