[sane-devel] uploading color transformation matrix on HP 4c/3c --- mapping color -> greyscale

[Michal Maruška]

Peter Kirchgessner <peter at kirchgessner.net> writes:

> You can start xscanimage and switch to matrix-type Custom. Then you see what
> is used to enter the values for matrix-rgb. This was the reason why custom
> matrix has been disabled. Using 9 sliders would be an alternative.

when scanning in greyscale, the selection is a 3D vector. It might be good to
have (as the GUI element) something like a view of a semisphere  of the
unit ball in the RGB space, and have it rotated directly by the trackball (yes i
don't use mouse). This way you just select the color of the background (which
you don't want) and ....