[argyllcms] Re: Profile input white not mapping to output white

  • From: Ben Goren <ben@xxxxxxxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sat, 24 Nov 2012 09:47:14 -0700

On 2012-11-23, at 11:03 PM, Graeme Gill wrote:

> But away from sample points
> all that controls it is the smoothness constraints. So all it needs
> is for there to be a slight "tilt" near the edge of the gamut, and
> the smoothness constraint will happily go extrapolating in that
> direction.

EUREKA!

Based on this, I added the following two lines to the .ti3:

ZZ1 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.00000 0.00000 0.00000
ZZ1 96.4220 100.00 82.5210 100.00 100.00 100.00 0.00000 0.00000 0.00000

And, now, as a result, it does *EXACTLY* what I was expecting it to do, just 
using colprof -v without any other arguments. No more non-white white -- and 
the DE figures reported by the check at the end of colprof were a little bit 
better, as well.

THANK YOU!

Is there any chance this behavior could get added as a switch to colprof? 
Perhaps -uc, for ``input from a camera,'' and with a description along the 
lines of ``force input pure black and white to output pure black and white''?

> I'm happy to take a look at any .ti3 that triggers a poor input profile
> result using colprof -u.

I'll forward it under separate cover. I had sent one to the list a few messages 
back, but the archive stripped out the attachment.

Cheers,

b&


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