根据提出的虚拟通道技术，提出一种在载体中嵌入灰度图像作为水印的数字水印算法．通过修改载体频率域系数，载体通道可被看成一个虚拟的水印通道，它由若干个缺损的水印子通道构成，水印的提取不需要原始载体或原始水印的参与．实验结果表明提出的算法很好地保证了水印的不可见性和稳健性．

A novel blind watermarking algorithm based on virtual channel technique was proposed,by which a gray-scale image was embedded into host image. By modifying coefficients of host image in frequency domain,the host channel can be regarded as a virtual watermark channel,which was composed of several deficient sub-channels. Neither original image nor original watermark was necessary in extraction. Experimental results show that proposed algorithm provides good invisibility and robustness.