Feature extraction from a binary image .

I have a binary image of a hand , this image will be the target image of my perceptron network , now i have to extract features from the image to feed it to a perceptron network , the features extracted will be the input to the network and the perceptron network needs to show that the network is able to recognise the target image with the help of the features supplied as input. I am very new to matlab and am struggling , any idea of how to proceed to accomplish this task ? I will be very thankful.