可恢复的脆弱图像水印技术的研究与实现

Research and Implementation of Restorative Fragile Digital Watermarking

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。该算法利用纠错码和置乱技术可以恢复较大面积的被篡改的图像数据。首先提取原始图像的最重要位MSB,将其分成4块并进行置乱处理,然后对置乱后的MSB信息进行(7,4)汉明纠错编码,最后将校验符号作为水印,并将其Arnold置乱后埋植于图像的最低有效位LSB。经实验验证,该算法对于图像的擦除攻击和剪切攻击有很强的恢复作用。

An auto-restorable fragile watermarking algorithm for image content authentication was proposed. The tampered image data can be largely restored by this algorithm, which uses the correct-encode and shuffling techniques. First, MSB of original image was picked up. Second, MSB was cut into four blocks, and then Arnold shuffling techniques were used in four blocks. Third (7,4) hamming correct-encode technology was used to encode the chaotic four blocks of MSB. Finally, the correct code was embedded into the lowest bits of the image data after being changed with Arnold shuffling techniques. Experimental results show that this algorithm has a strong restored ability for the erasure and cut tampering.