INHERITANCE IN SAMPLE ARRAY MULTITREE SUBDIVISION

• US 20130034157A1
• Filed: 10/11/2012
• Published: 02/07/2013
• Est. Priority Date: 04/13/2010
• Status: Active Grant

• Current Assignee: GE Video Compression, LLC (General Electric Company)
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Wiegand, Thomas, Marpe, Detlev, OUDIN, Simon, HELLE, Philip
• Granted Patent: US 10,038,920 B2
• Time in Patent Office: Days
• US Class Current: 375/240.12
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/129 Scanning of coding units, e.g. zig-zag scan of transform coefficients or flexible macroblock ordering [FMO]
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/159 Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/439 using cascaded computational arrangements for performing a single operation, e.g. filtering
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/463 by compressing encoding parameters before transmission
• CPC Class Codes: H04N 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/52 by predictive encoding
• CPC Class Codes: H04N 19/53 Multi-resolution motion estimation; Hierarchical motion estimation
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/96 Tree coding, e.g. quad-tree coding

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.

Claims

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 comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region, and

copying the inheritance subset into, or 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 comprising at least one syntax element of a predetermined syntax element type from the data stream, and

copy the inheritance subset into, or 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 extractor/checker 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 extractor/checker 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 extractor/checker 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 comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region, and

copying the inheritance subset into, or 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, 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 encoder comprising

a data stream inserter for inserting the subdivision information and inheritance information into the data stream so that the inheritance information is signaled within the data stream in addition to the subdivision information, 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 encoder is configured to, if inheritance is indicated to be used,

insert an inheritance subset comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region into the data stream, and

suppress coding 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, or using the inheritance subset inserted as a prediction in residual encoding the 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, into the data stream.

12. A method 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, 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 comprises

inserting the subdivision information into the data stream;

inserting, into the data stream, an inheritance information so that the inheritance information is signaled within the data stream in addition to the subdivision information, 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,

inserting an inheritance subset comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region into the data stream, and

suppressing coding 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, or using the inheritance subset inserted as a prediction in residual encoding the 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, into the data stream.

13. A computer readable digital storage medium having stored thereon a computer program comprising a program code for performing, when running on a computer, 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 said 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 comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region, and

copying the inheritance subset into, or 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.

14. A computer readable digital storage medium having stored thereon a computer program comprising a program code for performing, when running on a computer, a method 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, 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 said method comprises

inserting the subdivision information into the data stream;

inserting, into the data stream, an inheritance information so that the inheritance information is signaled within the data stream in addition to the subdivision information, 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,

inserting an inheritance subset comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region into the data stream, and

suppressing coding 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, or using the inheritance subset inserted as a prediction in residual encoding the 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, into the data stream.

15. A data stream having encoded therein 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, 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, wherein the data stream comprises

the sub-division information;

an inheritance information signaled within the data stream in addition to the subdivision information, the inheritance information and 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,

an inheritance subset comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region into the data stream, so that the inheritance subset

is to be copied into 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, or is to be used as a prediction for 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, with the data stream further comprising residuals of the 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, relative to the inheritance subset inserted as a prediction.

16. A decoder for reconstructing an array of information samples representing a spatially sampled information signal, which is subdivided into a multi-tree structure of leaf regions of different sizes by multi-tree subdivision, from a data stream, wherein the multi-tree structure is divided into a primary and a sub-ordinate sub-division defined in a sub-ordinate manner to each other, so that a tree-root block of the primary sub-division is sub-divided leaf blocks of the primary sub-division which, in turn, form the tree-root blocks of the sub-ordinate sub-division, further sub-divided into leaf regions of the multi-tree structure, each leaf region of the multi-tree structure has associated therewith a hierarchy level out of a sequence of hierarchy levels of the multi-tree subdivision, each leaf region of the multi-tree structure 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 comprises

an extractor for extracting the multitree structure from the data stream, so as to acquire an inheritance 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 of the multi-tree structure, 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 of the multi-tree structure are associated, and is formed by leaf regions of the primary sub-division;

wherein the extractor is further configured to extract an inheritance subset comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region, wherein the at least one syntax element of the predetermined syntax element type is an intra-prediction mode syntax element,

wherein the decoder is configured to

decode, in an residual decoding order, a residual signal for each of the leaf regions of the multi-tree structure which the respective inheritance region is composed of,

copy the inheritance subset into a corresponding inheritance subset of syntax elements within the set of syntax elements representing the coding parameters associated with the set of leaf regions of the multi-tree structure which the respective at least one inheritance region is composed of, and

calculate, in the residual decoding order, a separate intra prediction signal for each of the leaf regions of the multi-tree structure 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 of the multi-tree structure as a reference signal, with reconstructing the respective leaf region of the multi-tree structure by adding the intra prediction signal and the residual signal.

17. A method for reconstructing an array of information samples representing a spatially sampled information signal, which is subdivided into a multi-tree structure of leaf regions of different sizes by multi-tree subdivision, from a data stream, wherein the multi-tree structure is divided into a primary and a sub-ordinate sub-division defined in a sub-ordinate manner to each other, so that a tree-root block of the primary sub-division is sub-divided leaf blocks of the primary sub-division which, in turn, form the tree-root blocks of the sub-ordinate sub-division, further sub-divided into leaf regions of the multi-tree structure, each leaf region of the multi-tree structure has associated therewith a hierarchy level out of a sequence of hierarchy levels of the multi-tree subdivision, each leaf region of the multi-tree structure 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 comprises

extracting the multitree structure from the data stream, so as to acquire an inheritance 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 of the multi-tree structure, 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 of the multi-tree structure are associated, and is formed by leaf regions of the primary sub-division;

extracting an inheritance subset comprising at least one syntax element of a predetermined syntax element type from the data stream per inheritance region, wherein the at least one syntax element of the predetermined syntax element type is an intra-prediction mode syntax element,

decoding, in an residual decoding order, a residual signal for each of the leaf regions of the multi-tree structure which the respective inheritance region is composed of,

copying the inheritance subset into a corresponding inheritance subset of syntax elements within the set of syntax elements representing the coding parameters associated with the set of leaf regions of the multi-tree structure which the respective at least one inheritance region is composed of, and

calculating, in the residual decoding order, a separate intra prediction signal for each of the leaf regions of the multi-tree structure 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 of the multi-tree structure as a reference signal, with reconstructing the respective leaf region of the multi-tree structure by adding the intra prediction signal and the residual signal.