This study presents a fast intra-predictionalgorithm for a high-profile H.264 encoder. First, a pre-decision algorithm is proposed to reject the impossible block size based on image variance. Then a fast 4x4 block pr...
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This study presents a fast intra-predictionalgorithm for a high-profile H.264 encoder. First, a pre-decision algorithm is proposed to reject the impossible block size based on image variance. Then a fast 4x4 block prediction algorithm is proposed to select four possible modes from nine predicted modes based on the edge-filtering detection. With a hierarchical approach, the 8x8 blockprediction is based on the result of the chosen 4x4 block mode. This approach selects only one to five modes of H.264 coding from nine prediction modes. Following the prediction of the 16x16 luminance block and 8x8 chrominance block is mapped by the result of the 8x8 luminance block by checking only one to two modes. The pre-decision algorithm, the fast 4x4, 8x8 and 16x16 block prediction algorithms can be combined to improve the coding speed. Simulations demonstrate that the proposed algorithm can save about 70% coding time at most for intra-frame coding in the H.264 system while increasing only about 1% bit-rate with a negligible peak signal-to-noise ratio drop.
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