METHOD OF IMAGE ENCODING BASED ON TRANSFORMATION AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2024 - IPC H04N19/18 H04N19/176 H04N19/186 H04N19/132 H04N19/124 H04N19/96 

FIELD: image encoding means.

SUBSTANCE: modified transform coefficients are derived from transform coefficients by applying low-frequency non-separable transform (LFNST). Transform coefficients or modified transform coefficients are quantised, wherein the LFNST index is encoded, indicating that the LFNST is used for the current block. Quantization is performed based on a predetermined scaling matrix or a predetermined constant value. Whether to apply a scaling matrix is determined based on the LFNST index and the tree type of the current block, which is one of three predetermined tree types, including a single tree, a dual luma tree, a dual chroma tree. When the tree type of the current block is a single tree and the current block is a chroma component, it is determined that a scaling matrix is applied to the current block. When the tree type of the current block is a dual chroma tree, it is determined that said predetermined constant value is applied to the current block.

EFFECT: high efficiency of encoding images.

13 cl, 16 dwg, 13 tbl