Elena [service address] wrote:
Any way I proceed, I'm more or less getting bluish bumps in the deep blacks. And xicclu seems to confirm some serious problem in that area, when looking with it at the kplot. I included details, using a ofps 1300 target as reference.
This is not unusual, given the way the code currently works. It prioritises accuracy over smoothness at the grid points, which can lead to sudden jumps in the black separation near the dark gamut boundary, resulting in less accurate color in the device space interpolated (ie. between grid point) areas. Increasing the quality level (ie. grid resolution) can help a bit, but the best way of minimizing the problem is to set a suitable black generation curve. See <http://www.argyllcms.com/doc/Scenarios.html#PP6>. (You can demonstrate that this is going to have an effect by seeing what -kz and -kr do.) Graeme Gill.