Picture prediction method and picture prediction apparatus

A picture prediction apparatus, comprising:

• a non-transitory memory storage comprising instructions;
• and
• one or more hardware processors in communication with the memory storage, wherein the one or more hardware processors execute the instructions to:
• determine motion vectors of W control points in a current picture block, wherein the motion vectors of the W control points is determined based on a predictor with precision of 1/n of a pixel precision and a difference of motion vector with precision of 1/n of the pixel precision;
• adjust, the precision of the motion vector of W control points to be 1/N of the pixel precision;
• obtain, by calculation, motion vectors of P pixel units of the current picture block by using a motion model and the motion vectors of the W control points, wherein precision of the motion vector of each of the P pixel units is 1/N of the pixel precision, the motion vector of each of the P pixel units is used to determine a corresponding reference pixel unit in a reference picture of a corresponding pixel unit, W, n, and N are integers greater than 1, N is greater than n, and P is a positive integer;
• and
• perform interpolation filtering on a pixel of the corresponding reference pixel unit by using an interpolation filter with a phase of Q, to obtain a predicted pixel value of each of the P pixel units, wherein Q is an integer greater than n.

A non-transitory computer-readable medium storing computer instructions, that when executed by one or more hardware processors, cause the one or more hardware processors to perform operations comprising:

• determining motion vectors of W control points in a current picture block, wherein the motion vectors of the W control points is determined based on a predictor with precision of 1/n of a pixel precision and a difference of motion vector with precision of 1/n of the pixel precision;
• adjusting, the precision of the motion vector of W control points to be 1/N of the pixel precision;
• obtaining, by calculation, motion vectors of P pixel units of the current picture block by using a motion model and the motion vectors of the W control points, wherein precision of the motion vector of each of the P pixel units is 1/N of the pixel precision, the motion vector of each of the P pixel units is used to determine a corresponding reference pixel unit in a reference picture of a corresponding pixel unit, W, n, and N are integers greater than 1, N is greater than n, and P is a positive integer;
• and
• performing interpolation filtering on a pixel of the corresponding reference pixel unit by using an interpolation filter with a phase of Q, to obtain a predicted pixel value of each of the P pixel units, wherein Q is an integer greater than n.