# An Innovative Information Hiding Scheme Based on Block-Wise Pixel Reordering
## 3 Proposed Scheme
### Data Hiding
In Table 7, it can be seen that the embedding capabilities of our proposed schemes outperform all the other schemes. Moreover, our proposed scheme consistently provides stable embedding capacity for any image, as long as the pixel-block size and the number of blocks within a group remain unchanged. The independence of embedding capacity from image content is attributed to our utilization of indices within each group for data embedding. So, as long as the number of blocks in the group and the size of the pixel-blocks are consistent, images of the same size will have the same embedding capacity. From Table 7, it is evident that our proposed scheme also outperforms most SOTA methods based on the PSNR values and SSIM values. Even though the PSNR is slightly lower than [17], our proposed scheme achieves a PSNR of approximately 51 dB, which is adequate for visual quality of a recovered image. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Image Name** & **Embedding** & \
\begin{tabular}{c} **Recovered** \\ **Image** \\ \end{tabular} &
\begin{tabular}{c} **Extraction** \\ **and Recovery** \\ \end{tabular} \\ \hline Airplane & 5.98 & 1.95 & 0.83 & 2.80 \\ [PERSON] & 6.30 & 2.00 & 0.78 & 2.85 \\ Barbara & 6.19 & 1.98 & 0.80 & 2.78 \\ Boat & 6.13 & 1.95 & 0.82 & 2.83 \\ Couple & 6.17 & 1.97 & 0.79 & 2.73 \\ Lena & 6.29 & 1.96 & 0.81 & 2.77 \\ Peppers & 6.18 & 1.98 & 0.77 & 2.77 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Experimental runtime on different test images. In Figure 11, we further compare the PSNR of our scheme with more SOTA schemes under different embedding capacities, with a pixel-block size of 8 and 256 blocks within a codeword table. In Figure 11, we use the embedding ratio (ER) to represent the embedding capacity (ER = EC/total number of pixels). As depicted in Figure 11, in most cases, the PSNR values of other schemes tends to decrease with increasing embedding capacity. In contrast, our proposed scheme consistently has a stable PSNR for the recovered image. Therefore, as the amount of embedded secret data increases, the advantages of our proposed scheme become more pronounced in terms of the PSNR and the SSIM of the recovered image. As long as the embedding rate is greater than 0.25 bpp, the proposed scheme has better visual quality and higher embedding capability than other schemes. ## 5 Conclusions

In the proposed scheme, a content owner encrypts an image first using the Stream Cipher technique with an encryption key and embedding pixel-block numbers in each block-group by replacing LSBs of pixels in each pixel-block. The encrypted image with embedding pixel-block numbers is then sent to a data hider to embed a secret message and create a marked image using a data hiding key and the codeword table index reordering technique. The marked image is sent to the receivers. When a receiver has the data hiding key, the secret message can be extracted. When a receiver has the encrypted key, the image can be reconstructed with minor distortions because of LSB replacements. With our experiment results, we are confident that the proposed scheme could achieve our goal of increasing embedding capacity by a significant amount compared to the SOTA schemes. Our experiments showed that the embedding capability with any cover image is consistent as long as the sizes of pixel-blocks and block-groups were the same. As for PSNRs, the results showed that the proposed scheme could outperform the SOTA schemes

Figure 11: PSNR comparisons with SOTA schemes [15; 16; 17; 18; 19; 20; 21; 22; 23]. as well. Because of LSB replacements, our scheme has a limitation in that the images are not fully recovered, yet the PSNR reaches 50 dB, which indicates that the images have good visual performance. Conceptualization and methodology, J.-C.L., H.-X.C., C.-C.C. ([PERSON]) and C.-C.C. ([PERSON]); software, H.-X.C. ; validation, J.-C.L., H.-X.C., C.-C.C. ([PERSON]) and C.-C.C. ([PERSON]); data curation, H.-X.C. ; writing--original draft preparation, J.-C.L. and H.-X.C. ; writing--review and editing, J.-C.L. and H.-X.C.