With the development of manipulations techniques of digital images, digital image forensic technology is becoming more
and more necessary. However, the determination of processing history of multi-operation is still a challenge problem. In
this paper, we improve the traditional seam insertion algorithm, and propose corresponding detection method. Then an
algorithm that focuses on detecting the processing history of seam insertion and contrast enhancement is proposed, which
can be widely used in practical image forgery. Based on comprehensive analysis, we have discovered the inherent
relationship between seam insertion and contrast enhancement. Different orders of processing make different impacts on
images. By using the newly proposed algorithm, both contrast enhancement followed by seam insertion and seam insertion
followed by contrast enhancement can be detected correctly. Plenty of experiments have been implemented to prove the
KEYWORDS: Forensic science, Detection and tracking algorithms, Photography, Image compression, Signal to noise ratio, Statistical analysis, Reliability, Digital forensics, Digital filtering, Image quality
We proposed a technique to detect the global addition of noise to a digital image. As an anti-forensics tool, noise addition is typically used to disguise the visual traces of image tampering or to remove the statistical artifacts left behind by other operations. As such, the blind detection of noise addition has become imperative as well as beneficial to authenticate the image content and recover the image processing history, which is the goal of general forensics techniques. Specifically, the special image blocks, including constant and strip ones, are used to construct the features for identifying noise addition manipulation. The influence of noising on blockwise pixel value distribution is formulated and analyzed formally. The methodology of detectability recognition followed by binary decision is proposed to ensure the applicability and reliability of noising detection. Extensive experimental results demonstrate the efficacy of our proposed noising detector.
Recently, a category of watermarking techniques based on binary phase-only filter (BPOF) has been proposed for image authentication. In such techniques, the authentication is implemented by evaluating the correlation between Fourier phase information and the hidden watermark bitplane. In this paper, we reveal the security flaws of BPOF-based watermarking algorithms and propose sophisticated tampering attacks against them. We show how the attacker can easily tamper with a watermarked image without being detected. Experimental results demonstrate that our attacks are successful in tampering watermarked images. The watermarking schemes are proven to be fundamentally flawed.