Coding/decoding video with reference boundary correction

A picture coding method that divides a coding tree block into one or more intra block copy standard blocks, comprising:

• a block vector candidate derivation step of deriving block vector candidates of a coding target block in a coding target picture from coding information stored in a coding information storage memory;
• a selection step of selecting a selected block vector from the block vector candidates;
• a storage step of storing coded pictures of a predetermined number of intra block copy standard blocks immediately before a coding target intra block copy standard block as a referenceable region and storing a coded picture of the coding target intra block copy standard block in a memory space which has stored a coded picture of the oldest intra block copy standard block in a coding order;
• and
• a reference region boundary correction step of:
• setting to be invalid the coding target intra block copy standard block from a referenceable region, and
• determining whether an upper left position and a lower right position of a reference block indicated by the selected block vector are both included in the referenceable region.

A non-transitory computer-readable medium storing executable instructions that, in response to execution of a picture coding program that divides a coding tree block into one or more intra block copy standard blocks, cause a computer to perform operations comprising:

• a block vector candidate derivation step of deriving block vector candidates of a coding target block in a coding target picture from coding information stored in a coding information storage memory;
• a selection step of selecting a selected block vector from the block vector candidates;
• a storage step of storing coded pictures of a predetermined number of intra block copy standard blocks immediately before a coding target intra block copy standard block as a referenceable region and storing a coded picture of the coding target intra block copy standard block in a memory space which has stored a coded picture of the oldest intra block copy standard block in a coding order;
• and
• a reference region boundary correction step of:
• setting to be invalid the coding target intra block copy standard block from a referenceable region, and
• determining whether an upper left position and a lower right position of a reference block indicated by the selected block vector are both included in the referenceable region.

A picture decoding device that divides a coding tree block into one or more intra block copy standard blocks, comprising:

• a block vector candidate derivation unit structured to derive block vector candidates of a decoding target block in a decoding target picture from coding information stored in a coding information storage memory;
• a selector structured to select a selected block vector from the block vector candidates;
• a storage structured to store decoded pictures of a predetermined number of intra block copy standard blocks immediately before a decoding target intra block copy standard block as a referenceable region and to store a decoded picture of the decoding target intra block copy standard block in a memory space which has stored a decoded picture of the oldest intra block copy standard block in a decoding order;
• and
• a reference region boundary correction unit structured to
• set to be invalid the decoding target intra block copy standard block from a referenceable region, and
• determine whether an upper left position and a lower right position of a reference block indicated by the selected block vector are both included in the referenceable region.

A picture decoding method that divides a coding tree block into one or more intra block copy standard blocks, comprising:

• a block vector candidate derivation step of deriving block vector candidates of a decoding target block in a decoding target picture from coding information stored in a coding information storage memory;
• a selecting step of selecting a selected block vector from the block vector candidates;
• a storage step of storing decoded pictures of a predetermined number of intra block copy standard blocks immediately before a decoding target intra block copy standard block as a referenceable region and storing a decoded picture of the decoding target intra block copy standard block in a memory space which has stored a decoded picture of the oldest intra block copy standard block in a decoding order;
• and
• a reference region boundary correction step of:
• setting to be invalid the decoding target intra block copy standard block from a referenceable region, and
• determining whether an upper left position and a lower right position of a reference block indicated by the selected block vector are both included in the referenceable region.

A non-transitory computer-readable medium storing executable instructions that, in response to execution of a picture decoding program that divides a coding tree block into one or more intra block copy standard blocks, cause a computer to perform operations comprising:

• a block vector candidate derivation step of deriving block vector candidates of a decoding target block in a decoding target picture from coding information stored in a coding information storage memory;
• a selecting step of selecting a selected block vector from the block vector candidates;
• a storage step of storing decoded pictures of a predetermined number of intra block copy standard blocks immediately before a decoding target intra block copy standard block as a referenceable region and storing a decoded picture of the decoding target intra block copy standard block in a memory space which has stored a decoded picture of the oldest intra block copy standard block in a decoding order;
• and
• a reference region boundary correction step of:
• setting to be invalid the decoding target intra block copy standard block from a referenceable region, and
• determining whether an upper left position and a lower right position of a reference block indicated by the selected block vector are both included in the referenceable region.