影像DCT係數的低頻部分對於抵抗幾何攻擊有良好的強韌性，本論文將各訊框低頻係數分成數個區塊，再根據浮水印資訊將視訊訊框間之低頻係數區塊在時間軸上進行調制，使其成為同時放入空間軸與時間軸的雙重浮水印，以達成盲偵測與倍增浮水印資訊嵌入量的目的，實驗結果顯示本論文的方法對於旋轉、裁切、縮放、濾波、及壓縮等攻擊有良好的強韌性。
The low-frequency DCT coefficients of an image are relatively insensitive to geometric processing. In this paper, the low-frequency DCT coefficients of a full DCT domain are divided into several blocks, and the mean of the coefficients of each block is temporally modulated based on the watermark information bits. This method can embed watermark information both in space and time domain, and achieves the goal of blind detection and incremental of watermark information. The experimental results show that the proposed method is robust against rotating, cropping, scaling, filtering, and compressing attacks.
