## 4 Experiments and Analysis
### Experimental Results and Analysis  
In Figures 9-12, give four groups visualization results obtained by BL, AGS, GFD, IHST, MOD, MPCA, PRACS, VLGC, BDSD-PC, and WTSR, and the proposed method on the first image pair, the second image pair and the third image pair, respectively. Moreover, the last one gives the MS image as reference. In order to more visually compare the differences between the fusion results obtained by each method, all fusion results were locally enlarged. Figure 9: The first group of visualization results. Figure 11: The third group of visualization results. Figure 10: The second group of visualization results. Tables 1-4 show four groups of quantitative results for the fusion results obtained by eleven different pan-sharpening methods on the four image pairs, respectively. There are five quantitative indices in total, including spectral and spatial quality evaluation. These five indices are Correlation Coefficient (CC), Erreur Relative Global Adimensionnelle de Synthese (ERGAS), Relative Average Spectral Error (RASE), Spectral Information Divergence (SID) and No Reference Quality Evaluation (QNR). In particular, the best values for all quantitative indices are displayed in bold red. The second best values for all quantitative indices are displayed in bold green. The third best values for all quantitative indices are displayed in bold blue. In Figure 9, compared with the reference MS image, the BL, AGS, IHST, and MPCA methods appear spectral distortion with different degrees in the overall region. In particular, for the BL method, the green part becomes dark blue in the local magnification region. For the GSA and MPCA methods, the green part becomes yellowish in the local magnification \begin{table}
\begin{tabular}{c c c c c c} \hline  & **CC (1)** & **ERGAS (0)** & **SID (0)** & **RASE (0)** & **QNR (1)** \\ \hline BL & 0.663 & 7.519 & 0.014 & 20.753 & 0.586 \\ AGS & 0.494 & 8.804 & 0.019 & 28.837 & 0.373 \\ GFD & 0.755 & 7.216 & 0.010 & 16.435 & 0.629 \\ IHST & 0.663 & 7.643 & 0.009 & 24.117 & 0.521 \\ MOD & 0.945 & 1.801 & 0.004 & 7.334 & 0.887 \\ MPCA & 0.500 & 7.900 & 0.011 & 24.146 & 0.552 \\ PRACS & 0.943 & 1.813 & 0.008 & 7.369 & 0.784 \\ VLGC & 0.946 & 1.789 & 0.004 & 7.358 & 0.863 \\ BDSD-PC & 0.945 & 1.809 & 0.003 & 7.335 & 0.843 \\ WTSR & 0.841 & 3.044 & 0.006 & 12.392 & 0.498 \\ Proposed & 0.948 & 1.488 & 0.002 & 4.956 & 0.948 \\ \hline \end{tabular}
\end{table} 
Table 1: The first group of quantitative results. Figure 12: The fourth group of visualization results. area. Moreover, the WTSR and GFD method have some distortion with different degrees in the spatial details. The fused images obtained by the MOD, PRACS, VLGC, and BDSD-PC methods have higher spectral resolution and retain the spectral information contained in the MS images. However, compared with these methods, the spatial details of the proposed method are more defined, especially in the local magnification region. In Figure 7, from the analysis of subjective vision, the proposed method has clearer spatial details and higher spectral resolution, which means that the proposed method improves spatial details while more spectral information contained in the MS images is retained. In Table 1, the proposed method can obtain the best values on all six quantitative indices. Moreover, the VLGC method can obtain the second best values on the CC and ERGAS indices, and the third best values on the SID and QNR indices. The MOD method can obtain the second best values on the RASE and QNR indices, and the third best values on the CC, ERGAS, and SID indices. The BDSD-PC method can obtain the second best