中文摘要
　　在本篇論文中，提出了一個有效的數位視訊浮水印的方法。數位視訊浮水印在許多應用領域上扮演著很重要的角色，例如拷貝控制、使用者身份識別、以及廣播監控等等。視訊浮水印相對於影像浮水印的主要困難處在於多了時間軸這一項元素；攻擊端可利用此項資訊去破壞所藏入數位浮水印的內容，或是達到使偵測端無法正確偵測數位浮水印所在的位置。
我們的方法主要是根據各視訊畫面內容來執行空間局部數位浮水印的藏入，因此可抵抗線性串連攻擊和數位浮水印位置不同調的問題。為了能夠增強對其他一般攻擊(如：模糊攻擊及壓縮攻擊)的抵抗力，我們運用區塊機制來產生所要藏入的數位浮水印。此外，為了改善在相同的浮水印藏入強度下視訊的品質，我們根據人眼視覺系統以相對不同的強度將浮水印藏入不同的頻帶裡。最後，我們利用了一個動態臨界值來決定偵測浮水印的結果。實驗結果證實了上述的機制可以有效的抵抗空間軸上平均濾波器的攻擊、時間軸上數個畫面平均的攻擊、以及動態影像壓縮的攻擊。

ABSTRACT
This paper proposes an effective approach for video watermarking. Video watermarking plays an important role in many applications such as copy control, owner identification, broadcast monitoring, and so on. The main difficulty comes from the temporal dimension because it provides useful information for attackers to remove or desynchronize the embedding watermark.
We propose a video watermarking method motivated from the spatially localized image-dependent (SLIDE) sub-frame watermarking system to resist the linear collusion attacks and de-synchronization attacks. In order to enhance the robustness to other common attacks, such as averaging and compression attacks, we generate watermarks by the block-based mechanism. In addition, in order to improve the imperceptibility under the same embedding strength, we embed watermarks in multi-channels by Human Visual System (HVS). Finally, we employ a blind threshold technique to determine the detection result. Our experimental results demonstrate that the above mechanisms are effective to resist spatial average filtering attacks, temporal frame averaging attacks, and MPEG compression attacks.

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