Improved Watermark Estimation Scheme Based on Neighborhood Filter

This paper introduces a new watermark estimation scheme for an additive watermark embedding model in spatial domain. Unlike traditional estimating filters only considering spatially adjacent pixels, the proposed method takes into account pixels which are both in close intensity value and spatially near distance. Thus, it is possible for the proposed method to estimate stably the watermark signal from a watermarked image that severely fluctuates in intensity value. Also, this paper proposes the preprocessing method that boosts the performance of our watermark estimation filter by suppressing host signal noises. Extensive experimental results show that the proposed method outperforms the traditional filters under various attacks.