GNOME Bugzilla – Bug 768950
TIFF: Unknown field with tag 59932 (0xea1c) encountered
Last modified: 2016-07-23 17:13:03 UTC
I get this error message when opening a TIFF file into GIMP. This file has been previously rotated by 90 degrees using Windows Photo Viewer under Win 10 before loading into GIMP. If I load image without using rotate under Photo Viewer then message does not appear. Message disappears after loading, so does not cause a problem. Just annoying.
Hi, So that's only this one file, not any tiff file, right? Would it be possible to upload this file so that we get a look at it? Thanks.
Created attachment 332027 [details] Sample file exhibiting problem I attach a sample file which exhibits the problem. The problem seems to occur in any file rotated by Photo Viewer. I don't see the message if I load from Explorer into GIMP, only if I open inside GIMP
I get this error with ImageMagick too (`identify` command) on your file: > $ identify bla.tiff > bla.tiff TIFF 4871x7760 4871x7760+0+0 1-bit Bilevel Gray 1.722MB 0.000u 0:00.000 > identify: Unknown field with tag 59932 (0xea1c) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/887. > identify: Unknown field with tag 59932 (0xea1c) encountered. `TIFFReadCustomDirectory' @ warning/tiff.c/TIFFWarnings/887. > identify: Unknown field with tag 59932 (0xea1c) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/887. It looks like Windows Photo Viewer recorded private tags (i.e. which are not in the spec) inside the tiff. ImageMagick developer seem to say this is not standard (http://www.imagemagick.org/discourse-server/viewtopic.php?t=13587) but actually in the TIFF spec (http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf), I read: > An organization might wish to store information meaningful to only that organi-zation in a TIFF file. Tags numbered 32768 or higher, sometimes called privatetags, are reserved for that purpose (page 8: Private Fields and Values) So I agree this should not be considered a problem. GIMP should simply ignore the private tags (and probably copy them along) but not popup warnings for these.
Ok. So we used to have this working as expected (i.e. no warning showing up for private tags), hence this was a regression of bug 131975. This is because libtiff changed some of its warning messages in version 4.0.0. commit 3cb70e67cce56960ab1055e6ef7f72eff1abf55c Author: Jehan <jehan@girinstud.io> Date: Sat Jul 23 18:07:58 2016 +0200 Bug 768950 - TIFF private tags should not generate warnings. This is a regression from bug 131975. Any unknown tag over 32768 is not an error. This is a reserved zone where it is allowed to create custom tags. The warning indeed changed since libtiff 4.0.0alpha where it has become: "Unknown field with tag %d (0x%x) encountered" This explains why it was not recognized anymore.
Many thanks for the explanation.