Abstract: A method for processing information about a polygonal pattern in the context of pattern recognition in a computer environment, the method comprising the steps of: (a) taking the corners of the pattern in turn in order from a first of the corners through the last of the corners, forming a first ordered sequence M of values representing the respective scalar distances between each corner of the polygonal pattern and each other corner, the sequence including (i) the distances between said first of said corners and each other corner in turn and (ii) taking each other corner in turn, the distances between that other corner and each other corner starting with the said first corner, and (iii) including at appropriate positions in the sequence zero values to correspond to the distance between each corner and itself; (b) re-ordering the values of said first sequence M to form a second ordered sequence P1 comprising a set of values p1 which includes for each corner starting with said first corner, values in a series