基于DCT技术彩色图像水印算法的研究

采用DCT技术进行彩色图像水印的嵌入与提取,提出一种基于DCT域的彩色图像数字水印算法.该算法利用Amold变换置乱图像,给出DCT系数所对应的径向频率的排列图,通过人类视觉系统特性计算权值因子的方法确定鲁棒值系数,利用最小可察觉误差嵌入最大可能的水印信息量,分析并研究数字水印信息在嵌入位置选择上对水印算法性能的影响.在嵌入水印时,针对HSI色彩空间,在亮度分量I以及两个色差分量H和S中嵌入鲁棒水印,通过分块把原始图像各分量的DC系数嵌进鲁棒水印,进行标识版权,实现嵌入强度与区域特性的自适应变化,有效加强同类水印方案的鲁棒性,提高多媒体版权保护能力.

Research color image watermarking algorithm based on DCT technology

Based on color image watermark embedding and extraction with DCT technology, a color image digital watermarking algorithm is proposed. The algorithm uses the Arnold transform scramb- ling image, radial frequency corresponding DCT coefficients are given for the arrangement graph. It also uses the characteristics of human visual system calculation of weight factor to determine robust coefficient. The minimum detectable watermarking information is embedded in the maximum possible error, analyzing the digital watermark information in the choice of embedding position on the per- formance of the watermark algorithm. When the watermark is embedded, in HSI color space, the lu- minance component I and two color components H and S embed robust watermark, through block DC coefficients embedded robust watermark of each component of the original image, for copyright iden- tification and adaptive changes. It can realize the embedding strength and regional characteristics, ef- fectively strengthen the robustness of the watermarking scheme multimedia copyright protection abil- ity.