IMAGE ENCODING METHOD 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.

SUBSTANCE: modified transform factors are derived from the transform factors by applying a low frequency non-separable transform (LFNST). The transform factors or modified transform factors are quantized, and an LFNST index is encoded indicating that LFNST is applied to the current block. Quantization is performed based on a predefined scaling matrix or a predefined constant value. Whether to apply a scaling matrix is determined based on the index LFNST and the tree type of the current block, which is one of three predefined 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 the scaling matrix applies to the current block. When the tree type of the current block is a dual chroma tree, it is determined that the predetermined constant value is applied to the current block.

EFFECT: improved efficiency of image encoding.

13 cl, 16 dwg, 13 tbl