关键词: 数字水印, 广义高斯分布, 小波变换, 视觉模型, 接收者操作特征曲线

Abstract: The additive watermarking algorithm has good imperceptibility, however, the robustness of watermark is poor. As a result, a multiplicative image watermarking method was proposed by combining the visual model in the wavelet domain. In the proposed embedding scheme, the middle-frequency subband acted as the watermark embedding space, which was used to achieve the tradeoff between the imperceptibility and the robustness of watermarking system. Besides, the embedding strength factor was determined by considering the frequency masking, luminance masking and texture masking of host image. In the proposed detection scheme, the probability density function of wavelet coefficients was modeled by the Generalized Gaussian Distribution (GGD), and the watermark decision threshold was obtained by using the Neyman-Pearson (NP) criterion, and the Receiver Operating Characteristic (ROC) curve between the probability of false alarm and the probability of detection was derived. Finally, the robustness of the proposed watermarking was tested when being against common image processing attacks such as JPEG compression, Additive White Gaussian Noise (AWGN), scaling and cropping. The experimental results demonstrate that the proposed method has good detection performance and good robustness.

Key words: digital watermarking, Generalized Gaussian Distribution (GGD), wavelet transform, visual model, Receiver Operating Characteristic (ROC) curve