可恢复的脆弱数字图像水印

Fragile Digital Image Watermarking with Restoration Capability

该文提出一种用于图像内容认证和保护的脆弱数字图像水印算法 .该算法不但可以检测定位出图像中任何细微的篡改 ,而且可以恢复较大面积的被篡改的图像数据 .首先该文给出了一种被称之为基于块交叉交插RS编码的水印生成算法 ;随后使用基于块交叉交插RS码的校验符号作为水印并将其埋植到图像数据的最低位 ;最后利用基于块交叉交插RS解码实现水印信号检测以及对图像篡改数据的定位和恢复 .此外该文算法使用由密码生成的掩膜图像参与水印信号的生成和检测 ,很好地保证了水印的安全性和保密性 .经实验验证 ,该算法不但可以有效地检测出图像中被篡改内容的位置 ,而且能恢复被篡改的图像数据 .

This paper gives an auto-restorable fragile watermarking algorithm for image content authentication, which can not only detect the location of any minute changes in images but also restore the altered image data. Firstly, authors give called cross-interleaved-RS code block generation scheme. Then authors use parities of the cross-interleaved-RS block-based codes as watermarking and embed them into the lowest bits of the image data. Finally, authors use these cross-interleaved-RS codes to detect watermarking, identify the change positions and restore the altered data in an image. In addition, a mask image generated by a secret algorithm is participated in the procedure of cross-interleaved-RS encoding to increase the security of watermarking and prevent forged watermarking. Experimental results demonstrate that the watermarking produced by above method is sensitive to tiny changes in images, and the method also provides very good results of detecting the tampered location and restoring the tampered data.