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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 Bougerolle2007.07.02 19:06 "Re: Old corrupted TIFF data - "Can not read directory count"", by Steve Bougerolle
They're all separate standalone images. I should mention that back when I created them, they were all readable (I ran off JPEG thumbnails of each) so the whole data is in there somewhere, definitely. Kevin Myers wrote: > This may sound stupid, and I don't specifically know of any formats like > this, but could some of these files actually be separate parts (tiles or > pages) of a larger overall composite image file, and each of these > offsets are pointing to a directory near the beginning of the next > portion of the file? > > Just grasping... > > Kevin M. > > > ----- Original Message ----- From: "Steve Bougerolle" > <steveb@sebgitech.com> > To: <tiff@lists.maptools.org> > Sent: Monday, July 02, 2007 13:49 > Subject: Re: [Tiff] Old corrupted TIFF data - "Can not read directory > count" > > >> >> This file is 16822272 bytes in size. The field points to 16823130, just >> past it (858 bytes). >> >> Some of the other files I've looked at basically the same pattern as >> below, with different (wrong) values for that offset. For example, I've >> got one here that's 17149952 bytes in size and has offset pointer >> 84B20501, which translates to 17150596 - again, just past the end of the >> file (644 bytes). >> >> >> Kevin Myers wrote: >>> Hi Steve, >>> >>> What is your file size on disk? Are you reading the bytes backwards? >>> The 4 bytes that you gave below only indicate a 16 MB offset (Intel >>> hex 01 00 b3 5a), so that could easily be realistic... >>> >>> HTH, >>> Kevin M. >>> >>> >>> ----- Original Message ----- From: "Steve Bougerolle" >>> <steveb@sebgitech.com> >>> To: <tiff@lists.maptools.org> >>> Sent: Monday, July 02, 2007 13:00 >>> Subject: [Tiff] Old corrupted TIFF data - "Can not read directory count" >>> >>> >>>> >>>> Hi all >>>> >>>> I've got a bunch of TIFF files created back in 1998, which I find I >>>> can't read any more. The error from libtiff is "Can not read >>>> directory count" and I haven't been able to rebuild whatever old >>>> library these were made with, so now I'm looking at the file format >>>> trying to work out what went wrong. If any of you can help me along >>>> that'd be much appreciated! >>>> >>>> I've attached the first few rows of a hex dump at the bottom of this >>>> email. Here's what I've puzzled out about the data so far: >>>> >>>> 49 49 2A 00 - The usual first four bytes >>>> >>>> 5A B3 00 01 - Should be the directory offset? Can't be valid, though, >>>> because it points past the end of the file. I haven't >>>> been able to figure out what else this might identify. >>>> >>>> Date string - the last byte is zero so I assume it's written out with >>>> null termination. This is the date the image was >>>> created, >>>> as best I remember. >>>> >>>> 60 09 00 00 - no idea what all this is >>>> 01 00 00 00 >>>> 60 09 00 00 >>>> 01 00 00 00 >>>> 08 00 08 00 >>>> >>>> (then it trails off into less regular stuff) >>>> >>>> Does this form suggest anything to anybody? I think these files >>>> were created on Linux using libtiff (around version 3.5.5) but I'm >>>> not sure of it. They might also have come from PaintShopPro as I was >>>> still using that for some work back then. >>>> >>>> The actual hex dump, first 64 bytes: >>>> >>>> 49 49 2a 00 5a b3 00 01 31 39 39 38 3a 31 32 3a |II*.Z...1998:12:| >>>> 31 38 20 30 36 3a 32 35 3a 35 36 00 60 09 00 00 |18 06:25:56.`...| >>>> 01 00 00 00 60 09 00 00 01 00 00 00 08 00 08 00 |....`...........| >>>> 08 00 ba 08 00 00 72 d1 00 00 af 97 01 00 c5 62 |......r........b| >>>> >>>> Thanks for any help! >>>> >>>> -- >>>> Steve Bougerolle <steveb@sebgitech.com> >>>> http://www.sebgitech.com >>>> http://www.bougerolle.net >>>> _______________________________________________ >>>> Tiff mailing list: Tiff@lists.maptools.org >>>> http://lists.maptools.org/mailman/listinfo/tiff >>>> http://www.remotesensing.org/libtiff/ >>>> >>>> >>> >>> >>> >> >> >> -- >> Steve Bougerolle <steveb@sebgitech.com> >> http://www.sebgitech.com >> http://www.bougerolle.net >> >> _______________________________________________ >> Tiff mailing list: Tiff@lists.maptools.org >> http://lists.maptools.org/mailman/listinfo/tiff >> http://www.remotesensing.org/libtiff/ >> >> > > > -- Steve Bougerolle <steveb@sebgitech.com> http://www.sebgitech.com http://www.bougerolle.net