Date: Sat, 17 Feb 2001 03:00:00
From: Greg Ward <greg@shutterfly.com>
Subject: new version of TIFF LogLuv (SGILOG) modules
Message-Id: <3A8D8EF5.E188FB5D@shutterfly.com>

1) I improved the gamut-mapping function in tif_luv.c for imaginary
colors, because some images were being super-saturated on the input side
and this resulted in some strange color shifts in the output.

2) I added a psuedotag in tiff.h to control random dithering during
LogLuv encoding.  This is turned off by default for 32-bit LogLuv and on
for 24-bit LogLuv output.  Dithering improves the average color accuracy
over the image.
 
3) I added a #define for LOG_LUV_PUBLIC, which is enabled by default in
tiffio.h, to expose internal routines for converting between LogLuv and
XYZ coordinates.  This is helpful for writing more efficient,
specialized conversion routines, especially for reading LogLuv files.
 
Since I'm not exactly certain what branch I have of the library, you had
best do some careful diff's with your current tiff.h and tiffio.h files
before you incorporate these changes.  Or if you prefer, I can do it for you.

I am attaching the modified files for your examination/approval/rejection.
