# Deep-Space Background Low-Light Image Enhancement Method Based on Multi-Image Fusion
## 4 Experiments
### Quantitative Evaluation
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Satellite Name** & **Metrics** & **SSR** & \
\begin{tabular}{c} **Gamma** \\ **(\(\gamma\) = 0.6/0.8)** \\ \end{tabular} &
\begin{tabular}{c} **Gamma** + \\ **CLAHE** \\ **(\(\gamma\) = 0.6/0.8)** \\ \end{tabular} & **NeRCo** & **Retinexformer** & **Ours 1** & **Ours\_BGD 2** \\ \hline \multirow{3}{*}{AcrimSat} & PSNR \(\uparrow\) & 28.81 & 27.57 (37.45) & 30.14 (28.04) & 27.55 & 28.98 & 39.67 3 & 52.46 3 \\  & SSIM \(\uparrow\) & 0.0242 & 0.3202 (0.7539) & 0.2103 (0.3406) & 0.0225 & 0.2126 & 0.5550 & 0.9934 \\  & LPIPS \(\downarrow\) & 0.880 & 0.370 (0.133) & 0.450 (0.343) & 0.887 & 0.590 & 0.255 & 0.012 \\ \hline \multirow{3}{*}{Aquarius} & PSNR \(\uparrow\) & 29.07 & 30.13 (40.85) & 26.69 (28.94) & 27.59 & 37.42 & 44.11 & 52.44 \\  & SSIM \(\uparrow\) & 0.0236 & 0.2954 (0.7809) & 0.1380 (0.2445) & 0.0139 & 0.6357 & 0.8165 & 0.9952 \\  & LPIPS \(\downarrow\) & 0.970 & 0.545 (0.195) & 0.645 (0.467) & 0.940 & 0.409 & 0.173 & 0.010 \\ \hline \multirow{3}{*}{Aura} & PSNR \(\uparrow\) & 29.24 & 30.18 (40.28) & 27.10 (29.07) & 27.57 & 35.59 & 42.84 & 51.01 \\  & SSIM \(\uparrow\) & 0.0116 & 0.2868 (0.7846) & 0.1305 (0.2415) & 0.0129 & 0.5581 & 0.7982 & 0.9927 \\  & LPIPS \(\downarrow\) & 0.916 & 0.469 (0.167) & 0.567 (0.400) & 0.875 & 0.471 & 0.270 & 0.013 \\ \hline \multirow{3}{*}{Calipso} & PSNR \(\uparrow\) & 30.12 & 31.21 (42.05) & 27.11 (29.75) & 27.50 & 39.13 & 45.58 & 55.71 \\  & SSIM \(\uparrow\) & 0.0650 & 0.3475 (0.0899) & 0.1392 (0.2411) & 0.0096 & 0.7099 & 0.8628 & 0.9960 \\  & LPIPS \(\downarrow\) & 0.971 & 0.573 (0.190) & 0.673 (0.478) & 0.965 & 0.399 & 0.169 & 0.009 \\ \hline \multirow{3}{*}{CloudSat} & PSNR \(\uparrow\) & 33.22 & 33.87 (41.84) & 31.04 (31.86) & 27.55 & 35.46 & 42.92 & 53.88 \\  & SSIM \(\uparrow\) & 0.1633 & 0.5142 (0.8807) & 0.1697 (0.2572) & 0.0076 & 0.5945 & 0.8462 & 0.9522 \\  & LPIPS \(\downarrow\) & 0.698 & 0.272 (0.082) & 0.335 (0.222) & 0.816 & 0.337 & 0.480 & 0.006 \\ \hline \multirow{3}{*}{CubeSat} & PSNR \(\uparrow\) & 30.32 & 31.28 (42.23) & 27.03 (29.83) & 27.55 & 39.00 & 45.94 & 58.73 \\  & SSIM \(\uparrow\) & 0.0711 & 0.3525 (0.8099) & 0.1414 (0.2418) & 0.0085 & 0.7036 & 0.8651 & 0.9986 \\  & LPIPS \(\downarrow\) & 0.962 & 0.553 (0.182) & 0.649 (0.461) & 0.971 & 0.407 & 0.169 & 0.005 \\ \hline \multirow{3}{*}{Jason} & PSNR \(\uparrow\) & 30.19 & 30.63 (0.494) & 27.14 (29.46) & 27.49 & 36.72 & 43.80 & 53.83 \\  & SSIM \(\uparrow\) & 0.0169 & 0.2994 (0.7962) & 0.1288 (0.2386) & 0.0102 & 0.6144 & 0.8270 & 0.9946 \\  & LPIPS \(\downarrow\) & 0.919 & 0.486 (0.170) & 0.584 (0.409) & 0.891 & 0.458 & 0.264 & 0.011 \\ \hline \multirow{3}{*}{Sentinel-6} & PSNR \(\uparrow\) & 29.88 & 31.03 (41.78) & 27.07 (29.60) & 27.56 & 39.18 & 45.14 & 53.39 \\  & SSIM \(\uparrow\) & 0.0710 & 0.3500 (0.8058) & 0.1446 (0.2464) & 0.0138 & 0.7073 & 0.8477 & 0.9929 \\ \cline{1-1} \cline{2-10}  & LPIPS \(\downarrow\) & 0.984 & 0.587 (0.192) & 0.686 (0.494) & 0.977 & 0.363 & 0.139 & 0.012 \\ \hline \multirow{3}{*}{Tera} & PSNR \(\uparrow\) & 29.95 & 30.92 (41.33) & 27.31 (29.62) & 27.52 & 37.42 & 44.19 & 53.80 \\  & SSIM \(\uparrow\) & 0.0423 & 0.3253 (0.8039) & 0.1343 (0.2407) & 0.0113 & 0.6425 & 0.8363 & 0.9940 \\ \cline{1-1}  & LPIPS \(\downarrow\) & 0.933 & 0.512 (0.174) & 0.610 (0.430) & 0.912 & 0.434 & 0.231 & 0.010 \\ \hline \multirow{3}{*}{TRMM} & PSNR \(\uparrow\) & 29.80 & 30.47 (0.488) & 26.73 (29.24) & 27.56 & 38.19 & 44.02 & 50.79 \\ \cline{1-1}  & SSIM \(\uparrow\) & 0.444 & 0.322 (0.7922) & 0.1443 (0.2492) & 0.0149 & 0.6686 & 0.8233 & 0.9909 \\ \cline{1-1}  & LPIPS \(\downarrow\) & 0.986 & 0.573 (0.195) & 0.670 (0.486) & 0.966 & 0.380 & 0.149 & 0.016 \\ \hline \end{tabular}  
* \({}^{1}\)Ours’ means only the target is enhanced without retaining the deep-space background. 2 \({}^{2}\)Ours_BDG’ denotes enhancing the target while retaining the deep-space background. 3 In the table, values highlighted in red indicate the best performance, whereas values in blue denote the second-best performance.  
\end{table}