Searching for Rotational Symmetries Based on the Gestalt Algebra Operation

Among the Gestalt algebra operations the one for rotational symmetries needs a special search strategy. This contribution briefly recalls Gestalt algebra in overview and then concentrates on the rotational "mandalas". Though these are very salient to human perception, they have not been studied much in the classical over hundred years old Gestalt literature. A search procedure is given which can find such patterns in sets of primitive Gestalten extracted from images. Experiments are performed using selected pictures from the 2013 symmetry recognition competition data and SIFT key points as primitive extractor.