基于数字调制的信息隐藏算法

将数字图像置乱技术中的幻方变换与数字通信中的数字调制技术相结合，提出一种新的文字信息隐藏算法。以二值文字图像为待隐藏的秘密信息，以静止图像为隐秘载体。算法针对二值文本图像，首先用幻方变换对其进行置乱预处理，并用一数值控制置乱次数，在提取时作为密匙；然后对作为隐秘载体的原始图像作分块离散余弦变换，根据每个分块灰度值的方差与秘密信息进行块匹配；根据秘密信息的值对原始图像的分块余弦值进行数字调制嵌入信息。实验表明该算法实现的隐藏图像透明性好，具有良好的抗剪切性。对不同的量化阶数下，对秘密信息的提取进行了实验比较。

Information hiding algorithm based on digital modulation

An information hiding algorithm combing magic transform with digital modulation was presented. A literal image was the secret message and a still image was the cover message. This algorithm preprocessed the binary literal image by Magic Transform and controled the scrambling numbers by using a key. The DCT was applied in the cover message,then the DCT blocks of cover were matched to the blocks of the secret message according to their standard deviation. Then the secret message was embedded by modulating the DCT coefficients of the cover message according to the secret message. Experiment results show this algorithm can get an embedded image that is perceptual invisible,robust and can endure crops. Experiments also show the effect of the quantified degrees on the quality of the decoded message.