DEVICE AND METHOD FOR PROCESSING IMAGE

摘要

PROBLEM TO BE SOLVED: To prevent embedded authentication information from being lost, even if quantizing processing is performed after the authentication information is embedded. SOLUTION: A pre-embedding part 32 converts the value of image data, so that the value after quantizing processing can not be changed by an error added by embedding processing of embedded data. A hash value calculating part 300 calculates a hash value from image data and key information and a hash value embedding part 302 embeds the hash value in the image data. An output format converting part 304 generates JPEG data, by applying quantizing processing or the like to the image data embedded with the hash value.