IMAGE PROCESSING DEVICE AND IMAGE PROCESSING METHOD

• US 20130251029A1
• Filed: 12/25/2011
• Published: 09/26/2013
• Est. Priority Date: 01/18/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ikeda, Masaru
• Granted Patent: US 10,080,015 B2
• Time in Patent Office: Days
• US Class Current: 375/240.02
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/14 Coding unit complexity, e.g. amount of activity or edge presence estimation H04N19/146 takes precedence
• CPC Class Codes: H04N 19/169 characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/80 Details of filtering operations specially adapted for video compression, e.g. for pixel interpolation H04N19/635, H04N19/86 take precedence
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness

Abstract

Provided is an image processing device including a decoding section that decodes an encoded stream to generate an image, a line determining section that determines whether to apply a deblocking filter to each of lines perpendicular to a boundary in neighboring blocks neighboring across the boundary in the image generated by the decoding section, and a filtering section that applies the deblocking filter to each line to which the line determining section determines to apply the deblocking filter.

Claims

1. An image processing device comprising:

a decoding section that decodes an encoded stream to generate an image;

a line determining section that determines whether to apply a deblocking filter to each of lines perpendicular to a boundary in neighboring blocks neighboring across the boundary in the image generated by the decoding section; and

a filtering section that applies the deblocking filter to each line to which the line determining section determines to apply the deblocking filter.

2. The image processing device according to claim 1, wherein

the line determining section determines whether to apply the deblocking filter to each line by using a per-line determination condition.

3. The image processing device according to claim 2, wherein

the line determining section determines whether to apply the deblocking filter to each line by using a reference pixel value belonging to the line.

4. The image processing device according to claim 3, wherein

the per-line determination condition is based on a comparison of a value computed from a reference pixel value belonging to each line against a determination threshold value.

5. The image processing device according to claim 2, wherein

the line determining section respectively determines whether to apply the deblocking filter to each of one or more basis lines and other lines by using reference pixel values belonging to the one or more basis lines, the one or more basis lines being one or more lines that are not updated by a deblocking filter applied in an identical direction as the boundary.

6. The image processing device according to claim 1, further comprising:

a control section that controls the line determining section so as to determine in parallel whether to apply the deblocking filter with respect to a plurality of lines perpendicular to the boundary.

7. The image processing device according to claim 5, wherein

the one or more basis lines are a plurality of lines perpendicular to the boundary,

the image processing device further comprising:

a control section that controls the line determining section so as to determine in parallel whether to apply the deblocking filter to the basis lines and other lines.

8. The image processing device according to claim 1, further comprising:

a block determining section that determines whether to apply the deblocking filter to the neighboring blocks by using a per-block determination condition;

wherein, in the case where the block determining section determines to apply the deblocking filter to the neighboring blocks, the line determining section additionally determines whether to apply the deblocking filter to each line in the neighboring blocks.

9. The image processing device according to claim 1, wherein

the line determining section determines whether to apply the deblocking filter to each line by comparing a value of a per-line determination parameter against a determination threshold value,

the image processing device further comprising:

an estimating section that estimates, from a value of the determination parameter calculated for one or more basis lines set in the neighboring blocks, the value of the determination parameter for an estimated line other than the one or more basis lines.

10. The image processing device according to claim 9, wherein

the estimating section estimates the value of the determination parameter for the estimated line by interpolation or extrapolation using the values of the determination parameters calculated for the basis lines according to line positions.

11. The image processing device according to claim 10, wherein

the estimating section uses, as the basis lines, lines not updated by a deblocking filter applied in an identical direction as the boundary.

12. The image processing device according to claim 10, wherein

the estimating section uses lines set every other line in the neighboring blocks as the basis lines.

13. The image processing device according to claim 10, wherein

the estimating section uses outermost lines in the neighboring blocks as the basis lines, and estimates the value of the determination parameter for the estimated line by interpolation using the values of the determination parameters calculated for the basis lines according to line positions.

14. The image processing device according to claim 9, further comprising:

a selecting section that selects a filter strength of the deblocking filter that the filtering section applies to respective lines by comparing a per-line strength selection parameter against a threshold value,

wherein the estimating section estimates a value of the strength selection parameter for the estimated line from the value of the strength selection parameter calculated for the one or more basis lines.

15. The image processing device according to claim 14, wherein

the estimating section estimates the value of the strength selection parameter for the estimated line by interpolation or extrapolation using the values of the strength selection parameters calculated for the basis lines according to line positions.

16. The image processing device according to claim 15, wherein

the estimating section uses lines set every other line in the neighboring blocks as the basis lines.

17. The processing device according to claim 15, wherein

the estimating section uses outermost lines in the neighboring blocks as the basis lines, and estimates the value of the strength selection parameter for the estimated line by interpolation using the values of the strength selection parameters calculated for the basis lines according to line positions.

18. An image processing method comprising:

decoding an encoded stream to generate an image;

determining whether to apply a deblocking filter to each of lines perpendicular to a boundary in neighboring blocks neighboring across the boundary in the generated image; and

applying the deblocking filter to each line to which the application of the deblocking filter is determined.

19. An image processing device comprising:

a line determining section that determines whether to apply a deblocking filter to each of lines perpendicular to a boundary in neighboring blocks neighboring across the boundary in a locally decoded image at a time of encoding an image to be encoded;

a filtering section that applies the deblocking filter to each line to which the line determining section determines to apply the deblocking filter; and

an encoding section that encodes the image to be encoded by using the image filtered by the filtering section.

20. An image processing method comprising:

determining whether to apply a deblocking filter to each of lines perpendicular to a boundary in neighboring blocks neighboring across the boundary in a locally decoded image at a time of encoding an image to be encoded;

applying the deblocking filter to each line to which the application of the deblocking filter is determined; and

encoding the image to be encoded by using the filtered image.