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Spatial models for localization of image tampering using distributed source codes
- in Proc. Picture Coding Symp
, 2007
"... Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded ..."
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Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded images from tampering but also localize the tampered regions in an image already deemed to be inauthentic. An authentication decoder was supplied with a Slepian-Wolf encoded image projection as authentication data. A localization decoder required only incremental localization data beyond the authentication data since we use rate-adaptive distributed source codes. We extend the localization decoder with 1D and 2D spatial models to exploit the contiguity of the tampered regions. Our results show that the spatial decoders save 10 % to 17 % of authentication plus localization data size and offer greater confidence in tampering localization. Index Terms — image authentication, image tampering localization, distributed source coding 1.
Distributed Video Coding: Trends and Perspectives
, 2009
"... This paper surveys recent trends and perspectives in distributed video coding. More specifically, the status and potential benefits of distributed video coding in terms of coding efficiency, complexity, error resilience, and scalability are reviewed. Multiview video and applications beyond coding ar ..."
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This paper surveys recent trends and perspectives in distributed video coding. More specifically, the status and potential benefits of distributed video coding in terms of coding efficiency, complexity, error resilience, and scalability are reviewed. Multiview video and applications beyond coding are also considered. In addition, recent contributions in these areas, more thoroughly explored in the papers of the present special issue, are also described.
DISTRIBUTED SOURCE CODING AUTHENTICATION OF IMAGES WITH AFFINE WARPING
"... Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded ..."
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Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded images from tampering but also to localize tampered regions in an image already deemed to be inauthentic. In both cases, authentication requires a Slepian-Wolf encoded image projection that is supplied to the decoder. We extend our scheme to authenticate images that have undergone affine warping. Our approach incorporates an Expectation Maximization algorithm into the Slepian-Wolf decoder. Experimental results demonstrate that the proposed algorithm can distinguish legitimate encodings of authentic images from illegitimately modified versions, despite an arbitrary affine warping, using authentication data of less than 250 bytes per image. Index Terms — Image authentication, distributed source coding, Expectation Maximization 1.
Authenticating contrast and brightness adjusted images using distributed source coding and expectation maximization
- in Proc. IEEE International Conference on Multimedia and Expo, ICME 2008
, 2008
"... Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many dif-ferently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded ..."
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Media authentication is important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many dif-ferently encoded versions of a media file might exist. Our previous work applied distributed source coding not only to distinguish the legitimate diversity of encoded images from tampering but also lo-calize the tampered regions in an image already deemed to be inau-thentic. An authentication decoder was supplied with a Slepian-Wolf encoded image projection as authentication data. We extend our scheme to authenticate contrast and brightness adjusted images using an Expectation Maximization algorithm. Ex-perimental results demonstrate that the proposed algorithm can dis-tinguish legitimate encodings of authentic contrast and brightness adjusted images from illegitimately modified versions using authen-tication data of about 100 bytes. Index Terms — Image authentication, distributed source coding, Expectation Maximization 1.
RATE EFFICIENT REMOTE VIDEO FILE SYNCHRONIZATION
"... Video file synchronization between remote users is an important task in many applications. Re-transmission of a video that has been only slightly modified is expensive, wasteful and avoidable. We propose a scheme that automatically detects and sends only modified content according to some user defin ..."
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Video file synchronization between remote users is an important task in many applications. Re-transmission of a video that has been only slightly modified is expensive, wasteful and avoidable. We propose a scheme that automatically detects and sends only modified content according to some user defined distortion constraint to enable rate savings under a wide range of video edits. Through the use of a low-rate hierarchical hashing scheme, we can detect modifications with some spatial granularity. We also apply distributed source coding techniques to exploit correlation between remote copies for a further rate rebate. Experimental results show that the proposed approach achieves up to 7 × rate reduction when compared to re-transmitting. Index Terms — VSYNC, rsync, video file synchronization, video hash, video coding
QUALITY-CONTROLLED VIEW INTERPOLATION FOR MULTIVIEW VIDEO
"... Multiview video coding systems are characterized by their high en-coding complexity. In this paper, we propose to reduce the encoding complexity by omitting frames at the encoder in a pattern that keeps the ability to reconstruct an interpolated version of each omitted frame, by motion-compensated a ..."
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Multiview video coding systems are characterized by their high en-coding complexity. In this paper, we propose to reduce the encoding complexity by omitting frames at the encoder in a pattern that keeps the ability to reconstruct an interpolated version of each omitted frame, by motion-compensated and inter-view interpolation. Since our goal is maintaining good visual quality, we propose a method to estimate the quality of the interpolated frames at the decoder by transmitting a small amount of error control information in lieu of an omitted frame. This information is obtained from a projection of the frame on a suitable low-dimensional basis. The projection coefficients can be compressed by conventional techniques or, more efficiently, by Slepian-Wolf coding. Based on the quality estimate, the decoder can adaptively detect the interpolation technique that re-sults in better visual quality. Moreover, it can suppress occasional frames for which interpolation yields noticeable artifacts. Experi-mental results demonstrate that our approach eliminates most inter-polation artifacts and achieves much better visual quality at a very small increase in bit-rate. Index Terms — video quality, multiview video, interpolation 1.
LOCALIZATION OF TAMPERING IN CONTRAST AND BRIGHTNESS ADJUSTED IMAGES USING DISTRIBUTED SOURCE CODING AND EXPECTATION MAXIMIZATION
"... ABSTRACT Media authentication and tampering localization are important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding to authenticate the le ..."
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ABSTRACT Media authentication and tampering localization are important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Many differently encoded versions of a media file might exist. Our previous work applied distributed source coding to authenticate the legitimate diversity of encoded images and also localize the tampered regions in an inauthentic image. The authentication/localization decoder was supplied with a Slepian-Wolf encoded image projection as authentication data. We extend our scheme to localize tampering in contrast and brightness adjusted images using an Expectation Maximization algorithm at the decoder. Experimental results demonstrate that tampered image blocks can be identified with high probability using data of only a few hundred bytes for a 512x512 image.
eecs.berkeley.edu
"... eecs.berkeley.edu VSYNC is a novel incremental video file synchronization system that efficiently synchronizes two video files at remote ends through a bi-directional communications link. Retransmission of a video file that has been modified only slightly, for the purpose of synchronization with a r ..."
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eecs.berkeley.edu VSYNC is a novel incremental video file synchronization system that efficiently synchronizes two video files at remote ends through a bi-directional communications link. Retransmission of a video file that has been modified only slightly, for the purpose of synchronization with a remote-end copy, is extremely expensive but avoidable. VSYNC is a bi-directional algorithm designed to automatically detect and transmit changes in the modified video file without the knowledge of what was changed. Another feature of VSYNC is that it allows synchronization to within some user defined distortion constraint. A hierarchical hashing scheme is designed to compare video chunks, converting the high-level content information to a low-level hash stream that is more amenable to the tools of coding theory. Our approach shows impressive gains in transmission rate-savings. In a typical example of two 12 sec video files with about 10 % of the frames being edited, transmission savings of 44 % to 87 % can be obtained compared to directly sending the updated video files using H.264 and rsync [1].
Image Authentication System using LDPC and Watermarking Technique
"... Now a days, the rate of using digital image is increasing exponentially because of its low cost and easy manipulation property. It is obvious that digital images captured from CCD cameras or other digital image devices have to be analyzed and determined before processing it, to keep the integrity an ..."
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Now a days, the rate of using digital image is increasing exponentially because of its low cost and easy manipulation property. It is obvious that digital images captured from CCD cameras or other digital image devices have to be analyzed and determined before processing it, to keep the integrity and ensure the accuracy and reliability of the digital image. We need some sort of robust methods and standard procedures that guarantee and strengthen the authenticity of digital image. Image authentication is a technique that analyzes a digital image and determines whether it is altered or not. Image authentication technique is very useful for various organizations such as health care, law enforcement agencies and insurance sector etc. Image authentication is also important in content delivery via untrusted intermediaries, such as peer-to-peer (P2P) file sharing. Untrusted intermediaries might tamper the contents of image. Distinguishing the legitimate diversity of encodings from malicious manipulation is the challenge addressed in this paper. We developed a LDPC and watermark based new approach for image authentication. With the help of this approach we can authenticate images effectively. In our technique, we provide LDPC quantized image projection and the Encrypted image as authentication data. As well as watermark image that was embedded into original image to identify legitimate or illegitimate state of image authentication system. These data can be correctly decoded only with the help of an authentic image as side information. This technique provides the desired robustness against legitimate encoding alteration, while detecting illegitimate variations.
AN OVERVIEW OF THE USE OF DISTRIBUTED SOURCE CODING IN MULTIMEDIA SECURITY
"... In the 1970’s Slepian and Wolf proved that lossless source coding without side information at the encoder may perform as well as encoding with side information at the encoder. Wyner and Ziv extended the result to establish ratedistortion bounds for lossy compression. This has been used to examine th ..."
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In the 1970’s Slepian and Wolf proved that lossless source coding without side information at the encoder may perform as well as encoding with side information at the encoder. Wyner and Ziv extended the result to establish ratedistortion bounds for lossy compression. This has been used to examine the problem of coding multiple correlated distributed sources. In distributed coding, source statistics are exploited at the decoder and the encoder can be simplified. Since then these theoretic results were revisited in the late 1990s and several methods have been developed to achieve the results predicted by the theory. They are generally based on the channel coding techniques. In the past several years we have seen a great deal of work done in distributed video coding.
