隨著影像技術不斷進步，在3D影像上的應用，將提供觀賞者一種新的視覺享受，而目前已列JVT (Joint Video Team) H.264延伸計畫中之3D影像壓縮技術是以多視角視訊編碼(Multi-view Video Coding, MVC)為主，MVC不僅保有原本H.264 編碼上的特性並增加視角間的參考方向來達到更好的壓縮效率，但是這樣一來卻大幅地提高計算上的複雜度，因此如何有效地降低其計算複雜度為當前研究之重要方向。
為了減少多視角視訊編碼之大量的計算量，有效地決定可能的編碼模式，本篇論文提出一個快速模式決策演算法，主要是利用視差資訊來表示其物體深度，根據不同的視差大小可將畫面分成前、中、背景三個區域，接著再針對這三個區域可能的編碼模式各別去做分析，另外，我們利用提早決定跳躍模式的方法和減少模式選擇的機制來達到更進一步的加速，本篇論文所提出的演算法是實現於JMVC4.0當中，由實驗結果得知，本篇論文提出的演算法可以加速約80%的編碼時間並且只造成少部分的PSNR值下降和位元率提高。

With the rapid development of video techniques, various applications of 3D video provide viewers a new viewing sensation. Joint Video Team (JVT) started working on the multi-view video coding (MVC) extension for H.264 video coding. The MVC extension achieves higher coding efficiency by not only inheriting from H.264 video standard but also including the inter-view correlation between neighboring views. However, the computational complexity obviously increases as well. Therefore, how to reduce the computational complexity effectively has become an important issue.
In this thesis, a fast mode decision algorithm is proposed to reduce the huge computation and decide the most appropriate mode in efficient way. We utilize the disparity information to represent the depth of objects. According to the different sizes of disparities, a frame can be classified into three regions: Near region, Middle region, and Far region. Then, we assign the appropriate modes to the three regions by analyzing the characteristics of each region, respectively. Additionally, the two methods which are the early skip mode decision and reducing the candidate modes based on RDcost are applied to remove some unnecessary inter modes to achieve better compression efficiency. Finally, the proposed algorithm is implemented in MVC reference software JMVC4.0. From experimental results, our proposed algorithm can reduce around 80% of the encoding time with negligible PSNR drop and bit-rate increasing.

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