Power-spectrum condition for energy-efficient watermarking

This paper presents a model for watermarking and some attacks on watermarks. Given the watermarked signal, the so-called Wiener attack performs minimum mean-squared error (MMSE) estimation of the watermark and subtracts the weighted MMSE estimate from the watermarked signal. Under the assumption of a fixed correlation detector, the attack is shown to minimize the expected correlation statistic for the same attack distortion among linear, shift-invariant filtering attacks. It also leads to the idea of energy-efficient watermarking--watermarking that resists MMSE estimation as much as possible--and provides a meaningful way to evaluate robustness. The paper shows that energy-efficient watermarks must satisfy a power-spectrum condition (PSC), which states that the watermark's power spectrum should be directly proportional to the original signal's. PSC-compliant watermarks are proven to be most robust. Experiments with signal models and natural images demonstrate that watermarks ...

• Type: Journal
• Year: 2002
• Where: TMM
• Authors: Jonathan K. Su, Bernd Girod
• Keywords: TMM 2002, Watermarked Signal, Watermarks, Wiener Attack