i.his.rgb processes three input images as hue, intensity and saturation components. The output images represent the red, green and blue colors.
Hue values are expected to be degrees ranging in [0, 360] while intensity and saturation should range within [0,1]. The output images base upon a standard hue-intensity-saturation (HIS) to red-green-blue (RGB) color space transformation. The derived values are of double precision. A user may convert the output in integer values using i.rgb.his.
Each output raster map layer is given a linear gray scale color table. The current geographic region definition and mask settings are respected.