DIGITAL SIGNAL CONVERTING METHOD AND DEVICE, TRANSFORMATION MATRIX GENERATING METHOD AND DEVICE, AND SUPPLY MEDIUM

摘要

An inverse orthogonal transformation matrix (Ts(k)<-1>) which expresses the inverse transformation of an orthogonal transformation to which are subjected input digital signals (15) in an orthogonally transformed region, is generated by an input orthogonal transformation matrix generating unit (11). An orthogonal transformation matrix (Td(k)) which expresses the inverse processing of an inverse orthogonal transformation which is subjected to output digital signals (16) as a decoded processing in an orthogonally transformed region is generated by an output orthogonal transformation matrix generating unit (12). A transformation matrix generating unit (13) generates a transformation matrix (D) based on the inverse orthogonal transformation matrix (Ts(k)<-1>) and the orthogonal transformation matrix (Td(k)). The transformation matrix (D) is applied to the input digital signals (15) by a signal conversion unit (14) to generate the output digital signals (16) in the orthogonally transformed region. Thus, by applying conversion processes such as a resolution conversion in the orthogonally transformed region to the input digital signals in the orthogonally transformed region, the amount of calculation can be reduced, calculation errors can be reduced and a high speed and high quality conversion can be realized.