依据图像受到几何攻击时亮度值统计特性不变原理提出了一种基于统计量化的抗几何攻击图像水印算法。用二值序列作为水印,水印嵌入时,首先选取一段亮度值范围,然后根据一定的步长将其划分为小区间,每一水印位对应一区间,最后对亮度值进行量化,使每个区间的像素都被量化到一个亮度值上。水印提取时,首先统计每个亮度值的像素个数,然后按照嵌入时的方法选取亮度范围并且划分区间,从每个区间提取一位水印信息。实验表明,这种方法对图像缩放、旋转和剪切等几何攻击有很强的鲁棒性,对中值滤波、噪声等常规攻击也具有较强鲁棒性。
In order to resist geometric attacks,a statistic-quantization-based image watermarking algorithm is proposed based on the invariant property of the statistic characteristic of an image.During embedding,a particular range of pixel values is first selected and divided into intervals according to a predefined step.Then the pixels within each interval are quantized to have the same value according to the watermark bit.During watermark extraction,the numbers of pixels are computed at each gray level.Then the pix...