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 decoding method of decoding three-dimensional data, the three-dimensional data decoding method comprising:

• calculating a predicted value of a current value to be decoded included in the three-dimensional data;
• arithmetic decoding encoded data included in a bitstream to generate binary data including a prefix and a suffix;
• debinarizing the binary data to generate a prediction residual;
• and
• calculating the current value by adding the predicted value and the prediction residual, wherein
• the three-dimensional data decoding method further comprises:
• selecting a first context to be used to arithmetic decode a current bit of the suffix;
• and
• selecting a second context to be used to arithmetic decode a current bit of the prefix, and
• in the arithmetic decoding of the encoded data, (i) the first context is applied to the current bit of the suffix, and (ii) the second context is applied to the current bit of the prefix.

A three-dimensional data encoding device which encodes three-dimensional data, the three-dimensional data encoding device comprising:

• a processor;
• and
• memory,
• wherein, using the memory, the processor:
• calculates a predicted value of a current value to be encoded included in the three-dimensional data;
• calculates a prediction residual which is a difference between the current value and the predicted value;
• binarizes the prediction residual to generate binary data including a prefix and a suffix;
• selects a first context to be used to arithmetic encode a current bit of the suffix;
• selects a second context to be used to arithmetic encode a current bit of the prefix;
• and
• arithmetic encodes the binary data, and
• in the arithmetic encoding of the binary data, (i) the first context is applied to the current bit of the suffix, and (ii) the second context is applied to the current bit of the prefix.

A three-dimensional data decoding device which decodes three-dimensional data, the three-dimensional data decoding device comprising:

• a processor;
• and
• memory,
• wherein, using the memory, the processor:
• calculates a predicted value of a current value to be decoded included in the three-dimensional data;
• arithmetic decodes encoded data included in a bitstream to generate binary data, the binary data including a prefix and a suffix;
• debinarizes the binary data to generate a prediction residual;
• and
• calculates the current value by adding the predicted value and the prediction residual,
• the processor further:
• selects a first context to be used to arithmetic decode a current bit of the suffix;
• and
• selects a second context to be used to arithmetic decode a current bit of the prefix, and
• in the arithmetic decoding of the encoded data, (i) the first context is applied to the current bit of the suffix, and (ii) the second context is applied to the current bit of the prefix.