[Image-SIG] 16 bit TIFF's, SAMPLEFORMAT tag
Julian Humphries
julian@essaustin.com
Fri, 25 May 2001 15:48:49 -0500
I regularly use 16 bpp TIFF files and was having problems opening simple
unsigned integer grayscale TIFF's with PIL 1.1.1. I took a look at
TiffImagePlugin.py and noticed that the I:16 format was recognized only
if the SAMPLEFORMAT tag (339) was '2'. Upon further research, this
seemed odd, the default for the tag is 1 (unsigned integer) and many
programs leave off the tag when saving 16 bit TIFF's. The code later
in the module assigns a default of '1' as well, assuring the file won't
be recognized.
My question is whether there is a reason for only recognizing type '2'
which is a "two s complement signed integer data" according to Adobe. I
tried changing/and adding a recognized format of (1,1,(16,),()) as I;16
and things seemed to work but I didn't exercise PIL very much.
Any thoughts or suggestions?
Julian Humphries
University of Texas
P.S. PIL 1.1.1, Python 1.5.2, on PC with NT4