https://kr.mathworks.com/help/images/texture-analysis.html
kernel = [-1, -1, -1, -1, 8, -1, -1, -1]/8;
diffImage = conv2(double(grayImage), kernel, 'same');
cpp = mean2(diffImage);
https://www.mathworks.com/matlabcentral/fileexchange/42904-imoverlay
http://dismac.dii.unipg.it/glcm/code/GraycoProps.m
https://www.mathworks.com/help/images/ref/graycoprops.html
https://github.com/edfreeburg/MATLAB-roughness-image-analysis/blob/master/texture_start.m