Object Recognition with SIFT
SIFT or Scale Invariant Feature Transform is a nifty transform for object recognition using images , to make them scale invariant and to some extent illumination invariant as well. The first image shows a lamp being recognized in a larger photoof the room.
The second image (of the cameraman) shows how even after an image is scaled, rotated and tampered with its brightness a bit, the algorithm still matches it with the original one. This was implemented in MatLab for a Computer Vision class.
We (group of 4 people) had a lot of fun experimenting at every stage to check what the results were. Since the algorithm works on an image on various Octaves and different scales, at one stage we had more than a dozen images to look at. The last image is a screenshot of that one time!