Stereoscopic analysis

GRASS 5

Creating a DEM from overlapping images

There is some old GRASS 5 software in

http://grass.osgeo.org/outgoing/grass5/ → stereo

which does this job. It awaits integration into GRASS 6+.

Tutorial: http://grass.osgeo.org/gdp/stereo-grass/index.html

GRASS 6

Viewing existing data as stereo 3D

The d.anaglyph addon module provides an easy way to create 3D anaglyphs and stereographs. It uses the m.nviz.image module to render two viewpoints, then from those two images composes the 3D image into a single PNG file. In time it should be possible to port this functionality into NVIZ itself.

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Anaglyph

Red/cyan anaglyph created with the d.anaglyph module

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Stereogram

Stereogram with fiducials created with the d.anaglyph module (requires stereoscope viewer)

Stereoscope viewer

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"Free-view" Stereogram

• No special viewing equipment needed: just focus into the distance or cross your eyes.
• Here is a nice how-to-view article
• Screenshot: (created with the d.anaglyph module)

See also

• The Stereo anaglyphs wiki page

Other approaches:

• Structure from Motion (SfM): 3D surface and DEM construction from images

Other software:

• Principles of Photogrammetry: Stereoscopic Parallax
• nasa/StereoPipeline: The NASA Ames Stereo Pipeline is a suite of automated geodesy & stereogrammetry tools designed for processing planetary imagery captured from orbiting and landed robotic explorers on other planets
• e-Foto is a free educational digital photogrammetric workstation for Mac, Linux, Windows; GNU GPL
• Hugin (stiches images together into panoramas) and Autopano tools (finds control points in overlapping image pairs)