@inproceedings { VG:PVP2000a,
    author = { Shelby Pereira and Sviatoslav Voloshynovskiy and Thierry Pun },
    title = { Effective channel coding for DCT watermarks },
    booktitle = { IEEE International Conference on Image Processing ICIP 2000 },
    year = { 2000 },
    vgclass = { refpap },
    vgproject = { watermarking },
    address = { Vancouver, Canada },
    month = { September 10--13 },
    abstract = { We describe effective channel coding strategies which can be used in conjunction with linear programming optimization techniques for the embedding of robust perceptually adaptive DCT domain watermarks. The main contributions lie in the proposal of a coding strategy based on the magnitude of a DCT coefficient, the use of turbo codes for effec-tive error correction, and finally the incorporation of JPEG quantization tables at embedding. }
}

@inproceedings { VG:VDP2000,
    author = { Sviatoslav Voloshynovskiy and Fr{\'e}d{\'e}ric Deguillaume and Thierry Pun },
    title = { Content adaptive watermarking based on a stochastic multiresolution image modeling },
    booktitle = { Tenth European Signal Processing Conference (EUSIPCO'2000) },
    year = { 2000 },
    vgclass = { refpap },
    vgproject = { watermarking },
    address = { Tampere, Finland },
    month = { sep 5--8 }
}

@techreport { VG:VPI2000,
    author = { Sviatoslav Voloshynovskiy and Shelby Pereira and Victor Iquise and Thierry Pun },
    title = { Attack Modelling: Towards a Second Generation Watermarking Benchmark },
    institution = { Computer Vision Group, Computing Centre, University of Geneva },
    year = { 2000 },
    vgclass = { report },
    vgproject = { watermarking },
    number = { 00.05 },
    address = { rue G\'en\'eral Dufour, 24, CH-1211 Gen\`eve, Switzerland },
    month = { may },
    abstract = { Digital image watermarking techniques for copyright protection have become increasingly robust. The best algorithms perform well against the now standard benchmark tests included in the Stirmark package. However the stirmark tests are limited since in general they do not properly model the watermarking process and consequently are limited in their potential to removing the best watermarks. Here we propose a stochastic formulation of the watermark removal problem, considering the embedded watermark as additive noise with some probability distribution. The attack scheme consists of two main stages: a) watermark estimation and partial removal by a filtering based on a Maximum a Posteriori (MAP) approach; b) watermark alteration and hiding through addition of noise to the filtered image, taking into account the statistics of the embedded watermark and exploiting HVS characteristics. In a second stage we propose a ``second generation benchmark''. We follow the model of the Stirmark tests and propose the 6 following categories of tests: denoising attacks, wavelet compression, denoising/compression with following perceptual remodulation, template/ACF (synchronization) removal, denoising and random banding, the watermark copy attack. Our results indicate that even though some algorithms perform well against the stirmark benchmark, all algorithms perform poorly against our benchmark. This indicates that much work remains to be done before claims about ``robust'' watermarks can be made. We also propose a new method of evaluating image quality based on the Watson metric which overcomes the limitations of PSNR. }
}

@inproceedings { VG:PVP2000,
    author = { Shelby Pereira and Sviatoslav Voloshynovskiy and Thierry Pun },
    title = { Optimized wavelet domain watermark embedding strategy using linear programming },
    booktitle = { Wavelet Applications VII (part of SPIE AeroSense 2000) },
    year = { 2000 },
    vgclass = { refpap },
    vgproject = { watermarking },
    editor = { Harold H. Szu and Martin Vetterli },
    address = { Orlando, Florida USA },
    month = { April 26--28 },
    abstract = { Invisible Digital watermarks have been proposed as a method for discouraging illicit copying and distribution of copyright material. In recent years it has been recognized that embedding information in a transform domain leads to more robust watermarks. In particular, several approaches based on the Wavelet Transform have been proposed to address the problem of image watermarking. The advantage of the wavelet transform relative to the DFT or DCT is that it allows for localized watermarking of the image. A major di culty, however, in watermarking in any transform domain lies in the fact that constraints on the allowable distortion at any pixel are speci ed in the spatial domain. In order to insert an invisible watermark, the current trend has been to model the Human Visual System (HVS) and specify a masking function which yields the allowable distortion for any pixel. This complex function combines contrast, luminance, color, texture and edges. The watermark is then inserted in the transform domain and the inverse transform computed. The watermark is nally adjusted to satisfy the constraints on the pixel distortions. However this method is highly suboptimal since it leads to irreversible losses at the embedding stage because the watermark is being adjusted in the spatial domain with no care for the consequences in the transform domain. The central contribution of the paper is the proposal of an approach which takes into account the spatial domain constraints in an optimal fashion. The main idea is to structure the watermark embedding as a linear programming problem in which we wish to maximize the strength of the watermark subject to a set of linear constraints on the pixel distortions as determined by amasking function. We consider the Haar wavelet and Daubechies 4-tap filter in conjunction with a masking function based on a non-stationary Gaussian model, but the algorithm is applicable to any combination of transform and masking functions. Our results indicate that the proposed approach performs well against lossy compression such as JPEG and other types of filtering which do not change the geometry of the image. }
}

@misc { VG:PVP2000b,
    vgclass = { patent },
    vgproject = { watermarking },
    author = { Shelby Pereira and Sviatoslav Voloshynovskiy and Thierry Pun },
    title = { A method for generating and decoding image dependant watermarks },
    howpublished = { European Patent Application PCT/IB00/00494 },
    month = { Filed April 20 },
    year = { 2000 }
}

@inproceedings { VG:KVH2000,
    author = { Martin Kutter and Sviatoslav Voloshynovskiy and Alexander Herrigel },
    title = { Watermark copy attack },
    booktitle = { IS\&T/SPIE's 12th Annual Symposium, Electronic Imaging 2000: Security and Watermarking of Multimedia Content II },
    year = { 2000 },
    vgclass = { refpap },
    vgproject = { watermarking },
    editor = { Wah Wong, Ping and Edward J. Delp },
    volume = { 3971 },
    series = { SPIE Proceedings },
    address = { San Jose, California USA },
    month = { 23--28~jan },
    note = { (Paper EI 3971-35) },
    abstract = { Research in digital watermarking has progressed along two paths. While new watermarking technologies are being developed, some researchers are also investigating di erent ways of attacking digital watermarks. Common attacks to watermarks usually aim to destroy theembedded watermark or to impair its detection. In this paper we propose a conceptually new attack for digitally watermarked images. The proposed attack doesnot destroy anembedded watermark, but copies it from one image to a di erent image. Although this new attack does not destroy awatermark or impair its detection, it creates new challenges, especially when watermarks are used for copyright protection and identi cation. The process of copying the watermark requires neither algorithmic knowledge of the watermarking technology nor the watermarking key. The attack is based on an estimation of the embedded watermark in the spatial domain through a ltering process. The estimate of the watermark is then adapted and inserted into the target image. To illustrate the performance of the proposed attack we applied it to commercial and non-commercial watermarking schemes. The experiments showed that the attack is very e ective in copying a watermark from one image to a di erent image. In addition, we have a closer look at application dependent implications of this new attack. }
}

@misc { VG:VDPHP2000,
    vgclass = { patent },
    vgproject = { watermarking },
    author = { Sviatoslav Voloshynovskiy and Fr{\'e}d{\'e}ric Deguillaume and Shelby Pereira and Alexander Herrigel and Thierry Pun },
    title = { Method for adaptive digital watermarking robust against geometric transforms },
    howpublished = { European Patent Application PCT/IB00/01089 },
    month = { filed August 3, 2000 },
    year = { 2000 }
}

@inproceedings { VG:VPH2000,
    author = { Sviatoslav Voloshynovskiy and Shelby Pereira and Alexander Herrigel and Nazanin Baumg{\"a}rtner and Thierry Pun },
    title = { Generalized watermark attack based on watermark estimation and perceptual remodulation },
    booktitle = { IS\&T/SPIE's 12th Annual Symposium, Electronic Imaging 2000: Security and Watermarking of Multimedia Content II },
    year = { 2000 },
    vgclass = { refpap },
    vgproject = { watermarking },
    editor = { Wah Wong, Ping and Edward J. Delp },
    volume = { 3971 },
    series = { SPIE Proceedings },
    address = { San Jose, California USA },
    month = { 23--28jan },
    note = { (Paper EI 3971-34) - slides },
    abstract = { Digital image watermarking has become a popular technique for authentication and copyright protection. For verifying the security and robustness of watermarking algorithms, specific attacks have to be applied to test the proposed algorithms. In contrast to the known Stirmark attack, which degrades the quality of the image while destroying the watermark, this paper presents a new approach which is based on the estimation of a watermark and the exploitation of the properties of Human Visual System (HVS). The new attack satisfies two important requirements. First, image quality after the attack as perceived by the HVS is not worse than the quality of the stego image. Secondly, the attack uses all available prior information about the watermark and cover image statistics to perform the best watermark removal or damage. The proposed attack is based on a stochastic formulation of the watermark removal problem considering the embedded watermark as additive noise with some probability distribution. The attack scheme consists of two main stages: watermark estimation based a Maximum a Posteriori (MAP) approach and watermark alteration through addition of the noise to the filtered image taking into account the statistics of the embedded watermark and exploiting HVS characteristics. Experiments on a number of real world and computer generated images show the high efficiency of the proposed attack against several known academic and commercial methods: the watermark is completely destroyed in all tested images without altering the image quality. The approach can be used against watermark embedding schemes that operate either in coordinate domain, or transform domains like Fourier, DCT or wavelet. }
}

@article { VG:VAH2000,
    author = { Sviatoslav Voloshynovskiy and A. Allen and Z. Hrytskiv },
    title = { Robust edge-preserving image restoration in the presence of non-Gaussian noise },
    journal = { Electronics Letters },
    year = { 2000 },
    vgclass = { refpap },
    vgproject = { watermarking },
    note = { (accepted) }
}