title: Still-image watermarking robust to local geometric distortions.
abstract: Geometrical distortions are the Achilles heel for many watermarking schemes. Most countermeasures proposed in the literature only address the problem of global affine transforms (e.g., rotation, scaling, and translation). In this paper, we propose an original blind watermarking algorithm robust to local geometrical distortions such as the deformations induced by Stirmark. Our method consists in adding a predefined additional information to the useful message bits at the insertion step. These additional bits are labeled as resynchronization bits or reference bits and they are modulated in the same way as the information bits. During the extraction step, the reference bits are used as anchor points to estimate and compensate for small local and global geometrical distortions. The deformations are approximated using a modified basic optical flow algorithm.
authors.affiliation: Eurécom Institute, 06904 Sophia-Antipolis, France. dugelay@eurecom.fr
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Dugelay
authors.forename: Stéphane
authors.initials: S
authors.lastname: Roche
authors.forename: Christian
authors.initials: C
authors.lastname: Rey
authors.forename: Gwenaël
authors.initials: G
authors.lastname: Doërr
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003196:Computer Graphics; D016494:Computer Security; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016247:Information Storage and Retrieval / Q000379:methods*; D010330:Patents as Topic; D010363:Pattern Recognition, Automated / Q000379:methods*; D011356:Product Labeling / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted