數位相機及智慧型手機已成為生活中不可缺少的部分，因此我們隨處可見數位影像，但由於數位化資料擁有容易修改的特性，且影像處理軟體功能日益強大的狀況下，往往可以記錄真實事物的特性面臨極大的考驗。
本論文以區塊擴張及SIFT特徵點之使用來探討區塊比對的複製移動竄改偵測技術，先使用SIFT關鍵點內的資訊作為特徵點的提取及角度的計算，再利用SIFT的關鍵點位置，對影像以9 9大小進行擷取，並進行特徵提取進行，若在於門檻值之內，就以同心矩形的方式依序擴大，再來進行小範圍的區域擴張，使得偵測的圖形可以更加完整。經實驗結果本論文研究利用多種不同的特徵值集合，可以有效降低偵測的時間，及改善前人因竄改區域變化無法偵測的問題。

Since digital cameras and smart phones have become an indispensable part of life, a lot of digital images are widely used. However, digital image has the property of easy to modify through image editing software, the ability to find real image is a great challenge.
This paper presents an algorithm to detect copy-move image regions by SIFT keypoints and region growing technique. First, the SIFT keypoints denotes important image’s feature points. By using scale similarity comparison technique, the similar starting 99 pair blocks are acquired. The region growing technique is adopted to generate the copy-move regions. Experimental results show that the SIFT keypoints are useful to detect starting copy-move blocks and further image-growing technique can detect copy-move regions effectively.

目錄
目錄	III
圖目錄	V
表目錄	VII
第一章 緒論	1
1.1	研究背景與目的	1
1.2	論文架構	3
第二章 相關研究	4
2.1	Hu不變動量值特徵提取方法[8]	4
2.2	Chen等人所提出的方法[4]	6
2.3	尺度不變特徵轉換	9
第三章 本論文提出方法	16
3.1	以SIFT與區塊擴張技術進行複製移動竄改區域偵測	16
3.2	理論分析	21
第四章 實驗結果與比較	22
4.1	實驗結果	22
4.2	比較與討論	27
第五章 結論	32
參考文獻	33
附錄─英文論文	35

圖目錄
圖1.1複製移動竄改影像	3
圖2.1產生新的區域比對範圍	8
圖2.2對生成範圍進行區域比對順序示意圖	8
圖2.3以金字塔結構生成比對範圍示意圖	8
圖2.4高斯金字塔提取圖層示意圖	10
圖2.5 DoG金字塔提取圖層示意圖	11
圖2.6候選特徵點的提取法	12
圖2.7利用方向直方圖決定特徵點方向	14
圖2.8特徵點描述示意圖	15
圖3.1本論文提出的方法流程圖	16
圖3.2關鍵點的位置座標、強度及方向	18
圖3.3初始範圍擴張	19
圖3.4依照關鍵點角度將範圍旋轉	20
圖3.5邊緣範圍擴張	20
圖4.1二張圖所呈現的實驗結果	23
圖4.2均值濾波攻擊圖	25
圖4.3均值濾波攻擊實驗結果	26
圖4.4原圖及均值濾波攻擊後之正確率	28
圖4.5原圖及均值濾波攻擊後之偵測率	28
圖4.6原圖及其他方法之正確率	29
圖4.7原圖及其他方法之偵測率	30
圖4.8原圖及其他方法之執行時間	31
 
表目錄
表3.1比對資料量與效能比較	21
表4.1原圖及均值濾波攻擊後之正確率及偵測率	27
表4.2原圖及其他方法之正確率及偵測率	29

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