Jpeg Anti-Forensics of Undetectability and Image Quality

Abstract

This paper proposes aJPEG anti-forensic method, which aims at removing the footprints left by JPEG compression in both the spatial domain and DCT domain, with reasonable loss of image quality, the proposed method can defeat existing forensic detectors that attempt to identify traces of the image JPEG compression history or JPEG anti-forensic processing. In our framework, first because of a total variation-based deblocking operation, the partly recovered DCT information is thereafter used to build an adaptive local dithering signal model, which is able to bring the DCT histogram of the processed image close to that of the original one. Then, a perceptual DCT histogram smoothing is carried out by solving a simplified assignment problem, where the cost function is established as a total perceptual quality loss due to the DCTcoefficient modification. The second-round deblocking and decalibration operations successfully bring the image statistics that are used by the JPEG forensic detectors to the normal status. Experimental results show that the proposed method outperforms the state-of-the-art methods in a better tradeoff between theJPEG forensic undetectability and the visual quality of processed images.