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August 2003
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2003.08.07 06:11 "Custom tags", by Andrey Kiselev
Ashley, On Thu, Aug 07, 2003 at 11:12:53AM +1000, Ashley Dreier wrote: > I've been trying to port some of our old software to use the new > CUSTOM tag facility (v3.6.0 beta 2 TIFF source). I am able to read out > the custom tags stored in my TIFF images using TIFFGetField() after > making a call to TIFFSetTagExtender() to 'configure' my custom tags. > The problem I'm having at the moment is that I don't seem able to > store modifed versions of the custom tag data to the file. I open the > files using the 'r+' mode (i.e. read/write) and grab the directory/tag > information. The TIFFGetField() function confirms that I'm reading the > custom data correctly. I then use TIFFSetField() to modify the custom > tag data and again call TIFFGetField() to confirm that the data has > changed (at least in the TIFF data structure). The next thing I do is > a TIFFClose(). This appears to close the file handle, but the file has > not been updated with the new tag data. I tried doing a > 'TIFFRewriteDirectory()' before calling TIFFClose() to try to force > the directory update, but this generates a 'segfault', so I assume > that I'm not using the CUSTOM tags correctly. I've also tried > 'TIFFCheckpointDirectory()' with a similar problem. In both cases, the > resultant TIFF file is corrupted and no longer readable by the TIFF > library. Segfault is always an issue for Bugzilla. Could you provide a sample code, demostrating the problem? Andrey -- Andrey V. Kiselev Home phone: +7 812 5274898 ICQ# 26871517