基于小波变换和视觉感知特性的盲水印算法

Blind Watermarking Algorithm Based on Wavelet Transform and Visual Perception Characteristics

借鉴基于视觉感知特性的图像压缩思想,提出了一种基于小波变换和视觉感知特性的自适应盲水印算法.首先,将载体图像进行小波变换,利用视觉系统的照度掩蔽特性和纹理掩蔽特性把载体小波系数分为9类.其次,对二值水印图像分别进行3次不同的置乱,得到3个随机水印序列.最后依据载体图像小波系数的分类,将3个随机水印序列以不同强度嵌入到3个方向的小波系数中.该算法在抽取水印图像时不需要原始载体图像和原始水印图像.实验结果表明,该算法对裁剪、JPEG压缩、加噪、图像增强、滤波等处理都有很好的抵抗力.

In this paper, an adaptive blind watermarking algorithm based on the wavelet transform and the human visual perception characteristics is proposed by drawing on the concept of the human perception-based image compression. In this algorithm, the carrier image is first decomposed by means of the wavelet transform, and the wavelet coefficients of the image are classified into 9 kinds according to the characteristics of the illumination mask, the texture mask and the edge mask in the visual system. Then, the bilevel watermarking image is disarranged for 3 times, thus obtaining three random watermarking sequences, which, according to the classification of the wavelet coefficients, are finally embedded into 3 bands of carrier wavelet coefficients with different intensities. The proposed algorithm can detect watermarking images without the help of the original carrier images and the original watermarking images. Experimental results show that the proposed algorithm is robust enough to some image degradation processes such as cropping, JPEG compression, noise adding, image enhancing and filtering.