Overlapped block motion compensation based on blended predictors

Abstract

Exemplary video processing methods and apparatuses for coding a current block. One implementation operates by receiving input video data associated with a current block in a current picture; determining one or more Motion Vectors (MVs) for generating an OBMC region; generating one or more converted MVs by changing said one or more MVs to one or more integer MVs or changing a MV component of said one or more MVs to an integer component; deriving the OBMC region by motion compensation using said one or more converted MVs; applying OBMC by blending an OBMC predictor in the OBMC region with an original predictor; and encoding or decoding the current block.

1 . A video processing method of sub-block motion compensation in a video coding system, comprising:
 receiving input video data associated with a current block in a current picture;   partitioning the current block into multiple overlapped sub-blocks according to an overlapped sub-block partition, wherein each sub-block is overlapped with one or more other sub-blocks in a horizontal direction, a vertical direction, or both the horizontal and vertical directions;   determining one or more sub-block Motion Vectors (MVs) associated with each sub-block of the overlapped sub-blocks in the current block;   deriving an initial predictor for each sub-block of the overlapped sub-blocks by motion compensation using said one or more sub-block MVs;   deriving a final predictor for each overlapped region by blending the initial predictors of the overlapped region; and   encoding or decoding the current block based on the final predictors of the overlapped regions.   
     
     
         2 . The method of  claim 1 , wherein the overlapped sub-block partition is explicitly signaled at a sequence level, picture level, tile group level or slice level of a video bitstream. 
     
     
         3 . The method of  claim 1 , wherein the overlapped sub-block partition is implicitly decided according to one or a combination of motion information of the current block, a size of the sub-blocks, and a prediction mode of the current block. 
     
     
         4 . The method of  claim 1 , wherein the overlapped sub-block partition is predefined and not signaled in a video bitstream. 
     
     
         5 . The method of  claim 1 , wherein the final predictor is derived by blending the initial predictors of the overlapped region using weighted sum. 
     
     
         6 . The method of  claim 5 , wherein weighting factors for the initial predictors are position dependent or depending on a number of overlapped sub-blocks. 
     
     
         7 . The method of  claim 1 , wherein the current block contains the overlapped regions and non-overlapped regions, and the current block is encoded or decoded according to the final predictors of the overlapped regions and the initial predictors of the non-overlapped regions. 
     
     
         8 . An apparatus of processing video data in a video coding system, the apparatus comprising one or more electronic circuits configured for:
 receiving input video data associated with a current block in a current picture;   partitioning the current block into multiple overlapped sub-blocks according to an overlapped sub-block partition, wherein each sub-block is overlapped with one or more other sub-blocks in a horizontal direction, a vertical direction, or both horizontal and vertical directions;   determining one or more sub-block Motion Vectors (MVs) associated with each sub-block of the overlapped sub-blocks in the current block;   deriving an initial predictor for each sub-block of the overlapped sub-blocks by motion compensation using said one or more sub-block MVs;   deriving a final predictor for each overlapped region by blending the initial predictors of the overlapped region; and   encoding or decoding the current block based on the final predictors of the overlapped regions.   
     
     
         9 . An apparatus of processing blocks with Overlapped Block Motion Compensation (OBMC) in a video coding system, the apparatus comprising one or more electronic circuits configured for:
 receiving input video data associated with a current block in a current picture;   determining one or more Motion Vectors (MVs) for generating an OBMC region;   generating one or more converted MVs by changing said one or more MVs to one or more integer MVs or changing a MV component of said one or more MVs to an integer component;   deriving the OBMC region by motion compensation using said one or more converted MVs;   applying OBMC by blending an OBMC predictor in the OBMC region with an original predictor; and   encoding or decoding the current block.