Three-dimensional data encoding method, three-dimensional data decoding method, three-dimensional data encoding device, and three-dimensional data decoding device

A three-dimensional data encoding method comprising:

• obtaining first three-dimensional points;
• encoding the first three-dimensional points using a selected one of a plurality of encoding schemes, the plurality of encoding schemes including a first scheme using an octree structure and a second scheme using a predictive tree structure;
• and
• generating a bitstream including first encoded data and a first identification information item, the first encoded data being generated by encoding the first three-dimensional points,
• wherein the encoding of the first three-dimensional points includes:
• determining whether a context used for encoding is continuously used;
• and
• encoding the first three-dimensional points using a context corresponding to a determination result in the determining, the context being included in contexts used in the encoding scheme used for the encoding and included in the plurality of encoding schemes,
• the first identification information item indicates the determination result in the determining,
• in the obtaining, second three-dimensional points are further obtained, the second three-dimensional points being encoded next to the first three-dimensional points,
• in the encoding of the first three-dimensional points, when an encoding scheme for the second three-dimensional points is different from the encoding scheme for the first three-dimensional points, it is determined that the context used for the encoding is not continuously used, and the second three-dimensional points are encoded using a context initialized and for the encoding scheme for the second three-dimensional points, the encoding scheme being included in the encoding schemes,
• in the generating, the bitstream including second encoded data and a second identification information item is further generated, the second encoded data being generated by encoding the second three-dimensional points, and
• the second identification information item indicates that the context used for the encoding is not continuously used.

A three-dimensional data decoding method comprising:

• obtaining a bitstream including first encoded data and a first identification information item, the first encoded data being generated by encoding first three-dimensional points using a selected one of a plurality of encoding schemes, the plurality of encoding schemes including a first scheme using an octree structure and a second scheme using a predictive tree structure, the first identification information item indicating whether a context used for encoding is continuously used;
• and
• decoding the first encoded data using a decoding scheme corresponding to the selected one of the plurality of encoding schemes,
• wherein in the decoding of the first encoded data, the first encoded data is decoded using a context according to the first identification information item,
• when the first encoded data is decoded using a decoding scheme corresponding to the first scheme, a first context is continuously used according to the first identification information item, and
• when the first encoded data is decoded using a decoding scheme corresponding to the second scheme, a second context, different from the first context, is continuously used according to the first identification information item.

A three-dimensional data encoding device comprising:

• a processor;
• and
• memory,
• wherein using the memory, the processor:
• obtains first three-dimensional points;
• encodes the first three-dimensional points using a selected one of a plurality of encoding schemes, the plurality of encoding schemes including a first scheme using an octree structure and a second scheme using a predictive tree structure;
• and
• generates a bitstream including first encoded data and a first identification information item, the first encoded data being generated by encoding the first three-dimensional points,
• wherein the encoding of the first three-dimensional points includes:
• determining whether a context used for encoding is continuously used;
• and
• encoding the first three-dimensional points using a context corresponding to a determination result in the determining, the context being included in contexts used in the encoding scheme used for the encoding and included in the plurality of encoding schemes,
• the first identification information item indicates the determination result in the determining,
• when the first three-dimensional points are encoded using the first scheme, in the determining, it is determined that a first context used for encoding is continuously used, and
• when the first three-dimensional points are encoded using the second scheme, in the determining, it is determined that a second context, different from the first context, used for encoding is continuously used.

A three-dimensional data decoding device comprising:

• a processor;
• and
• memory,
• wherein using the memory, the processor:
• obtains a bitstream including first encoded data and a first identification information item, the first encoded data being generated by encoding first three-dimensional points using a selected one of a plurality of encoding schemes, the plurality of encoding schemes including a first scheme using an octree structure and a second scheme using a predictive tree structure, the first identification information item indicating whether a context used for encoding is continuously used;
• and
• decodes the first encoded data using a decoding scheme corresponding to the selected one of the plurality of encoding schemes,
• wherein in the decoding of the first encoded data, the first encoded data is decoded using a context according to the first identification information item,
• when the first encoded data is decoded using a decoding scheme corresponding to the first scheme, a first context is continuously used according to the first identification information item, and
• when the first encoded data is decoded using a decoding scheme corresponding to the second scheme, a second context, different from the first context, is continuously used according to the first identification information item.