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We present an algorithm for detecting cyclic and dihedral symmetries of an object. Both synwnetry types can be detected by the special patterns they generate in the object’s Fourier transfom These pattern are effectively detected and analyzed using the “angular diflerence $ mction”(ADF), which measures the diflerence in the angular content of images. The ADF is accurately computed by using the pseudo-polar Fourier tramfomz, which rapidly computes the Fourier tramfom of an object on a near-polar grid. The algorithm detects all the axes of centered and non-centered symmetries. The proposed algorithm is algebraically accurate and uses m interpolations.