A reversible data hiding scheme for encrypted images with pixel difference encoding

In recent years, reversible data hiding of encrypted images (RDHEI) has attracted extensive attention in academia. Pixel difference is an important technique for embedding hiding information. In this paper, we propose a reversible data hiding scheme for encrypted images based on pixel prediction and pixel difference. To be specific, we first use the MED predictor to generate the predicted image, and then subtract the original image from the predicted image to obtain the difference image. Then, the histogram shifting method is used to preprocess the difference image and retain the overflow pixel value. Then, block scrambling and pixel scrambling are used to encrypt the preprocessed image. Finally, the encrypted image is embedded with pixel difference technology. The proposed scheme makes full use of the correlation of pixels and has high utilization of images. In addition, we propose a cover image selection mechanism. Experimental results show that our scheme can achieve a higher embedding rate than some of the state-of-the-art RDHEI schemes.