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<TITLE>Re: [GRASS-user] shaded relief maps & custom color DEM</TITLE>
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<FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>In addition to these, you can use d.his with a new brightness enhancement (thanks to Hamish) to display a color map (in the hue field) draped over a shaded relief map (in the intensity field). This is built into the GUI for raster display, where you can drape a color map over a shaded relief map and enhance the brightness. Transparency is also built into the GRASS GUI, allowing you to display a relief map and overlay it with a semitransparent color map. Finally, you can also display very nice looking relief maps using NVIZ. Use a DEM (not shaded relief map) for the base map and any color raster you want for the coloration of the base map.<BR>
<BR>
Michael<BR>
<BR>
<BR>
On 5/24/07 10:26 AM, "M S" <mseibel@gmail.com> wrote:<BR>
<BR>
</SPAN></FONT><BLOCKQUOTE><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Thanks to Pablo and Eric.<BR>
<BR>
Pablo's solution is a good one for a quick output. The transparancy seems to decrease the richness of the color DEM, but still produces good results.<BR>
<BR>
Eric's solution is marvelous. It retains the rich color of the input color DEM (I used the "elevation" color ramp) and integrates shaded relief. Very cool! Thanks for the direction to the right tools for the job. While I have yet try the script he wrote, that looks cool too. <BR>
<BR>
Thanks to both for the help. These will create some very nice illustrations.<BR>
<BR>
On 5/24/07, <B>Patton, Eric</B> < epatton@nrcan.gc.ca <a href="mailto:epatton@nrcan.gc.ca"><mailto:epatton@nrcan.gc.ca></a> > wrote:<BR>
</SPAN></FONT><BLOCKQUOTE><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Mark,<BR>
<BR>
The grass commands you are looking for are r.his and r.composite.<BR>
<BR>
r.his uses a coloured DEM as the hue component, and the shaded-relief map as the intensity component. The saturation component can be left blank in this case. r.his will output 3 maps, one each for red, blue and green color components, which you can then combine together in one map with r.composite.<BR>
<BR>
You may be interested in trying out a script I wrote called r.csr that integrates all these steps in the Grass Add-ons:<BR>
<BR>
<a href="http://grass.gdf-hannover.de/wiki/GRASS_AddOns#Raster_add-ons">http://grass.gdf-hannover.de/wiki/GRASS_AddOns#Raster_add-ons</a> <a href="http://grass.gdf-hannover.de/wiki/GRASS_AddOns#Raster_add-ons"><http://grass.gdf-hannover.de/wiki/GRASS_AddOns#Raster_add-ons></a> <BR>
<BR>
r.csr allows you to input one or more rasters using a wildcard search pattern, and can apply color rules, shading parameters, and the r.his and r.composite steps described above all in one go.<BR>
<BR>
Hope this helps, <BR>
<BR>
~ Eric.<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: grassuser-bounces@grass.itc.it on behalf of M S<BR>
Sent: Thu 5/24/2007 11:29 AM<BR>
To: grass user<BR>
Subject: [GRASS-user] shaded relief maps & custom color DEM <BR>
<BR>
Hello all!<BR>
<BR>
I have been exploring the best way to make a shaded relief map with color<BR>
gradient. Although I have been using GIS for many years, this is a new<BR>
topic for me. (New is always fun, especially with GRASS!) <BR>
<BR>
I have several questions relating to this topic.<BR>
<BR>
1) I have used r.color to change the color gradient for the DEM I am<BR>
using. There are a lot of nice palettes to use! One that I am looking for<BR>
is a tan to green gradient (tan=high elev, green=low). There are some nice <BR>
ones that are close, but is there a way to create a new color map going from<BR>
color #1 to color #2? In the mean time, the red to yellow to blue is<BR>
working well.<BR>
<BR>
2) r.shaded.relief creates some nice outputs! very cool. I have a ryb <BR>
color map for the DEM, and have created a shaded relief map that is<BR>
grayscale. Is there a way to make a color shaded relief map? I have been<BR>
looking for examples illustrating the tools to use in GRASS that will do <BR>
this. I found r.blend, and it seems to produce something very close, if not<BR>
exactly what I am looking for with more tuning of parameters. Is this the<BR>
best combination of tools to use? --> r.color on DEM + r.shaded.relief +<BR>
r.blend = color ramped shaded relief map?<BR>
<BR>
3) I have done a fair amount of researching the web for color shaded relief<BR>
maps, but was unable to find techniques relating to GRASS production of<BR>
these datasets, or a gallery of shaded relief maps produced by GRASS. Does <BR>
anyone know of such a link?<BR>
<BR>
Thanks<BR>
Mark<BR>
<BR>
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__________________________________________<BR>
Michael Barton, Professor of Anthropology<BR>
School of Human Evolution & Social Change <BR>
Center for Social Dynamics and Complexity<BR>
Arizona State University<BR>
<BR>
phone: 480-965-6213<BR>
fax: 480-965-7671<BR>
www: <a href="http://www.public.asu.edu/~cmbarton">http://www.public.asu.edu/~cmbarton</a> <BR>
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