

New to the Archaeologist’s Tool Kit: The Drone - kanamekun
http://www.nytimes.com/2014/08/14/arts/design/drones-are-used-to-patrol-endangered-archaeological-sites.html

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benjamincburns
Does anyone have any experience with this sort of thing? Would love to be able
to make such 3D models from go-pro videos - preferably w/ a FOSS toolkit.

Would also be grateful for any papers or articles which discuss the algorithms
involved -- especially anything with implementation tips/strategies. I
understand the basics of photo stitching, but structure from motion is a bit
more nebulous and something I've been meaning to learn more about.

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votingprawn
From the image in the article it looks to me like the researchers are using
commercial software from Agisoft, called PhotoScan[0].

For free (but not enitrely OS) you can look at VisualSfM[1], which is a GUI
which pulls together a variety of separate tools to generate SfM. You can run
all these tools seperately too, VisualSfM just vastly simplifies things. The
author (Changchang Wu, now at Google) has a couple of interesting papers on
the algorithims[2].

Both the commercial and the free software largely give you the same quality of
result, the commercial stuff is just usually much much easier to work with.

As always, quality of your source imagery is paramount. I can't over emphasise
how much geo-referenced images will help you. Second best is some "ground
control points" (ideally with GPS locations). I've had limited success with
completely unreferenced datasets but it is a slow process.

My workflow with GoPro video is to first defisheye the footage in CineForm
Studio (there are other ways, but I find their defisheyeing to be pretty
good), then I grab a frame every second or so from the footage depending on
how fast I was flying around the object of interest. Too much data can almost
be as bad as too little data!

[0] [http://www.agisoft.ru/](http://www.agisoft.ru/) [1]
[http://ccwu.me/vsfm/](http://ccwu.me/vsfm/) [2]
[http://ccwu.me/vsfm/vsfm.pdf](http://ccwu.me/vsfm/vsfm.pdf)

