Adaptive global motion temporal prediction for video coding
Depending on the content of a video sequence and the settings used for encoding it, the amount of bits spent for the transmission of motion vector information can be enormous and in some cases even take the largest fraction of the bit rate. This is not always necessary since often wide areas, i.e. background or large foreground regions, fit the same global motion. Additionally, a global motion model using sophisticated interpolation techniques can be a better representation of movement in these regions than a motion vector that has only quarter-pel accuracy. This is true especially if scaling, rotation or perspective transformation occur. This paper presents a novel prediction technique that is based on global motion compensation and temporal filtering of previously decoded pictures. The new approach is incorporated into an H.264/AVC reference software. The new encoder outperforms the reference by up to 14%.