Re: How test quality of ICC profiles?
Re: How test quality of ICC profiles?
- Subject: Re: How test quality of ICC profiles?
- From: Henrik Holmegaard <email@hidden>
- Date: Fri, 23 Mar 2001 09:38:57 +0100
Andy Davidson <email@hidden> wrote:
How can one test the quality of ICC profiles? I have been looking at the
profiles of laser and inkjet printers and find the vendor-supplied profiles
vary in size from 37KB to 2MB, from 8 nodes per side of the CLUT to 33
nodes per side. Some use 8-bit values, some 16.
Are there tests or evaluations that allow one to determine the quality of
these profiles other than just eyeballing the results? Are there guidelines
on which of these variables are most important to color management?
All other things being equal, a fully 16 bit profile is preferable,
meaning that a large printer profile is better than a small printer
profile. For instance, the greater precision makes for lesser impact
from white point problems in ColorSync 2.6.
The Kodak ICM1 implementation only supported 8 grid points while the
Heidelberg ICM2 implementation gives the same accuracy as on Mac OS.
You don't want to use the older ICM1 framework nor profiles made for
it.
Still on the quantitative side, if you are working with Photoshop the
BtoA0 Perceptual and BtoA1 Relative Colorimetric tables should have
the same total area coverage.
The black generation controls are different from one print profiler
to another. The print profilers in actual use are Printopen and
ProfileMaker.
As for the 'color kerning' of the Perceptual tables, then each print
profiler has its own approach. There is no universal answer to what
is good and what is bad.
--
Henrik Holmegaard
TechWrite, Denmark