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July 2007
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2007.07.02 18:49 "Re: Old corrupted TIFF data - "Can not read directory count"", by Steve Bougerolle
2007.07.02 19:06 "Re: Old corrupted TIFF data - "Can not read directory count"", by Steve Bougerolle
2007.07.03 17:06 "Re: Old corrupted TIFF data - "Can not read directory count"", by Steve Bougerolle
2007.07.03 18:11 "Re: Old corrupted TIFF data - "Can not read directory count"", by Steve Bougerolle2007.07.03 18:06 "Re: Old corrupted TIFF data - "Can not read directory count"", by Bob Friesenhahn
On Tue, 3 Jul 2007, Steve Bougerolle wrote: > I think I've cracked this. It looks like these were read improperly off CD > originally. I re-read the original CDs using Windows rather than Linux (a > tremendous moral defeat, that) and got back readable TIFFs that were longer > than the originals and for which the directory offsets made sense. It sounds like the Linux CD filesystem code has a bug. > Can TIFF files be sparse? That is, could the directory have been written at > a specific location set by block size, even though the data didn't actually > reach that far? That's my best theory so far: that the files were dumped out > with file system offsets then read back in sequentially, losing a few hundred > (meaningless) bytes in the process. TIFF files on any filesystem which supports 'holes' could have a hole in them when all the data in a long contiguous region (at least a disk block's worth) is zeros. But it is unlikely that your CD filesystem supports sparse files. Bob ====================================== Bob Friesenhahn bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/