利用差值扩展进行可逆数据隐藏的新算法

基于整数哈尔(Haar)小波变换，提出一种新的利用横向和纵向差值图像进行扩展嵌入的数据隐藏算法。传统的差值嵌入技术最大的缺点是在第二重嵌入开始之前图像的质量已经遭到破坏，原因是前一重嵌入用到了很大的差值。针对这个问题，该方法动态地把负载分配到两个正交方向上的图像进行嵌入。尽量使这两个方向上用于嵌入的差值属于同一个幅值范围。与其他算法相比，本算法在同等嵌入率下可取得更好的图像质量。

New reversible data hiding algorithm using difference expansion embedding

Based on integer Haar wavelet transform, we proposed a new re.versible data hiding algorithm using the horizontal and vertical difference images for difference expansion. The major disadvantage of traditional difference expansion techniques is that, before performing the second-level embedding, the image quality has been degraded due to the use of large difference values in the first-level embedding. To solve this problem, our algorithm dynamically divided the payload into two parts for the two difference images obtained in orthogonal transformation directions, so that it can utilize small difference values in two difference images. For a payload, our algorithm aims at using the differences in two difference images under the same selection threshold. Compared with other new or classical algorithms, the proposed algorithm yields better image quality under the same embedding rate.