數(shù)字圖像操作取證技術(shù)研究
發(fā)布時間：2018-08-02 18:57
【摘要】：隨著數(shù)字媒體編輯技術(shù)的快速發(fā)展,數(shù)字圖像修改或篡改變得非常容易,違規(guī)編輯和虛假圖像也頻繁出現(xiàn),嚴重損害了數(shù)字媒體信息的可信性與安全性。在司法取證和新聞紀實等應(yīng)用領(lǐng)域,常需要通過技術(shù)手段驗證圖像數(shù)據(jù)的原始性和真實性,并還原圖像的操作歷史以獲取更多取證信息。因此,研究數(shù)字圖像取證技術(shù)對于實現(xiàn)數(shù)字媒體內(nèi)容認證具有重要意義和實用價值。本論文以數(shù)字圖像操作取證技術(shù)為主要研究內(nèi)容,取得創(chuàng)新性研究成果包括： 1)提出了兩種基于邊緣特征一致性分析的圖像拼接檢測方法。第一種方法利用自然邊緣與拼接邊界在CFA (Color Filter Array)內(nèi)插特征一致性方面的差異,提出了一種快速有效的圖像拼接檢測算法,可有效克服現(xiàn)有大多數(shù)拼接檢測技術(shù)需要統(tǒng)計學(xué)習(xí)導(dǎo)致算法復(fù)雜度較高的缺陷。第二種方法針對圖像拼接后進行邊界模糊潤飾這一實際篡改情形,提出了一種基于邊緣模糊度估計的拼接檢測算法,可有效定位模糊潤飾后的拼接邊界。 2)提出了分別針對USM(Unsharp Masking)銳化和中值濾波的圖像操作取證算法。在國際上較早提出了數(shù)字圖像銳化和中值濾波取證問題。對圖像USM銳化過程進行信號建模且給出了相應(yīng)的數(shù)學(xué)描述,分析了過沖效應(yīng)的產(chǎn)生機理,由此設(shè)計了有效的USM銳化檢測方案。同時,從理論上分析了中值濾波所引起的圖像一階微分域統(tǒng)計特性異常,提出了一種快速有效的中值濾波操作檢測算法。實驗結(jié)果表明,此銳化和中值濾波取證算法均可有效鑒別相應(yīng)的圖像濾波操作。 3)提出了圖像對比度增強取證系列算法。為有效檢測中低等質(zhì)量JPEG圖像上的對比度增強操作,提出了一種基于灰度直方圖峰谷形狀分析的對比度增強檢測方法；利用峰谷位置分布與像素值映射函數(shù)之間的對應(yīng)關(guān)系設(shè)計了一種快速有效的伽瑪參數(shù)盲估計方法；針對源圖像區(qū)域經(jīng)歷不同的對比度增強情形,設(shè)計了一種有效的圖像拼接檢測方法；最后簡要分析了現(xiàn)有對比度增強取證算法的安全性。實驗結(jié)果表明,所提對比度增強取證相關(guān)算法均取得較高性能。 4)提出了一種半侵入式重采樣算子源取證算法。從理論上推導(dǎo)出嚴格單調(diào)信號在經(jīng)歷傳統(tǒng)型和幾何抖動型重采樣后一階微分極性的變化規(guī)律,通過設(shè)計合適的模式圖像,提出了一套完整的重采樣算子源鑒別方法。實驗結(jié)果表明,該方法既可識別重采樣軟件的內(nèi)含算子,也可在特定情形下檢測反取證型重采樣操作。
[Abstract]:With the rapid development of digital media editing technology, digital image modification or tampering becomes very easy, illegal editing and false images appear frequently, which seriously damages the credibility and security of digital media information. In the field of judicial forensics and news documentary, it is often necessary to verify the originality and authenticity of image data by technical means, and to restore the operating history of image to obtain more evidential information. Therefore, the research of digital image forensics technology is of great significance and practical value for the realization of digital media content authentication. In this paper, digital image operation forensics technology is the main research content, and the innovative research results are as follows: 1) two image mosaic detection methods based on edge feature consistency analysis are proposed. In the first method, a fast and effective image mosaic detection algorithm is proposed by taking advantage of the differences between the natural edges and the stitched edges in the CFA (Color Filter Array) interpolation feature consistency. It can effectively overcome the high complexity of most existing stitching detection techniques due to the need of statistical learning. The second method is based on edge ambiguity estimation to solve the problem of edge fuzzy retouching after image stitching. It can effectively locate the stitching boundary after fuzzy retouching. 2) an image operation forensics algorithm for USM (Unsharp Masking) sharpening and median filtering is proposed. The problems of digital image sharpening and median filter forensics have been put forward earlier in the world. The signal modeling and mathematical description of image USM sharpening process are given. The mechanism of overshoot effect is analyzed and an effective USM sharpening detection scheme is designed. At the same time, the first order differential domain statistical anomaly caused by median filter is analyzed theoretically, and a fast and effective median filter operation detection algorithm is proposed. Experimental results show that both the sharpening and median filtering forensics algorithms can effectively identify the corresponding image filtering operations. 3) A series of image contrast enhancement forensics algorithms are proposed. In order to detect contrast enhancement in JPEG images of low and low quality, a contrast enhancement detection method based on peak and valley shape analysis of gray histogram is proposed. A fast and effective blind estimation method for gamma parameters is designed based on the correspondence relationship between peak and valley position distribution and pixel mapping function. An effective image mosaic detection method is designed, and the security of the existing contrast enhancement forensics algorithm is briefly analyzed. Experimental results show that the proposed contrast enhancement forensics correlation algorithms are of high performance. 4) A semi-invasive resampling operator source forensics algorithm is proposed. The variation law of the first order differential polarity of strictly monotone signals after the traditional and geometric jitter resampling is deduced theoretically. A set of complete resampling operator source identification method is proposed by designing suitable pattern images. The experimental results show that this method can not only identify the embedded operators of the resampling software, but also detect the anti-forensics resampling operations under certain circumstances.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：TP391.41;D918.1
本文編號：2160407
[Abstract]:With the rapid development of digital media editing technology, digital image modification or tampering becomes very easy, illegal editing and false images appear frequently, which seriously damages the credibility and security of digital media information. In the field of judicial forensics and news documentary, it is often necessary to verify the originality and authenticity of image data by technical means, and to restore the operating history of image to obtain more evidential information. Therefore, the research of digital image forensics technology is of great significance and practical value for the realization of digital media content authentication. In this paper, digital image operation forensics technology is the main research content, and the innovative research results are as follows: 1) two image mosaic detection methods based on edge feature consistency analysis are proposed. In the first method, a fast and effective image mosaic detection algorithm is proposed by taking advantage of the differences between the natural edges and the stitched edges in the CFA (Color Filter Array) interpolation feature consistency. It can effectively overcome the high complexity of most existing stitching detection techniques due to the need of statistical learning. The second method is based on edge ambiguity estimation to solve the problem of edge fuzzy retouching after image stitching. It can effectively locate the stitching boundary after fuzzy retouching. 2) an image operation forensics algorithm for USM (Unsharp Masking) sharpening and median filtering is proposed. The problems of digital image sharpening and median filter forensics have been put forward earlier in the world. The signal modeling and mathematical description of image USM sharpening process are given. The mechanism of overshoot effect is analyzed and an effective USM sharpening detection scheme is designed. At the same time, the first order differential domain statistical anomaly caused by median filter is analyzed theoretically, and a fast and effective median filter operation detection algorithm is proposed. Experimental results show that both the sharpening and median filtering forensics algorithms can effectively identify the corresponding image filtering operations. 3) A series of image contrast enhancement forensics algorithms are proposed. In order to detect contrast enhancement in JPEG images of low and low quality, a contrast enhancement detection method based on peak and valley shape analysis of gray histogram is proposed. A fast and effective blind estimation method for gamma parameters is designed based on the correspondence relationship between peak and valley position distribution and pixel mapping function. An effective image mosaic detection method is designed, and the security of the existing contrast enhancement forensics algorithm is briefly analyzed. Experimental results show that the proposed contrast enhancement forensics correlation algorithms are of high performance. 4) A semi-invasive resampling operator source forensics algorithm is proposed. The variation law of the first order differential polarity of strictly monotone signals after the traditional and geometric jitter resampling is deduced theoretically. A set of complete resampling operator source identification method is proposed by designing suitable pattern images. The experimental results show that this method can not only identify the embedded operators of the resampling software, but also detect the anti-forensics resampling operations under certain circumstances.
【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：TP391.41;D918.1
【參考文獻】
相關(guān)期刊論文 前1條
1 曹剛;趙耀;倪蓉蓉;;基于邊緣CFA內(nèi)插特征一致性的圖像拼接檢測[J];東南大學(xué)學(xué)報(自然科學(xué)版);2009年03期
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