一种基于图像边缘的鲁棒水印算法

本文基于图像的边缘，提出一种鲁棒水印算法．该算法使用Prewitt检测算子对载体图像进行边缘检测，并对边缘点进行选取，将水印信息嵌入在边缘点像素处的梯度方向上．由于人类视觉感知在图像边缘处的掩蔽效应，同时由于图像边缘的感知重要性和在图像处理中的稳定性，使得本文算法在不可见性和鲁棒性方面具有较好的效果．本文从理论上分析了算法抵抗攻击的能力．并在试验中得到了验证．同时结合人类视觉感知的掩蔽效应．提出了一种客观评价图像质量的方法．试验中对该方法进行了验证，并表明本文算法在该方法下具有较好的不可见性．

An image edge based robust watermarking algorithm

Based on the edges of inmge, a robust watermarking algorittml is proposed in this paper. W＇e use the Prewitt method to detect the edge of cover image and embed tile watermark into the direction of the edges＇ grads. Because of the masking effect of human vision, tile invisibility of our algorithm is good. Because of the stability of the edges to image processing and tile essentiality of human vision, the robustness of our algorithm is good as well. We analyze its ability to resist attack of the algorithm theoretically, and validate it through experimentation. In addition, based on the masking effect of human vision, we propose a method for evaluating watermarked image quality. We validate this method by experiments. This resnlt shows that the proposed watermarking algorithm has good invisibility.