2005.08.04 23:42 "[Tiff] RE: NEWBIE HELP NEEDED: Efficiently changing orientation tags in multipage tiff files", by Bradley Feldman

2005.08.04 15:10 "Re: [Tiff] tiff unknown field of tag", by Bob Friesenhahn

i got back some scaned tiff's from a photo lab. openning with xv or gimp

just got a warning message: unkown field of tag 34665(0x8769). i want to know with thoese files and how do a work around. what's wrong

The warning does not mean there is something "wrong" with the file, it just means that there is a tag in the file that libtiff does not support. Usually this is benign.

for the tiffinfo output, i still has two questions desiring kind help from you.

1. what means "ICC Profile: <present>"? and what is ICC?

ICC is the International Color Consortium (http://www.color.org/) and an ICC profile is a type of reference "lookup table" which ensures accurate color as long as the using software also properly support ICC profiles. It allows you to do things like print your photo to a printer (which also has an ICC profile) and obtain accurate color.

2. i noticed this file is uncompressed. so what's the benefit the lab save
tiff rather than a bmp? result in

While the latest BMP version supports attaching ICC profiles, many software packages will simply fail to load the BMP entirely. TIFF is seen as a format used by "professionals" and is well supported by desktop publishing software. As far as the actual image goes, a 24-bit BMP is just as good as a 24-bit TIFF.

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