【摘要】 提出了一种改进的数字图像扩频水印技术。该算法将水印序列经过伪随机序列扩展频谱后,根据图像本身的亮度掩盖特性和DCT域的频率掩盖特性,计算出图像子块不同部分的最小掩盖阈值,由此在图象的不同部分嵌入不同强度的水印,从而在保证水印不可视的前提下,提高了算法的鲁棒性,使其对JPEG压缩、中值滤波等攻击具有很好的抵抗能力。更多还原

【Abstract】 An improved digital watermarking algorithm in DCT domain is put forward. It utilizes the visual masking in DCT domain to embed pseudo-randomly coded watermarks in different image parts with different intensity, which enhances the robustness of watermarking and keep it invisible. Experimental results show that the algorithm can stand against several attacks, such as JPEG compression, median filtering,etc..更多还原