A novel reversible data hiding scheme with two-dimensional histogram shifting mechanism

In this paper, we propose a novel reversible data hiding technique based on two-dimensional histogram shifting for quantized discrete cosine transformation coefficients (QDCT). In the proposed scheme, a two-dimensional histogram is constructed by QDCT coefficients blocks with the size of 8 × 8 of the left image and the right image. Once most of the QDCT coefficients are located at the top-right corner of the two-dimensional histogram, the QDCT coefficients are selected for embedding data to achieve high embedding capacity. In the embedding procedure, the three main steps, i.e., expanding, shifting, and embedding, are only used for QDCT coefficients in this corner not only to gain embedding capacity, but also to maintain good visual quality of stego images. The experimental results demonstrated that the proposed scheme is superior to the previous schemes in terms of embedding capacity and image quality.