Bin Reservation Based on IVPO Reversible Data Hiding Using Smoothness Mode Selection Strategy

Pixel value ordering (PVO) is a popular reversible data hiding (RDH) technology. The embedding strategy of the PVO method is to divide the image into blocks of the same size, sort the pixel values in each blocks, and embed the secret data to the maximum and minimum pixel values when embeddable conditions are satisfied. The embedding capacity of the PVO method will change due to the complexity of the block. If the pixels in the block is too different from each other, the embedding capacity of the PVO method will be limited. Therefore, in view of this limitation of the PVO method, this research proposes the smoothness mode selection (SMS) strategy. The SMS strategy determines the image shape according to the complexity of the pixels within image blocks, and then uses the bin reservation based on improved PVO RDH method to embed the secret data in the picture. The embedding strategy of this method enables each block of four pixels to carry at most four bits, so it has a significant higher embedding capacity. The experimental results show that the embedding capacity of our proposed method is higher than other PVO-based RDH schemes, and it also maintains a certain good image quality.