Video encoding and decoding methods and video encoder and decoder

• US 20060013309A1
• Filed: 07/15/2005
• Published: 01/19/2006
• Est. Priority Date: 07/15/2004
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ha, Ho-jin, Han, Woo-jin
• Application Number:
  US11/181,803
• Publication Number:
  US 20060013309A1
• Time in Patent Office: Days
• US Class Current: 375/240.160
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567
• CPC Class Codes: H04N 19/187 the unit being a scalable video layer
• CPC Class Codes: H04N 19/517 by encoding
• CPC Class Codes: H04N 19/567 Motion estimation based on rate distortion criteria

Abstract

Video coding and decoding methods capable of providing motion scalability and video encoder and decoder are provided. The video coding method includes estimating a base layer motion vector and an enhancement layer motion vector for each block in a video frame, removing temporal redundancies in the video frame using the enhancement layer motion vectors, spatially transforming the video frame in which the temporal redundancies have been removed and quantizing the spatially transformed video frame to obtain texture information, selecting one of the estimated base layer motion vector and the estimated enhancement layer motion vector for each block, and generating a bitstream containing the motion vector selected for each block and the texture information.

Claims

1. A video coding method comprising:

estimating a base layer motion vector and an enhancement layer motion vector for each block in a video frame;

removing temporal redundancies in the video frame using the enhancement layer motion vectors;

spatially transforming the video frame in which the temporal redundancies have been removed and quantizing the video frame which has been spatially transformed to obtain texture information;

selecting one of the base layer motion vector and the enhancement layer motion vector for each block; and

generating a bitstream containing the base layer motion vector or the enhancement layer motion vector which is selected for each block and the texture information.

2. The method of claim 1, wherein the base layer motion vector is estimated using hierarchical variable size block matching.

3. The method of claim 1, wherein the enhancement layer motion vector is estimated by readjusting the base layer motion vector.

4. The method of claim 1, wherein the base layer motion vector and the enhancement layer motion vector each have one of a plurality of block modes.

5. The method of claim 1, wherein the selecting of the one of the base layer motion vector and the enhancement layer motion vector comprises:

calculating a difference between residual blocks obtained using a base layer motion vector and an enhancement layer motion vector;

determining a significance order of blocks according to the difference; and

selecting enhancement layer motion vectors for a predetermined percentage of the blocks in the order from a block with a largest significance to a block with a smallest significance and base layer motion vectors for a remaining percentage of the blocks.

6. A video coding method comprising:

estimating a base layer motion vector and an enhancement layer motion vector for each block in a video frame;

removing temporal redundancies in the video frame using the enhancement layer motion vectors;

spatially transforming the video frame in which the temporal redundancies have been removed and quantizing the video frame which has been spatially transformed to obtain texture information; and

generating a bitstream containing the base layer motion vector, a residual motion vector which is a difference between the base layer motion vector and the enhancement layer motion vector, and the texture information, for each block.

7. The method of claim 6, wherein the base layer motion vector is estimated using hierarchical variable size block matching.

8. The method of claim 6, wherein the enhancement layer motion vector is estimated by readjusting the base layer motion vector.

9. The method of claim 6, wherein the base layer motion vector and the enhancement layer motion vector respectively each have one of a plurality of block modes.

10. The method of claim 6, further comprising calculating a difference between encoding of each block using the enhancement layer motion vector and the base layer motion vector, and determining an order of significance of blocks according to the degree of difference,

wherein the order of significance of blocks is contained in the bitstream.

11. The method of claim 10, wherein the difference is obtained by calculating a difference between a residual block obtained using the enhancement layer motion vector for the block and a residual block obtained using the base layer motion vector for the block.

12. A video encoder comprising:

a motion estimator which estimates a base layer motion vector and an enhancement layer motion vector for each block in a video frame;

a motion compensator which removes temporal redundancies in the video frame using the enhancement layer motion vectors;

a spatial transformer which spatially transforms the video frame in which the temporal redundancies have been removed;

a quantizer which quantizes the video frame which has been spatially transformed to obtain texture information;

a motion vector selector which selects one of the base layer motion vector and the enhancement layer motion vector for each block; and

a bitstream generator generating a bitstream containing the base layer motion vector or the enhancement layer motion vector selected for each block and the texture information.

13. The video encoder of claim 12, wherein the motion estimator estimates the base layer motion vector using hierarchical variable size block matching.

14. The video encoder of claim 12, wherein the motion estimator estimates the enhancement layer motion vector by readjusting the base layer motion vector.

15. The video encoder of claim 12, wherein the motion estimator estimates the base layer motion vector and the enhancement layer motion vector for the respective blocks in at least one of a plurality of block modes.

16. The video encoder of claim 12, wherein the motion estimator calculates a difference between residual blocks obtained using a base layer motion vector and an enhancement layer motion vector, and determines the significance order of blocks according to the difference, and the motion vector selector selects enhancement layer motion vectors.

17. A video encoder comprising:

a motion estimator which estimates a base layer motion vector and an enhancement layer motion vector for each block in a video frame;

a motion compensator which removes temporal redundancies in the video frame using the enhancement layer motion vectors;

a spatial transformer spatially which transforms the video frame in which the temporal redundancies have been removed;

a quantizer quantizing the video frame which has been spatially transformed to obtain texture information; and

a bitstream generator which generates a bitstream containing the base layer motion vector, a residual motion vector which is a difference between the base layer motion vector and the enhancement layer motion vector, and the texture information for each block.

18. The video encoder of claim 17, wherein the motion estimator estimates the base layer motion vector using hierarchical variable size block matching.

19. The video encoder of claim 17, wherein the motion estimator estimates the enhancement layer motion vector by readjusting the base layer motion vector.

20. The video encoder of claim 17, wherein the motion estimator estimates the base layer motion vector and the enhancement layer motion vector for the respective blocks in at least one of a plurality of block modes.

21. The video encoder of claim 17, wherein the motion estimator calculates a difference between residual blocks obtained using a base layer motion vector and an enhancement layer motion vector, determines the significance order of blocks according to the difference, and carries the significance order of blocks to the bitstream generator so that the bitstream generator inserts the significance order of blocks into the bitstream.

22. A predecoding method comprising:

receiving a bitstream containing a base layer motion vector, a residual motion vector which is a difference between the base layer motion vector and an enhancement layer motion vector for each block of a video frame, and texture information obtained by encoding the video frame, associated with each block in the video frame; and

truncating at least a part of the residual motion vectors.

23. The method of claim 22, wherein the bitstream further includes a significance order of the blocks, and

wherein in the truncating of the at least the part of the residual motion vectors, the residual motion vectors are truncated from a residual motion vector with least significance using the significance order of the blocks as a reference.

24. The method of claim 22, wherein if a rate of a requested bitstream is lower than a predetermined reference point, the at least the part of the residual motion vectors is truncated.

25. A video decoding method comprising:

interpreting an input bitstream and obtaining texture information and motion information containing base layer motion vectors and enhancement layer motion vectors;

readjusting the base layer motion vectors;

performing inverse quantization and inverse spatial transform on the texture information to obtain frames in which temporal redundancies are removed; and

performing inverse motion compensation on the frames in which the temporal redundancies have been removed using the base layer motion vectors which have been readjusted and the enhancement layer motion vectors.

26. The method of claim 25, wherein the base layer motion vectors are readjusted using enhancement layer motion vectors for neighboring blocks as a reference.

27. The method of claim 25, wherein the base layer motion vectors are readjusted using a predicted frame generated during the inverse motion compensation.

28. A video decoding method comprising:

interpreting an input bitstream and obtaining texture information and motion information containing base layer motion vectors and residual motion vectors;

merging a base layer motion vector with a residual motion vector for each of a plurality of blocks having both the base layer motion vector and the residual motion vector and obtaining merged motion vectors;

performing inverse quantization and inverse spatial transform on the texture information and obtaining frames in which temporal redundancies are removed; and

performing inverse motion compensation on the frames in which the temporal redundancies have been removed using the merged motion vectors and unmerged base layer motion vectors.

29. The method of claim 28, further comprising readjusting the unmerged base layer motion vectors,

wherein the inverse motion compensation is performed on the frames in which the temporal redundancies have been removed using the merged motion vectors and the unmerged base layer motion vectors which have readjusted.

30. A video decoder comprising:

a bitstream interpreter which interprets an input bitstream and obtains texture information and motion information containing base layer motion vectors and enhancement layer motion vectors;

a motion vector readjuster which readjusts the base layer motion vectors;

an inverse quantizer which performs inverse quantization on the texture information;

an inverse spatial transformer which performs inverse spatial transform on the inversely quantized texture information to obtain frames in which temporal redundancies are removed; and

an inverse motion compensator which performs inverse motion compensation on the frames in which the temporal redundancies have been removed using the base layer motion vectors which have been readjusted and the enhancement layer motion vectors, and reconstructs a video frame.

31. The decoder of claim 30, wherein the motion vector readjuster readjusts the base layer motion vectors using enhancement layer motion vectors for neighboring blocks.

32. The decoder of claim 30, wherein the motion vector readjuster readjusts the base layer motion vectors using a predicted frame generated by the inverse motion compensator.

33. A video decoder comprising:

a bitstream interpreter which interprets an input bitstream and obtains texture information and motion information containing base layer motion vectors and residual motion vectors;

a motion vector merger which merges a base layer motion vector with a residual motion vector for each of a plurality of blocks having both the base layer motion vector and the residual motion vector, and obtains merged motion vectors;

an inverse quantizer which performs inverse quantization on the texture information;

an inverse spatial transformer which performs inverse spatial transform on the inversely quantized texture information and obtains frames in which temporal redundancies are removed; and

an inverse motion compensator which performs inverse motion compensation on the frames in which the temporal redundancies have been removed using the merged motion vectors and unmerged base layer motion vectors.

34. The decoder of claim 33, further comprising a motion vector readjuster readjusting the unmerged base layer motion vectors.

35. A recording medium having a computer readable program recorded therein, the program for executing a video coding method, the method comprising:

estimating a base layer motion vector and an enhancement layer motion vector for each block in a video frame;

removing temporal redundancies in the video frame using the enhancement layer motion vectors;

spatially transforming the video frame in which the temporal redundancies have been removed and quantizing the video frame which has been spatially transformed to obtain texture information;

selecting one of the base layer motion vector and the enhancement layer motion vector for each block; and

generating a bitstream containing the base layer motion vector or the enhancement layer motion vector selected for each block and the texture information.

36. A recording medium having a computer readable program recorded therein, the program for executing a video coding method, the method comprising:

estimating a base layer motion vector and an enhancement layer motion vector for each block in a video frame;

removing temporal redundancies in the video frame using the enhancement layer motion vectors;

spatially transforming the video frame in which the temporal redundancies have been removed and quantizing the video frame which has been spatially transformed to obtain texture information; and

generating a bitstream containing the base layer motion vector, a residual motion vector which is a difference between the base layer motion vector and the enhancement layer motion vector, and the texture information, for each block.

37. A recording medium having a computer readable program recorded therein, the program for executing a predecoding method, the method comprising:

receiving a bitstream containing a base layer motion vector, a residual motion vector which is a difference between the base layer motion vector and an enhancement layer motion vector for each block of a video frame, and texture information obtained by encoding the video frame, associated with each block in the video frame; and

truncating at least a part of the residual motion vectors.

38. A recording medium having a computer readable program recorded therein, the program for executing a video decoding method, the method comprising:

interpreting an input bitstream and obtaining texture information and motion information containing base layer motion vectors and enhancement layer motion vectors;

readjusting the base layer motion vectors;

performing inverse quantization and inverse spatial transform on the texture information to obtain frames in which temporal redundancies are removed; and

performing inverse motion compensation on the frames in which the temporal redundancies have been removed using the base layer motion vectors which have been readjusted and the enhancement layer motion vectors.

39. A recording medium having a computer readable program recorded therein, the program for executing a video decoding method, the method comprising:

interpreting an input bitstream and obtaining texture information and motion information containing base layer motion vectors and residual motion vectors;

merging a base layer motion vector with a residual motion vector for each of a plurality of blocks having both the base layer motion vector and the residual motion vector and obtaining merged motion vectors;

performing inverse quantization and inverse spatial transform on the texture information and obtaining frames in which temporal redundancies are removed; and

performing inverse motion compensation on the frames in which the temporal redundancies have been removed using the merged motion vectors and unmerged base layer motion vectors.