[GRASS-user] Re: anaglyph for GRASS?

[William Kyngesburye]

I did something like this recently.  I didn't know about the wiki page, but it ended up similar to that process: take two snapshots in NVIZ, then merge them together to produce the anaglyph.

For the anaglyph, on the Mac there is a nice program called Red Green to do this.  It can do all the varieties of red-green|blue|cyan, and in true color (red-cyan only).  It also has some fine tuning to balance the two colors.

I tried it with Photoshop once (similar to selecting out specific RGB bands from the two images as mentioned in the wiki), but it's hard to get the colors just right.

It would be cool to have some automated way to do this.  Especially as an option within NVIZ - imagine creating a flythru in stereo.

On Nov 24, 2009, at 9:40 AM, Michael Barton wrote:

> Hi Markus,
> 
> Thanks much. I saw that.
> 
> What we are looking for are some guidelines or script to create anaglyphs within GRASS. We want to use the 3D perspective of an anaglyph to map stream terraces. This is commonly done in geomorphology using paper stereo pairs and glasses. With an anaglyph, we can move this process into the GIS environment for greater accuracy. We have stereo aerial photos of many areas that we can put into an xy location and map terraces. We can also use Terra ASTER imagery. At 15m resolution, all Terra ASTER comes with a forward and backward facing band 3.
> 
> I assume that we'd need to set a color table to grade through red and blue (or cyan) for each image and then use r.blend. I thought I remembered that someone had done this in the past. But maybe I was remembering the stuff on the wiki page. I'll go ahead and forward this to the list to see what comes up.
> 
> Best
> Michael
> ______________________________
> C. Michael Barton
> Director, Center for Social Dynamics & Complexity
> Professor of Anthropology, School of Human Evolution & Social Change
> Arizona State University
> Tempe, AZ  85287-2402
> USA
> 
> voice: 	480-965-6262; fax: 480-965-7671
> www: 	http://csdc.asu.edu, http://shesc.asu.edu
> 		http://www.public.asu.edu/~cmbarton
> 
> On Nov 24, 2009, at 2:36 AM, Markus Neteler wrote:
> 
>> Michael,
>> 
>> please take a look here:
>> 
>> http://grass.osgeo.org/wiki/Stereo_anaglyphs
>> 
>> cheers
>> Markus
>> 
>> On Mon, Nov 23, 2009 at 5:58 PM, Michael Barton <Michael.Barton at asu.edu> wrote:
>>> Markus,
>>> I remember discussion of an anaglyph script for GRASS but we can't find it.
>>> Do you know of such a beast? We should be able to turn Terra ASTER band 3
>>> and band 3b into great 15m resolution anaglyphs.
>>> Thanks
>>> Michael
>>> ______________________________
>>> C. Michael Barton
>>> Director, Center for Social Dynamics & Complexity
>>> Professor of Anthropology, School of Human Evolution & Social Change
>>> Arizona State University
>>> Tempe, AZ  85287-2402
>>> USA
>>> voice:  480-965-6262; fax: 480-965-7671
>>> www:  http://csdc.asu.edu, http://shesc.asu.edu
>>> http://www.public.asu.edu/~cmbarton
>>> 
> 
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-----
William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>
http://www.kyngchaos.com/

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