2009.02.13 03:24 "[Tiff] TIFFReadRGBAImage w/ 8bit-gray + aplha", by Chris Losinger

2009.02.13 21:34 "Re: [Tiff] TIFFReadRGBAImage w/ 8bit-gray + aplha", by Frank Warmerdam

Joris Van Damme (AWare Systems) wrote:

i've tested with a clean copy of LibTiff v3.7.1, using the code below, and my own slightly tweaked version of v3.8.2 - same crash.

I've tested with current beta of LibTiff 4. Low-level LibTiff (TIFFReadEncodedXxx) does not get into trouble. However, the LibTiff RGBA interface does crash and burn, access violation style, even in version 4.0. At first examination, there's nothing that much out of the ordinary to this image, except that the two channels (MinIsBlack grayscale channel and the pre-calculated alpha channel) are stored planar, not chunky (in LibTiff speak, the tag TIFFTAG_PLANARCONFIG has the value PLANARCONFIG_SEPARATE) which is not all that common but certainly is perfectly legit.


As Joris supposed, the problem was that the RGBA (tif_getimage.c) logic did not have appropriate handling for grey+alpha separated files. I have added this though I suspect that separated palette + alpha files still don't work.

As always, the RGBA interface is a work in progress. But even when it does not work, is should not crash!


Best regards,

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