| 1. | In semi-fragile image watermarking algorithm, a robust watermark and a fragile watermark are extracted from the third approximation coefficient of wavelet transform of the original image . the two watermarks are embedded into the third vertical and horizontal detail coefficients . when authenticating image, image can be authenticated correctly and attacked parts can be localized through comparing the original watermarks and extracted watermarks
其中,完全认证方法,利用qr分解的特性把图像的边缘信息嵌入到载体图像中,算法对各种攻击都具有很好的敏感性;内容认证方法,从载体图像中提取出一个脆弱水印和一个鲁棒水印,并把它们重新嵌入到载体图像中,认证时,通过两个水印在图像传输前后的变化情况来对图像的保留价值进行评估,并准确定位受攻击部位。 |
