针对二值图像仅有两种颜色,对像素修改敏感的特点。提出了一种基于行程编码的二值图像数字隐写算法。将原始图像划分成子块,并以zigzag扫描的顺序对块内像素进行行程编码,通过修改较大的行程来嵌入信息。修改行程时采用行程拆分与合并策略,并考虑对应像素的“可翻转度”。同时,秘密信息嵌入时利用纠错码数字隐写的原理,通过使用共享密钥来进一步增强算法的安全性。实验结果表明,该算法不仅具有一定的隐藏容量,而且保证了载密图像质量.并能够较好地保持行程统计特性,从而说明该算法具有较高的安全性。
Aimed at the characteristics of binary images, with two colors and the pixels being sensitive to the modification, a steganographic algorithm is proposed for binary images based on run-length encoding. Dividing thecover image into blocks firstly, then the pixels in each block are run-length encoded in zigzag scanning order and the secret bits are embedded by modifying the larger runs. When modifying the runs, the strategy of run splitting and run combining is adopted and the "flippability" of the pixels corresponding to the modified runs is considered. Moreover, utilizing the principle of steganography based on error-correcting code, the shared keys are introduced to further strengthen the security. Experimental results and the analysis show that the proposed algorithm has a considerable embedding capacity, a good visual imperceptibility and a high security.