一種魯棒性數字水印系統的設計與實現

論文字數:15513,頁數:38  有開題報告，任務書

摘要
 計算機網絡和通信技術的迅猛發展，使得數字信息的產生、復制、傳播更為容易。在這個背景下，如何防止具有版權的數字數據在未經允許的情況下，被非法的使用或是傳播，這就提出新的研究的課題：就是如何運用現有的理論和技術，更好的解決數字產品所有者的合法權益的保護問題。數字水印技術就是在這樣的背景下誕生的。
 本文就基于離散小波變換的數字水印技術做以下的工作：（1）對數字水印的概念、框架、分類及應用做一個簡要的介紹；（2）簡單回顧一下水印嵌入策略核心小波理論，并著重介紹多分辨分析及Mallat算法；（3）簡要介紹人類視覺感知系統（HVS），討論其在水印嵌入過程中的作用；（4）設計并實現基于小波變換與人類視覺系統的水印嵌入算法；（5）通過各種常見攻擊驗證系統的魯棒性，證明該水印系統對于常見攻擊具有魯棒性并且保證水印的不可見性。最后總結所做工作并指出不足之處。
 關鍵詞：數字水印，離散小波變換，人類視覺系統

 Design and Implement of a robust digital watermarking system
Abstract
   The revolution in digital technology has increased the case of manipulation, reproduction, retransmission, and distribution of digital images. However, it also offers the potential for illegal use, known as a piracy of digital images. Consequently, the need to manage and protect these digital properties has become crucial.                                                                             Watermarking technology is considered as an alternative tool for protecting these intellectual properties. It attempts to identify the true owner by hiding perceptually invisible information (watermark) inside the digital data. In this thesis, for the purpose of protecting the Intellectual Property Rights (IPR) of digital images, a Discrete Wavelet Transform (DWT) based digital watermark algorithm is described. The proposal is designed for images.
 The key points of research addressed in this proposal include: (1) The structures of watermark being embedded that enhance the perceptual invisibility and watermark detection efficiency. (2) Watermark embedding strategy. For instance, watermark embedding function and watermark embedding parameters (weighting function-embedding energy, embedding level and spatial location), which maximize the robustness and invisibility of the watermark. (3) The possibility of using Human Visual System (HVS) in the Watermark Embedding Process (WEP). (4) The Watermark Detection Process (WDP), especially, the reliability of the proposed watermarking algorithm after distortion by several kinds of watermark attacks. (5) The robust watermarking protocol for proving ownership.
Key word: Digital Watermarking, Discrete Wavelet Transform, Human Visual System

 目       錄

1緒論 1
1.1 課題研究的背景和意義 1
1.2 國內外研究狀況 1
1.3 本文的結構與內容 3
2 數字水印概述 5
2.1 數字水印的基本框架 5
2.2 數字水印的技術特點 7
2.3 數字水印分類 8
3 小波分析及其應用 12
3.1 引言 12
3.2 小波的發展歷程 13
3.3 小波變換 14
3.3.1 連續小波變換 15
3.3.2 離散小波變換 16
3.3.3 多分辨分析 16
3.4 Mallat算法及應用 19
4 基于HVS與DWT的數字水印系統的設計與實現 21
4.1 HVS模型簡介 21
4.2 水印嵌入位置的選擇 22
4.3 水印嵌入強度的計算 22
4.4 本文算法的具體實現步驟 24
4.4.1水印的嵌入算法及步驟： 24
4.4.2水印的提取算法及步驟： 24
4.5 魯棒性測試 24
4.5.1 JPEG壓縮攻擊 25
4.5.2增強處理攻擊 27
4.5.3附加噪聲攻擊 27
4.5.4測試結果分析 29
總結 30
致謝 31
參考文獻 32