Adaptive quantization watermarking

In this paper we study the use of an adaptive quantization step size, instead of a fixed one, for the Scalar Costa Scheme. We propose an adaptation method based on Weber's law. This allows for a more effective embedding, which is also shown to render the watermark robust against sample value scaling. A model for the bit error probability due to the estimation of the adaptive quantization step size at the detector is derived, which provides insight in the required precision of estimating the quantization step size in the detector.