JPS6417170A - Feature extracting device for picture - Google Patents

Abstract

PURPOSE:To extract the quantity of feature of an edge, ridge, a vertex, a directional characteristic in a picture by executing a differential sum of squares operation based on a differentiated two-dimensional picture signal. CONSTITUTION:The two-dimensional picture signal f(x, y) is read (301), a time space differentiation operation is executed to obtain the quantity of x differentiation fx(x, y) and the quantity of y differentiation fy(x, y) (302). Then, the sum of the squares of the quantity of the differentiation x, y in a local area GAMMA, Sxx=integral integral fx(x, y)<2>.dxdy and Sxy=integral integral fx(x, y).fy(x, y)dxdy and Syy=integral integral fy(x, y)<2>dxdy is obtained as the quantity of an intermediate operation (303). Then, in a feature extracting circuit 304, the quantity of the feature such as the edge point and the ridge is extracted based on the quantity of the intermediate operation Sxx, Sxy, Syy. Thereby, since a general purpose is high to respective types of objects and a line, a point and the directional characteristic or the like separately react, so that the feature of the picture strong in noise is extracted.