一种基于小波对比度和LSB的密写

A Steganographic Method Based on Wavelet Contrast and LSB

为了提供较大的秘密信息嵌入量和保持良好的载密图像质量,依据人眼对变换剧烈及较暗区域均不敏感的视觉特点,提出了一种基于小波对比度和最低比特位替换(LSB)的图像密写方法.该方法先将载体图像分成固定大小的小块,对每一小块进行小波分解后计算小波对比度.然后,根据该块小波对比度绝对值之和确定该块可以嵌入的位平面层数.最后,采用LSB密写技术逐层嵌入秘密信息.实验结果表明,该密写方法能嵌入较多的信息和保持良好的载密图像质量,并且可直接从载密图像中提取秘密信息.

In order to provide larger capacity of the hidden secret data and to maintain a good visual quality of stego-image, in accordance with the visual property that human eyes are insensitive to edged area and dark area novel steganographic method based on wavelet contrast and Least-Significant-Bit（ LSB）replacement is presented. First, an image is divided into blocks, and every block is decomposed into one-level wavelet to obtain the wavelet contrast. Then, the number of bit-plane embedded is decided with the sum of abstract of wavelet contrast. Finally, secret information is embedded by LSB. From the experimental results, the proposed method can hide much larger information and maintain a good visual quality of stego-image. Besides,the embedded data can be ex- tracted from the stego-image without referencing the original image.