JPS56123055A - Picture processing method - Google Patents

Abstract

PURPOSE:To obtain a picture magnification converting method of a high resolving power, by determining the density level of original sampled picture elements on a basis of weighting coefficients inversely priportional to distances between the picture element, which is obtained by re-sampling, and original picture elements due to sampling which surround the said picture element. CONSTITUTION:Picture element O(k,1) after conversion is surrounded with original four picture elements S(i,j), S(i+1,j), S(i,j+1) and S(i+1,j+1), and the operation of expression [I] is executed when distances from picture element O(k,1) to respective picture elements are benoted as ra, rb, re and rd. However, O=Si is true for ri=0. Two-dimensional conversion function (r) for conversion of the picture magnification is given by expression [II] where the variable magnification in the X axis direction and the variable magnification in the Y axis direction are denoted as lambdaX and lambdaY respectively. X-direction and Y-direction variable magnifications lambdaX and lambdaY are given by expression [III]. Consequently, (X,Y) expression of coordinates (k,1) of the picture element after conversion is given by expression IV based on original picture elements surrounding picture element (k,1). Thus, picture magnification conversion of a high resolving power is performed by the operation processing.