Patent ID: 7912243

Claim:
A decoding device for a code embedded in an image, comprising: a data extracting unit to extract data from an image embedded with a reference code into image segments a plural number of times (N-times), wherein the reference code is organized by pieces of data of one or more digits (M-digits) and serves as a reference for detecting falsification; a data occurrence frequency calculating unit to calculate, if the data, extracted from the image segments disposed in the same digit in the image, become discrepant with a plurality of different reference codes, an occurrence frequency of each piece of data on a digit-by-digit basis; a weighting unit to set a weight for every reference code so that the data with a smaller occurrence frequency in the extracted data becomes a majority in a decision by a weighted majority; a first decision-by-majority unit to decide the detection result of the data for each digit on the basis of the decision by the weighted majority that adds the weight to the occurrence frequency of the data; and a judging unit to judge whether the image is falsified or non-falsified in accordance with whether the detection code organized by combining the detection results per digit decided by the first decision-by-majority units, is correct or erroneous.