Que produire un watermarking resistant aux compressions destructives actuelles n'existe pas encore, je veux bien. Que cela ne soit jamais, j'ai plus de mal a le croire... un algo de compression destr. ne detruit pas TOUTES les données non perceptible (et pour cause...ca finirait par le devenir, perceptible). On peut donc, a mon sens, toujours trouver un watermarking capable de resister aux algos CONNUS de compression.
A fins d'illustration, une url sur le sujet: http://www.cs.cornell.edu/Info/People/mateev/Watermark/watermarking(...)
...et un extrait choisi: " * it should be difficult (if not impossible) to remove watermarks without significantly reducing the quality of the image. In particular, we would want to be able to retrieve the watermark after the following manipulations:
* common signal processing operations such as adding noise, change of brightness, change of contrast, and requantization;
* common geometric distortions such as translation, scaling, rotation, and cropping;
* collusion by multiple users who possess different watermarked copies of the data."
[^] # Re: Loi SSSCA aux USA
Posté par Olivier M. . En réponse à la dépêche Screamer cracke MS-DRM. Évalué à 2.
A fins d'illustration, une url sur le sujet:
http://www.cs.cornell.edu/Info/People/mateev/Watermark/watermarking(...)
...et un extrait choisi: " * it should be difficult (if not impossible) to remove watermarks without significantly reducing the quality of the image. In particular, we would want to be able to retrieve the watermark after the following manipulations:
* common signal processing operations such as adding noise, change of brightness, change of contrast, and requantization;
* common geometric distortions such as translation, scaling, rotation, and cropping;
* collusion by multiple users who possess different watermarked copies of the data."