基于纠错码的健壮性图像信息隐藏算法

Robust image information hiding algorithm based on error correcting codes

针对空域图像信息隐藏(IH)算法健壮性较差的缺陷,研究了基于纠错码的图像信息隐藏算法。利用纠错码能够纠正随机错误的特性提高空域信息隐藏算法抵抗攻击者修改载体的能力。给出了两类不同的算法:基于纠错码的最低有效位(LSB)信息隐藏算法与基于纠错码的灰度位信息隐藏算法。前者将秘密信息进行编码并以LSB的形式进行嵌入,能够在低密度噪声的情况下实现较高的健壮性;后者利用图像像素灰度值的结构特点,以Hamming码的形式对每一个已嵌入秘密信息的像素灰度值进行编码,可以达到独立纠正一个错误的目的。理论分析和实验结果表明,在相同的噪声密度和噪声幅度下,这两类算法恢复的秘密信息百分比均高于基本的LSB算法,是两种具有较高健壮性的信息隐藏算法。

The research on image Information Hiding （IH） algorithm based on error-correcting code is aimed at overcoming poor robustness flaws of spatial domain image information hiding algorithm. The property of correcting random error of the error-correcting code could be used to improve the robustness of spatial domain information hiding algorithm, so that the modifications to the covers by attacker could be effectively resisted. Two different algorithms were proposed： the Least Significant Bit （LSB） information hiding algorithm based on error-correcting code and the gray-bit information hiding algorithm based on error-correction code. By embedding the coding form of secret information in LSB in the first algorithm, relatively high robustness could be achieved in the case of low density noise; while in the second one, by applying the structural characteristics of image pixel gray values, and coding each pixel gray value which had been embedded the secret information in the form of Hamming code, one error could he corrected by each pixel independently. Both theoretical analysis and experimental results show that, under the condition of same density and value of noise, the percentages of secret information recovered of these two algorithms are higher than the basic LSB algorithm, so they are two information hiding algorithms with higher robustness.