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&