Alibaba Group Holding Limited
METHODS AND APPARATUSES FOR PREDICTION REFINEMENT WITH OPTICAL FLOW IN REFERENCE PICTURE RESAMPLING

Abstract:

The disclosed embodiments provide methods and apparatuses for reference picture resampling in video coding. A disclosed method includes: in response to receiving a sample block in a reference picture, mapping a boundary sample of the sample block to a mapped coordinate outside the sample block; determining, in the reference picture, a reference sample including the mapped coordinate; determining a gradient based on the reference sample; and refining, based on the gradient, the sample block for prediction.