Black line in GLCM result

Question

It is the result of GLCM matrix. What is the meaning of black horizontal and vertical lines in GLCM image? Are they a problem?

N = numel(unique(img)); % img is u         


        

Answer 1

I suspect this is the problem: For the function graycomatrix, You have supplied a 'NumLevels' argument which is larger than the number of unique graylevels in your image. For instance, a 256-level (8-bit) image will have only 256 graylevels. Asking for 1000 levels in the output means 744 levels will have no data! i.e. Yes, this is a problem. You can check how many graylevels your image has using numel(unique(I)).

p.s. In the future, please attach the code you used to generate the problem.