What is Corner Detection Please briefly describe one corner

What is Corner Detection? Please briefly describe one corner method. Please compare SIFT and Speeded Up Robust Features (SURF) methods.

Solution

Corner detection is very useful for shape description and matching.

Example

The HARRIS CORNER detector, measures the strength of detected corner, and only marks those above a given strength as actual corners.the number detected can be attended by varying the value of k.

Comparison between sift and surf

SIFT

It solves image rotation, scaling and affine deformation, view point change, noise, illumination changes, also has strong robustness.

It has four main steps 1) scale space extreme a detection 2) key point localization 3) orientation assignment and 4)description generation.

SURF

It creates a stack without 2:1 down sampling for higher levels in the pyramid resulting in image of the same resolution. Due to the use of integral images, SURF filters the stack using a box filter approximation of second order Gaussian partial derivatives.