On 13.11.2008, at 00:34, Alexander Shmelev wrote:
Our customer asks us to save images in TIFF files with JPEG compression. But in NSImage documentation is written that JPEG compression is no longer supported. Why Apple decided to stop support JPEG compression in NSImage class?
The difficulties with JPEG-compression in TIFF-files reach back to 1995. In that year a draft <http://www.remotesensing.org/libtiff/TIFFTechNote2.html> from the TIFF-people (formerly Aldus, now Adobe) was published and give a deep look into these difficulties. One of the first sentences is:
... TIFF writers are strongly discouraged from using the 6.0 JPEG design
In another document <http://netghost.narod.ru/gff/graphics/summary/ tiff.htm>
search for a statement by Tom Lane (the jpeg guru) where he explains :
TIFF 6.0 added JPEG to the list of TIFF compression schemes. Unfortunately, the approach taken in the 6.0 specification is a very poor design. A new design has been developed by the TIFF Advisory Committee. If you are considering implementing JPEG in TIFF, I strongly urge you to follow the revised design described in TIFF Tech Note #2 rather than that of the 6.0 spec.
Meanwhile some fixes have been made. But we still have TIFF 6.0 and maybe the long expected TIFF 7.0 will never come. The Adobe - TIFF story has never been a love story.
To directly use the current TIFF library tiff-3.8.2 may help if really needed.
Heinrich -- Heinrich Giesen [EMAIL PROTECTED] _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
