Position-dependent intra-prediction combination for angular intra-prediction modes for video coding

A device for decoding video data, the device comprising:

• a memory configured to store video data;
• and
• one or more processors implemented in circuitry and configured to:
• generate an intra-prediction block for a current block of video data using an angular intra-prediction mode, the angular intra-prediction mode being an upper-right angular intra-prediction mode or a lower-left angular intra-prediction mode;
• determine a prediction direction of the angular intra-prediction mode;
• for at least one sample of the intra-prediction block for the current block:
• calculate a gradient term for the at least one sample along the prediction direction;
• and
• combine a value of an intra-predicted sample of the intra-prediction block at a position of the at least one sample of the intra-prediction block with the gradient term to produce a value of the at least one sample of the intra-prediction block;
• and
• decode the current block using the intra-prediction block.

A computer-readable storage medium having stored thereon instructions that, when executed, cause processor to:

• generate an intra-prediction block for a current block of video data using an angular intra-prediction mode, the angular intra-prediction mode being an upper-right angular intra-prediction mode or a lower-left angular intra-prediction mode;
• determine a prediction direction of the angular intra-prediction mode;
• for at least one sample of the intra-prediction block for the current block:
• calculate a gradient term for the at least one sample along the prediction direction;
• and
• combine a value of an intra-predicted sample of the intra-prediction block at a position of the at least one sample of the intra-prediction block with the gradient term to produce a value of the at least one sample of the intra-prediction block;
• and
• decode the current block using the intra-prediction block.