<title>Robust content-dependent high-fidelity watermark for tracking in digital cinema</title>

TLDR

Forensic digital watermarking must be imperceptible, robust to degraded copies, and secure, yet no existing technology satisfies all three simultaneously. The authors present a watermarking approach that simultaneously achieves fidelity, robustness, and security. The method uses very low spatiotemporal frequency carriers and a placement strategy that makes jamming attacks prohibitively damaging to picture quality, even when the embedding algorithm is known. In tests on HD Cinemascope material, the watermark remained invisible and was recoverable after camcorder capture and after low‑pass filtering, noise, geometric shifts, and brightness/contrast adjustments.

Abstract

Forensic digital watermarking is a promising tool in the fight against piracy of copyrighted motion imagery content, but to be effective it must be (1) imperceptibly embedded in high-definition motion picture source, (2) reliably retrieved, even from degraded copies as might result from camcorder capture and subsequent very-low-bitrate compression and distribution on the Internet, and (3) secure against unauthorized removal. No existing watermarking technology has yet to meet these three simultaneous requirements of fidelity, robustness, and security. We describe here a forensic watermarking approach that meets all three requirements. It is based on the inherent robustness and imperceptibility of very low spatiotemporal frequency watermark carriers, and on a watermark placement technique that renders jamming attacks too costly in picture quality, even if the attacker has complete knowledge of the embedding algorithm. The algorithm has been tested on HD Cinemascope source material exhibited in a digital cinema viewing room. The watermark is imperceptible, yet recoverable after exhibition capture with camcorders, and after the introduction of other distortions such as low-pass filtering, noise addition, geometric shifts, and the manipulation of brightness and contrast.