基于多通道小波变换的彩色图像数字水印嵌入算法研究

Research on digital watermarking embedding algorithm based on multi-channel wavelet transform for color image

提出了一种基于多通道与离散小波变换(DWT)的彩色图像数字水印嵌入算法。该算法利用彩色图像人类视觉系统(HVS)的掩蔽特性,首先将彩色图像由RGB彩色空间映射到YCbCr彩色空间,然后利用YCbCr的空间独立特性获取3个相对独立的彩色通道Y、Cb、Cr。其次,计算视觉阈值矩阵JND,最后在离散小波域内进行水印的自适应嵌入。实验结果表明,该算法不仅具有较好的透明性,而且对诸如叠加噪声、JPEG压缩、几何剪切、图像增强、彩色图像的分色攻击等攻击性实验均具有较好的鲁棒性。

This paper presents an algorithm of digital watermarking embedding based on multi-channel and discrete wavelet transform （DWT） for color image. First of all, the scheme maps color image from RGB color space into YCbCr color space with masking characters of human visual system （HVS） for color image. And then, the algorithm acquires 3 color channel, Y, Cb, Cr that are relatively independent with each others by using the spatial independent characteristics of Y, Cb, Cr. Next, the approach calculates the visual threshold value matrix JND （just noticeable difference）. Finally, the algorithm embeds watermarks self-adaptively in discrete wavelet domain. Experiment results indicate that this scheme not only has good imperceptibility, but also has good robustness for the attacks of adding noises, JPEG compression, geometric clipping, image enhancement and the attack from every channel of color image.