Dual image reversible data hiding using trinary assignment and centre folding strategy with low distortion

Abstract Dual image Reversible Data Hiding (RDH) algorithms generate two stego images instead of one. These algorithms are considered more secure because the secret data can be recovered only if both stego images are available. This paper proposes a dual image RDH algorithm based on the Centre Folding Strategy (CFS) and the Shiftable Pixel Coordinate Selection Strategy. The proposed algorithm improves the visual quality of the two stego images while maintaining a high embedding rate. It uses a look-up table containing the shifts that the cover pixel will undergo after the data has been embedded. Some overhead information is required for accurate extraction of the hidden data and it is delivered to the users as a password after embedding. The results show that the proposed algorithm outperforms other methods in terms of visual quality with an average Peak-Signal-to-Noise-Ratio (PSNR) of 50.66 dB with an embedding rate of 1.56 bits per pixel.