Method and apparatus for multiple line intra prediction in video compression

A video decoder for video decoding, comprising:

• processing circuitry configured to:
• determine, for a current block of a picture, one of a plurality of reference lines, each reference line being parallel to a side of the current block,
• determine an intra prediction mode for the current block in accordance with the determined one of the plurality of reference lines, and
• perform intra prediction for the current block based on the determined intra prediction mode and one or more samples included in the determined one of the plurality of reference lines, wherein
• the plurality of reference lines includes an adjacent reference line that is adjacent to the current block and at least one non-adjacent reference line that is not adjacent to the current block,
• a number of intra prediction modes associated with each of the at least one non-adjacent reference line is equal to or less than half a number of intra prediction modes associated with the adjacent reference line, and
• each of the at least one non-adjacent reference line is associated with a same number of intra prediction modes.

A non-transitory computer readable medium having instructions stored therein, which when executed by a processor in video decoder causes the processor to execute a method comprising:

• determining, for a current block of a picture, one of a plurality of reference lines, each reference line being parallel to a side of the current block;
• determining an intra prediction mode for the current block in accordance with the determined one of the plurality of reference lines;
• and
• performing intra prediction for the current block based on the determined intra prediction mode and one or more samples included in the determined one of the plurality of reference lines, wherein
• the plurality of reference lines includes an adjacent reference line that is adjacent to the current block and at least one non-adjacent reference line that is not adjacent to the current block,
• a number of intra prediction modes associated with each of the at least one non-adjacent reference line is equal to or less than half a number of intra prediction modes associated with the adjacent reference line, and
• each of the at least one non-adjacent reference line is associated with a same number of intra prediction modes.