Reversible Data Hiding using Prediction Error Adoption

Reversible data hiding in encrypted images is a technique that embedded additional data into an encrypted image without accessing the content of the original image, the embedded data can be extracted and the encrypted image can be recovered to the original one. In this work, two reversible data hiding methods in encrypted images, namely a joint method and a separable method, are introduced by adopting prediction error. In this paper, we propose joint and separable RDH techniques using an improved embedding pattern and a new measurement function in encrypted images with a high payload. The first problem in recent joint data hiding is that the encrypted image is divided into blocks, and the spatial correlation in the block cannot fully reflect the smoothness of a natural image. The second problem is that half embedding is used to embed data and the prediction error is exploited to calculate the smoothness, which also fails to give good performance  In the joint method, data extraction and image reconstruction are performed at the same time. The reversibility, number of incorrect extracted bits are significantly improved while maintaining good visual quality of recovered image, especially when embedding rate is high. In the separable method, data extraction and image recovery are separated. The separable method also provides improved reversibility and good visual quality of recovered image for high payload embedding.