I have a checker board patterns with small and big rectangle shapes crossings. I want to detect only these big crossing points not small rectagular crossing using intrest operaters. Is there any option??

Answer 1

[Image Analyst]

Try using hough() or houghlines(). What are the "small rectagular crossing"? I don't know if I see any of those. And what are "intrest operaters"?

[Thorsten]

He probably refers to "interest point detection" using "interest operators".

[Image Analyst]

I don't know what that is either. I've heard of "salient point detection" like is used in SIFT and SURF. Maybe it's the same thing.

Or maybe this: https://en.wikipedia.org/wiki/Kadir%E2%80%93Brady_saliency_detector

Anyway, you might also be able to use the corner() function in the Image Processing Toolbox.