Modified Integer Sine Transforms. Construction Method and Separable Directional Adaptive Transforms for Intra Prediction in Image/Video Coding

Abstract

The author proposes a matrix method for constructing a modified order 8 integer sine type VII transform. Based on the method, two modified order 8 integer sine type VII transforms are constructed and algorithms for fast implementation of 8-point modified integer sine type VII transforms are developed, which require only integer operations. These algorithms have low computational complexity that is 4.5 and 10.9 times less than that of the known algorithm. These transforms have higher coding performance in terms of quality and compression ratio than the known sine transforms do. Algorithms for fast implementation of 2D 8-point separable directional integer cosine and modified adaptive sine transforms for intra prediction with low computational complexity are developed, and their computational complexity is 4.62 and 8.24 times lower than that of the known algorithms.