2005.04.11 00:03 "[Tiff] TIFF Technote 3, draft 1", by Chris Cox

2005.04.15 18:44 "Re: [Tiff] TIFF Technote 3, draft 2", by Chris Cox

I've just posted draft 2 of TIFF Technote 3 at http://chriscox.org/TIFF_TN3_Draft2.pdf

This technote covers improvements for floating point image data support available in Photoshop CS2.

The new data formats and new predictor now (partially) supported by libtiff (you should grab development version from CVS). "Partially" means that you should not try the new predictor on big-endian hosts, I must solve one technical issue before it will be possible. But on little-endian boxes you can start playing. I should note that the new predictor works very well, in some cases I have ~25% reduction of image sizes over the plain LZW/ZIP methods.

The improvement depends on the source data (of course). I've got a few cases where it's up to 50% improvement over ZIP alone, but it averages closer to 20% improvement.

And with floating point data, ZIP always outperforms LZW.