System and method to process motion vectors of video data

• US 8,320,455 B2
• Filed: 03/05/2009
• Issued: 11/27/2012
• Est. Priority Date: 03/05/2009
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Dane, Gokce, Motta, Giovanni
• Primary Examiner(s): Ustaris, Joseph
• Assistant Examiner(s): BAILEY, FREDERICK D
• Application Number:
  US12/398,379
• Publication Number:
  US 20100226436A1
• Time in Patent Office: 1,363 Days
• Field of Search: None
• US Class Current: 375/240.16
• CPC Class Codes: H04N 19/109 among a plurality of temporal predictive coding modes
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/139 Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability
• CPC Class Codes: H04N 19/154 Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion use of rate-distortion criteria H04N19/147
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• 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 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/577 Motion compensation with bidirectional frame interpolation, i.e. using B-pictures
• CPC Class Codes: H04N 19/587 involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness

Abstract

Systems and methods to process motion vectors of video data are disclosed. According to an embodiment, an intra-block in a video frame of the video data is identified. At least a first set and a second set of inter-blocks that neighbor the identified intra-block are identified, where each inter-block in a set of inter-blocks has a motion vector associated therewith. Data of the first and second set of inter-blocks is evaluated to determine an error associated with each of the first and second sets. A motion vector associated with motion vectors of the inter-blocks of the set with the least error is determined. The determined motion vector may be associated with the identified intra-block.

Claims

1. A method of processing received video data in a video receiver, the method comprising:

identifying an intra-block in a video frame of the video data;

identifying a first set of inter-blocks neighboring the intra-block and identifying a second set of inter-blocks neighboring the intra-block, each of the inter-blocks in the first and second sets having a motion vector associated therewith;

evaluating data of the first set of inter-blocks and of the second set of inter-blocks to determine which of the first and second set of inter-blocks has a least error associated therewith;

determining a motion vector associated with the motion vectors of the set of inter-blocks determined to have the least error, the determined motion vector to be associated with the intra-block;

comparing a first difference between motion vectors of two blocks that are adjacent to a center block to a first threshold;

in response to the first difference being less than the first threshold, determining whether a second difference between a motion vector of the center block and an average motion vector of motion vectors of the two blocks exceeds a second threshold; and

in response to the second difference exceeding the second threshold, assigning a motion vector to the center block that is an average of the motion vectors of the two blocks.

2. The method of claim 1, wherein at least one of the sets of inter-blocks comprises a corner pattern of inter-blocks neighboring the intra-block.

3. The method of claim 1, wherein at least one of the sets of inter-blocks comprises a side pattern of inter-blocks neighboring the intra-block.

4. The method of claim 1, wherein each inter-block in the first and second sets of inter-blocks represents four by four groups of pixels.

5. The method of claim 1, further comprising:

determining whether content of the video frame of the video data is static; and

disabling frame rate up-conversion in response to determining that the content of the frame is static.

6. The method of claim 1, further comprising:

determining whether the video frame exhibits a panning motion; and

performing a panning-adaptive prediction of a block in a subsequent video frame in response to a determination that the panning motion is exhibited.

7. The method of claim 6, wherein panning motion is identified based on statistics of motion vectors associated with the video frame.

8. The method of claim 6, wherein an amount of panning is determined based on a median value of motion vectors associated with the video frame.

9. The method of claim 6, further comprising computing a difference between a panning vector and a motion vector for each of a plurality of blocks in the video frame to determine a number of blocks exhibiting the panning motion.

10. The method of claim 6, further comprising, in response to determining that the video frame exhibits the panning motion, deriving motion vectors for the video frame by using panning motion.

11. The method of claim 1, further comprising selecting between use of motion vectors provided in a received video bit stream to predict motion and use of motion compensated prediction at the video receiver to determine motion vectors, based upon a comparison of a measured parameter of the video bit stream to a threshold.

12. The method of claim 1, further comprising determining a boundary strength for each block in a row.

13. The method of claim 1, further comprising:

determining a number of motion vectors of blocks in a first row of blocks that exceeds a first threshold;

determining whether the number of motion vectors that exceeds the first threshold exceeds a second threshold; and

in response to the number of motion vectors that exceeds the first threshold exceeding the second threshold, determining a boundary strength for each block in the first row.

14. A method of processing received video data in a video receiver, the method comprising:

identifying an intra-block in a video frame of the video data;

identifying a first set of inter-blocks neighboring the intra-block and identifying a second set of inter-blocks neighboring the intra-block, each of the inter-blocks in the first and second sets having a motion vector associated therewith;

evaluating data of the first set of inter-blocks and of the second set of inter-blocks to determine which of the first and second set of inter-blocks has a least error associated therewith;

determining a motion vector associated with the motion vectors of the set of inter-blocks determined to have the least error, the determined motion vector to be associated with the intra-block;

calculating a weighted difference between a processed motion vector of a first block of the video frame and a motion vector of a corresponding block of a previous frame of the video data;

comparing the weighted difference to a threshold; and

in response to the weighted difference exceeding the threshold, replacing the processed motion vector with a replacement motion vector that is a median value of motion vectors of neighboring blocks in a three block by three block array that includes the first block corresponding to the processed motion vector.

15. The method of claim 14, wherein at least one of the sets of inter-blocks comprises a corner pattern of inter-blocks neighboring the intra-block.

16. The method of claim 14, wherein at least one of the sets of inter-blocks comprises a side pattern of inter-blocks neighboring the intra-block.

17. The method of claim 14, wherein each inter-block in the first and second sets of inter-blocks represents four by four groups of pixels.

18. The method of claim 14, further comprising:

determining whether content of the video frame of the video data is static; and

disabling frame rate up-conversion in response to determining that the content of the frame is static.

19. The method of claim 14, further comprising:

determining whether the video frame exhibits a panning motion; and

performing a panning-adaptive prediction of a block in a subsequent video frame in response to a determination that the panning motion is exhibited.

20. The method of claim 19, wherein panning motion is identified based on statistics of motion vectors associated with the video frame.

21. The method of claim 19, wherein an amount of panning is determined based on a median value of motion vectors associated with the video frame.

22. The method of claim 19, further comprising computing a difference between a panning vector and a motion vector for each of a plurality of blocks in the video frame to determine a number of blocks exhibiting the panning motion.

23. The method of claim 19, further comprising, in response to determining that the video frame exhibits the panning motion, deriving motion vectors for the video frame by using panning motion.

24. The method of claim 14, further comprising selecting between use of motion vectors provided in a received video bit stream to predict motion and use of motion compensated prediction at the video receiver to determine motion vectors, based upon a comparison of a measured parameter of the video bit stream to a threshold.

25. The method of claim 14, further comprising determining a boundary strength for each block in a row.

26. The method of claim 14, further comprising:

determining a number of motion vectors of blocks in a first row of blocks that exceeds a first threshold;

determining whether the number of motion vectors that exceeds the first threshold exceeds a second threshold; and

in response to the number of motion vectors that exceeds the first threshold exceeding the second threshold, determining a boundary strength for each block in the first row.

27. A method of processing received video data in a video receiver, the method comprising:

identifying an intra-block in a video frame of the video data;

identifying a first set of inter-blocks neighboring the intra-block and identifying a second set of inter-blocks neighboring the intra-block, each of the inter-blocks in the first and second sets having a motion vector associated therewith;

evaluating data of the first set of inter-blocks and of the second set of inter-blocks to determine which of the first and second set of inter-blocks has a least error associated therewith;

determining a motion vector associated with the motion vectors of the set of inter-blocks determined to have the least error, the determined motion vector to be associated with the intra-block;

detecting a block adjacent to a boundary of the video frame;

determining an average value of absolute values of differences between a motion vector of the block adjacent to the boundary and motion vectors of blocks that neighbor the block adjacent to the boundary;

comparing the average value to a threshold; and

setting the motion vector of the block adjacent to the boundary equal to a motion vector of a block that neighbors the block adjacent to the boundary in response to the average value exceeding the threshold.

28. The method of claim 27, wherein at least one of the sets of inter-blocks comprises a corner pattern of inter-blocks neighboring the intra-block.

29. The method of claim 27, wherein at least one of the sets of inter-blocks comprises a side pattern of inter-blocks neighboring the intra-block.

30. The method of claim 27, wherein each inter-block in the first and second sets of inter-blocks represents four by four groups of pixels.

31. The method of claim 27, further comprising:

determining whether content of the video frame of the video data is static; and

disabling frame rate up-conversion in response to determining that the content of the frame is static.

32. The method of claim 27, further comprising:

determining whether the video frame exhibits a panning motion; and

performing a panning-adaptive prediction of a block in a subsequent video frame in response to a determination that the panning motion is exhibited.

33. The method of claim 32, wherein panning motion is identified based on statistics of motion vectors associated with the video frame.

34. The method of claim 32, wherein an amount of panning is determined based on a median value of motion vectors associated with the video frame.

35. The method of claim 32, further comprising computing a difference between a panning vector and a motion vector for each of a plurality of blocks in the video frame to determine a number of blocks exhibiting the panning motion.

36. The method of claim 32, further comprising, in response to determining that the video frame exhibits the panning motion, deriving motion vectors for the video frame by using panning motion.

37. The method of claim 27, further comprising selecting between use of motion vectors provided in a received video bit stream to predict motion and use of motion compensated prediction at the video receiver to determine motion vectors, based upon a comparison of a measured parameter of the video bit stream to a threshold.

38. The method of claim 27, further comprising determining a boundary strength for each block in a row.

39. The method of claim 27, further comprising:

determining a number of motion vectors of blocks in a first row of blocks that exceeds a first threshold;

determining whether the number of motion vectors that exceeds the first threshold exceeds a second threshold; and

in response to the number of motion vectors that exceeds the first threshold exceeding the second threshold, determining a boundary strength for each block in the first row.