FAST RECOVERY OF ROTATIONAL SYMMETRY PARAMETERS USING GRADIENT ORIENTATION

Symmetry detection is important in the area of computer vision. A simp le and fast algorithm for the recovery of rotational symmetry paramete rs is developed. The fold number of a rotationally symmetrical shape i s obtained from the gradient orientation histogram of the input gray-l evel image using the Fourier method, based on the relationship between the periodicity of the orientation histogram and the fold number of t he symmetrical shape. It takes only 0.06 a CPU time for a 256 x 256 gr ay image on a Sun SPARCIO. Both simulated and real images are tested a nd the results are very convincing. (C) 1997 Society of Photo-Optical Instrumentation Engineers.