# Secure NIfTI Image Authentication Scheme for Modern Healthcare System
## 4 Proposed Watermarking Method
### Watermark Extraction Process
The average NC is 0.99973. The comparison between the NC of the proposed system and that of [PERSON] et al. [1], [PERSON] et al. [2], and [PERSON] et al. [17] is seen rather well on the graph. The NC of the proposed approach is closer to one compared to the NC of any other technique, which means the quality of the watermarked picture produced by the proposed method is superior to that produced by any other method. Figure 8: Different sizes of watermark embedding and extraction without any attack. (**a**) Embedding and Extraction Results on the embedded watermark size \(256\times 256\). (**b**) Embedding and Extraction Results on the embedded watermark size \(128\times 128\). (**c**) Embedding and Extraction results on the embedded watermark size \(64\times 64\). \begin{table}
\begin{tabular}{l c c c c c c c c c c c c c c c c} \hline \multirow{2}{*}{**Image**} & \multicolumn{3}{c}{**Proposed Scheme**} & \multicolumn{3}{c}{**[PERSON] et al. [1]**} & \multicolumn{3}{c}{**[PERSON] et al. [2]**} & \multicolumn{3}{c}{**[PERSON] et al. [17]**} & \multicolumn{3}{c}{**[PERSON] et al. [21]**} & \multicolumn{3}{c}{**[PERSON] et al. [24]**} & \multicolumn{3}{c}{**[PERSON]**} & \multicolumn{3}{c}{**[PERSON]**} \\ \cline{2-13}  & **SSIM** & **NC** & **PSNR** & **PSNR** & **NC** & **SSIM** & **PSNR** & **NC** & **PSNR** & **NC** & **PSNR** & **SSIM** & **PSNR** & **SSIM** & **PSNR** & **PSNR** & **PSNR** \\ \hline Sclcl 1 & 0.9894 & 0.9997 & 54.31 & 41.89 & 0.9975 & 0.9474 & 46.98 & 0.998893 & 44.2034 & 0.9982 & 38.71 & 0.9714 & 52.36 & 0.9938 & 42.254 & 53.8014 \\ Scl 2 & 0.9947 & 0.9994 & 53.82 & 41.9 & 0.9986 & 0.9476 & 46.38 & 0.999815 & 51.6799 & 1 & 40.077 & 0.972 & 51.36 & 0.9966 & 42.078 & 54.0554 \\ Scl 3 & 0.9912 & 1 & 53.86 & 41.86 & 0.9977 & 0.9999 & 46.94 & 0.998919 & 35.7588 & 0.9948 & 36.48 & 0.9958 & 50.27 & 0.9891 & 40.5544 & 54.3838 \\ Scl 4 & 0.9928 & 0.9989 & 53.75 & 41.87 & 0.9996 & 0.9469 & 46.88 & 0.99874 & 35.4769 & 0.9573 & 37.14 & 0.995 & 54.09 & 0.9929 & 32.8568 & 53.7501 \\ Scl 5 & 0.9899 & 1 & 54.16 & 41.85 & 0.9976 & 0.9485 & 46.92 & 0.998716 & 48.7506 & 0.9991 & 42.25 & 0.947 & & 42.2742 & 53.854 \\ Scl 5 & 0.9963 & 0.9969 & 53.21 & 41.91 & 0.9976 & 0.9475 & 46.91 & 0.998719 & 44.7388 & 0.9903 & 39.38 & 0.9572 & & 39.4181 & 25.8699 \\ Scl 5 & 0.9986 & 1 & 53.86 & & & & & & & & & & & & & & & & & \\ Scl 0.98988 & 1 & 54.21 & & & & & & & & & & & & & & & & & & & \\ Scl 0.98999 & 0.99997 & 53.87 & & & & & & & & & & & & & & & & & & & \\ Scl 0.9999 & 1 & 53.88 & & & & & & & & & & & & & & & & & & & \\ \hline Average & 0.9921 & 0.9997 & 53.88 & & 41.88 & 0.9974 & 0.9485 & 46.84 & 0.99886 & 43.4347 & 0.9936 & 36.6288 & 0.9662 & 52.02 & 0.9916 & 39.8024 & 53.2717 \\ \hline \end{tabular}
\end{table} 
Table 2: PSNR, SSIM, and NC compared to other existing methods. The PSNR of the watermarked image is a significant parameter to evaluate the quality of any watermarking system. The average PSNR of our scheme is 53.89 db, whereas the average PSNR of other schemes such as [PERSON] et al. [1] is 41.88 db, [PERSON] et al. [2] is 46.84 db, [PERSON] et al. [17] is 43.4347 db, [PERSON] et al. [21] is 38.6288 db, [PERSON] et al. [24] is 52.02 db, [PERSON] et al. [25] is 39.8924 db, and [PERSON] et al. [26] is 53.2716 db as depicted in Figure 10. Only the PSNR of [PERSON] et al. [26] is closer to the proposed scheme; otherwise, they lie between 38 db and 52 db. Figure 11 shows another important quality evaluation parameter of the watermarked scheme, i.e., SSIM. This graph illustrates a comparison of the proposed approach with the three previously presented approaches viz. [PERSON] et al. [24], [PERSON] et al. [1], and [PERSON] et al. [21]. In the sequence of comparison scenario, the next parameter compared the SSIM shown in Figure 11. The proposed scheme is compared with [PERSON] et al. [1], [PERSON] et al. [21], and [PERSON] et al. [24], and we found that the average SSIM of the proposed scheme is 0.99208, whereas, for [PERSON] et al. [1], [PERSON] et al. [21], and [PERSON] et al.