[GRASS5] d.photo

Radim Blazek blazek at itc.it
Thu Apr 17 08:11:52 EDT 2003

Hi all,

I am currently digitizing vectors using many large orthophotos 
on background. I had been a bit annoyed by speed of d.rgb
so I wrote d.photo (slightly modified d.rgb) which can display
orthophoto raster map created from 3 (RGB) raster maps (1 byte/cell) by
r.mapcalc pok2="043130.r + 043130.g * 256 + 043130.b * 65536"
(3 bytes/cell in result)

d.photo is significantly faster than d.rgb:

time d.rgb r=043130.r g=043130.g b=043130.b
real    0m6.810s
user    0m6.000s
sys     0m0.393s

time d.photo map=pok2
real    0m3.199s
user    0m2.760s
sys     0m0.211s

Does it make sense to add d.photo to GRASS? As it is so simple
and d.photo take less than 50% of time of d.rgb I think that 
I am missing something. Maybe we already have such module?


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