基于矩不变量的易碎图像水印

为了能够在没有额外密码或图像索引的情况下,使VQ攻击无法执行,一种基于矩不变量的易碎图像水印算法被提出。图像矩不变量被提取出来作为图像的索引,来生成依赖于原始图像的、攻击者不知道且不同图像不同的水印。嵌入水印时,图像块的最高信息位MSB位流数据被加密后,作为Hash函数的输入,Hash函数的输出与生成的水印相互处理后,嵌入到图像块的LSB上。实验结果证明,该算法可以很好地定位检测图像发生的任何细小的改动,而且可以在没有任何额外的特有密码或图像索引的情况下,成功地抵抗VQ攻击。

Moment Invariants Based Fragile Image Watermarking

To make vector quantization (VQ) attack impossible without the need of any unique keys or image indexes, a moment invariants based fragile image watermarking scheme is proposed. Image moment invariants are extracted as the index to generate the image-dependent watermark, which is unknown to the attacker and different for different images. Encoding with the output of hash function of the seven most significant bits stream serial of image blocks, watermark is embedded into the LSB of image blocks under the consideration of security and localization. Experimental results demonstrate that our algorithm can detect even one bit image alteration with graceful localization, and successfully resist vector quantization attack simultaneously without the need of any unique keys or image indexes.