2010.11.16 17:48 "[Tiff] unknown field with tag 317 (0x13d) encountered.", by E. Rosten

2010.11.16 19:22 "Re: [Tiff] unknown field with tag 317 (0x13d) encountered.", by Bob Friesenhahn

I'm trying to read a TIFF file, which seems to have the predictor set. I get the error message:

TIFFReadDirectory: Warning, std::istream: unknown field with tag 317 (0x13d) encountered.

and the TIFF appears to be quantized to a very small number of levels.

This is from my own software and I get very similar results from other software installed on the system. I have tried the latest version (3.9.4), with the following results from the configure script:

This file seems to use 16-bits per sample. Perhaps the "quantization" you are seeing is due to 16-bits being squashed down to 8-bits/sample as supported by common image display software. Sometimes 16-bit/sample images only use levels which don't map well to 8-bit. This is a common problem.

Feel free to try free GraphicsMagick (a Q16 build) to read your file. You can retrieve it from http://www.GraphicsMagick.org/.

Bob
--
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/