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May 1993
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1993.06.21 17:51 "Re: modified version of xtiff.c", by Sam Leffler
To: tiff@ucbvax.Berkeley.EDU
Subject: modified version of xtiff.c
From: hlange@kogs26.informatik.uni-hamburg.de (Harald Lange)
Date: Thu, 27 May 93 15:20:53 N
we have used xtiff (Revision 2.0 90/12/20, actual version coming with TIFF
3.21) for displaying RGB-images (24bit) on our Sun 4/370 (32bit
TAAC-Framebuffer) under X-Windows, but the result was not satisfying. A little
look to the source reveal some typing errors in the index-value of the
pixel_map variable, which we have corrected.
Another important change is the new name for the tagfield
TIFFTAG_TRANSFERFUNCTION, which is now called TIFFTAG_COLORRESPONSECURVE.
No. These tags are not interchangeable--the new TransferFunction
tag requires that you use the other new colorimetry-related tags
in calculating the corrected screen pixel values. Please look
at the appropriate appendix in the 6.0 spec.
Beyond that we have made the following expansions to xtiff:
1.) Show Pagenumber Tagfield if present
2.) Consider Fillorder Tagfield
FillOrder is handled by the TIFF library, so using it to
set the bit-order of the data that you hand to the X code
is wrong--unless you are reading raw data directly from the
file (which you do not appear to be doing).
I think it is a good idea to make this corrected version available in the
following TIFFLibrary Distribution. I have tried to mail these bug to Dan Sears
directly, but the mail came back, because of unknown user dbs@decwrl.dec.com
Dan&Chris Sears no longer work on Unix systems. I include the
last version of xtiff that they provided me in the sources I
give away in the hope that someone will properly update it to
use the 6.0 tags.
Sam