[GRASSLIST:9190] Re: Color shaded relief
Ian MacMillan
ian_macmillan at umail.ucsb.edu
Tue Nov 22 17:19:03 EST 2005
Jason, the method I generally use is similar to yours with some slight
changes. I am pretty happy with my results, but each person has their
own tastes naturally.
Using r.shaded.relief, set your altitude to a higher angle, I typically
use 60.
Your color map is important. I use the following color map for maps
with topography and bathymetry.
8200 255 255 255
7000 255 252 225
5000 252 245 193
4000 252 237 147
3250 250 231 105
2000 177 157 72
230 70 120 50
0 0 82 30
-1 255 255 255
-511 211 227 237
-915 152 218 235
-1519 127 255 255
-2165 204 255 255
-2722 224 251 255
-4200 33 163 255
-5800 38 57 224
-6500 148 33 255
-10799 0 0 0
You can set this (or another color scheme) to your map by first copying
and pasting this table into a file (make sure to preserve UNIX carriage
returns). Then use
cat your_file | r.colors color=rules map=DEM
then use d.his h_map=DEM i_map=DEM.shade
g'luck
-Ian
On Nov 22, 2005, at 1:59 PM, Jason Horn wrote:
> Hi all,
>
> I'm wondering if anyone out there has had experience creating
> attractive color shaded relief images from DEMs. The basic procedure I
> have used is as follows:
>
> 1) r.shaded.relief DEM azimuth=270 altitude=30
> 2) d.his h_map=DEM_shadei_map=DEM
>
> This is the procedure suggested in Markus' book. My problem is that
> I always end up with rather muddy-looking results. I have tried all
> kinds of variations on this procedure, including different altitude
> settings, recoloring the hillshade with a contrast-enhancing
> greyscale color scheme before running r.his, etc. No real
> improvement. As an example of what I'm shooting for, have a look at
> this:
>
> http://www.srh.noaa.gov/ridge/grk.shtml
>
> Can anyone suggest a technique for achieving this quality?
>
>
> - Jason
>
>
> Jason Horn
> Boston University Department of Biology
> 5 Cumington Street Boston, MA 02215
>
> jhorn at bu.edu
> office: 617 353 6987
> cell: 401 588 2766
>
>
>
>
What happens if a big asteroid hits Earth? Judging from realistic
simulations involving a sledge hammer and a common laboratory frog, we
can assume it will be pretty bad.
- Dave Barry
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