Just out of curiousity, does anyone know how does google map put together all those massive quantity of satellite pictures with with high accuracy? What advanced computer science technology has it employed?

  • $\begingroup$ I added the tag for you. $\endgroup$
    – Jason R
    Sep 22, 2011 at 12:13
  • $\begingroup$ How is this signal processing? The question even goes on to say "what computer science technology"... without even mentioning any signal processing. computer science questions are for stackoverflow.com. (FWIW, i'm sure there is signal processing used in google maps somewhere (lpf when zoomed out, algorithmically aligning the road maps with the picture maps, etc)... but the question doesn't have a lick of signal processing in it.) $\endgroup$ Sep 22, 2011 at 14:38
  • $\begingroup$ Even if I give the benfit of the doubt the question is interpreted by me as "what hardware/software is needed to do what google maps does?"... hardware/software is not signal processing. $\endgroup$ Sep 22, 2011 at 14:40
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    $\begingroup$ @TrevorBoydSmith Is image-processing / computer-vision not part of Signal Processing? $\endgroup$
    – bjoernz
    Sep 23, 2011 at 5:06

1 Answer 1


This certainly is a signal processing question albeit a little vague. I can't say for certain that Google use it but the SIFT (shift invariant feature transform) algorithm http://www.cs.ubc.ca/~lowe/keypoints/ has been used in variant form in technologies such as Microsoft's Photosynth. It allows key features of multiple images containing overlapping content (supject to arbitrary X,Y,Z shifts) to be registered and matched. In simple terms...very clever image stitching. The link provides all the paper references to the original algorithm. For another example of such technology check out this lecture about photosynth > http://www.ted.com/talks/blaise_aguera_y_arcas_demos_photosynth.html


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