Encoding with Combination Orientation Technique for RDH in Dual Stego Images

Abstract In this paper, initially, message intensities are used to create two encoding tables: an index and a code sequence. The table is then updated with $n$ secret data encoded into it. If the code sequence of the second encoding table matches the code sequence of the preceding or succeeding half of the two encoding tables, the second encoding table is folded. The folding is done when maximum intensity occurs in the utmost succeeding part of the two encoding tables. Finally, using the combination orientation approach, the encoded indices are embedded in the stego images. In the extraction phase, using the two stego images and the encoding with the combination orientation method, the encoded indices are obtained. The decoding is performed to extract the secret message as well as the cover image and there is no occurrence of overflow and underflow problems. It has a high visual quality and a high embedding capacity. The proposed technique achieved a maximum $\mathrm{PSNR}$ of $49.49$dB and a $648\ 242$-bit embedding capacity. When compared to traditional techniques, the experimental results show that the proposed method outperforms them.