Re: Uniform Perceptual Lab
Re: Uniform Perceptual Lab
- Subject: Re: Uniform Perceptual Lab
- From: "Bruce J. Lindbloom" <email@hidden>
- Date: Thu, 17 Jul 2003 19:39:20 -0500
Boris Oicherman wrote:
>
There is a colour space called IPT, which has same lightness and chroma
>
dimensions as Lab, but much more uniform hue contours. It was at first
>
reported in, I think, 1998; as far as I heard there are some gamut
>
mapping algorithms which already make use of it
Yes, there have been many models developed over the years, but each has its
imperfections, as may be seen in this comparison report by Mark Fairchild
and David Wyble of RIT:
<
http://www.cis.rit.edu/people/staff/wyble/ISCCtalk.pdf>
IPT is one of eight models evaluated and does not have any outstanding rank
compared to others, either overall, or even with respect to hue linearity in
particular (p. 11). All models are evaluated using the Munsell renotation
data. As I said before, the only way to really achieve the ideal performance
is to use a LUT as I have done. My ICC profile would have basically a zero
error for all metrics discussed in the above paper. The only error would be
due to interpolation errors that always accompany LUTs, but these errors
would be extremely small compared to those of any of the models.
--
Bruce J. Lindbloom
email@hidden
http://www.brucelindbloom.com
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