【摘要】： 隨著互聯(lián)網技術的快速發(fā)展,高分辨率數(shù)碼相機以及功能強大的圖像編輯軟件的出現(xiàn),圖像篡改已經越來越普遍,它在一定程度上豐富了人們的日常生活,雜志封面和商業(yè)廣告上精美的圖片讓人目不暇接。但是篡改圖像也帶來了許多問題。如果將篡改圖像用在新聞媒體或法律上,對社會將會造成很大的影響。因此,對數(shù)字圖像的真?zhèn)舞b別非常重要。而JPEG是目前主流的圖像壓縮標準,大多數(shù)圖片是用JPEG格式存儲的。在此背景下,本文提出了一種基于雙JPEG壓縮的數(shù)字圖像篡改的檢測方法。 本文首先介紹了JPEG壓縮標準,JPEG編解碼原理及其實現(xiàn)過程。同時介紹了雙JPEG壓縮原理以及幾個相關概念。著重分析了單量化、雙量化、多次量化后DCT系數(shù)直方圖的特性,并闡述了雙量化后DCT系數(shù)直方圖周期性產生的原因。 其次,文章提出了一種基于雙JPEG壓縮的數(shù)字圖像篡改的檢測方法。首先描述了篡改圖像、DCT塊、篡改塊、非篡改塊等幾個相關的概念,分析了JPEG圖像的雙量化效果,指出了被篡改的JPEG圖像中篡改塊與非篡改塊可分的依據(jù)。并且給出了一種簡單有效的估計直方圖周期的算法。其次,根據(jù)貝葉斯決策理論設計了針對圖像中篡改塊與非篡改塊的兩類別分類器,用于檢測篡改塊。再次,建立了一個包含110幅圖像的圖像庫,對其中一部分圖像做篡改之后,用不同的壓縮質量因子進行JPEG壓縮,將其中60幅輸入SVM用作訓練數(shù)據(jù),另外50幅用作測試數(shù)據(jù)。文中分析了兩次JPEG壓縮的質量因子與錯誤分類個數(shù)的對應關系。 最后,給定一幅待檢測圖像,抽取一個四維特征向量輸入到訓練好的SVM中檢測圖像真?zhèn)�。通過大量實驗對該算法進行測試并對實驗結果進行分析,總結了不同的壓縮質量因子以及篡改圖像的尺寸與該方法有效性的關系。實驗證明,本文提出的基于雙JPEG壓縮的數(shù)字圖像篡改的檢測方法是非常有效的。
[Abstract]:With the rapid development of Internet technology and the emergence of high-resolution digital cameras and powerful image editing software, image tampering has become more and more common. To a certain extent, it enriches people's daily life, and the exquisite pictures on magazine covers and commercial advertisements are dizzying. However, tampering with images also brings many problems. If tampering images are used in news media or law, it will have a great impact on society. Therefore, it is very important to distinguish the authenticity of digital images. JPEG is the current mainstream image compression standard, most of the pictures are stored in JPEG format. In this paper, a digital image tampering detection method based on double JPEG compression is proposed. This paper first introduces JPEG compression standard, JPEG coding and decoding principle and its implementation process. At the same time, the principle of double JPEG compression and several related concepts are introduced. The characteristics of DCT coefficient histogram after single quantification, double quantification and multiple quantification are analyzed, and the causes of periodicity of DCT coefficient histogram after double quantification are expounded. Secondly, a digital image tampering detection method based on double JPEG compression is proposed. Firstly, several related concepts, such as tampering image, DCT block, tampering block, non-tampering block and so on, are described, the double quantification effect of JPEG image is analyzed, and the basis for the separation of tampered block and non-tampered block in tampered JPEG image is pointed out. A simple and effective algorithm for estimating the period of histogram is presented. Secondly, two classes of classifiers for tampering blocks and non-usurped blocks in images are designed according to Bayesian decision theory, which are used to detect tampering blocks. Thirdly, an image library containing 110 images is established. After tampering with some of the images, JPEG compression is carried out with different compression quality factors, 60 of which are input SVM as training data and 50 as test data. In this paper, the corresponding relationship between the quality factor of twice JPEG compression and the number of misclassification is analyzed. Finally, given an image to be detected, a four-dimensional feature vector is extracted and input into the trained SVM to detect the authenticity of the image. Through a large number of experiments, the algorithm is tested and the experimental results are analyzed, and the relationship between different compression quality factors and the size of tampered image and the effectiveness of the method is summarized. The experimental results show that the proposed digital image tampering detection method based on double JPEG compression is very effective.
【學位授予單位】：上海師范大學
【學位級別】：碩士
【學位授予年份】：2007
【分類號】：TP391.41

【引證文獻】

相關期刊論文 前1條

1 徐剛;劉東權;;基于自然圖像復制區(qū)域的篡改認證[J];西南民族大學學報(自然科學版);2008年05期

相關博士學位論文 前1條

1 王波;利用成像引入特征的數(shù)字圖像被動盲取證研究[D];大連理工大學;2010年

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1 趙涵;數(shù)字圖像盲取證技術的一些研究[D];杭州電子科技大學;2009年

2 史芳玲;JPEG雙重壓縮圖像檢測及中值濾波檢測研究[D];西北大學;2012年

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本文編號：2499386