I just studied about SURF and going for its implementation , but i still didn't get why we use descriptor in it , i understand about keypoints in it , their purpose , but when we extract the keypoints than why we need to go for descriptors ? and whats their importance and role in recognition ?
I read about it from paper , through forums and net , but i didn't get it through that equations , I just want to know about it in simple words as someone may not good in understanding the equations.