ENCODING METHOD, DECODING METHOD, ENCODER AND DECODER OF DYNAMIC IMAGE DATA

摘要

PROBLEM TO BE SOLVED: To provide an encrypting method, an encryptor, a decrypting method and a decryptor of dynamic image data in which encoding is effected using a quantization matrix. SOLUTION: In the encrypting method and decrypting method of encoded data of dynamic image, decryption lag is reduced without sacrifice of safety by encrypting a quantization matrix being used in the encoding of dynamic image and encoding the encrypted quantization matrix into the encoded data of dynamic image thereby not altering the format of the encoded data of dynamic image.