METHOD FOR AUTOMATICALLY RECOGNIZING LINE SYMMETRY OF A FIGURE

In a line-symmetrical figure shaping system, all the symmetry axis candidates of an input figure are generated based on feature data extracted from the input figure. Pairs of points on the input figure on both sides of each symmetry axis candidate are extracted, and a symmetry axis judgment segment is generated which connects the points of each pair. The distance between the middle point of the symmetry judgment segment and the symmetry axis candidate is calculated. The angle formed by the symmetry judgment segment and the symmetry axis candidate and the difference from 90.degree. are also calculated. Based on the distances and angular differences for the respective symmetry judgment segments, it is judged whether the input figure is symmetrical with respect to the symmetry axis candidate. The input figure is shaped into a figure that is completely line-symmetrical with respect to the symmetry axis candidate that has been judged to provide line symmetry.