Patent ID: 8363945
Filing Date: 2013-01-29
Classification: G06K

Abstract:
1. A similar semicircle detecting apparatus that detects a similar semicircular shape similar to a semicircular shape from an image represented by pixels which are two-dimensionally arranged, the similar semicircle detecting apparatus comprising: a first evaluation value calculating means for calculating a pixel evaluation value to evaluate whether a current evaluation pixel is a pixel on a circular arc in which a predetermined pixel in interest is centered, for each of a plurality of evaluation pixels which are arranged along a circle in which the predetermined pixel in interest is centered and surround the predetermined pixel in interest; a second evaluation value calculating means for performing a process of integrating plural pixel evaluation values corresponding to the plurality of evaluation pixels on the circular arc overlapping the circle so as to calculate an integrated evaluation value to evaluate whether the circular arc is a circular arc corresponding to the similar semicircular shape, for each of a plurality of circular arcs which overlap the circle in overlapping phases which are different from each other; and a circular arc extracting means for comparing a plurality of integrated evaluation values corresponding to the plural circular arcs, and extracts the circular arc with which the integrated evaluation value indicating the most approximation to the similar semicircular shape is associated, from the plural circular arcs.