Image decoding apparatus, image decoding method, image coding apparatus, and image coding method

Patent metadata

Field	Value
Publication number	US-9307260-B2
Application number	US-201113498685-A
Country	US
Kind code	B2
Filing date	Jul 27, 2011
Priority date	Jul 30, 2010
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

An image decoding apparatus ( 100 ) capable of appropriately executing parallel decoding processing by a simple structure includes: a stream segmentation control unit ( 140 ) that designates a processing target area, and selects a portion of a segment stream based on a position of the processing target area; M stream segmentation units ( 130 ) that generate M×N segment streams by executing stream segmentation processing on designated M processing target areas in parallel; and N decoding engines ( 120 ) that decode respective portions of the N segment streams including the selected portion in parallel. In the case where a slice included in the processing target area is segmented into a plurality of slice portions and assigned to a plurality of segment streams, each stream segmentation unit ( 130 ) reconstructs, for each segment stream, a slice portion group made up of one or more slice portions assigned to the segment stream, as a new slice.

First claim

The invention claimed is:

1. An image decoding apparatus that decodes a bit stream generated by coding image data, said image decoding apparatus comprising:
a processor;
a non-transitory computer-readable medium having stored thereon executable instructions, which when executed by the processor, cause the image decoding apparatus to:
designate processing target areas included in the bit stream;
generate M×N segment streams by executing stream segmentation processing in parallel on M processing target areas of the designated processing target areas;
execute the stream segmentation processing on one of the M processing target areas each time M processing target areas are designated, the stream segmentation processing being a process of generating at least a portion of N segment streams from one of the M processing target areas, M being an integer equal to or greater than 2, and N being an integer equal to or greater than 2;
for each processing target area of the designated processing target areas, select a portion of each of at least one segment stream from the generated M×N segment streams, based on a position of the respective processing target area in the bit stream;
each time the portion of each of the at least one segment stream is selected, decode respective portions of the N segment streams in parallel, the portions of the N segment streams including the portion of each of the at least one segment stream;
execute the stream segmentation processing, by segmenting one of the processing target areas into a plurality of structural units and assigning each of the plurality of structural units to a portion of a corresponding one of the generated N segment streams; and
for a slice included in the one of the processing target areas, the slice being segmented into a plurality of slice portions and the plurality of slice portions being assigned to a plurality of segment streams as a result of segmenting the one of the processing target areas into the plurality of structural units, reconstruct, for each of the plurality of segment streams, a slice portion group made up of one or more slice portions assigned to the segment stream, as a new slice.

2. The image decoding apparatus according to claim 1 ,
wherein the executable instructions, when executed by the processor, further cause the image decoding apparatus to analyze each piece of first header information included in the bit stream and generate the N segment streams based on a result of the analysis, irrespective of the designated processing target areas.

3. The image decoding apparatus according to claim 1 ,
wherein the executable instructions, when executed by the processor, further cause the image decoding apparatus to generate N segment streams that include second header information included in the bit stream, and
generate N segment streams that do not include the second header information.

4. The image decoding apparatus according to claim 1 ,
wherein the executable instructions, when executed by the processor, further cause the image decoding apparatus to generate selection information indicating the selected portion of the segment stream, and output the generated selection information, and
decode the portions of the N segment streams indicated by the outputted selection information, in parallel.

5. The image decoding apparatus according to claim 4 ,
wherein the executable instructions, when executed by the processor, further cause the image decoding apparatus to output the selection information including a data size of the selected portion of the segment stream, and
to specify the portions of the N segment streams based on the data size included in the outputted selection information, and decode the specified portions in parallel.

6. The image decoding apparatus according to claim 5 ,
wherein the executable instructions, when executed by the processor, further cause the image decoding apparatus to output the selection information including, as a data size, a number of bits or a number of data structural units constituting each of the N segment streams.

7. The image decoding apparatus according to claim 1 ,
wherein the executable instructions, when executed by the processor, further cause the image decoding apparatus to:
judge whether or not the stream segmentation processing executed on the designated M processing target area is completed; and
in the case of judging that the stream segmentation processing is completed, preferentially designate a new processing target area.

8. The image decoding apparatus according to claim 1 ,
wherein in the case where a first slice portion is decoded and included in an assigned segment stream from among the N segment streams and a second slice portion is decoded and included in an another assigned segment stream from among the N segment streams, the first slice portion and the second slice portion being spatially adjacent to each other:
the executable instructions, when executed by the processor, further cause the image decoding apparatus to start decoding the first slice portion before decoding the second slice portion; and
to obtain adjacency information generated as a result of the decoding of the first slice portion, and decode the second slice portion using the adjacency information or decode the second slice portion without using the adjacency information.

9. The image decoding apparatus according to claim 1 ,
wherein the executable instructions, when executed by the processor, further cause the image decoding apparatus to designate, as a processing target area of the processing target areas, a slice, a picture, or a picture group made up of a plurality of pictures in the bit stream.

10. An image decoding method for decoding a bit stream generated by coding image data, said image decoding method comprising:
designating processing target areas included in the bit stream;
generating M×N segment streams by executing stream segmentation processing in parallel on M processing target areas designated in said designating, the stream segmentation processing being a process of generating at least a portion of N segment streams from one of the M processing target areas each time M processing target areas are designated in said designating, M being an integer equal to or greater than 2, and N being an integer equal to or greater than 2;
selecting, for each processing target area of the processing target areas designated in said designating, a portion of each of at least one segment stream from the M×N segment streams generated in said generating, based on a position of the respective processing target area in the bit stream; and
decoding, each time the portion of each of the at least one segment stream is selected in said selecting, respective portions of the N segment streams in parallel, the portions of the N segment streams including the portion of each of the at least one segment stream,
wherein said generating includes:
executing the stream segmentation processing, by segmenting one of the processing target areas into a plurality of structural units and assigning each of the plurality of structural units to a portion of a corresponding one of the generated N segment streams; and
for a slice included in the one of the processing target areas, the slice being segmented into a plurality of slice portions and the plurality of slice portions being assigned to a plurality of segment streams as a result of segmenting the one of the processing target areas into the plurality of structural units, reconstructing, for each of the plurality of segment streams, a slice portion group made up of one or more slice portions assigned to the segment stream, as a new slice.

11. An image codi

Assignees

• Yoshimatsu Naoki
• Tanaka Takeshi
• Kurokawa Keiichi
• Panasonic Ip Man Co Ltd

Inventors

• Yoshimatsu Naoki
• Tanaka Takeshi
• Kurokawa Keiichi

Classifications

• H04N19/174

  the region being a slice, e.g. a line of blocks or a group of blocks · CPC title

• H04N19/167

  Position within a video image, e.g. region of interest [ROI] · CPC title

• H04N19/70

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title

• H04N19/61

  in combination with predictive coding · CPC title

• H04N19/44

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title