1994.01.27 16:11 "JPEG support", by Dwight Kelly

1994.01.27 11:55 "Re: JPEG support", by Niles Ritter

Has anyone added JPEG compress/decompress support to the libtiff library?

The problem is that the JPEG implementation, as specified in the TIFF 6.0 Documentation from Aldus, has some ambiguities/design flaws, particularly in the "restart intervals" issues. One can create a functional JPEG-in-TIFF (for example, by merging the libtiff and the IJG's libjpeg codes), but you inevitably have to break something in the specs, and usually something in the TIFF libs as well. Also, you have no guarantee that other peoples JPEG-TIFF code will have made the same compromises, and so there is no "standard" yet.

I've got some intermediate modules that merge libtiff/libjpeg, but, There is a mailing list dedicated to trying to resolve these issues for the next TIFF specs called tiffjpeg@cs.columbia.edu. Tom Lane (Tom_Lane@G.GP.CS.CMU.EDU) runs the list; you can contact him or subscribe directly by sending e-mail to listserver@cs.columbia.edu with the body of the message:

    subscribe tiffjpeg YOUR_FULL_NAME_HERE

Like everyone else, I'm waiting for the next, internally consistent, set of TIFF-JPEG specs to be settled on and published. The end is not yet apparently in sight (Any news, Tom?)

--Niles Ritter.