1:00, IMDSP-P7.1
DATA HIDING IN HALFTONE IMAGES BY STOCHASTIC ERROR DIFFUSION
O. AU, M. FU
In this paper, we propose a novel method called DHSED to hide binary visual patterns in two error diffused halftone images. While one halftone image is only a regular error diffused image, stochastic error diffusion is applied to the other image to generate special stochastic characteristics with respect to the first image such that the visual pattern would appear when the two halftone images are overlaid. Simulation results show that the two halftone images have good visual quality, and the hidden pattern appears with "normal" and "lower-than-normal" intensity when the two halftone images are overlaid.

1:00, IMDSP-P7.2
ANALYSIS OF WATERMARKING SYSTEMS IN THE FREQUENCY DOMAIN AND ITS APPLICATION TO DESIGN OF ROBUST WATERMARKING SYSTEMS
A. MIYAZAKI, A. OKAMOTO
This paper aims to design robust watermarking systems in the frequency domain. We first present the general model of watermark embedding and extracting processes and carry out their analysis. Then we examine the robustness of the watermarking system against common image processing and clarify the reason why detection errors occur in the watermark extracting process. Based on the result, we improve the watermark extracting process and design the robust watermarking systems. The improvement is accomplished using deconvolution filter and neural network techniques. Numerical experiments using the DCT-based watermarking system show good performance as we expected.

1:00, IMDSP-P7.3
ROBUST SPATIAL IMAGE WATERMARKING USING PROGRESSIVE DETECTION
A. TEFAS, I. PITAS
A novel method for image watermarking robust to geometric distortions is proposed. A binary watermark is embedded in a grayscale or a color host image. The ability of progressive watermark detection enables fast and robust watermark detection even after several geometric distortions of the watermarked image. Simulation results indicate the ability of the proposed method to deal with the aforementioned attacks. Experiments conducted using the StirMark Benchmarking tests, indicate the superiority of the proposed method.

1:00, IMDSP-P7.4
BLIND WATERMARKING APPLIED TO IMAGE AUTHENTICATION
J. EGGERS, B. GIROD
To prevent image manipulations and fraudulent use of modified images, the embedding of semi-fragile digital watermarks into image data has been proposed. The watermark should survive modifications introduced by random noise or compression, but should not be detectable from non-authentic regions of the image. The original image cannot be used by the watermark detector to verify the authenticity of the image. In this paper, we investigate the application of a recently developed quantization based watermarking scheme to image authentication. The watermarking technology, called Scalar Costa Scheme (SCS), allows reliable blind watermark detection from a small number of pixels, and thus enables the detection of local modifications to the image content. http://www.lnt.de/~eggers/publications.html

1:00, IMDSP-P7.5
EFFECT OF JPEG COMPRESSION ON IMAGE WATERMARK DETECTION
M. XIA, B. LIU
Compression on a watermarked image can significantly affect the detection of the embedded watermark. To show that a particular watermarking scheme is robust against compression, simulation is often relied upon. In this paper, we investigate this problem analytically. We first characterize the noise introduced by JPEG compression. We then propose a maximum a posteriori (MAP) detector, analyze its performance, and demonstrate that it has superior performance over the correlation detector.

1:00, IMDSP-P7.6
SET PARTITIONING IN OBLIVIOUS DATA HIDING
L. GANG, M. RAMKUMAR, A. AKANSU
In the oblivious steganography, host noise suppression is a great concern. Watermark signal energy is usually much less than that of the host signal. In this paper, we model the data hiding as a more general H0/H1 hypothesis testing problem. Decision making is based on the statistical distinction between H0 and H1. A simple embedding scheme, viz., set partitioning, is proposed. The coefficients are divided into two sets to represent bit value 1 and 0. Its performance is discussed. Experiments show improvement over existing schemes.

1:00, IMDSP-P7.7
BERNOULLI SHIFT GENERATED CHAOTIC WATERMARKS: THEORETIC INVESTIGATION
S. TSEKERIDOU, V. SOLACHIDIS, N. NIKOLAIDIS, A. NIKOLAIDIS, A. TEFAS, I. PITAS
The paper statistically analyzes the behaviour of chaotic watermark signals generated by n-way Bernoulli shift maps. For this purpose, a simple blind copyright protection watermarking system is considered. The analysis involves theoretical evaluation of the system detection reliability, when a correlator detector is used. The aim of the paper is twofold: (i) to introduce the n-way Bernoulli shift generated chaotic watermarks and theoretically contemplate their properties with respect to detection reliability and (ii) to theoretically establish their potential superiority against the widely used pseudorandom watermarks. Experimental verification of the theoretical analysis results is also performed.

1:00, IMDSP-P7.8
A NEW INTERPRETATION OF DATA HIDING CAPACITY
C. CANDAN, N. JAYANT
We present a new definition of data hiding capacity which complements the established theory in the field and produces practical estimates under many attacks. We discuss the relation between the proposed definition and the current theoretical work on data hiding capacity. The definition proposed is applied to still images to estimate the hiding capacity of a particular image under attacks such as JPEG compression and additive noise.

1:00, IMDSP-P7.9
INDEPENDENT COMPONENT ANALYSIS APPLIED TO DIGITAL IMAGE WATERMARKING
F. GONZALEZ-SERRANO, H. MOLINA-BULLA, J. MURILLO-FUENTES
The authors propose a new solution to the watermarking of images. This approach uses Independent Component Analysis (ICA) to project the image into a basis with its components as statistically independent as possible. The watermark is then introduced in this representation of the space. Thus, the change of basis is the key of the steganography problem. The algorithm applied to the fragile watermarking problem locates any change in the image since it also applies to the watermark. The problem of robust watermarking is also addressed from this new point of view. Some results are included to illustrate the method. http://alcaudon.tsc.uc3m.es/~murillo/