2010.05.11 15:32 "[Tiff] Tiff with varying bit depths", by Thomas Richter

Hi folks,

I currently have a need to read and write TIFF files with a varying bit depth. To be specific, this is a BGR565 image packed into TIFF:

$ tiffdump out.tif

out.tif:
Magic: 0x4949 <little-endian> Version: 0x2a
Directory 0: offset 8 (0x8) next 0 (0)
ImageWidth (256) LONG (4) 1<64>
ImageLength (257) LONG (4) 1<64>

BitsPerSample (258) SHORT (3) 3<5 6 5>
Compression (259) SHORT (3) 1<1>
Photometric (262) SHORT (3) 1<2>
StripOffsets (273) LONG (4) 1<140>
SamplesPerPixel (277) SHORT (3) 1<3>
RowsPerStrip (278) LONG (4) 1<64>
StripByteCounts (279) LONG (4) 1<8192>
SampleFormat (339) SHORT (3) 1<1>

Obviously, the library does not support this, but what are my options if I need to read this file? I'm not too keen to write a tiff-parser myself, unless I really really have to - and - I afraid - I really really have to read this file in one way or another.

Is there a way to get at least hands on the raw stripe data without the lib falling over? Failing that, what is the patch acceptance policy for libTIFF? Would you accept a patch that adds support for this, probably in a limited way?

Greetings,
    Thomas