[argyllcms] Re: Photoshop CS4/CS5 believes colprof XYZ LUT profiles are 'defective'
- From: Graeme Gill <graeme@xxxxxxxxxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Thu, 20 Jan 2011 09:40:56 +1100
Alexander wrote:
"The monitor profile * appears to be defective." When I say use anyway, it
seems to be
OK, but something must be a bit off if Photoshop is balking at it.
OK, the response from Adobe is:
ACE contains some monitor profile validation code to attempt to filter out bad
profiles.
One test it performs is to convert Lab white (100,0,0) -> RGB to check that
it’s at
least (f7,f7,f7). It also converts RGB (ff,ff,ff) -> Lab to test that it’s
reasonably
close to white.
With this particular profile, GDM-F520_2011-01-14.icm, ACE got RGB (f1,f6,ef),
which
caused it to report that it was a “bad” monitor profile to Photoshop.
So it is a result of a not very accurate B2A white point mapping. This is likely
a result of the D50 white not falling exactly on a grid point, given that
D50 XYZ is 0.9642, 1.0000, 0.8249, while the PCS range is to 1.999969, so
that unlike Lab PCS, the white point falls somewhere in the middle...
I'll see if I can do something about this for the next release.
Graeme Gill.
Other related posts:
