基于IWT和HVS的彩色图像数字水印算法

Digital Watermarking Algorithm for Color Image Based on IWT and HVS

针对目前大多数图像水印技术是关于灰度图像并且基于离散小波变换的。提出了一种基于整数小波变换(IWT:Integer Wavelet Transform)和人类视觉系统(HVS:Human Visual System)特性的彩色图像数字水印算法。本算法根据原始彩色图像的整数小波系数高、低频分量的特点,选择彩色图像的YIQ色彩空间的Y分量嵌入水印,利用人类视觉系统的特性,将二值水印图像加密后嵌入到Y分量的整数小波系数中。实验证明,该算法对锐化、JPEG2000压缩和旋转等图像处理均具有很强的抵抗能力,复杂度较低,实用性较强,更好地兼顾了水印不可见性与鲁棒性之间的矛盾。

Most of the present image watermarking techniques are about gray image and based on DWT （ Disceret Wavelet Transform. A digital watermarking algorithm for color image based on IWT （Integer Wavelet Transform） and HVS （ Human Visual System） is proposed. According to different characteristics of the high and the low frequency components of wavelet coefficients of the original color image, the original color image is transformed into the YIQ color space. Exploiting the excellent properties of the wavelet transform and some characteristics of Human Visual System （ HVS）, encrypted watermark is embedded into the Y luminance component of the YIQ in IWTdomain. Experimental results have proved that the method is robust to some image process such as sharpening, JPEG2000 compression and rotation etc, and it can well balance the contradiction between transparency and robustness of the digital watermark.