AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

Thread

2002.03.07 19:01 "TIFF LAB with JPEG compression", by John Cupitt
2002.03.07 20:15 "Re: TIFF LAB with JPEG compression", by Tom Lane
2002.03.08 13:08 "Re: TIFF LAB with JPEG compression", by Martí Maria
2002.03.08 12:10 "Re: TIFF LAB with JPEG compression", by Vipin Aravind

2002.03.08 13:08 "Re: TIFF LAB with JPEG compression", by Martí Maria

Hi,

I've noticed some small problems with TIFF JPEG compression.

I did experiece similar problems on Lab and JPEG. Seems JPEG is not adecuate on such high gamma spaces. If you are using Lab because its color accurancy, you should reconsider the compression scheme. JPEG yelds great compression ratios, but is lossy. And since Lab is hardly perceptually uniform, the noise comes easely evident. A better choice would be to use RGB and embed icc profile. If the profile is accurate enough, you will better results on this way than using Lab.

Here's an odder problem:

The rightmost two tiles are a bit mangled.

TIFF 6 states that tiles shouldn't hold any alignment. Your image seems somehow dword aligned.

Hope this helps,

Martí Maria
The little cms project
http://www.littlecms.com
marti@littlecms.com