@inproceedings { VG:HVH1999,
    author = { Alexander Herrigel and Sviatoslav Voloshynovskiy and Z. Hrytskiv },
    title = { Optical/digital identification/verification system based on digital watermarking technology },
    booktitle = { SPIE International Workshop on Optoelectronic and Hybrid Optical/Digital Systems for Image/Signal Processing ODS'99 },
    year = { 1999 },
    vgclass = { refpap },
    vgproject = { watermarking },
    series = { SPIE Proceedings },
    address = { Lviv, Ukraine },
    month = { 20--24~sep },
    abstract = { This paper presents a new approach for the secure integrity verification of driver licenses, passports or other analogue identification documents. The system embeds (detects) the reference number of the identification document with the DCT watermark technology in (from) the owner photo of the identification document holder. Since the watermark technology is resistant against many image distortions such as affine transformations, lossy compression, quantization, dithering and other common image processing operations, the owner photo my even be damaged without any performance decrease in the detection process. During verification the reference number is extracted and compared with the reference number printed in the in the identification document. The approach combines optical and digital image processing techniques. The detection system must be able to scan an analogue driver license or passport, convert the image of this document into a digital representation and then apply the watermark verification algorithm to check the payload of the embedded watermark. If the payload of the watermark is identical with the printed visual reference number of the issuer, the verification was successful and the passport or driver license has not been modified. This approach constitutes a new class of application for the watermark technology, which was originally targeted for the copyright protection of digital multimedia data. The presented approach substantially increases the security of the analogue identification documents applied in many European countries. }
}

@inproceedings { VG:VHB1999,
    author = { Sviatoslav Voloshynovskiy and Alexander Herrigel and Nazanin Baumg{\"a}rtner and Thierry Pun },
    title = { A stochastic approach to content adaptive digital image watermarking },
    booktitle = { International Workshop on Information Hiding },
    year = { 1999 },
    vgclass = { refpap },
    vgproject = { watermarking },
    volume = { LNCS 1768 },
    series = { Lecture Notes in Computer Science },
    pages = { 212--236 },
    address = { Dresden, Germany },
    month = { 29~September~--1~October },
    publisher = { Springer Verlag },
    abstract = { This paper presents a new stochastic approach which can be applied with different watermark techniques. The approach is based on the computation of a Noise Visibility Function (NVF) that characterizes the local image properties, identifying textured and edge regions where the mark should be more strongly embedded. We present precise formulas for the NVF which enable a fast computation during the watermark encoding and decoding process. In order to determine the optimal NVF, we first consider the watermark as noise. Using a classical MAP image denoising approach, we show how to estimate the ``noise''. This leads to a general formulation for a texture masking function, that allows us to determine the optimal watermark locations and strength for the watermark embedding stage. We examine two such NVFs, based on either a non-stationary Gaussian model of the image, or a stationary Generalized Gaussian model. We show that the problem of the watermark estimation is equivalent to image denoising and derive content adaptive criteria. Results show that watermark visibility is noticeably decreased, while at the same time enhancing the energy of the watermark. }
}

@inproceedings { VG:VHJ1999,
    author = { Sviatoslav Voloshynovskiy and Alexander Herrigel and Fr{\'e}d{\'e}ric Jordan and Nazanin Baumg{\"a}rtner and Thierry Pun },
    title = { A noise removal attack for watermarked images },
    booktitle = { Multimedia and Security Workshop },
    year = { 1999 },
    vgclass = { refpap },
    vgproject = { watermarking },
    editor = { J. Dittmann and K. Nahrstedt and P. Wohlmacher },
    address = { Orlando, Florida, USA },
    month = { 30--31~October },
    note = { (at the 7th ACM Multimedia Conference (Multimedia 99)) }
}

@inproceedings { VG:VPP1999,
    author = { Sviatoslav Voloshynovskiy and Shelby Pereira and Thierry Pun },
    title = { Watermark attacks },
    booktitle = { Erlangen Watermarking Workshop },
    year = { 1999 },
    vgclass = { fullconf },
    vgproject = { watermarking },
    address = { Erlangen, Germany },
    month = { 5--6~October },
    note = { (invited presentation) }
}