please someone help me in finding feature vector using GLCM (image texture) for the features such as energy, entropy, correlation,homogenity etc., when i use matlab function glcm=graycomatrix(I), it returns 8x8 matrix. but energy, entropy ,correlation features are calculated using following formula double sigma on x and y of 256 by 256 matrix. i don't understand these feature are calculated on resultant GLCM matrix or on original 256x256 matrix. also i am facing some problem in implementation i.e writing MATLAB code for exracting these features, kindly give your suggestions.
my aim is to extract texture information from image.