基于JPEG量化的数字图像水印容量估计

Digital Image Watermark Capacity Estimation Based on JPEG Quantification

提出一种基于JPEG量化的容量自适应数字图像水印算法.从JPEG量化出发,对可嵌水印位置进行选择.在此基础上,结合人眼视觉模型和图像纹理特性,得出水印最大可嵌强度,并给出相应的容量估计.水印的嵌入和提取采用修改极性方法.仿真结果表明,该算法能同时满足压缩和水印嵌入要求,不仅具有较好的不可视性和鲁棒性,而且在保证这些性能基础上,实现了自适应容量,较好地协调了水印三要素间的关系.

An algorithm of capacity self-adaptive digital image watermark based on JPEG quantification is put forward. First, from the principle of JPEG quantification, the embedding positions are selected. Then, the maximum watermark amplitude and watermark capacity are obtained with the aid of the human vision system and image feature. Finally, a simple amending polarity method is used to embed and extract the watermark. The simulation results show that this algorithm not only meets the need of watermark embedding and compression, but also has good invisibility and robustness properties. Moreover, this algorithm has realized the self-adaptive capacity. Thus, the relationship among the invisibility, robustness and capacity has been well balanced.