#774: i.rgb.his, i.his.rgb, d.his support for >8 bit --------------------------+------------------------------------------------- Reporter: hamish | Owner: [email protected] Type: enhancement | Status: new Priority: normal | Milestone: 6.5.0 Component: Raster | Version: svn-develbranch6 Resolution: | Keywords: i.rgb.his, i.his.rgb, d.his Platform: All | Cpu: All --------------------------+------------------------------------------------- Comment (by glynn):
Replying to [comment:3 hamish]: > These modules write out colr/ tables as min,max of channel. Would it be better to write them out as 0,max_level for the particular bit-depth? e.g. 0,255 for 8-bit and 0,2047 for 11-bit. Then d.rgb and d.his give natural looking results without subtle extra steps. Apart from anything else, assigning black/white to the min/max of the data is definitely wrong. Beyond that, I suggest: 1. changing bit_depth= to max_level=, and reading the maps as DCELL, so that the modules work with both integer and FP data, including integer data where max isn't a power of two. 2. making the output FCELL, with values in the range 0.0 to 1.0 (or possibly 0.0 to 360.0 for hue), and using those values for 0% and 100% intensity. Note that d.his uses G_get_raster_row_colors(), so it doesn't care about the actual values, only the corresponding colours. 3. replacing both modules with scripts which use r.mapcalc. 4. Offering the option of "conical" HSV, i.e. RGB->YUV, H=atan2(U,V). -- Ticket URL: <https://trac.osgeo.org/grass/ticket/774#comment:4> GRASS GIS <http://grass.osgeo.org>
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