Apparatus and method for encoding and decoding a picture using picture boundary handling

An apparatus for decoding a picture, configured to

• partition the picture into leaf blocks using recursive multi-tree partitioning,
• block-based decode the picture from a data stream using the partitioning of the picture into leaf blocks,
• wherein the apparatus is configured to, in partitioning the picture into the leaf blocks,
• for a predetermined block that corresponds to a predetermined tree level of the multi-tree partitioning and which extends beyond a boundary of the picture, reduce an available set of split modes for splitting the predetermined block depending on a position at which the picture boundary crosses the predetermined block to acquire a reduced set of one or more split modes, wherein
• if a cardinality of the reduced set is one, the apparatus is configured to apply the split mode of the reduced set for splitting the predetermined block, and
• if a cardinality of the reduced set is greater than one, the apparatus is configured to select one of the split modes of the reduced set and to apply the selected one of the split modes for splitting the predetermined block according to a signalization in the data stream.

A method for encoding a picture, comprising:

• partitioning the picture into leaf blocks using recursive multi-tree partitioning,
• block-based encoding the picture into a data stream using the partitioning of the picture into the leaf blocks,
• wherein the method further comprises, in partitioning the picture into the leaf blocks,
• for a predetermined block that corresponds to a predetermined tree level of the multi-tree partitioning and which extends beyond a boundary of the picture, reducing an available set of split modes for splitting the predetermined block depending on a position at which the picture boundary crosses the predetermined block in order to acquire a reduced set of one or more split modes, wherein
• if a cardinality of the reduced set is one, the method comprises applying the split mode of the reduced set for splitting the predetermined block, and
• if a cardinality of the reduced set is greater than one, the method comprising selecting one of the split modes of the reduced set and applying the selected one of the split modes for splitting the predetermined block and signaling the selection in the data stream.

A method for decoding a picture, comprising:

• partitioning the picture into leaf blocks using recursive multi-tree partitioning,
• block-based decoding the picture from a data stream using the partitioning of the picture into leaf blocks,
• wherein the method further comprises, in partitioning the picture into the leaf blocks,
• for a predetermined block, which corresponds to a predetermined tree level of the multi-tree partitioning and which extends beyond a boundary of the picture, reducing an available set of split modes for splitting the predetermined block depending on a position at which the picture boundary crosses the predetermined block in order to acquire a reduced set of one or more split modes, wherein
• if a cardinality of the reduced set is one, the method comprises applying the split mode of the reduced set for splitting the predetermined block, and
• if a cardinality of the reduced set is greater than one, the method further comprising selecting one of the split modes of the reduced set and applying the selected one of the split modes for splitting the predetermined block according to a signalization in the data stream.

A non-transitory digital storage medium having stored thereon a computer program for performing a method for encoding a picture, comprising:

• partitioning the picture into leaf blocks using recursive multi-tree partitioning,
• block-based encoding the picture into a data stream using the partitioning of the picture into the leaf blocks,
• wherein the method further comprises, in partitioning the picture into the leaf blocks,
• for a predetermined block that corresponds to a predetermined tree level of the multi-tree partitioning and which extends beyond a boundary of the picture, reducing an available set of split modes for splitting the predetermined block depending on a position at which the picture boundary crosses the predetermined block in order to acquire a reduced set of one or more split modes, wherein
• if a cardinality of the reduced set is one, the method comprises applying the split mode of the reduced set for splitting the predetermined block, and
• if a cardinality of the reduced set is greater than one, the method comprising selecting one of the split modes of the reduced set and applying the selected one of the split modes for splitting the predetermined block and signaling the selection in the data stream,
• when said computer program is run by a computer.

A non-transitory digital storage medium having stored thereon a computer program for performing a method for decoding a picture, comprising:

• partitioning the picture into leaf blocks using recursive multi-tree partitioning,
• block-based decoding the picture from a data stream using the partitioning of the picture into leaf blocks,
• wherein the method further comprises, in partitioning the picture into the leaf blocks,
• for a predetermined block, which corresponds to a predetermined tree level of the multi-tree partitioning and which extends beyond a boundary of the picture, reducing an available set of split modes for splitting the predetermined block depending on a position at which the picture boundary crosses the predetermined block in order to acquire a reduced set of one or more split modes, wherein
• if a cardinality of the reduced set is one, the method further comprises applying the split mode of the reduced set for splitting the predetermined block, and
• if a cardinality of the reduced set is greater than one, the method further comprising selecting one of the split modes of the reduced set and applying the selected one of the split modes for splitting the predetermined block according to a signalization in the data stream,
• when said computer program is run by a computer.