ENCODING APPARATUS, DECODING APPARATUS, COMMUNICATION SYSTEM, ENCODING METHOD AND DECODING METHOD

摘要

PROBLEM TO BE SOLVED: To secure sufficient security by suppressing required computational amount without lowering the compressibility of moving image data by encoding.

SOLUTION: The encoding apparatus is provided with a DCT (discrete cosine transform) part 204 for orthogonally transforming moving image data of unit of frame, a motion compensation part 213 for generating predictive image data for predicting the motion of the moving image data and motion vector information containing a vector component for the motion, a mode selection part 208 for selecting an encoding method in the DCT part 204 and outputting it as mode information, an electronic key insertion part 206 for encrypting coefficient information and the motion vector information on the basis of the mode information and encrypting the mode information on the basis of predetermined identification information, and a variable length encoding part 207 for applying variable length encoding to the encrypted mode information, coefficient information and motion vector information and multiplexing the information for outputting as a data stream.

COPYRIGHT: (C)2005,JPO&NCIPI