Hierarchy-based Fast Intra Prediction Algorithm

In order to solve the problem of the inaccuracy in predicting pixels at the boundary of the block in H.264 intra prediction, a hierarchy-based intra prediction algorithm was presented in this paper. Because of the close dependency of pixels within marco block, the predicted pixels within the same block were taken as references to predict other pixels. A hierarchy-based fast intra prediction algorithm was presented to reduce the computational complexity of intra coding in H. 264, which adopted candidate modes required for hierarchy-based structure by utilizing characteristics of 4×4 block in spatial and frequency domain to reduce the quantity of modes for computation. Furthermore, the relationship between 4×4 mode and 16×16 mode was exploited in fast algorithm. The test results indicate that other than previous fast algorithms, hierarchy-based fast algorithm can not only decrease the computational complexity in intra coding, but also, more important, improve coding efficiency.