Inheritance in sample array multitree subdivision

Patent metadata

Field	Value
Publication number	US-2016309197-A1
Application number	US-201615196113-A
Country	US
Kind code	A1
Filing date	Jun 29, 2016
Priority date	Apr 13, 2010
Publication date	Oct 20, 2016
Grant date	—

Abstract

A better compromise between encoding complexity and achievable rate distortion ratio, and/or to achieve a better rate distortion ratio is achieved by using multitree sub-divisioning not only in order to subdivide a continuous area, namely the sample array, into leaf regions, but using the intermediate regions also to share coding parameters among the corresponding collocated leaf blocks. By this measure, coding procedures performed in tiles—leaf regions—locally, may be associated with coding parameters individually without having to, however, explicitly transmit the whole coding parameters for each leaf region separately. Rather, similarities may effectively exploited by using the multitree subdivision.

First claim

What is claimed is:

1 . A decoder for reconstructing an array of information samples representing a spatially sampled information signal, which is subdivided, according to subdivision information, into leaf regions of different sizes by multi-tree subdivision, from a data stream, wherein each leaf region has associated therewith a hierarchy level out of a sequence of hierarchy levels of the multi-tree subdivision, each leaf region has associated therewith coding parameters, the coding parameters are, for each leaf region, represented by a respective set of syntax elements, each syntax element is of a respective syntax element type out of a set of syntax element types, and the decoder comprising:
an extractor for extracting the subdivision information and inheritance information, signaled within the data stream in addition to the sub-division information, from the data stream, the inheritance information indicating as to whether inheritance is used or not, and if inheritance is indicated to be used, at least one inheritance region of the array of information samples which is composed of a set of the leaf regions and corresponds to an hierarchy level of sequence of hierarchy levels of the multi-tree subdivision, being lower than each of the hierarchy levels with which the set of leaf regions are associated; wherein the decoder is configured to, if inheritance is indicated to be used, extracting an inheritance subset including at least one syntax element of a predetermined syntax element type from the data stream per inheritance region, and using the inheritance subset as a prediction for a corresponding inheritance subset of syntax elements within the set of syntax elements representing the coding parameters associated with the set of leaf regions which the respective at least one inheritance region is composed of.

2 . The decoder according to claim 1 , wherein the extractor is configured to:
extract, for each, but the leaf regions, of the regions defined by the multi-tree subdivision, and using an hierarchy level order from lower hierarchy level to higher hierarchy level, an inheritance flag from the data stream associated with said region; wherein the decoder is configured to check, for each, but the leaf regions, of the regions defined by the multi-tree subdivision, whether the inheritance flag prescribes inheritance or not for the respective region, wherein the extractor and the decoder are further configured not to perform the extraction and check for regions which are child nodes of said each of the regions for which said inheritance flag prescribes inheritance; wherein the extractor and the decoder are further configured to, for each region for which the associated inheritance flag prescribes inheritance, extract an inheritance subset including at least one syntax element of a predetermined syntax element type from the data stream, and use the inheritance subset as a prediction for a corresponding inheritance subset of syntax elements within the set of syntax elements representing the coding parameters associated with the leaf regions which the region for which the associated inheritance flag prescribes inheritance, is composed of.

3 . The decoder according to claim 1 , wherein the decoder is a hybrid decoder.

4 . The decoder according to claim 1 , wherein the decoder is configured to decode a residual for each leaf block.

5 . The decoder according to claim 1 , wherein the decoder is configured to extract at least one syntax element of the predetermined syntax element type within the set of syntax elements representing the coding parameters associated with leaf regions which do not belong to any set of leaf regions which any inheritance region indicated by the inheritance information indicates, is composed of, from the data stream.

6 . The decoder according to claim 1 , wherein the decoder is configured to, if inheritance is indicated not to be used, extract at least one syntax element of the predetermined syntax element type within the set of syntax elements representing the coding parameters associated with all leaf regions of the array of information samples.

7 . The decoder according to claim 1 , wherein the decoder is configured to reconstruct the array information samples by way of prediction using a prediction mode depending on the at least one syntax element of the predetermined syntax element type associated with the leaf regions.

8 . The decoder according to claim 1 , wherein the at least one syntax element of the predetermined syntax element type is an intra-prediction mode syntax element, and the decoder is configured to, per inheritance region,
decode, in an residual decoding order, a residual signal for each of the leaf regions which the respective inheritance region is composed of, and calculate, in the residual decoding order, a separate intra prediction signal for each of the leaf regions which the respective inheritance region is composed of, according to an intra-prediction mode indicated by the intra-prediction mode syntax element, by using neighboring samples of a reconstructed signal of already reconstructed leaf regions as a reference signal, with reconstructing the respective leaf region by adding the intra prediction signal and the residual signal.

9 . The decoder according to claim 8 , the decoder is configured such that the residual decoding order is a depth-first traversal order.

10 . A method for reconstructing an array of information samples representing a spatially sampled information signal, which is subdivided, according to subdivision information, into leaf regions of different sizes by multi-tree subdivision, from a data stream, wherein each leaf region has associated therewith a hierarchy level out of a sequence of hierarchy levels of the multi-tree subdivision, each leaf region has associated therewith coding parameters, the coding parameters are, for each leaf region, represented by a respective set of syntax elements, each syntax element is of a respective syntax element type out of a set of syntax element types, and the method comprising:
extracting the subdivision information from the data stream; extracting an inheritance information, signaled within the data stream in addition to the subdivision information, from the data stream, the inheritance information indicating as to whether inheritance is used or not, and if inheritance is indicated to be used, at least one inheritance region of the array of information samples which is composed of a set of the leaf regions and corresponds to an hierarchy level of sequence of hierarchy levels of the multi-tree subdivision, being lower than each of the hierarchy levels with which the set of leaf regions are associated; if inheritance is indicated to be used, extracting an inheritance subset including at least one syntax element of a predetermined syntax element type from the data stream per inheritance region, and using the inheritance subset as a prediction for a corresponding inheritance subset of syntax elements within the set of syntax elements representing the coding parameters associated with the set of leaf regions which the respective at least one inheritance region is composed of.

11 . An encoder for encoding an array of information samples representing a spatially sampled information signal, which is subdivided, according to subdivision information, into leaf regions of different sizes by multi-tree subdivision, into a data stream, wherein each leaf region has associated therewith a hierarchy level out of a sequence of hierarchy levels of the multi-tree subdivision, each leaf region has associated therewith coding parameters, the coding parameters are, for each leaf region,

Assignees

• Ge Video Compression Llc

Inventors

• Helle Philipp
• Marpe Detlev
• Oudin Simon
• Wiegand Thomas

Classifications

• H04N19/593

  involving spatial prediction techniques · CPC title

• H04N19/96 Primary

  Tree coding, e.g. quad-tree coding · CPC title

• H04N19/52 Primary

  by predictive encoding · CPC title

• H04N19/124

  Quantisation · CPC title

• H04N19/463

  by compressing encoding parameters before transmission · CPC title