1993.09.07 23:21 "Re: JPEG in TIFF", by Sam Leffler

I hope I am not annoying people by asking FAQs. If I am, just point me to a FAQ guide. Thanks.

I want to do JPEG compression inside a TIFF file. I see there are tags for doing so, but I am unclear how to proceed beyond this. Sam Leffler's nifty TIFF library doesn't appear to have code to do this, at least in the version I picked up a few months ago. Is there code out there to do this, preferably that fits with the library?

Yes, but not publicly available.

Also, do any TIFF readers currently read JPEG? XV doesn't seem to. I would like other people to be able to read the files I produce.

Yes, but they are commercial. NeXTStep, for example, supports JPEG-in-TIFF according to the 6.0 spec and their implementation is derived from my library.

Has anyone here done JPEG using JFIF? This seems to be the more popular way to do JPEG, but it appears to be a fairly stripped format. I would like to be able to include in the header my own information (like ASCII strings to describe the image) but I have no clue if this is possible or not.

There is a separate mailing list of people that is discussing how to revise the JPEG-related aspects of the 6.0 specification to resolve problems and ambiguities. When that work is completed there will likely be JPEG-in-TIFF support for my library that is based on the Independent JPEG Group's software. If you believe that you have something to contribute to this work, then you should contact listserver@cs.columbia.edu to get on the JPEG-specific mailing list (if this is wrong, I figure that Tom Lane will correct me.)

Sam