摘要： 提出一种空域和时频域相结合的多分辨率灰度图像水印算法。该算法对原始载体图像进行离散小波分解，并对灰度水印图像先进行拉普拉斯金字塔分解再进行位平面分解。将水印图像位平面分解系数嵌入到原始图像的水平和垂直分量上，水印嵌入小波系数的位置由具有混沌特性的Arnold映射确定，从而实现水印的盲提取。实验结果证明，该算法对图像的普通处理，如噪声、滤波、剪切、JPEG压缩和旋转等，均具有较好的鲁棒性。

关键词: 灰度图像水印, 离散小波变换, 拉普拉斯金字塔分解, 位平面分解, Arnold映射

Abstract: Based on space and time-frequency, a multi-resolution gray image watermarke algorithm is proposed. For the original carrier image, it is decomposed by Discrete Wavelet Transform(DWT). For the watermarke, it is decomposed by Laplacian pyramid transformation, and is decomposed by bit-plane. After that the coefficients of the bit-plane decomposition are embedded in each layer in the horizontal and vertical components of wavelet decomposition. The chaotic Arnold mapping is utilized to generate the watermarking embedding position in order to enhance the security of watermarke. Through the inverse transformation, the embedded digital watermarke is extracted. The watermarke can be extracted without the original image. Experimental results show that the proposed algorithm is robust to some image processing operations, such as noise attacks, filtering attacks, cutting attacks, JPEG compressing attacks and rotation attacks.

Key words: gray image watermark, Discrete Wavelet Transform(DWT), Laplacian pyramid decomposition, bit-plane decomposition, Arnold mapping

中图分类号: 

• TP309