| 摘要 |
PURPOSE:To make it possible to confirm a pattern like a hand-written character having a large degree of deformation by specially differentiating a character pattern without finding out a center line in order to extract directivity and extracting the directivity in case of attaining a pattern matching method utilizing directivity and large vignetting processing. CONSTITUTION:A position and size are normalized by checking an extracting pattern f(i, j) and determining the upper end coordinate is, lower end coordinate ie, of a vertical character and the left end coordinate js and right end coordinate je of a horizontal character. Directivity extraction is applied to a pattern g(i, j) obtained after the normalization of the position and size. The pattern g(i, j) are divided into patterns htheta(i, j) (theta=1, 2...8; i=1, 2...m2; j=1, 2...n2) of eight faces in accordance with directions. The value theta is obtained by quantizing the whole direction (360 deg.) every 45 deg. and indicates eight directions. The directivity can be detected by executing space differentiation. Then, vignetting processing is applied to the obtained directional pattern htheta. The vignetting processing is obtained by superposing a two-dimensional point spread function to the directional pattern htheta. The succeeding processing in recognition is hierarchical pattern matching. The pattern matching method (similarity method) recognizes a pattern by finding out the similarity between an unknown pattern whose feature is extracted and a reference pattern.
|
