An improved fast mode decision algorithm for intraprediction in H.264/AVC video coding

In this article, an improved version of one of the most cited intra mode decision algorithms in H.264/AVC video coding is proposed with the aim to improve its efficiency and performance. The reference algorithm determines the interpolation/extrapolation spatial direction (mode) for achieving the best intra prediction using the Sobel gradient calculation. The proposed algorithm suggests reducing the number of gradients calculated and changing the Sobel operator to that of Roberts. In addition to this, it also proposes including the previously encoded neighboring block modes among the evaluated modes. Experimental results show that the proposed algorithm reduces the computational load of the original algorithm and substantially improves its rate-distortion performance.