[GRASS5] GRASS very slow with raster maps > 8000 colors

[Bob Covill]

Markus Neteler wrote:
> 
> Hi again,
> 
> some of you already know: GRASS is very slow displaying raster
> maps > 8000 colors. Just curious (as I don't know too much about this
> problem): is there are chance to speed up GRASS' color system?
> I don't understand the reason for this slowness.
> 
> To give you an idea: a 250x250 pixel color infrared image takes
> 4sec to display (3.5sec black screen, then rather fast display)
> on a 1Ghz Athlon. How do "xv", "gimp" etc. manage this color
> troubles? 250x250 pixel are not really much.
> 
> Regards
> 
>  Markus
> 
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Markus,

I have looked into this problem a while back. If it helps I have traced
the slow drawing function from d.rast to a call to R_reset_colors in the
raster library. This routine is called from the display library function
D_set_colors in raster2.c.

Unfortunaltely this was as far as I got in tracking down the speed
problem. The R_reset_colors routine is called from Reset_colrs.c in the
raster library. 

Hopefully this information is of some help.
-- 
Bob Covill

Tekmap Consulting
P.O. Box 2016 Fall River, N.S.
B2T 1K6
Canada

E-Mail: bcovill at tekmap.ns.ca
Phone: 902-860-1496
Fax: 902-860-1498
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