Dct matrix decomposing method and dct device

Abstract

The purpose is the provision of each of a DCT matrix decomposing method and a DCT device, wherein the device decomposes a one-dimensional DCT matrix to make it possible to carrying out a DCT operation only through addition and subtraction. The method is characterized by comprising: a first step of decomposing an N×N one-dimensional DCT matrix into a plurality of sub-matrices and a zero matrix by using the symmetry of a cosine function; a second step of factorizing each of the sub-matrices to make it possible to express each of the sub-matrices by the product of an intermediate matrix and one or more first matrices the elements of which are 1, −1 or 0, wherein the intermediate matrix contains a cosine coefficient as a matrix element; and, a third step of repeating a factorization process of each of the intermediate matrices a desired number of times to make it possible to express each of the intermediate matrices by the product of second matrices the elements of which are 1, −1 or 0.

Dependencies are inferred from the claim text.