Patent ID: 8165212

Claim:
A video coding method for compressing and coding a video signal, said video coding method comprising: outputting a coded bit stream obtained by compressing and coding the video signal; generating a temporarily decoded image signal by temporarily decoding the coded bit stream; calculating temporarily decoded orthogonal transformation coefficients by performing orthogonal transformation on the temporarily decoded image signal; generating coefficient modification information for modifying orthogonal transformation coefficients obtained by performing orthogonal transformation on a decoded video signal obtained from the coded bit stream, the coefficient modification information being generated based on (i) orthogonal transformation coefficients obtained by performing orthogonal transformation on the video signal and (ii) the temporarily decoded orthogonal transformation coefficients; and outputting the coefficient modification information as additional information of the coded bit stream, wherein the coefficient modification information indicates a correlation between the temporarily decoded orthogonal transformation coefficients and the orthogonal transformation coefficients obtained by performing the orthogonal transformation on the video signal, and wherein said generating of the coefficient modification information includes generating the coefficient modification information by calculating correlation levels between (i) a set of the orthogonal transformation coefficients, obtained by performing the orthogonal transformation on the video signal, for each frequency band for a plurality of blocks of a plurality of frequency bands and (ii) a set of the temporarily decoded orthogonal transformation coefficients for each frequency band for the plurality of blocks of the plurality of frequency bands, each block of the plurality of blocks being a unit of orthogonal transformation.