盲水印提取时不需要参考原始载体图像，在信息隐藏、版权保护等方面具有更广泛的应用前景。提出的盲水印算法在分块离散余弦变换（DCT）和离散小波变换（DWT）的基础上，利用关系双方DCT系数和DWT系数在受到攻击时具有相同变化趋势的特点，采用关系嵌入和量化嵌入的自适应选择嵌入策略，较大幅度地提高了盲水印提取的鲁棒性。同时在量化嵌入中采用抖动调制，实现了水印透明性和鲁棒性调节的便捷性。大量仿真实验结果表明该算法对噪声干扰、低通滤波、JPEG压缩、对比度增强等攻击有很好的鲁棒性和透明性。

Blind watermark extraction can be fulfilled without referring to the original host image. Therefore it has much prospective applications in the fields of information hiding and copyright protection. Based on blocking Discrete Cosine Transform (DCT) and blocking Discrete Wavelet Transform (DWT), the proposed blind watermarking algorithm uses an embedding strategy of adaptively selecting either relationship embedding or quantization embedding. The relationship embedding comes from the observation that both the magnitudes of coefficients concerned in the relationship usually have the same change trend when the image is attacked. This strategy remarkably improves the robustness of watermark extraction. In addition, dither modulation is used in quantization embedding, by which the tradeoff between transparency and robustness of watermarking can be easily adjusted. Simulation results show that the algorithm is fairly robust against the attacks such as noise, filtering, compression, and contrast enhancement, and it maintains satisfying transparency.