Élimination des artefacts pour un codage JPEG optimisé

Dans notre travail, nous avons traité le problème des effets de blocs qui apparaissent sur l'image reconstruite dans le cas d'une compression JPEG, en particulier à très bas débits. L'originalité consiste à appliquer une opération de lissage non linéaire sur l'image reconstruite basée sur les statistiques de l'image et d'utiliser un codeur JPEG permettant d'optimiser le compromis débit/distorsion avec un contrôle du débit. Les résultats de simulation montrent une amélioration au niveau de la qualité en terme de PSNR de l'ordre (0.2-0.8 dB) par rapport au même algorithme de compression sans lissage et une réduction importante des effets de blocs du point de vue visuel

Improved quantization index modulation-based watermarking integrated to JPEG2000 coding scheme

International audienc

JP3D compressed-domain watermarking of volumetric medical data sets

International audienc

JP3D compressed-domain watermarking of still and volumetric medical images

International audienc

Summary Wavelet Domain Watermark Embedding Strategy using TTCQ Quantization

Invisible Digital watermarks have been proposed as a method for discouraging illicit copying and distribution of copyright material. Due to its characteristics, one of the problems in image watermarking is to decide how to hide in an image as many bits of information as possible while ensuring that the information can be correctly retrieved at the detecting stage, even after various attacks. Several approaches based on Discrete Wavelet Transform (DWT) have been proposed to address the problem of image watermarking. The advantage of DWT relative to the DCT is that it allows for localized watermarking of the image. The central contribution of this paper is to develop a watermarking algorithm, resilient to like lossy compression attack, by exploring the use of turbo trellis-coded quantization techniques (turbo TCQ) on the wavelet domain. Our results indicate that the proposed approach performs well against lossy wavelet-based compression attacks such as JPEG2000 and SPIHT. Key words: Wavelet transform, watermark embedding, TTCQ quantization, Image compression 1

ImprovedQIM based watermark design for secure imaging in JPEG2000

International audienc

Codage conjoint des images médicales volumiques sur le tatouage par TTCQ et la compression JP3D

National audienc

Improved QIM based watermarking integrated to JPEG2000 coding Scheme

International audienc

JP3D compressed domain watermarking of volumetric medical data

International audienc

Blind watermarking integrated to wavelet image coding scheme

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