TWO-DIMENSIONAL ORTHOGONAL TRANSFORMATION METHOD

摘要

PROBLEM TO BE SOLVED: To eliminate the need of a memory for storing the results of first-stage one-dimensional orthogonal transformation and to obtain desired result data of two-dimensional orthogonal transformation at high speed. SOLUTION: In the two-dimensional orthogonal transformation method, the first matrix element 23a of intermediated data is first obtained by performing sum of products operation on the first-row vector 21a of input image data and the first-column vector 22 of a transformation factor matrix. Then the second matrix element 23b of the intermediate data is obtained by performing sum of products operation on the second-row vector 21b of the input image data and the first-column vector 22 of the transformation coefficient matrix. Thus each matrix element of the intermediate data is generated in the vertical direction in first-stage one-dimensional orthogonal transformation. Immediately after the matrix element of eighth (eighth in one column) intermediate data is decided, second-stage (in the vertical direction) one-dimensional orthogonal transformation can be started.