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...