Discriminative Feature Extraction Process for images

There are two images. First one flame reterdant feature better than the other. I found this via experiemtnal process. Now ı want to do that via image processing. How can ı extract signifcant, disriminative feature from these two images to compare them. I want to classify these feature after extraction process. The groups of the extracted features from the first one has to be better. May be I should use threshold level. Or just make a decision belong the features percentage without using classification.

Answer 1

[ali]

Is any suggestions for this surfaces.? What should be the discriminative or significant features from these features to characterize or classify.

Something like that the first surfaces(like the first image) is better surface then the second one. HOw can we group more than two something like that