Peter Kirchgessner <pe...@kirchgessner.net> writes: > not true. If you want to use the --matrix-rgb, you need to rebuild SANE (or > at least the hp-backend) from source. You need to modify hp.h: > > Change line > #define ENABLE_10BIT_MATRIXES > to > #undef ENABLE_10BIT_MATRIXES > > Change line > #undef ENABLE_CUSTOM_MATRIX > to > #define ENABLE_CUSTOM_MATRIX > > > After these changes rebuild SANE (be sure to remove all hp*o from the > backend's directory). Now the option --matrix-type has a new > choice "Custom". You need to use it along with --matrix-rgb: > > scanimage -d hp:/dev/sg0 --mode Grayscale --matrix-type Custom --matrix-rgb > 1.98,1.98,1.98,0,0,0,0,0,0 > scan.ppm > > This creates a grayscale scan where the data represents the data from the red > channel.
[sorry for the *huge* delay; i had to adapt my programs & do some experiments] i still don't understand the limits of the values, but it _definitely_ is worth using. I scan all my blue-ink written docs using (1.2 1.2 -1.4)/greyscale which is (0,1.200000,0,0,1.200000,0,0,-1.400000,0)/color. i scan using my emacs based frontend (http://maruska.dyndns.org/comp/emacs/scan/). I have defined several color combinations.... and limit myself to these now. thanks a lot!
