Hello all, I calibrated and measured two displays (a CRT and an LCD), with argyll (dispcal and dispread), using an Xrite DTP-94. I have the following problem with both displays: When i generate LUT profiles for the displays, everything is fine. When i generate shaper/matrix profiles, however, and then use these profiles (with Scribus, or with tifficc to manually correct images for the displays), i get bright false colors in some very dark image areas. Using -qh with 'profile' reduces these areas, but the problem itself persists. It's as if the color transformation leads to slightly negative values, which then get wrapped around into high positive unsigned 8-bit values in the output image. However shouldn't that be prevented by some clipping mechanism? # dispread -a -i94 # dispcal -gs -b 80 DisplayA # (only for the CRT) # targen -v -d3 -f500 DisplayA # dispread -v -i94 -yc -k DisplayA.cal DisplayA # profile -v -D"My Display" -qm -as DisplayA 'profile' report for the CRT: : profile check complete, peak err = 5.396173, avg err = 0.697510 'profile' report for the LCD: : profile check complete, peak err = 8.735311, avg err = 2.043373 I'm using argyll-0.60 and liblcms-1.14. I would be grateful for advice. Is this a bug in argyll or lcms? Am I doing something wrong? Thanks, Oliver