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October 1999

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1999.10.22 11:45 "LIBTIFF and OJPEG", by <ndenaant@anhyp.be>
1999.10.23 01:26 "Re: LIBTIFF and OJPEG", by Niles Ritter
1999.10.23 03:52 "Re: LIBTIFF and OJPEG", by Tom Lane

1999.10.23 03:52 "Re: LIBTIFF and OJPEG", by Tom Lane

ndenaant@anhyp.be writes:
> I'm trying to build libtiff so that it will support compression 6 (OJPEG),
> however I can't get it to worK

There is no OJPEG support in libtiff, only some hooks that are unlikely
ever to be filled in.

> I need OJPEG_SUPPORT in order to convert TIFF images that were made with
> this compression mode to PDF.

Made under whose interpretation of the ambiguous TIFF 6.0 spec?  See
TIFF Tech Note #2 at ftp://ftp.uu.net/graphics/jpeg/TIFFTechNote2.txt.gz
(among other places) for the gory details of the spec's problems.  And
the TN politely glosses over the fact that most known implementations
of OJPEG are demonstrably broken: they are incompatible with *any*
plausible reading of the spec.

In short, there's no such thing as old-JPEG TIFF, there is only a
Tower of Babel of mutually incompatible proprietary flavors of TIFF.
You'll almost certainly have to use the same program that made those
files in order to read them.  Possibly you could reverse-engineer the
files to develop a special-purpose reader, but is it worth your time?

                        regards, tom lane
                        organizer, Independent JPEG Group