Paper
20 June 2003 Registration methods for nonblind watermark detection in digital cinema applications
Philippe Nguyen, Raphaele Balter, Nicolas Montfort, Severine Baudry
Author Affiliations +
Proceedings Volume 5020, Security and Watermarking of Multimedia Contents V; (2003) https://doi.org/10.1117/12.479735
Event: Electronic Imaging 2003, 2003, Santa Clara, CA, United States
Abstract
Digital watermarking may be used to enforce copyright protection of digital cinema, by embedding in each projected movie an unique identifier (fingerprint). By identifying the source of illegal copies, watermarking will thus incite movie theatre managers to enforce copyright protection, in particular by preventing people from coming in with a handy cam. We propose here a non-blind watermark method to improve the watermark detection on very impaired sequences. We first present a study on the picture impairments caused by the projection on a screen, then acquisition with a handy cam. We show that images undergo geometric deformations, which are fully described by a projective geometry model. The sequence also undergoes spatial and temporal luminance variation. Based on this study and on the impairments models which follow, we propose a method to match the retrieved sequence to the original one. First, temporal registration is performed by comparing the average luminance variation on both sequences. To compensate for geometric transformations, we used paired points from both sequences, obtained by applying a feature points detector. The matching of the feature points then enables to retrieve the geometric transform parameters. Tests show that the watermark retrieval on rectified sequences is greatly improved.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Philippe Nguyen, Raphaele Balter, Nicolas Montfort, and Severine Baudry "Registration methods for nonblind watermark detection in digital cinema applications", Proc. SPIE 5020, Security and Watermarking of Multimedia Contents V, (20 June 2003); https://doi.org/10.1117/12.479735
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CITATIONS
Cited by 10 scholarly publications.
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KEYWORDS
Digital watermarking

Image registration

Projection systems

Cameras

Content addressable memory

Sensors

Automatic control

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