[GRASS-dev] [GRASS GIS] #778: i.rgb.his, i.his.rgb: propagate NULLs
GRASS GIS
trac at osgeo.org
Tue Jun 26 12:16:17 PDT 2012
#778: i.rgb.his, i.his.rgb: propagate NULLs
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Reporter: hamish | Owner: grass-dev@…
Type: defect | Status: new
Priority: major | Milestone: 7.0.0
Component: Raster | Version: svn-trunk
Keywords: i.rgb.his, i.his.rgb | Platform: All
Cpu: Unspecified |
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Comment(by glynn):
Replying to [comment:3 cmbarton]:
> I agree about the 0-255 range. Can it simply be a setting, like in
i.pca, with a default of 0,255 but changeable to a different min,max?
It could be, but that's limited to a linear scale. Using the colour table
is more flexible, although that limits you to 8-bit resolution.
Probably the easiest solution is to just add a "divisor" option, which
would default to 255 (or maybe to 1.0 for floating-point maps), and maybe
a flag to use the colour table. That would allow for more than 8-bit
resolution, and for floating-point maps using 0.0..1.0. If you want
anything more complex (e.g. "gamma" law), you have to pre/post-process the
maps with r.mapcalc.
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Ticket URL: <https://trac.osgeo.org/grass/ticket/778#comment:10>
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