EFFICIENT FIXED-POINT APPROXIMATION FOR DIRECT AND INVERSE DISCRETE COSINE TRANSFORMS

摘要

FIELD: information technology.SUBSTANCE: method comprises steps where each coefficient in an 8×8 matrix of encoded coefficients is scaled with one multiplier to create a matrix of scaled coefficients, scaled one-dimensional fixed-point transforms are repeatedly performed to transform the matrix of scaled coefficients into a matrix of transformed coefficients, the transformed coefficients are shifted to the right to create a matrix of corrected coefficients, wherein each corrected coefficient in the matrix of corrected coefficients approximates the corresponding value in the matrix of values, which can be created with application of an ideal two-dimensional inverse discrete cosine transform to the matrix of encoded coefficients, an 8×8 block of pixels is displayed, wherein each pixel in the said block includes a pixel component value taking into account the corrected coefficient.EFFECT: eliminating approximation errors for calculating an inverse discrete cosine transform using fixed-point calculations.27 cl, 12 dwg, 3 tbl