新的基于小波对比度的LSB密写

New LSB steganographic method based on wavelet contrast

利用图像块的小波对比度可以判定图像各像素的LSB(Least Significant Bit)嵌入深度,以提高嵌入容量并保持载密图像的质量。提出了一种新的基于小波对比度的密写方案,将图像块像素的低4位置0后进行小波变换并计算小波对比度作为嵌入深度的判决信息,由嵌入深度逐块逐像素密写。实验结果表明,该方法不仅保持了较高的嵌入容量,而且提取秘密信息时不需任何附加信息。

For steganography,using the wavelet contrast to decide the embedding depth in Least-Significant-Bit（LSB） can improve the hiding capacity and maintain a good visual quality of the stego-image.A new method is presented based on wavelet contrast.Firstly,the image is divided into blocks and set the least 4 bits of each pixel as 0,then decomposes with one-level wavelet transform to get the wavelet contrast and obtain the number of bit-planes for embedding.Finally,the secret information is embedded in LSB according to the different embedding length for each image block.The experimental results demonstrate the proposed method can hide large information,while maintain a good visual quality of the stego-image.Meanwhile,the embedded data can be extracted from the stego-image without any additional information.