[GRASSLIST:5567] Re: i.composite problem: gives minmax 1:1, grass5

[Philipp Molzer]

That did the trick!
Now with
    IMG=294.JPG
    d.rgb red=${IMG}.3 green=${IMG}.2 blue=${IMG}.1
g.rgb now produces a very nice looking image.  Just what I wanted.

i.composite now also works, so the d.rgb must have been a prerequisite 
for that.  

However, the image
quality of the composite as displayed with d.rast, is not as good as 
that from d.rgb.  I tried color levels
between 10 and 40 for i.composite, none of which produces an image with 
the subtle gradation of colors
displayed by d.rgb.  My computer really bogs down at 40 color levels.

Is it possible to produce a composite raster file with visual quality 
the same as that from d.rgb?

thanks,
Phil

Glynn Clements wrote:

>Philipp Molzer wrote:
>
>  
>
>>Thanks. Unfortunately, d.rgb gives me an image with quite bizarre 
>>colors.
>>    
>>
>
>Then you probably need to do:
>
>for i in 1 2 3 ; do
>  ( echo 0 black ; echo 255 white ) | r.colors map=294.JPG.$i color=rules
>done
>
>r.in.gdal really ought to set a colour table, but it doesn't.
>
>  
>