1999.05.19 16:15 "group 4 decompression bug", by François Dagand

Hello everybody

I just found the address of this mailing list in the distribution of libtiff, and since the address of Sam Leffler is no longer valid, I thought I'd ask my question here. Sorry if the question has already been asked, I could not get the recent archive of this list (the most recent archives are from Jan. 95. Is there anybody reading this? Hello ?)

I am using libtiff v3.4beta in some EDMS applications on Solaris, and have met some problems with images of width >= 65536. Although libtiff has no problems encoding the Group 4 for such bitmaps, it crashes (SEGV) when trying to decode them (like, for displaying the file)

Using a binary editor I noticed something strange in the IFD: the types for tags ImageWidth and ImageLength differ (Width is type 4 -LONG- and height is type 3 -SHORT-. This seems logical since in that case the width is > 65536 and the height is inferior. Still, it looks weird. But changing manually the type of Imagelength to LONG did not do change anything.

The generated TIFF file is ok (I could visualize it using Kodak "imaging" from MS-W98.

Does anyone have any idea of how the library could handle decoding such files?

Thanks in advance for any suggestions.

F. Dagand