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Integer DCT convergence for JPEG-75 forensics for images

Research Authors
G. Fahmy
Research Department
Research Year
2015
Research Journal
International Journal of Information Assurance and Security (JIAS)
Research Publisher
MIRLABS
Research Vol
ISSN 1554-1010 Volume 10 (2015)
Research Rank
1
Research_Pages
pp. 080-088
Research Website
http://www.mirlabs.org/jias/
Research Abstract

Many forensic techniques recently tried to detect the tampering and manipulation of JPEG compressed images thatbecame a critical problem in image authentication and origin tracking. Some techniques indicated that a knowledgeable attacker can make it very hard to trace the image origin, while others indicated that portions of the compressed image that has been compressed at different quality factor quantization matrices are distinguishable if they are re-compressed at a higher quality factor quantization matrix (with less quantization steps). In this paper we propose the idea of adopting Integer DCT (ICT) as an implementation technique that can be utilized in the detection of any hacking or tampering of JPEG/ICT compressed images. The proposed approach is based upon recent literature ideas of recompressing JPEG image blocks and detecting if this block has been compressed/touched before or not. We also propose an ICT implementation that has a onetime signature on processed coefficients or pixels and can be used as a tool to detect if this block has been compressed before using the proposed implementation or not. We finally propose to re-compress images originally compressed with ICT but with a different quantization matrix as a different compression parameter to analysis and detect more forgeries. Illustrative examples on several processed images are presented with complexity analysis.