alberto.ferrante@xxxxxxxxxx wrote: > yesterday I was able to do some further > experiments and I have discovered that by using the -q u option in > colprof almost all artifacts disappear. I just have some strange line on > a very dark background, but it is much better than with -q h (-q m and > -q l give reddish artifacts in the dark gray shadows). I tried to use -q > u in colprof 1.4 and I got no artifacts and, in fact, the profile looks > better than the one obtained by using -q h (I haven't had time to do any > measurement though). Hi, thanks for the feedback. My guess is that tuning the cLUT profile fit to improve some situations has made it worse in others. It's on my list of things to look into when I find the time. [I suspect that the same sort of problem is making Video profiling more tricky that in should be.] Graeme Gill.