Introduction to SURF (Speeded-Up Robust Features)

SIFT is really good, but not fast enough, so people came up with a speeded-up version called SURF.
BRIEF (Binary Robust Independent Elementary Features)

SIFT uses a feature descriptor with 128 floating point numbers. Consider thousands of such features. It takes lots of memory and more time for matching. We can compress it to make it faster. But still we have to calculate it first. There comes BRIEF which gives the shortcut to find binary descriptors with less memory, faster matching, still higher recognition rate.