基于视觉感知的立体图像零水印算法研究

人眼感知立体图像，主要是对图像内容和深度信息的感知，而视点之间的差异是形成立体图像深度感知的一个重要原因。本文基于人眼视觉感知特性，提出了视点零水印和视差零水印算法，视点零水印将视点图像的亮度Y分量分块做DCT变换，并根据DCT域中低频系数的大小关系来构造视点零水印，提高了水印的鲁棒性和不可见性；视差零水印通过求取左右视图的视差值，搜索得到左右视图的匹配区域，根据匹配区域内左右图像块的DC系数大小关系来构造视差零水印。统计两类零水印恢复率，达到对立体图像质量和立体感知质量客观评价的目的。实验结果表明，该水印算法具有良好的鲁棒性和不可见性，通过水印恢复率客观评价图像质量和立体感知质量，与人眼主观评价具有一致性。

Zero-Watermarking Algorithm Research of Stereo Images Based on Visual Perception

The human eye’ s perception to stereo image bases mainly on the perception of image content and depth information,and the difference between the viewpoints is an important clue for the depth per-ception of stereo image. In this paper,based on the characteristics of human visual perception,a view zero-watermark and disparity zero -watermark algorithm is proposed. In the algorithm, we choose the Y component of view image for respectively transforming in block DCT, and the view zero -watermark is constructed by the relationship between the low -frequency coefficients of block DCT, which improving the robustness and invisibility of the watermark. By computing the disparity according to the left and right views,we can work out their similar area,and the disparity zero-watermark is constructed by the rela-tionship between the DC coefficients of left view and right view. By computing the recovery rate of two categories of zero -watermark, we can objectively evaluate the quality of image and stereo perception, which is consistent with the result of the subjective evaluation of the human eye. The experimental results show that the watermark is remarked for high robustness and invisibility.