Methods and apparatuses for encoding and decoding an image or a video using combined intra modes

A non-transitory computer readable medium storing executable program instructions to cause a computer executing the program instructions to:

• for at least one block of an image or a video,
• decode an indicator indicating a first intra prediction mode, wherein the first intra prediction mode is one of an intra block copy prediction mode or a matrix-based intra prediction mode,
• determine whether the first intra prediction mode is to be combined with a second intra prediction mode for obtaining a prediction of the at least one block,
• responsive to determining that the first intra prediction mode is to be combined with a second intra prediction mode, obtain the second intra prediction mode, and
• decode the at least one block based on a combination of the first intra prediction mode and the second intra prediction mode.

An apparatus comprising one or more processors, wherein the one or more processors is operable to, for at least one block of an image or a video:

• decode an indicator indicating a first intra prediction mode, wherein the first intra prediction mode is one of an intra block copy prediction mode or a matrix-based intra prediction mode,
• determine whether the first intra prediction mode is to be combined with a second intra prediction mode for obtaining a prediction of the at least one block,
• responsive to determining that the first intra prediction mode is to be combined with a second intra prediction mode, obtain the second intra prediction mode, and
• decode the at least one block based on a combination of the first intra prediction mode and the second intra prediction mode.

A method, comprising, for at least one block of an image or a video:

• encoding an indicator indicating a first intra prediction mode, wherein the first intra prediction mode is one of an intra block copy prediction mode or a matrix-based intra prediction mode,
• determining whether the first intra prediction mode is to be combined with a second intra prediction mode for obtaining a prediction of the at least one block,
• responsive to determining that the first intra prediction mode is to be combined with a second intra prediction mode, obtaining the second intra prediction mode, and
• encoding the at least one block based on a combination of the first intra prediction mode and the second intra prediction mode.

An apparatus comprising one or more processors, wherein the one or more processors is operable to, for at least one block of an image or a video:

• encode an indicator indicating a first intra prediction mode, wherein the first intra prediction mode is one of an intra block copy prediction mode or a matrix-based intra prediction mode,
• determine whether the first intra prediction mode is to be combined with a second intra prediction mode for obtaining a prediction of the at least one block,
• responsive to determining that the first intra prediction mode is to be combined with a second intra prediction mode, obtain the second intra prediction mode, and
• encode the at least one block based on a combination of the first intra prediction mode and the second intra prediction mode.