US Patent 11330294 Method and device for image motion compensation

A video processing method includes determining a long-term reference image according to a frame identifier for a reference image obtained by analyzing a parameter set. The long-term reference image is updated according to a short-term reference image stored in a reference image buffer. The method further includes dividing a current image block into one or more sub-blocks and obtaining a candidate motion vector of one of the one or more sub-blocks. The method also includes, if the candidate motion vector of a sub-block points to the short-term reference image, scaling the candidate motion vector using a scaling factor not equal to 1, and, if the candidate motion vector of the sub-block points to the long-term reference image, scaling the candidate motion vector using a scaling factor set to 1. The method also includes performing prediction for the sub-block or the current image block according to the scaled candidate motion vector.