## Appendix A  
**Figure A2. Result and comparison of the proposed Pan sharpening method for the F5 area (zoomed), which is represented in a true color (RGB) combination. (**a**) MS; (**b**) Pan; (**c**) Lab; (**d**) GIIS; (**e**) GS; (**f**) HCS; (**g**) IHS; (**h**) NNDiffuse; (**i**) Ehlers. **Figure A3. ** Result and comparison of the proposed Pan sharpening method for the F6 area (zoomed), which is represented in a true color (RGB) combination. (**a**) MS; (**b**) Pan; (**c**) Lab; (**d**) GIIS; (**e**) GS; (**f**) HCS; (**g**) IHS; (**h**) NNDiffuse; (**i**) Ehlers. **Figure A4. ** Result and comparison of the proposed Pan sharpening method for the F6 area (zoomed), which is represented in a true color (RGB) combination. (**a**) MS; (**b**) Pan; (**c**) Lab; (**d**) GIIS; (**e**) GS; (**f**) HCS; (**g**) IHS; (**h**) NNDiffuse; (**i**) Ehlers. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & **ERGAS** & **QAVG** & **RASE** & **RMSE** & **SAM** & **PSNR** & **SSIM** \\ \hline  & Ehlers & 8.35973 & 0.70345 & 31.03779 & 0.00169 & 3.64069 & 55.45895 & 0.99423 \\  & GS & 3.53280 & 0.728  
Figure 17: Result and comparison of the proposed Pan sharpening method for the F2 test frame, zoomed areas, which are represented in a true color (RGB) combination. (**a**) MS; (**b**) Pan; (**c**) Lab; (**d**) GIHS; (**e**) GS; (**f**) HCS; (**g**) IHS; (**h**) NNDiffuse; (**i**) Ehlers. Figure 6: Result and comparison of the proposed Pan sharpening method for the F4 test frame, zoomed areas, which are represented in a true color (RGB) combination. (**a**) MS; (**b**) Pan; (**c**) Lab; (**d**) GIHS; (**e**) GS; (**f**) HCS; (**g**) IHS; (**h**) NNDiffuse; (**i**) Ehlers. Figure A7: Result and comparison of the proposed Pan sharpening method for the F9 test frame, zoomed areas, which are represented in a true color (RGB) combination. (**a**) MS; (**b**) Pan; (**c**) Lab; (**d**) GIHS; (**e**) GS; (**f**) HCS; (**g**) IHS; (**h**) NNDiffuse; (**i**) Ehlers. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & **ERGAS** & **QAVG** & **RASE** & **RMSE** & **SAM** & **PSNR** & **SSIM** \\ \hline \multirow{8}{*}{F2} & Ehlers & 11.86921 & 0.53991 & 47.33854 & 0.00401 & 4.71053 & 47.94083 & 0.97725 \\  & GS & 5.23770 & 0.58263 & 22.61594 & 0.00195 & 2.64855 & 55.16107 & 0.99458 \\  & GIHS & 7.34063 & 0.57639 & 33.87054 & 0.00287 & 2.46540 & 50.84869 & 0.98449 \\  & HCS & 15.71881 & 0.48541 & 62.43752 & 0.00529 & 2.73988 & 45.53622 & 0.97461 \\  & IHS & 11.04969 & 0.54971 & 51.03739 & 0.00432 & 3.46087 & 47.28736 & 0.95942 \\  & CIELab & 4.22351 & 0.68629 & 20.75741 & 0.00176 & 1.36201 & 65.10167 & 1 \\  & NNDiffuse & 9.43220 & 0.56867 & 49.55085 & 0.00420 & 3.40818 & 47.54411 & 0.96330 \\ \hline \multirow{8}{*}{F4} & Ehlers & 22.84143 & 0.52356 & 89.68352 & 0.00405 & 7.95294 & 47.84821 & 0.95598 \\  & GS & 12.57253 & 0.42386 & 65.56001 & 0.00296 & 6.13381 & 50.56968 & 0.96821 \\  & GIHS & 15.81385 & 0.63109 & 90.10525 & 0.00407 & 3.15646 & 47.80746 & 0.94837 \\  & HCS & 23.98628 & 0.28239 & 121.71057 & 0.00550 & 8.28181 & 45.19589 & 0.93994 \\  & IHS & 19.50133 & 0.38961 & 111.13086 & 0.00502 & 8.99373 & 45.98577 & 0.92838 \\  & CIELab & 6.86913 & 0.70144 & 26.93926 & 0.00122 & 1.89738 & 58.29474 & 1 \\  & NNDiffuse & 19.72400 & 0.63077 & 98.22609 & 0.00441 & 6.13952 & 50.53176 & 0.97519 \\ \hline \multirow{8}{*}{F9} & Ehlers & 9.89595 & 0.51189 & 39.61836 & 0.00495 & 4.27519 & 46.10242 & 0.97015 \\  & GS & 4.96528 & 0.55533 & 18.29249 & 0.00256 & 2.20216 & 51.30320 & 0.99273 \\ \cline{1-1}  & GIHS & 5.40401 & 0.53562 & 24.49466 & 0.00306 & 1.92496 & 50.27892 & 0.98486 \\ \cline{1-1}  & HCS & 10.02627 & 0.47659 & 39.67119 & 0.00496 & 2.02550 & 46.09085 & 0.93648 \\ \cline{1-1}  & IHS & 9.55051 & 0.51220 & 43.30832 & 0.00541 & 3.25101 & 45.32893 & 0.92951 \\ \cline{1-1}  & CIELab & 4.2936 & 0.6402 & 17.16686 & 0.00215 & 1.12493 & 54.36654 & 1 \\ \cline{1-1}  & NNDiffuse & 8.25412 & 0.58294 & 18.91789 & 0.01112 & 1.80691 & 39.08057 & 0.94984 \\ \hline \hline \end{tabular}
\end{table}