A method for identifying an object image shown in a picture using density differences between an object image and a background. A screen taken by a camera is first divided into blocks; for each block, a Standard Object image is positioned based upon an arbitrary point on each picture; from the density differences in the picture, a normal vector of the outline portion of the Standard Object image is determined; then related vector data, that includes a position information up to a normal vector group and an angle information, is determined; the related vector data is stored as standard data in a block from which the normal vector is detected; a normal vector for a picture that shows an object image to be recognized is determined; from the normal vector, Answer points are determined based on standard data of the Standard Object image; and a focus point region comprised of Answer points is evaluated.
Method for identifying an object image