clasifiy kitchenware using neural networks: What are the features

hi

i try to use neural network to build simple system that classify four element

Screw, Spoon, Knife, Thorn

my problem is in feature extraction

This is the first application to me So my experience a few in feature extraction

can any help in chose good feature

[Walter Roberson]

duplicates http://www.mathworks.co.uk/matlabcentral/answers/69931-clasifiy-kitchenware-using-neural-networks-what-are-the-features