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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 18:56 "Re: Old corrupted TIFF data - "Can not read directory count"", by Kevin Myers
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/ > >