METHOD OF PERFORMING NXM DISCRETE COSINE TRANSFORM

摘要

A fast and precise method to perform inverse and forward Discrete Cosine Transform (DCT) is disclosed. The method may be used for implementing a two-dimensional (2D) inverse or forward DCT that operates on an NxM coefficient block and has a higher accuracy than is specified by the IEEE 1180-1990 standard (for the inverse operation). The disclosed method comprises the following stages: based on integer operations, a fixed point one dimensional (1D) DCT may be performed on each row of an input coefficient block, an integer-to-single-precision floating point result conversion may be performed, and a single precision floating point 1D DCT may be performed on each column of the coefficient block resulting from the previous stages.