# Sharpening of Worldview-3 Satellite Images by Generating Optimal High-Spatial-Resolution Images
## 3 Results and Discussion  
### Quality Evaluation of Sharpened Image  
To evaluate the quality of the sharpened images, sharpened images generated by applying existing pansharpening techniques were utilized for comparative evaluations. Existing pansharpening techniques employing general pansharpening techniques were used to fuse the VNIR and SWIR bands using panchromatic images of Worldview-3 satellite images. In the comparative evaluation method, both a quantitative evaluation utilizing an evaluation index that quantifies spectral and spatial qualities and a qualitative evaluation performed through image interpretation were conducted simultaneously. Table 2 and Figures 4 and 5 present the quantitative evaluation results and sharpened images applying the existing and proposed pansharpening techniques to two sites. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**Site 1**} \\ \hline  & & \multicolumn{2}{c}{**Existing Technique**} & \multicolumn{2}{c}{**ProposedTechnique**} \\ \cline{3-8}
**Quality** & **Spatial** & & & \multicolumn{2}{c}{**Selected**} & \multicolumn{2}{c}{**Synthesized**} \\
**Index** & **Resolution** & **GSA** & **GS2** & \multicolumn{2}{c}{**BandScheme**} & \multicolumn{2}{c}{**BandScheme**} \\ \cline{3-8}  & & & & **GSA** & **GS2** & **GSA** & **GS2** \\ \hline \multirow{2}{*}{**ERGAS**} & 1.2 m (VNIR) & 1.2972 & 0.8981 & 0.8219 & 0.6688 & 0.8296 & 0.6688 \\  & 7.2 m (SWIR) & 1.7000 & 0.7183 & 0.7589 & 0.4413 & 0.6932 & 0.4410 \\ \hline \multirow{2}{*}{**SAM**} & 1.2 m (VNIR) & 1.3672 & 1.2246 & 0.9155 & 0.8950 & 0.9160 & 0.8950 \\  & 7.2 m (SWIR) & 4.9748 & 4.6347 & 2.7408 & 1.3620 & 1.8703 & 1.2305 \\ \hline \multirow{2}{*}{**UIQI**} & 1.2 m (VNIR) & 0.9656 & 0.9764 & 0.9823 & 0.9859 & 0.9822 & 0.9859 \\  & 7.2 m (SWIR) & 0.7748 & 0.9522 & 0.9290 & 0.9777 & 0.9385 & 0.9774 \\ \hline \multirow{2}{*}{**sCC**} & 1.2 m (VNIR) & 0.9883 & 0.9855 & 0.9821 & 0.9784 & 0.9822 & 0.9784 \\  & 7.2 m (SWIR) & 0.9992 & 0.9998 & 0.9990 & 0.9906 & 0.9081 & 0.9104 \\ \hline \multicolumn{8}{c}{**Site 2**} \\ \hline  & & \multicolumn{2}{c}{**Existing Technique**} & \multicolumn{2}{c}{**ProposedTechnique**} \\ \cline{3-8}
**Quality** & **Spatial** & & & \multicolumn{2}{c}{**Selected**} & \multicolumn{2}{c}{**Synthesized**} \\
**Index** & **Resolution** & **GSA** & **GS2** & \multicolumn{2}{c}{**BandScheme**} & \multicolumn{2}{c}{**BandScheme**} \\ \cline{3-8}  & & & & **GSA** & **GS2** & **GSA** & **GS2** \\ \hline \multirow{2}{*}{**ERGAS**} & 1.2 m (VNIR) & 1.0183 & 0.7854 & 0.6574 & 0.5732 & 0.6587 & 0.5732 \\  & 7.2 m (SWIR) & 1.7766 & 0.8019 & 0.5451 & 0.3472 & 0.5678 & 0.3460 \\ \hline \multirow{2}{*}{**SAM**} & 1.2 m (VNIR) & 1.0950 & 1.0582 & 0.7785 & 0.7745 & 0.7774 & 0.7745 \\  & 7.2 m (SWIR) & 6.6940 & 5.4152 & 2.0588 & 0.8097 & 1.6268 & 0.7674 \\ \hline \multirow{2}{*}{**UIQI**} & 1.2 m (VNIR) & 0.9559 & 0.9688 & 0.9763 & 0.9803 & 0.9763 & 0.9803 \\  & 7.2 m (SWIR) & 0.7759 & 0.9511 & 0.9428 & 0.9802 & 0.9369 & 0.9803 \\ \hline \multirow{2}{*}{**sCC**} & 1.2 m (VNIR) & 0.9816 & 0.9787 & 0.9724 & 0.9688 & 0.9724 & 0.9688 \\  & 7.2 m (SWIR) & 0.9983 & 0.9997 & 0.9884 & 0.9905 & 0.9564 & 0.9625 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Quantitative evaluation results of sharpened Worldview-3 satellite images. Figure 4: Pansharpening results of SWIR bands for site 1 (SWIR bands 8, 4, and 1 are shown as RGB): (**a**) panchromatic image; (**b**) original SWIR image; (**c**) GSA result from the existing method; (**d**) GS2 result from the existing method; (**e**) GSA result from the proposed algorithm based on the selected band scheme; (**f**) GS2 result from the proposed algorithm based on the selected band scheme; (**g**) GSA result from the proposed algorithm based on the synthesized band scheme; (**h**) GS2 result from the proposed algorithm based on the synthesized band scheme.