METHOD OF IMAGE ENCODING BASED ON TRANSFORMATION AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2025 - IPC H04N19/122 

FIELD: image encoding.

SUBSTANCE: image decoding includes the following steps: deriving the position of the last significant coefficient in the current block and transformation coefficients for the current block based on the residual information; determining whether the index of the sub-block including the last significant coefficient is equal to 0, and whether the position of the last significant coefficient in the sub-block is greater than 0; determining whether a significant coefficient exists in a second region other than the first region at the upper-left end of the current block; and analysing the LFNST index from the bitstream, when the position of the last significant coefficient is determined to be greater than 0, in a subblock in which index is 0 and the significant coefficient does not exist in the second region.

EFFECT: high efficiency of image encoding.

14 cl, 18 dwg, 13 tbl