Patent ID: 8422732

Claim:
An information processing apparatus for generating, from image data, verification information to be used to certify the integrity of the image data, comprising: an image input unit which inputs the image data as an integrity certification target; a block division unit which divides the image data input by said image input unit into blocks, each represented by a predetermined number of pixels; a block coefficient calculation unit which performs a calculation to obtain, for values of pixels included in each block, a block coefficient representing a feature of the block; a cell division unit which divides each of the blocks divided by said block division unit into cells, each having a size smaller than that of its block; a cell coefficient calculation unit which performs a calculation to obtain, for values of pixels included in each cell, a cell coefficient representing a feature of the cell; a first verification data generation unit which generates first verification data by selecting, from the block coefficients obtained by said block coefficient calculation unit, two block coefficients which form a block pair and generating data representing a magnitude relation of the two block coefficients which form the selected block pair; a second verification data generation unit which generates second verification data by selecting the cell coefficients corresponding to two cells at preset positions so as to select a cell pair and generating data representing a magnitude relation of the two cell coefficients which form the selected cell pair; and an output unit which outputs the image data as the integrity certification target input by said image input unit, and outputs the first verification data obtained by said first verification data generation unit and the second verification data obtained by said second verification data generation unit as the verification information for the image data as the integrity certification target.