Patent ID: 11943478
Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A decoder comprising:
a processor; and
memory coupled with the processor, wherein the memory comprises instructions that, when executed by the processor, cause the processor to perform operations comprising:
deriving a size of a current coding block of a picture from a bitstream as a width value and a height value based on decoding syntax elements in the bitstream;
determining whether the current coding block is an intra predicted block from decoding elements in the bitstream;
responsive to the current coding block being an intra predicted block, determining whether the current coding block can be predicted as a matrix based intra prediction, MIP, predicted block size;
responsive to determining that the current coding block can be predicted as a MIP block, determining whether the current coding block is a MIP predicted block from decoding elements in the bitstream;
determining whether the current coding block has one transform block or has multiple transform blocks;
determining a matrix vector to use for the current coding block from a matrix vector look-up table by using a prediction mode for the current coding block and a value based on the width value and the height value of the current coding block as a table index;
for the one transform block or each of the multiple transform blocks:
determining original boundary sample values for the current transform block;
determining a size of a reduced boundary bdryred by the value based on the width value and the height value of the current coding block;
determining a dimension size of a reduced prediction signal predred by the value based on the width value and the height value of the current coding block;
deriving the reduced boundary bdryred from the original boundary sample values;
deriving a reduced prediction signal, predredtemp, by matrix multiplication of the matrix vector and the reduced boundary bdryred;
deriving the reduced prediction signal predred by using sample value clipping on each sample of the predredtemp;
determining whether to apply vertical linear interpolation to the reduced prediction signal predred and whether to apply horizontal linear interpolation to the reduced prediction signal predred;
applying interpolation based on the determination of whether to apply vertical linear interpolation to the reduced prediction signal predred and whether to apply horizontal linear interpolation to the reduced prediction signal predred; and
determining one of a size of a reduced top boundary bdryredlltop and a size of a reduced left boundary bdryredllleft based on interpolation applied;
determining one of reduced top boundary bdryredtop and reduced left boundary bdryredllleft based on the interpolation applied; and
deriving a MIP prediction block pred by generating the sample values at remaining positions by using linear interpolation; and

decoding the current coding block by using each of the MIP prediction blocks.