新一代的視訊壓縮標準H.264/AVC 比目前的影像標準可獲得更高的壓縮率及影像品質。為此，效能的提升也必須使用龐大的計算量來達到此效果。因此，如何降低畫面內預測的複雜度，將是本篇論文討論的方向。根據統計分析結果，我們提出模糊區間低頻交流值快速畫面內模式預測，經由修改低頻交流值演算法架構，在畫面內模式預測加入模糊區間，利用不同大小區間，在固定參數模式用來做畫面內模式預測。藉以提高演算法的影像品質、降低位元率以及減少運算的時間。由實驗效能分析結果，在些微的效能品質降低的情況下，可以節省平均50%的編碼時間。

H.264 supports many advanced compression techniques that can achieve better coding performance than the previous standards. However, the compression techniques require high computational complexity, increase the encoding time .One important technique is intra mode decision. We present an enhanced AClow intra mode decision for H.264/AVC to reduce the computation complexity while maintaining coding performance. The correct rate of ambi AClow algorithm is increased to 87% when considering ambiguous region. To obtain high coding efficiency, SATD-based intra mode decision is also applied to intra mode decision. The experimental results show that our proposed algorithm can achieve 50% of time saving on average

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