How to determine how far an object is in a photograph from other objects in this photograph?

Question

So, for example, we have a photo from real life. how to get (for example, relative to the size of the image) the distance from the wall to the girls, from the girls to the trees, if all that we know from this picture?

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Work with algorithms and / or open source programs doing this will be welcome. For me, code is better than just an algorithm. So if you give algorithms, please provide links to the Open Source software representations of these algorithms!)

So, how to determine how far the object in the photo is from other objects in this photo?

Answer 1

To measure the distance of objects from a photograph, you need to map these objects in a space view. If you expect real distance, like in the real world (3D), you need to imagine 3D space.

First, it’s better to look at lenses and spatial distortion. http://www.beyondmegapixels.com/2008/12/spatial-relationships-and-distortion/

Back to the spatial representation, you need to understand how to build a 3D scene using photography. http://www.feargod.net/3dhowto.php

Here is an article on this topic. http://www.isprs.org/education/PDF/DAGM-Tutorial-Color.pdf

well, I know microsoft photosynth ( http://photosynth.net ) that can perform the reconstruction. ref: http://on10.net/blogs/larry/Fotomo-3D-scenes-from-photos/

Here is an interesting example of how this technology works http://olympus.co.jp/en/magazine/pursuit/feature_article/ ...

Googling for open source photosynthesis projects:
http://code.google.com/p/pixelstruct
http://phototour.cs.washington.edu/bundler
http://openphotovr.org
http://photosynth.net/discussion.aspx?cat=6b63cb81-8b57-4d5d-a978-41d5509bf59a&dis=1de0ba11-2eea-4cb3-907a-252fb30f1200 (additional link)