METHOD FOR IMBEDING INFORMATION RELATING TO COPYRIGHT SUCH AS SIGNATURE OF AUTHRO OF IMAGE AND COPYING DEVICE IMBEDING THE COPYRIGHT INFORMATION TO THE IMAGE

摘要

PROBLEM TO BE SOLVED: To provide a method by which a signature is imbeded in secret in a hard copy and the imbeded signature is verified as required. SOLUTION: An image S of a signature only whose size is equal to the size of a contrast image G on which the signature is signed is prepared. Let the size of the images G, S be n×n picture elements, then a value (luminance) of a picture element (i, j) of the image G is expressed as g(i, j) and similarly a value (luminance) of a picture element (i, j) of the image S is expressed as s(i, j). The image S is a binary image and then the value s(i, j) takes 0 or 1. Let an image R is an output image obtained by binarizing the image G by the density pattern method and is to be open in public. An image V is an image for verification purpose. The size of the images R, B are expanded both to nd×nd picture elements. In order to display the value g(i, j), density conversion is conducted by using a cell cd (m, kp ) and the result is displayed in a picture element area of the image R through magnification. If s (i, j)=0, that is, the picture element (i, j) of the image S is the photoelectric conversion element of a signature, a cell cd (m, kp ) to maximize the humming distance is arranged to the image V as soon as the image G is converted into the image R. If s(i, j)=1, the cell cd (m, kp ) is outputted also to the image V.