Learn More
This paper summarizes the rst international challenge on steganalysis called BOSS (an acronym for Break Our Steganographic System). We explain the motivations behind the organization of the contest, its rules together with reasons for them, and the steganographic algorithm developed for the contest. Since the image databases created for the contest(More)
This paper presents a novel method for detection of steganographic methods that embed in the spatial domain by adding a low-amplitude independent stego signal, an example of which is LSB matching. First, arguments are provided for modeling differences between adjacent pixels using first-order and second-order Markov chains. Subsets of sample transition(More)
Blind steganalysis based on classifying feature vectors derived from images is becoming increasingly more powerful. For steganalysis of JPEG images, features derived directly in the embedding domain from DCT coefficients appear to achieve the best performance (e.g., the DCT features 10 and Markov features 21). The goal of this paper is to construct a new(More)
The goal of this paper is to determine the steganographic capacity of JPEG images (the largest payload that can be undetectably embedded) with respect to current best steganalytic methods. Additionally, by testing selected steganographic algorithms we evaluate the influence of specific design elements and principles, such as the choice of the JPEG(More)
This paper presents a method for the detection of double JPEG compression and a maximum-likelihood estimator of the primary quality factor. These methods are essential for construction of accurate targeted and blind steganalysis methods for JPEG images. The proposed methods use support vector machine classifiers with feature vectors formed by histograms of(More)
YASS is a steganographic algorithm for digital images that hides messages robustly in a key-dependent transform domain so that the stego image can be subsequently compressed and distributed as JPEG. Given the fact that state-of-the-art blind steganalysis methods of 2007, when YASS was proposed, were unable to reliably detect YASS, in this paper we(More)
A quantitative steganalyzer is an estimator of the number of embedding changes introduced by a specific embedding operation. Since for most algorithms the number of embedding changes correlates with the message length, quantitative steganalyzers are important forensic tools. In this paper, a general method for constructing quantitative steganalyzers from(More)
PURPOSE The purpose of this study was to determine which femoral tunnel drilling technique most closely reproduces the anatomic femoral footprint and has acceptable tunnel length and tunnel orientation. METHODS We divided 20 cadaveric knees into 4 equal groups. Arthroscopically, the anatomic femoral footprint was marked with an awl as the tunnel starting(More)
During three consecutive ski seasons (1991 to 1994), 125 patients 40 years of age and older without previous shoulder injuries or surgery sustained a traumatic first-time anterior shoulder dislocation. At a minimum of 2 years' follow-up, patients were contacted to determine long-term outcome and to identify factors leading to prolonged morbidity or the need(More)