A system for efficient image feature extraction comprises a buffer for storing a slice of at least n lines of gradient direction pixel values of a directional gradient image. The buffer has an input for receiving the first plurality n of lines and an output for providing a second plurality m of columns of gradient direction pixel values of the slice to an input of a score network, which comprises comparators for comparing the gradient direction pixel values of the second plurality of columns with corresponding reference values of a reference directional gradient pattern of a shape and adders for providing partial scores depending on output values of the comparators to score network outputs which are coupled to corresponding inputs of an accumulation network having an output for providing a final score depending on the partial scores.