中文摘要：

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．

英文摘要：

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.