一种使用四叉树分割的分形信息隐藏算法

摘要

Existing information hiding algorithms of orthogonal fractal always divide original image into average partition when carrying out orthogonal fractal coding,which are not image-adaptive and are time consuming.What’s more,they fail to consider the correlation among components and the collage error in colour image processing,therefore the robustness is poor.We propose an improved orthogonal fractal information hiding algorithm which uses quad-tree partition.The algorithm can realise quad-tree partition on original image according image feature,and takes into account the correlation of three components (R,G,B)of colour image,as well as extracts the luminance component for fractal coding.Moreover,the algorithm uses collage error characteristics to dynamically regulate the modifying value of fractal parameters for embedding secret image.Experiments and applications show that the improved algorithm has short encoding time,good transparency and is robust to JPEG image compression,noise,filtering and geometric distortion.%目前的正交分形信息隐藏算法在进行正交分形编码时都是等分割原始图像，这样无法自适应图像内容且耗时，并且在处理彩色图像时没能考虑分量之间的相关性以及拼贴误差，因此鲁棒性较差。提出一种采用四叉树分割的正交分形信息隐藏算法。该算法能够根据图像特征实现原始图像的四叉树分割，同时考虑彩色图像 R、G、B 三个分量的相关性，提取亮度分量进行分形编码，并利用拼贴误差特性，动态调整分型参数的修改量来嵌入秘密图像。实验及应用表明，该算法编码时间短、具有很好的透明性以及对 JPEG 压缩、加噪、滤波、几何形变等具有较好的鲁棒性。