Algorithm for searching for an image in another image. (Collage)

Question

Is this even possible? I have one huge image, 80mb with a lot of tiny pictures. They are tilted and turned around as well. How can i search for an image with programming? I know how to use java and c++. How would you go about this?

Answer 1

You might want to look up the Scale Invariant Feature Transform (SIFT) algorithm. Just for example, it's used in a fair number of programs for automatically generating panoramas, to recognize the parts of pictures that match up, despite differences in scaling, tilting, panning, and so on.

Edit: Quite true -- it is patented, and I probably should have mentioned that to start with. In case anybody care's it's US patent # 6,711,293.

Answer 2

One algorithm I've used before is SIFT. If you're interested in implementing the algorithm for yourself, you can see course notes for CPSC 425 at UBC, which describes in gentle detail how to implement SIFT in MATLAB. If you just want code that does this, take a look at VLFeat, a C library that does SIFT and a number of other algorithms.

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Quotation from Jerry Coffin:

Edit: Quite true -- it is patented, and I probably should have mentioned that to start with. In case anybody care's it's US patent # 6,711,293.