Encoding device and method, decoding device and method, program, and recording medium

An encoding device for encoding a plurality of pieces of position information corresponding to a plurality of leaves and/or nodes at the same layer in a tree structure, comprising:

• rearranging unit for rearranging, in accordance with a predetermined order relationship, the plurality of pieces of position information to be encoded,
• determining unit for determining, in accordance with the predetermined order relationship, a branch layer of two consecutive pieces of position information from among the plurality of pieces of position information output from the rearranging unit, and
• encoding unit for outputting a code corresponding to the branch layer.

An encoding device for encoding a plurality of pieces of position information corresponding to a plurality of leaves and/or nodes at the same layer in a tree structure, the plurality of pieces of position information to be encoded being arranged in accordance with a predetermined order relationship, comprising:

• determining unit for determining, in accordance with the predetermined order relationship, a branch layer of two consecutive pieces of position information from among the plurality of pieces of position information to be encoded, and
• encoding unit for outputting a code corresponding to the branch layer.

An encoding device for encoding a plurality of pieces of position information corresponding to a plurality of leaves and/or nodes at the same layer in a tree structure, comprising:

• incremental width determining unit for determining an incremental width of the value of the position information based on the plurality of pieces of position information to be encoded,
• incremental width encoding unit for encoding the incremental width and outputting the encoded incremental width,
• determining unit for determining a branch layer of two consecutive pieces of position information from among the plurality of pieces of position information to be encoded, and branch layer encoding unit for outputting a code corresponding to the branch layer.

An encoding method for encoding a plurality of pieces of position information corresponding to a plurality of leaves and/or nodes at the same layer in a tree structure, comprising:

• a rearranging step of rearranging, in accordance with a predetermined order relationship, the plurality of pieces of position information to be encoded,
• a determining step of determining, in accordance with the predetermined order relationship, a branch layer of two consecutive pieces of position information from among the plurality of pieces of position information output in the rearranging step, and
• an encoding step of outputting a code corresponding to the branch layer.

An encoding method for encoding a plurality of pieces of position information corresponding to a plurality of leaves and/or nodes at the same layer in a tree structure, the plurality of pieces of position information to be encoded being arranged in accordance with a predetermined order relationship, comprising:

• a determining step of determining, in accordance with the predetermined order relationship, a branch layer of two consecutive pieces of position information from among the plurality of pieces of position information to be encoded, and
• an encoding step of outputting a code corresponding to the branch layer.

A decoding device for decoding a string of position information code composed of a plurality of pieces of encoded position information corresponding to a plurality of leaves and/or nodes at the same layer in a tree structure, comprising:

• storage unit for successively storing decoded position information,
• determining unit for determining a branch layer of two consecutive pieces of position information based on the position information code, and
• decoding unit for updating the value of the position information, stored in the storage unit, corresponding to the branch layer by one notch in accordance with a predetermined order relationship.

A decoding method for decoding a string of position information code composed of a plurality of pieces of encoded position information corresponding to a plurality of leaves and/or nodes at the same layer in a tree structure, comprising:

• a storage step of successively storing decoded position information,
• a determining step of determining a branch layer of two consecutive pieces of position information based on the position information code, and
• a decoding step of updating the value of the position information, stored in the storage step, corresponding to the branch layer by one notch in accordance with a predetermined order relationship.