How does the box filter look like (SURF) (DoB)

问题:

I'm trying to understand how the SURF alg. works. The understanding of the integral image is clear. But how does the box filter look like in horizontal, vertikal and diagonal direction.

Could some on give me an example?

回答1:

Box filter is an average filter where all pixels are weighted equally.

A normalized 5x5 box filter kernel: