基于块的索引图像认证水印算法

An Index Image Authentication Watermarking Algorithm Based on Image Block

根据索引图像的特点,结合新颖的样本选取方法提出了一种有效的彩色图像认证水印方法.水印嵌入器在不改变原始图像调色板的基础上,将水印嵌入到图像像素值对应的灰度排名中.水印信号为利用混沌序列生成的二值图像,水印的嵌入位置由密钥和8×8块中的32个像素共同决定,具有非常好的安全性;水印的提取和图像认证不需要原始图像.实验表明:该方法嵌入的水印不可见性好,对JPEG压缩、图像剪切和图像变换等处理具有很好的易碎性,适合于图像的区域认证和完整性验证.

An index image authentication watermarking algorithm is presented based on the choice swatch method. The watermark is embed in the index of gray, and not change the palette of image. The watermark is a binary image based on chaotic sequences, and use 32 pixels in the block to determine the position of watermark in the image block, which can assure security for the watermark. The watermark is extracted without the origial image. The experiments show that the algorithm can assure good imperceptibility for watermarked image and the watermark embedded using the algorithm has good fragility against the attacks such as JPEG compression, image shearing and transforming, and beseem to region and integrality authentication for image.