In recent years the wide band networks made the exchange of digital images, easy and fast. However, it is also easy to modify or forge digital images and the protection of their contents becomes very important. Digital watermarking is considered as a solution for authentication and recovery when the image is under an attack.
In this paper, a game-theoretic analysis of a hierarchical digital watermarking method for image tampering detection and recovery is proposed. We use a cooperative game to decide how many bits will be embedded according to the different types of blocks. One player is complex block, and the other is smooth block. Their strategies are number of bits in watermarking embedding. The two players are cooperate to choose an optimal embedding strategy profile to get the best recovery rate and best quality to generate the watermarked image. The proposed method use hierarchical detection to authenticate the watermarked image and localize its tampered region. The simulation shows the good performance of the proposed algorithm.

由於網路的蓬勃發展，使得數位資料可以透過網路輕易的傳送，也因為如此，影像很容易被惡意的篡改。所以影像認證與影像還原是非常重要的一環。最常見的解決方法就是使用數位浮水印。

在本篇論文中，我們提出了一個階層式數位浮水印的影像認證及復原機制，並套入賽局理論去分析最適合的嵌入策略。在此賽局中，分別有兩位玩家，複雜區塊與平滑區塊，他們會互相合作選擇出一個最佳的策略，讓我們得到良好的嵌入浮水印後圖像品質與復原率。並藉由階層式的認證機制，能有效找出被竄改的區域，並進行復原

由實驗結果得知，我們提出的方法 可以有效認證原圖是否被修改且對於修改的區域進行復原。

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