New reversible data hiding algorithm using difference expansion embedding
利用差值扩展进行可逆数据隐藏的新算法

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.