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This paper presents a new model of the content reconstruction problem in self-embedding systems, based on an erasure communication channel. We explain why such a model is a good fit for this problem, and how it can be practically implemented with the use of digital fountain codes. The proposed method is based on an alternative approach to spreading the(More)
The rapidly improving performance of modern hardware renders convolutional codes obsolete, and allows for the practical implementation of more sophisticated correction codes such as low density parity check (LDPC) and turbo codes (TC). Both are decoded by iterative algorithms, which require a disproportional computational effort for low channel noise. They(More)
A sliding window-based analysis is a prevailing mechanism for tampering localization in passive image authentication. It uses existing forensic detectors, originally designed for a full-frame analysis, to obtain the detection scores for individual image regions. One of the main problems with a window-based analysis is its impractically low localization(More)
Accurate unsupervised tampering localization is one of the most challenging problems in digital image forensics. In this paper, we consider a photo response non-uniformity analysis and focus on the detection of small forgeries. For this purpose, we adopt a recently proposed paradigm of multi-scale analysis and discuss various strategies for its(More)
In this paper, we address the problem of adaptive self-embedding, where the reconstruction quality is controlled individually for different fragments of a digital image. We focus on the impact of incorporating content adaptivity features on the restoration success conditions and the achievable reconstruction performance. We analyze the problem theoretically(More)
In this paper we propose to use maximal entropy random walk on a graph for tampering localization in digital image forensics. Our approach serves as an additional post-processing step after conventional sliding-window analysis with a forensic detector. Strong localization property of this random walk will highlight important regions and attenuate the(More)
In this paper we address the issue of the trade-off between the tampering rate and the reconstruction quality of image authentication systems. We adopt the fountain coding paradigm and design an adaptive content reconstruction scheme. The scheme conforms the reconstruction quality of individual image fragments both to the local texture properties and to the(More)
In this paper we analyze the content reconstruction problem with the use of a revised erasure communication channel. Based on this approach, we propose a reconfigurable self-embedding system which can be adapted to different requirements. Our approach eliminates two major problems with the design of efficient content reconstruction algorithms and allows for(More)
This paper deals with the design of a self-embedding scheme for JPEG-compressed images. Most of existing schemes are compatible only with loss-less images. Few of them are capable of handling lossy compression, but deliver very low restoration fidelity, and support only small amounts of tampered content. In this study, we extend a recently proposed(More)