# Pansharpening by Complementing Compressed Sensing with Spectral Correction
## 3 Results
### Experimental Results
\begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**Method**} & \multicolumn{2}{c}{**CC**} & \multicolumn{2}{c}{**UIQI**} & \multicolumn{2}{c}{**ERGAS**} \\  & **Nihonmatsu** & **Yokohama** & **Nihonmatsu** & **Yokohama** & **Nihonmatsu** & **Yokohama** \\ \hline Ideal & \multicolumn{2}{c}{1.0} & \multicolumn{2}{c}{1.0} & \multicolumn{2}{c}{0.0} \\ \hline \multirow{2}{*}{
\begin{tabular}{c} SCMP \\ SR \\ \end{tabular} } & \multicolumn{2}{c}{0.899} & 0.944 & 0.779 & 0.915 & 2.415 & 2.393 \\ \hline SR & 0.846 & 0.775 & 0.807 & 0.709 & 2.769 & 4.088 \\ \hline TP & **0.920** & **0.949** & **0.825** & **0.926** & **2.041** & **2.050** \\ \hline \end{tabular}
\end{table} 
Table 5: Numerical evaluation of image intensities obtained by SCMP, SR, and the tradeoff process. The best values are given in bold. was 4096, the size of the dictionary atom was \(8\times 8\times 4\), the sparsity regularization parameter was \(\lambda=0.15\), the number of training image patches was 2000, the upscale was 4 (ratio of resolution of PAN images and MS images of IKONOS), \(\beta=0.25\), the weight of each spectral band of IKONOS was \(w=[0.1071,0.2646,0.2696,0.3587]\), the overlap pixel in the patch of reconstruction process was 0, the back-projection filter size was \(3\times 3\), and the number of repetitions was 20. These settings of the existing methods followed those described in the original papers except the distinct block size of BDSD. The code of [PERSON] et al. [2] was used for GS and BDSD, and the code of [PERSON] et al. [13] was used for ISSR. In Tables 7 and 8, the highest scores are printed in bold, and the second highest scores are underlined. GS was generally not good except for the SAM of Yokohama. The results of BDSD were unremarkable but stable. SCMP was stable and gave good results. In ISSR, differences in training images had little effect on results. SRayas did not perform as well overall as ISSR and SRayas. Although some results, such as the CC of SR-D of Table 7, MDSIm of Table 8, and SAM of GS were better in part \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Method**} & \multicolumn{2}{c}{**ERGAS**} & \multicolumn{2}{c}{**SAM**} \\  & **Nihonmatsu** & **Yokohama** & **Nihonmatsu** & **Yokohama** \\ \hline ideal & \multicolumn{2}{c}{0.0} & \multicolumn{2}{c}{0.0} \\ \hline fast IHS [5] & 3.471 & 3.716 & 1.898 & 2.367 \\ \hline GS [7] & 5.046 & 3.563 & 2.748 & **1.950** \\ \hline BDSD [41] & 3.026 & 3.361 & 1.925 & 2.326 \\ \hline WLS [42] & 2.815 & 3.816 & 1.699 & 2.123 \\ \hline MDSIm [43] & 3.321 & 3.515 & **1.658** & 2.189 \\ \hline SCMP [35] & 2.673 & 2.697 & 1.753 & 2.176 \\ \hline ISSR (Dict-natural) [13] & 3.118 & 4.419 & 1.749 & 2.324 \\ \hline ISSR (Dict-self) [13] & 3.124 & 4.474 & 1.750 & 2.331 \\ \hline SR-D & 3.007 & 4.226 & 1.897 & 2.649 \\ \hline SRayas [34] & 3.497 & 4.476 & 1.765 & 2.299 \\ \hline Proposed & **2.336** & **2.424** & 1.688 & 2.159 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Numerical evaluation of the existing methods and the proposed method by ERGAS and SAM. The highest scores are printed in bold, and the second highest scores are underlined. Figure 6: Scores of quality metrics. Figures 7 and 8 show the reference and PS images from the Nihonmatsu and Yokohama datasets, respectively. Since the images were small, the enlarged image surrounded by the yellow frame of the original RGB image (b) is shown in (c)-(o). In Figure 7, in GS (f), the color of green was darker in the rice field area (indicated by the green arrow), while the forest area was whitish. BDSD (g) was more blurred than other images. In MDSIM (i), the color of the forest area was also whitish (indicated by the yellow arrow). In Figure 8, the vegetation area was whitish in GS (f) and MDSIM (i) (indicated by the red arrow). WLS (h) looked hazy. SR-D (m) had lower resolution than the other methods using sparse representation with back-projection. In both Figures 7 and 8, the results of ISSR (k) (l) and SRayas (n) had ringing artefacts.