QTR-Quadtone RIP

Hopefully I can interject this idea without hijacking this interesting
discussion regarding 3 way blending. I think the possibility of more
flexible blending of the existing 2 curves might also be of interest to
those doing split toning. Currently QTR only permits selection of toning
based on image density. The option of replacing the current slider with
something such as an alpha channel would permit an almost arbitrary balance
between two curves independently for each pixel of an image.

While 3 way blending is interesting, I would personally find more flexible
blending of the present 2 curves more useful for what I do now.

Tom Moore