AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2006.05.25 17:24 "[Tiff] libtiff writes zero valued tile offsets and byte counts", by Thomas Sharpless
2006.05.30 08:42 "Re: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Gerben Vos
2006.05.30 18:04 "Re: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Chris Cox
2006.06.01 03:42 "Re: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Joris Van Damme
2006.06.01 04:09 "Re: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Chris Cox
2006.06.08 22:27 "RE: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Mark R. Olin
2006.06.08 18:44 "Re: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Frank Warmerdam
2006.06.08 23:22 "Re: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Joris Van Damme

2006.06.01 04:09 "Re: [Tiff] libtiff writes zero valued tile offsets and byte counts", by Chris Cox

Yes, I missed that the offsets are zero.

Something is wrong, because Photoshop couldn't read that correctly.

My guess is that Thomas made a mistake in his description of the problem.

Chris

On 5/31/06 8:42 PM, "Joris" <joris.at.lebbeke@skynet.be> wrote:

Yes, Photoshop does try to read a lot of non-conforming TIFF images.

For the case given, it should only work if compression == none (so we can compute the tile size).

I can understand computing and auto-correcting tile sizes when there's no compression. However, Thomas indicated both tile sizes and offsets are 0. Can Photoshop handle that case, or did you not read the part where it says offsets too are 0? If the first is the case, would you mind giving us some indication of how Photoshop proceeds in guessing the location of the tiles, so as to establish a non-official recommended way to guess these, as it seems to me any such guess in this case is either very arbitrary, yielding garbage in many cases, and/or works from known behaviour of particular writer implementations?