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Automatic 3D Reconstruction of Scenes
Neil Halelamien writes "New Scientist reports on a piece of software by MDRobotics called instant Scene modeler (iSM), which automatically generates 3D reconstructions of scenes, using a few hundred frames from a pair of ordinary video cameras. The software uses David Lowe's SIFT vision algorithm to quickly locate common features between sequential images, for use in the reconstruction; SIFT has also been useful for generating panoramas and object recognition. MDRobotics has a demo page showing the software being used for crime scene reconstruction, along with animated GIFs of input video and the resulting 3D model."
Since slashdot will probably burn out the web server hosting images: http://www.mdrobotics.ca.nyud.net:8090/ism/behind. htm
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Wired article as proof
Here, and here. Lin/Win/Mac versions.
From one of the links: The SIFT algorithm is restricted by patents in the United States and hence this software is not completely free to use. For details see the LICENSE file included in the distribution, before you start to use this software.
Hopefully, they're liberal about the patent and will let noncommercial nonresearch applications use the algorithm. Otherwise, we would have to wait for the really interesting software to come out.
A C# implementation with support for Mono is available to play with for anyone who is interested: http://user.cs.tu-berlin.de/~nowozin/libsift/
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I have been waiting for the results for quite some time and they surely look impressive. I might add that the underlying concept is not very hard to understand and one could even make a simple 3-D model of distant objects (like e.g. buildings in your city) using only two eyes, paper, pencil and some basic trigonometry.
/|
Look at this model:
A---B
|\
| C |
|/ \|
D---E
Where D and E are your two eyes, two cameras, or two positions from which you look at the object C that appears to be eclipsing A and B respectively. The distance between any of those points and their relative 3-D positions can be calculated when you know some of the distances (e.g. DE and AD) with very high precision.
Recommended Wikipædia reading for anyone interested: Parallax, Triangulation, Stationary point, Pythagorean theorem, Euclidean geometry, Astrometry, Binocular vision, Stereoscopy. Have fun.
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
Olympus has had this functionality in their Camedia cameras for a few years now. The panorama stitching is actually pretty easy. You put it into pano mode, and the camera then uses the initial exposure/shutter setting for the entire series, and puts little bars on the sides of the LCD to tell you were to do the overlap. The (otherwise crappy) Camedia Master software recognizes that it is a series, and stitches pretty quickly and seamlessly. That function only works with original Olympus SM cards, though.
Autopano and Autopano-sift. I have't had good experiences with the SIFT-based software. They always tend to pick the most inappropriate points, like trees/leaves (that move between shots) and the middle of objects (where there aren't many features). I almost always have to go through and remove the bad points, adding in my own reliable ones (corners, unique features, etc). I just don't use them anymore because I actually spend less time if I do all the points myself manually. The GUI of Hugin usually saves me plenty of time already. It does a good job of picking the matching point when I click on one photo. That's all I need anymore.
Actually, now I'm even less impressed. The MDRobotics iSM uses a stereo camera system. I had thought it was a 3D-from-video method (particularly since it uses SIFT). I find those much more useful because I can use it with my home video cam. Making 3D models from a stereo-cam requires special equipment and has been done by everyone and their dog. I'm not so clear on why this is new or that interesting.