What is interest point detectors?
Interest Point in an image is a point that is exceptional from its neighborhood. To detect and describe this point typically it's used a two-step process: A. Feature Detectors: where a feature detector (extractor) is an algorithm taking an image as input and outputting a set of regions ('local features').
What is detector and descriptor?
The detector is a corner detector. The descriptor is a binary string representing the signs of the difference between certain pairs of pixels around the interest point.