基于单向差值扩展的彩色图像可逆数据隐藏

Reversible data hiding for color images based on single direction difference expansion

针对Tian差值扩展算法存在过分修改像素值、须嵌入定位图等缺点,提出一种基于单向差值扩展的彩色图像可逆数据隐藏算法。利用色彩分量间的相关性减小差值,并用较小的差值扩展量扩展单个色彩分量的像素值,扩展方向由上溢和下溢像素的数量决定;采用预先调整像素值的方法避免像素溢出,少量的调整信息即可代替定位图,嵌入容量大幅提高;提取端根据临界像素值的顺序定位调整像素的位置,用调整信息恢复调整像素,因此不需要嵌入定位图,在提取信息的同时可无损地恢复原始图像。实验结果表明,本文算法在保证图像质量的同时,嵌入容量有很大的提高。

To avoid the drawback of Tian′s algorithm,where a location map must be embedded,and the quality decline of stego-images from excessive modulation to pixels,a reversible data hiding algorithm for color images based on single direction difference expansion is proposed in this paper.The algorithm uses the correlation of color components to decrease difference and uses smaller expansion to expand the pixel values of a single component.The embedding process makes use of the same expansion direction which is determined by the number of overflow and underflow pixels,adopts the pixel value adjusting method to prevent overflow or underflow,and embeds a few adjusted values instead of a location map,so the embedding capacity is increased.According to the sequence of critical value,the adjusted pixel values can be restored.Experimental results show that the embedding capacity and the quality of stego-images are significantly improved compared with other algorithms.