Improved reversible data hiding in JPEG images based on new coefficient selection strategy

Recently, reversible data hiding (RDH) techniques for JPEG images have become more extensively used to combine image and authentication information conveniently into one file. Although embedding data in JPEG image degrades visual quality and increases file size, it is proven to be useful for data communication and image authentication. In this paper, a data hiding method in JPEG image using a new coefficient selection technique is proposed. The proposed scheme embeds data using the histogram shifting (HS) method. According to the number of zero AC coefficients, block ordering is used to embed data first in the blocks causing less distortion. In order to further reduce the distortion, positions of AC coefficients are selected carefully. Finally, AC coefficients valued +1 and −1 are used for embedding, and the remaining non-zero AC coefficients are shifted to the left or right directions according to their sign. Compared to the current state-of-the-art method, experimental results show that the proposed method has higher peak signal to noise ratio (PSNR) and smaller file size.