In this paper, we describe some attack strategies we have applied to three different grayscale watermarked images
in the particular context of BOWS (Break Our Watermarking System) Contest<sup>1</sup>; we also propose a possible use
of BOWS as a teaching tool for master students.
We describe a novel framework for watermarking 3-D objects using their texture or silhouette information. Unlike most conventional 3-D object-watermarking techniques, for which both insertion and extraction of the mark are performed on the object itself (3-D/3-D approach), we propose an asymmetric 3-D/2-D procedure. It consists in watermarking 3-D objects and retrieving the mark from rendering 2-D images or videos having used the 3-D synthetic object, thus protecting the visual representations of the object. Two 3-D object watermarking schemes are presented, a texture-based approach for 3-D photorealistic objects and a silhouette-based approach for 3-D CAD (computer-assisted design) objects.
In this paper we describe a novel framework for watermarking 3-D objects via contour information. Instead of classical existing watermarking technologies dealing with 3-D objects that operate on the object itself to insert and extract the mark (3-D/3-D approach), the goal of our work is to retrieve information originally hidden in the apparent contour of the object from resulting 2D images or videos having used the 3D synthetic object (3-D/2-D approach). In this paper we also propose an extension of 2-D polygonal line watermarking algorithm to 3-D silhouette.