OpenCV-Python dense SIFT

Question

OpenCV has very good documentation on generating SIFT descriptors, but this is a version of \"weak SIFT\", where the key points are detected by the original Lowe algorithm.

Answer 1

I'm not sure what your goal is here, but be warned, the SIFT descriptor calculation is extremely slow and was never designed to be used in a dense fashion. That being said, OpenCV makes it fairly trivial to do so.

Basically instead of using sift.detect(), you just fill in the keypoint array yourself by making a grid a keypoints however dense you want them. Then a descriptor will be calculated for each keypoint when you pass the keypoints to sift.compute().

Depending on the size of your image and the speed of your machine, this might take a very long time. If copmutational time is a factor, I suggest you look at some of the binary descriptors OpenCV has to offer.