2005.05.31 23:56 "Re: [Tiff] hot to detect corrupt tif file", by Andy Cave

Hi Gordon.

Two things that 'work':

1. Do a basic open on the tiff file. If that succeeds, you've got a good chance it's a tiff file.
2. Read the band/tile offsets & sizes, and check that 'they make sense' - that is that each band/tile offsets & offset+size lies within the physical size of the file (assuming it's a file). If the file is corrupt, there is a good chance that this will fail.

After that, the only thing you can do to check there is no corruption, is to read each band/tile (and decompress it et al). But that's a lot of overhead.

So, I'd suggest the first 2. We do that with our product FirstPROOF, and it seems to be a reasonable catch of corrupt files.

Andy.

Andy Cave,
Chief Executive Officer,
Hamillroad Software Limited.
www.firstproof.com
www.hamillroad.com