data position sequence 中文意思是什麼
data position sequence
解釋
數據位置順序-
In this paper, chroma dc coefficients are selected as the carrier data because chroma dc coefficients are robust. also, alterable steps are used to select one part of the coefficients, so the watermark is imperceptible ; before watermark embedding, the watermark is divided into many parts, every part is individually embedded into one gop of the video, even if a gop is destroyed, the watermark can be extracted correctly, this methods promotes the robustness of the watermark ; in addition, in order to promote the security of the watermark, the user ' s id and password are used to generate chaos sequence by the chaos system which is created in this paper, later, watermark is mixed by the chaos sequence. also, the embedding position of the watermark bit is modified by one chaos sequence, so, unauthorized person can not extract or remove the watermark, since the embedding position is unknown
本文認為，色度dc系數是魯棒性非常好的參數，因而選擇色度dc系數作為水印信息載體，同時，採用可變的步長選擇部分系數，保證了水印的隱形性；在嵌入水印時，本文採用水印信息「網格劃分」 、各子塊獨立嵌入視頻的方案，由於水印信息子塊是相對獨立的嵌入視頻中的每一相對獨立的圖組當中，即使某一圖組收到一定破壞，也能夠恢復水印信息，使水印的健壯性得到提高；此外，為了提高水印信息的安全性，在嵌入水印信息時，根據用戶輸入的id號和密碼，利用本文構造的混沌系統產生的混沌序列對水印信息進行變換，同時，對每一水印信息比特的嵌入位置也採用了偽隨機序列進行調整，這樣，未授權用戶不能提取水印信息，也難以擦除其中的水印信息，因為嵌入的位置是未知的。
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