[argyllcms] Re: Dark red turns orange

  • From: Graeme Gill <graeme@xxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sat, 07 Nov 2009 10:56:30 +1100

Martin Weberg wrote:

I rebuilt the profile using V1.1.0 RC1 and that orange spot is indeed
gone. The lower left image had banding around the sun, it's gone too.

The gamut of that image is pretty wacky. There are lots of pixels
with L* = 100 and a wide range of a* & b* values, so that the gamut
volume looks like it's been cut with a knife at L* 100. Not very
natural looking compared to a device gamut. Whether this is an
artifact of sharpening in Lab space, or truncating over white
values I'm not sure. Using a severe filter level (ie. -f50) with
tiffgamut started to make the volume look a bit more reasonable
though.

With such a large gamut I wonder whether there is a danger of over
compressing during gamut mapping, resulting in a "dull" looking result.

cheers,
        Graeme Gill.

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