Patent ID: 8681872

Claim:
A video decoding method for decoding a coded bit stream obtained by compressing and coding a video signal, said method comprising: obtaining, as additional information of the coded bit stream, coefficient modification information used for modifying orthogonal transformation coefficients obtained by performing an orthogonal transformation on a decoded video signal obtained from the coded bit stream; generating a first video signal by decoding the coded bit stream; obtaining decoded orthogonal transformation coefficients by performing an orthogonal transformation on the first video signal; calculating modified orthogonal transformation coefficients based on the coefficient modification information and the decoded orthogonal transformation coefficients; and outputting a second video signal obtained by performing an inverse orthogonal transformation on the modified orthogonal transformation coefficients, wherein the coefficient modification information indicates to which range of values, out of a predetermined number of ranges of values, each of the orthogonal transformation coefficients belongs, and wherein said calculating of the modified orthogonal transformation coefficients includes calculating the modified orthogonal transformation coefficients based on a predetermined threshold value and the information that indicates to which range of values, out of the predetermined number of ranges of values, each of the orthogonal transformation coefficients belongs.