GNOME Bugzilla – Bug 132297
Tiff: jpeg compression does not allow random access
Last modified: 2004-12-22 21:47:04 UTC
On tiffs compressed using traditional jpeg compression, I get the following message: "Tiff Message:\nCompression algorithm does not support random access" It is usually repeated several hundred times (for one particular 1024x768 image, it's repeated here 719 times). Adding the various TIFF experts to the CC (if any of you mind, just shout and I'll stop). Cheers, Dave. Shouldn't we just detect the compression, and not try to seek in the ifd if it's compressed? Otherwise, the image opens fine, and apart from getting the message, I have no problems. Dave.
Created attachment 23669 [details] Test file, Eliza Dushku. C original owner
Well, I shall try to come with more or less appropriate patch to return a reasonable results under that circumstances. I'm maintainer of the libtiff library and I can confirm that this problem will not be fixed soon. I'm aware of that problem, but you shold not rely on the upstream fix. Regards, Andrey
I will work on bug #131975 and bug #132297. As a workaround for 2.0, I will modify the tiff_warning() function in the plug-in so that it ignores a few messages from libtiff (unknown tag for tags > 32768, and random access not supported). A better solution for a future release (2.2 or later) should allow the user to select which messages should be ignored, but this will require an improved infrastructure for passing messages from plug-ins and allowing multiple severity levels.
Well, it turns out that the message about random access is reported by libtiff as an error, not a warning. So I added a workaround for this bug in the tiff_error() handler. See also bug #133093 for a better way to solve similar problems in a future release. 2004-01-31 Raphaël Quinet <quinet@gamers.org> * plug-ins/common/tiff.c (tiff_warning, tiff_error): Do not display the warning message about unknown tags for unregistered private tags (>= 32768). Fixes bug #131975. Do not display the error message about random access not supported for images using JPEG compression. Fixes bug #132297. It would be better to allow the user to customize which messages should be displayed or not, but this can be done in a future release. By the way, that was an interesting test image, Dave. ;-)