2000.03.21 14:57 "Re: Some CCITT Group 3 TIFFs crash libtiff", by Thad Humphries

I agree that they are not completely valid.

(Aside: However, it's difficult to convince end users of this, since most image viewers display these files without even a warning, and the image appears correct to the naked eye.)

I've been assuming that libtiff should not crash when it encounters an invalid file. Right?

I have found libtiff to be among the picker TIFF tools. For example, I came across some TIFF files that called ColorMap of type LONG and had the value wrong. It read (in MM format):

        0140 0004 0300 0000 0009 57B7

when it should have read

        0140 0003 0000 0300 0009 57B7

Now all the TIFF readers at my disposal read this file just fine *except* libtiff, TIFFAnalyzer4.1 (on Macintosh, uses libtiff), and Imaging on WinNT (does this use libtiff?). GraphicConvertor on the Macintosh and a Windows application written with SnowBound's libraries read the file just fine. Anyway, I had to modify tif_dirread.c to account for this bad tag.

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