Motion Estimation Based on Spatio-temporal Correlation

Many objects in a scene are composed of more than one block. So when the object moves, a set of blocks, move together. Most blocks are either completely in the background or are part of the moving object and in most cases (except boundary blocks) neighboring blocks move together. Given that a majority of the neighbors of a block move in a certain direction, it is reasonable to assume that the block under consideration also moves in the same direction. This kind of correlation is called Spatial Correlation. Owing to the continuity of motion in the temporal direction, the motion of temporally successive blocks will also be highly correlated. This is called Temporal Correlation.