Region merging and coding parameter reuse via merging

A decoder for decoding a data stream into which a two-dimensional information signal is coded, comprising:

• a sub-divider configured to spatially sub-divide, depending on a first subset of syntax elements contained in the data stream, an array of information samples representing a spatially sampling of the two-dimensional information signal into a plurality of blocks of different sizes by recursively multi-partitioning;
• a merger configured to combine, depending on a second subset of syntax elements within the data stream, being disjoined from the first subset, spatially neighboring blocks of the plurality of blocks to obtain an intermediate subdivision of the array of information samples into disjoint sets of blocks, the union of which is the plurality of blocks;
• and
• a reconstructor configured to reconstruct the array of information samples from the data stream using the intermediate subdivision by adopting coding parameters for predetermined blocks from blocks which neighbor the predetermined blocks and with which the predetermined blocks are combined,
• wherein the second subset of syntax elements defines merge information with a sequence of bins defining the merge information being entropy-coded using context modelling with the context models for some bins of the sequence of bins being derived based on already transmitted syntax elements of neighboring blocks, while other bins of the sequence of bins being coded with a fixed context model.

A method for decoding, comprising:

• extracting, for each of a plurality of blocks into which an array of information samples representing a spatially sampled information signal is sub-divided, payload data from a data stream;
• and
• reconstructing the array of information samples from the payload data for the blocks of the array of information samples, by processing, for each block, the payload data for a respective block in a way prescribed by coding parameters associated with the respective block,
• wherein the extracting comprises:
• identifying, for a predetermined block, a candidate set comprising a subset of blocks within the plurality of blocks for the predetermined block, the subset having a predetermined relative locational relationship to the predetermined block,
• if a number of blocks of the subset of blocks having the predetermined relative locational relationship to the predetermined block is greater than zero, extracting a merge indicator for the predetermined block from the data stream,
• if the number of blocks of the subset of blocks having the predetermined relative locational relationship to the predetermined block is greater than one and the coding parameters are not identical to each other, extracting, if the merge indicator suggests a merged processing of the predetermined block, a reference identifier from the data stream identifying a proper subset of the candidate set and adopting or predicting the coding parameters for the predetermined block from the coding parameters of the proper subset,
• wherein a sequence of bins defining merge information including the merge indicator and the reference identifier is entropy-coded using context modelling with the context models for some bins of the sequence of bins being derived based on already transmitted syntax elements of neighboring blocks, while other bins of the sequence of bins being coded with a fixed context model.

A method for decoding a data stream into which a two-dimensional information signal is coded, comprising:

• spatially sub-dividing, depending on a first subset of syntax elements contained in the data stream, an array of information samples representing a spatially sampling of the two-dimensional information signal into a plurality of blocks of different sizes by recursively multi-partitioning;
• combining, depending on a second subset of syntax elements within the data stream, being disjoined from the first subset, spatially neighboring blocks of the plurality of blocks to obtain an intermediate subdivision of the array of information samples into disjoint sets of blocks, the union of which is the plurality of blocks;
• and
• reconstructing the array of information samples from the data stream using the intermediate subdivision by adopting coding parameters for predetermined blocks from blocks which neighbor the predetermined blocks and with which the predetermined blocks are combined,
• wherein the second subset of syntax elements defines merge information with a sequence of bins defining the merge information being entropy-coded using context modelling with the context models for some bins of the sequence of bins being derived based on already transmitted syntax elements of neighboring blocks, while other bins of the sequence of bins being coded with a fixed context model.

An encoder for generating a data stream into which a two-dimensional information signal is coded, comprising:

• a subdivide/merger configured to determine a first subset of syntax elements defining a spatial sub-division of an array of information samples representing a spatially sampling of the two-dimensional information signal into a plurality of blocks of different sizes by recursively multi-partitioning, and a second subset of syntax elements being disjoined from the first subset, defining a combination of spatially neighboring blocks of the plurality of blocks to obtain an intermediate subdivision of the array of information samples into disjoint sets of blocks, the union of which is the plurality of blocks;
• and
• a data stream generator configured to code the array of information samples into a data stream using the intermediate subdivision by inserting the first and second subsets of syntax elements into the data stream,
• wherein coding parameters for predetermined blocks are indicated by way of the second subset of syntax elements as to be adopted from blocks which neighbor the predetermined blocks and with which the predetermined blocks are combined,
• wherein the second subset of syntax elements defines merge information with a sequence of bins defining the merge information being entropy-coded using context modelling with the context models for some bins of the sequence of bins being derived based on already transmitted syntax elements of neighboring blocks, while other bins of the sequence of bins being coded with a fixed context model.

A method for encoding an array of information samples representing a spatially sampled information signal into payload data for each of a plurality of blocks into which the array of information samples is sub-divided, and coding parameters associated with a respective block so as to prescribe the way the array of information samples is to be reconstructed from the payload data for the respective block,

• wherein the encoder is further configured to:
• identify, for a predetermined block, a candidate set comprising a subset of blocks within the plurality of blocks, the subset having a predetermined relative locational relationship to the predetermined block, if a number of blocks of the subset of blocks having the predetermined relative locational relationship to the predetermined block is greater than zero, insert a merge indicator for the predetermined block into a data stream which indicates whether the predetermined block is to be subject to merged processing with respect to the candidate set, and, if the number of blocks of the subset of blocks having the predetermined relative locational relationship to the predetermined block is greater than one and the coding parameters are not identical to each other, insert, if the merge indicator suggests a merged processing of the predetermined block, a reference identifier identifying a proper subset of the candidate set from the coding parameters of which the coding parameters for the predetermined block are to be adopted or predicted,
• wherein a sequence of bins defining merge information including the merge indicator and the reference identifier is entropy-coded using context modelling with the context models for some bins of the sequence of bins being derived based on already transmitted syntax elements of neighboring blocks, while other bins of the sequence of bins being coded with a fixed context model.

A method for generating a data stream into which a two-dimensional information signal is coded, comprising:

• determining a first subset of syntax elements defining a spatial sub-division of an array of information samples representing a spatially sampling of the two-dimensional information signal into a plurality of blocks of different sizes by recursively multi-partitioning, and a second subset of syntax elements being disjoined from the first subset, defining a combination of spatially neighboring blocks of the plurality of blocks to obtain an intermediate subdivision of the array of information samples into disjoint sets of blocks, the union of which is the plurality of blocks;
• and
• coding the array of information samples into a data stream using the intermediate subdivision by inserting the first and second subsets of syntax elements into the data stream, wherein coding parameters for the predetermined blocks are indicated by way of the second subset of syntax elements as to be adopted from blocks which neighbor the predetermined blocks and with which the predetermined blocks are combined,
• wherein the second subset of syntax elements defines merge information with a sequence of bins defining the merge information being entropy-coded using context modelling with the context models for some bins of the sequence of bins being derived based on already transmitted syntax elements of neighboring blocks, while other bins of the sequence of bins being coded with a fixed context model.