Encoder, decoder, encoding method, and decoding method
An encoder according to one aspect of the present disclosure encodes a block of an image, and includes a processor and memory connected to the processor. Using the memory, the processor partitions a block into a plurality of sub blocks and encodes a sub block included in the plurality of sub blocks in an encoding process including at least a transform process or a prediction process. The block is partitioned using a multiple partition including at least three odd-numbered child nodes and each of a width and a height of each of the plurality of sub blocks is a power of two.
1. An encoder that encodes a block of an image, the encoder comprising:
a processor; and
memory connected to the processor,
wherein, using the memory, the processor:
determines prediction mode information;
determines a set of partition modes in accordance with the prediction mode information;
selects a partition mode from the determined set of partition modes in accordance with the prediction mode information;
writes a parameter into a bitstream, wherein the parameter is a flag;
partitions a block into a plurality of sub blocks using the selected partition mode; and
encodes a sub block included in the plurality of sub blocks in an encoding process, wherein the processor:
partitions the block into three sub blocks, each having a width and a height that are powers of two, and sets the parameter to a first value in response; and
partitions the block into an even number of sub blocks, each of the even number of sub blocks having a same size, and sets the parameter to a second value in response, the second value being different from the first value.
2. An encoding method of encoding a block of an image, the encoding method comprising:
determining prediction mode information;
determining a set of partition modes in accordance with the prediction mode information;
selecting a partition mode from the determined set of partition modes in accordance with the prediction mode information;
writing a parameter into a bitstream, wherein the parameter is a flag;
partitioning a block into a plurality of sub blocks using the selected partition mode; and
encoding a sub block included in the plurality of sub blocks in an encoding process, wherein the encoding method comprises:
partitioning the block into three sub blocks, each having a width and a height that are powers of two, and setting the parameter to a first value in response; and
partitioning the block into an even number of sub blocks, each of the even number of sub blocks having a same size, and setting the parameter to a second value in response, the second value being different from the first value.
3. A decoder that decodes a block of an image, the decoder comprising:
a processor; and
memory connected to the processor,
wherein, using the memory, the processor:
determines prediction mode information;
determines a set of partition modes in accordance with the prediction mode information;
parses a parameter from the bitstream, wherein the parameter is a flag;
selects a partition mode from the determined set of partition modes in accordance with the parameter;
partitions a block into a plurality of sub blocks using the selected partition mode; and
decodes a sub block included in the plurality of sub blocks in a decoding process, wherein the processor:
partitions the block into three sub blocks, each having a width and a height that are powers of two, in response to the parameter indicating a first value; and
partitions the block into an even number of sub blocks, each of the even number of sub blocks having a same size, in response to the parameter indicating a second value, the second value being different from the first value.
4. A decoding method of decoding a block of an image, the decoding method comprising:
determining prediction mode information;
determining a set of partition modes in accordance with the prediction mode information;
parsing a parameter from the bitstream, wherein the parameter is a flag;
selecting a partition mode from the determined set of partition modes in accordance with the parameter;
partitioning a block into a plurality of sub blocks using the selected partition mode; and
decoding a sub block included in the plurality of sub blocks in a decoding process, wherein the decoding method comprises:
partitioning the block into three sub blocks, each having a width and a height that are powers of two, in response to the parameter indicating a first value; and
partitioning the block into an even number of sub blocks, each of the even number of sub blocks having a same size, in response to the parameter indicating a second value, the second value being different from the first value.
5. A non-transitory computer readable medium storing a bitstream, comprising:
the bitstream including a parameter according to which a decoder performs:
determining prediction mode information;
determining a set of partition modes in accordance with the prediction mode information;
parsing the parameter from the bitstream;
selecting a partition mode from the determined set of partition modes in accordance with the parameter, wherein the parameter is a flag;
partitioning a block into a plurality of sub blocks using the selected partition mode; and
decoding a sub block included in the plurality of sub blocks in a decoding process, wherein the decoder performs:
partitioning the block into three sub blocks, each having a width and a height that are powers of two, in response to the parameter indicating a first value; and
partitioning the block into an even number of sub blocks, each of the even number of sub blocks having a same size, in response to the parameter indicating a second value, the second value being different from the first value.