Métriques de distorsion pour l'analyse comparative de schémas de filigranage 3D

Rondao Alface, Patrice [UCL] De Craene, Mathieu [UCL] Macq, Benoît [UCL]

Three-dimensional image quality assessment causes new challenges for a wide set of applications and particularly for emerging 3-D watermarking schemes. New metrics have to be drawn for the distortion measurement from an original 3-D surface to its deformed version. Such metrics are necessary namely in the case of a watermarking scheme to determine whether a distortion is acceptable or not. We propose two complementary strategies to tackle this issue. First, we propose a global perceptive metric based on the analysis of the differences between correspondent 2D views of the original and deformed versions of the 3D model. We show that the mutual information criterion better captures slightly perceptible distortions to which watermarking schemes must resist. Secondly, we focus on local deformations by estimating the distortion energy, extending works on distortion minimization for planar and spherical parameterizations. Finally results of both methods are discussed and compa! red to the state of the art.