Planar shape recognition by directional flow-change method

A method based on directional flow-change concept is proposed in this paper for recognizing planar shapes. This method locates critical points by eval uating directional how-changes in terms of chain code directions along the contour. An angle string can be obtained by computing the sizes of angles a t the critical points and then converting them into some special angle code s. Possible shape numbers are generated by applying a set of rules to the a ngle string. Consequently, the task of shape recognition is transformed to the task of comparing shape numbers. Experimental results show that our met hod is very effective in recognizing shapes and more efficient in computati on than the curve bending function (CBF) method. (C) 1999 Elsevier Science B.V. All rights reserved.