Two-dimensional orthogonal transformation method

摘要

First, a multiply-add operation is performed on a first-row vector of input picture data and a first-column vector of a transform coefficient matrix to yield a first matrix element of intermediate data. Next, a multiply-add operation is performed on a second-row vector of the input picture data and the first-column vector of the transform coefficient matrix to obtain a second matrix element of the intermediate data. In this manner, respective matrix elements are yielded vertically for the intermediate data in performing the first-stage (horizontal) one-dimensional orthogonal transformation. Thus, as soon as the 8 matrix element (of the first column) has been obtained for the intermediate data, the second-stage (vertical) one-dimensional orthogonal transformation can be started. Consequently, desired resultant data of the two-dimensional orthogonal transformation can be obtained much faster and no memories are needed to store the result of the first-stage one-dimensional orthogonal transformation thereon.