基于误差分析的DCT域图像隐藏算法

为有效减少在AWGN信道下取整误差对秘密信息提取造成的影响,通过分析取整误差、DCT系数误差和秘密信息提取误差三者的关系,得出DCT系数误差是服从N（0,0.0833）正态分布,进而推导出在DCT域扩频算法和量化索引调制（QIM）盲提取算法中秘密信息提取误差的概率密度函数。基于误差分析分别提出采取容错和纠错编码方式的两种改进算法,提高图像隐藏的隐蔽性和秘密信息提取的准确率。仿真结果验证了这两种算法的可行性和有效性。

DCT Domain Image Hiding Algorithms Based on Errors Analysis

In order to effectively decrese the impact of round error on secret retrievsal in AWGN channel,it can be proved that the DCT coefficient errors submit to the N（0,0.0833） ganssian distribution,through analyzing the relationship of round errors.DCT coefficient errors and secrect information retrieval errors.Then the probability density function of secrect information retrieval errors of Spread Spectrum（SS） algorithm and Quantization Index Modulation（QIM） blind retrieval algorithmcan be deducted in DCT domain.Based on the errors analysis two improved algorithms one by fault-tolerant and the other by error correcting code are proposed,for achieving improvement of algorithm secrecy and accuracy of retrieval secret information.Simulation results verify the feasibility and validity of these algorithms.