2013.05.15 02:26 "[Tiff] TIFF conversion error", by tiuser Lassei
I have several TIFFs that I need to convert to PNG and I'm using imagemagick, which uses libtiff if i'm not mistaken, as a commandline tool in the backend.
The problem is that the some of the tiffs are experiencing an error during conversion(http://www.2shared.com/complete/vnb96t_9/error.html). convert.exe: Unknown field with tag 292 (0x124) encountered. `TIFFReadDirectory' @ warning/tiff.c/TIFFWarnings/824. convert.exe: Bad code word at line 5151 of strip 0 (x 3744). `Fax4Decode' @ error/tiff.c/TIFFErrors/562.
However, the TIFF can be viewed properly in the IMDisplay and other TIFF viewers and ImageMagick's identify.exe doesn't encounter the error. The PNG image is actually generated (so far there is no noticeable rendering errors) even though the above error is encountered however my program checks the error status which will be set to non-zero and the program will mark the conversion as failed.
From my initial investigation, this seems an error related to the compression used in TIFF (and I'm thinking that the underlying libtiff is throwing this). I'm not sure if this bug is related ( http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=630042) Though I can't find a post with the exact error as mine.
Can someone advise the cause and if the error can be ignored?
I can ignore the above error via handling in my program and be satisfied with the PNG but I'm reluctant as I do not really know the exact cause of this error and it seems like the error message used is a general one (can i use "Fax4Decode' @ error/tiff.c/TIFFErrors/562" as the specific error indicator so I can ignore it?).
Tested with: Windows XP SP2, ImageMagick-6.8.5-6 (portable version), I'm not sure the version of the libtiff used by IM..