高效率視訊編碼(High Efficiency Video Coding，簡稱HEVC)為目前的視訊壓縮標準，相較於前代標準高階影片編碼(Advanced Video Coding，簡稱AVC)，HEVC提出了更有彈性的編碼樹單元(Coding Tree Unit，簡稱CTU)，以四分樹(Quadtree)分割成數個編碼單元(Coding Unit，簡稱CU)，大小可從64×64到8×8，另外在畫面內預測模式，HEVC也從AVC中的9種增加到35種預測模式，因此可提高壓縮率，同時也增加了計算複雜度，編碼時所耗費的時間相當可觀。
本論文提出基於紋理偵測的畫面內編碼單元快速決策法，主要分為編碼單元大小決策及預測模式決策。在編碼樹切割時，利用偵測到的紋理複雜度來決定是否停止切割或跳過當前的大小，而在預測模式決策中，利用紋理來選擇較可能的角度模式、修正最可能的模式 (Most probable mode)，以及使用SATD (Sum of absolute transformed difference)分類，以減少HEVC在編碼樹切割及畫面內預測的計算複雜度，並維持一定的位元率-失真(Rate-distortion，簡稱RD)性能。實驗結果顯示，與HEVC的參考軟體HM-16.22相比，在All-Intra配置下可省下約45.8%的時間，且僅有1.07%的BDBR損耗。

High Efficiency Video Coding (HEVC) is the standard of video compression. Compare to the previous standard Advanced Video Coding (AVC), HEVC introduce a more flexible partitioning, using the quadtree structure divided the coding tree unit (CTU) into coding units (CUs), with the size range from 64×64 to 8×8. Also, HEVC added the mode of intra prediction from 9 in AVC to 35 modes. Therefore, HEVC can improve the compression rate, but it also increases the computational complexity and takes much more time to encode.
In this thesis, we propose a fast CU size and intra mode decision based on texture detection. We use the complexity of detected texture for the CU size decision to decide whether to stop split or skip the current depth. As for the intra mode decision, the texture is used to choose the rough mode and the modified most probable mode (MPM) and SATD (Sum of absolute transformed difference) classification. Both methods are propose to reduce the computational complexity in HEVC intra prediction while maintaining the Rate-Distortion (RD) performance. Our experiment results show that our method can save about 45.8% of computational complexity on average with 1.07% BDBR increase for the HEVC reference software HM-16.22 under all-intra configuration.

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