METHOD AND APPARATUS FOR NON-UNIFORM MAPPING FOR QUANTIZATION MATRIX COEFFICIENTS BETWEEN DIFFERENT SIZES OF QUANTIZATION MATRICES IN IMAGE/VIDEO CODING

摘要

A method for non-uniform mapping for quantization matrix coefficients between different sizes of quantization matrices in image/video coding includes obtaining a first quantization matrix and identifying a second quantization matrix to be formed therefrom. The second quantization matrix is a factor of two larger than the first quantization matrix. The second quantization matrix is populated with values from the first matrix through non-uniform mapping of the first quantization matrix. Non-uniform mapping to populate the second quantization matrix includes directly mapping values of all or a portion of the first quantization matrix into a most upper left portion of the second quantization matrix and mapping up-sampling values of the first quantization matrix into a remaining portion of the second quantization matrix. A frequency position pattern may be applied to the first quantization matrix to directly map only those values within the frequency position pattern into a most upper left portion of the second quantization matrix.