Abstract:In order to calculate centric coordinates and radius of quasicircular ripe fruits whose growing state was approached or overlapped, a kind of fast location and detection method for fruits object based on concave spots searching was proposed. After the object was segmented from background with hue according to statistical law, the freeman chain code algorithm was used to extract onepixel fruit contour, from which the edge character points were abstracted. Then the edge concave spots which were found by direction coding difference of N points were divided into several concave spot groups, and the segmentation concave spots were located by the threshold. At last, the centric coordinates and radius of several overlapped peaches were calculated based on optimized circular Hough transform. The research results showed that the proposed method had rapid speed, the highest obtainable right recognition rate was 90.0%, and the error rate of centric points and radius was below 7%.