Monocolor and thresholds

[tomczak]

Would anybody know how Monocolor actually works? What are the thresholds that determine what's colour, what's gray? I experimented on test image a bit, and it appears that if the chosen RBG channel has a higher value that the other two, it retains some saturation, but I'm still not sure if this is true.

Also, what would be a good preprocessing idea before Monocolor, to influence what's included in the 'color' part and what becomes pure gray?

[jsachs]

Monocolor attempts to render the image as accurately as possible using just varying amounts of white and the selected color and preserving luminance. The math - taken from a technical journal - is a little complicated and there are no thresholds as such.