that each neighboring blocks are almost the same therefore this approach uses the spatial correlation between the blocks to select some possible block prediction modes to perform and simplify the computation no matter what kind of prediction modes the neighboring block is mode 2 is always possible to be the best prediction mode if mode 2 happens in the neighboring blocks all kinds of prediction modes are possible to be the best prediction modes because mode 2 does not possess any obvious spatial direction thus all kinds of modes will be performed when mode 2 occurs in neighboring blocks in order to reduce the computation complexity the mode having higher occurrence probability is selected to substitute all previous modes therefore the approach wherein only mode 0 mode 1 mode 2 mode 3 and mode 4 are performed is called as half full search reference is made to fig1 c which illustrates a context correlation search mode of the condition correlation search mode in the second condition of the half full search mode when neither of the left and upper neighboring blocks is mode 2 the context correlation search mode is performed the prediction approach of context correlation search mode is described as following under the assumed condition when the prediction modes of two neighboring blocks are almost the same in addition to original prediction modes of the upper and left blocks other prediction modes similar to the upper and left blocks in spatial direction are also selected as the basis for prediction modes in the motion vector and the context correlation search table of fig1 c the upper and left prediction.