【摘要】 提出了一种DCT域量化索引调制水印算法.水印嵌入在经过像素置换的相邻图像块DCT系数的差值上,根据二值水印的信息位对该差值进行正/负调制,从而实现水印的嵌入.为了平衡不可见性和鲁棒性的要求,根据人类视觉系统的掩蔽特性及图像局部特征对不同嵌入点的嵌入强度进行自适应调整,在确保视觉质量的前提下,得到良好的水印性能.实验结果显示该算法对各种常见图像处理具有良好的鲁棒性.更多还原

【Abstract】 Quantization index modulation is a well-known method used for blind watermarking algorithm.A new QIM watermarking scheme in discrete cosine transform(DCT) domain is proposed.Watermark was embedded into the difference of DCT coefficients from neighboring blocks,which exchange pixels to each other before embedding.A bit of the watermarking could be embedded by modulating the difference to positive or negative.To keep the balance between invisibility and robustness,strength factor will be adjusted adaptively for each embedding position based on the masking feature of HVS.Using this adaptive adjusting,the watermarking performance is improved while keeping well perceptual effect.The experimental results show that this watermarking scheme is robust to various image processing.更多还原