# Hybrid Multimodal Medical Image Fusion Method Based on LatLRR and ED-D\({}^{2}\)GAN
## 3 Experimental Section
### Comparison Experiments
#### 3.3.2 CT Mediastimal Window Images and PET Images
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Images** & **Methods** & **AG** & **EI** & **IE** & **SF** & **QAB/F** & **SD** \\ \hline \multirow{4}{*}{1} & NSCT & 6.8779 & 61.7357 & 5.0360 & **32.0976** & 0.5116 & 5.7207 \\  & LatLRR & 6.0419 & 56.2118 & 5.9776 & 24.9882 & 0.4956 & 5.5529 \\  & WT & 5.1805 & 47.4596 & 4.8254 & 28.0206 & 0.3148 & 5.0303 \\  & LatLRR+NSCT & 6.9261 & 63.7558 & 6.0681 & 30.5653 & **0.5468** & 5.7738 \\  & GANMcC & 4.5108 & 30.4581 & 4.7010 & 22.6290 & 0.3114 & 4.6901 \\  & FusionGAN & 5.2713 & 48.2093 & 4.5326 & 26.2313 & 0.3069 & 4.5911 \\  & LatLRR-GAN & **11.3958** & **104.6724** & **6.7085** & **39.3140** & **0.5220** & **6.7189** \\ \hline \multirow{4}{*}{2} & NSCT & 7.9136 & 72.0494 & 5.9264 & 31.4682 & 0.5190 & 5.8663 \\  & LatLRR & 7.1379 & 67.3753 & **6.7216** & 24.5394 & 0.4857 & 5.9897 \\  & WT & 5.7516 & 53.0297 & 5.7662 & 26.6668 & 0.3893 & 5.3399 \\  & LatLRR+NSCT & **8.2567** & **77.0077** & **6.6908** & 30.3958 & **0.5355** & **6.1098** \\  & GANMcC & 5.2162 & 40.8938 & 5.8925 & 21.4760 & 0.3835 & 5.4296 \\  & FusionGAN & 5.6553 & 46.4851 & 5.9131 & 22.4006 & 0.4027 & 5.7214 \\  & LatLRR-GAN & **9.0267** & **87.3771** & 6.3032 & **34.9138** & 0.5201 & **6.5196** \\ \hline \multirow{4}{*}{3} & NSCT & 7.3579 & 66.9876 & 5.8889 & 29.2474 & 0.4906 & 5.7461 \\  & LatLRR & 6.7382 & 63.8525 & 6.6608 & 23.0331 & 0.4651 & 5.9029 \\  & WT & 5.5173 & 51.2336 & 5.7161 & 25.9284 & 0.3933 & 5.2259 \\  & LatLRR+NSCT & 7.7724 & 72.5752 & 6.6468 & 28.7566 & **0.5077** & 6.0418 \\  & GANMcC & 5.2840 & 40.6193 & 5.8015 & 22.4883 & 0.3154 & 5.5587 \\  & FusionGAN & 5.4292 & 42.8494 & 5.9772 & 20.3388 & 0.3390 & 5.5425 \\  & LatLRR-GAN & **10.6800** & **104.2155** & **6.9095** & **34.3389** & 0.4821 & **6.6913** \\ \hline \multirow{4}{*}{4} & NSCT & 9.1151 & 81.7507 & 6.2800 & 31.8276 & 0.5219 & 5.9192 \\  & LatLRR & 8.3223 & 77.1386 & 6.7648 & 25.3768 & 0.4811 & 5.8338 \\  & WT & 6.6501 & 60.7376 & 6.0900 & 28.0719 & 0.3975 & 5.1960 \\  & LatLRR+NSCT & 9.5643 & 88.0301 & 6.8263 & 30.9593 & **0.5320** & **6.0858** \\  & GANMcC & 6.5427 & 46.0002 & 6.0664 & 21.3119 & 0.3902 & 5.2568 \\  & FusionGAN & 6.6687 & 46.0735 & 6.0146 & 22.4728 & 0.3934 & 5.2173 \\  & LatLRR-GAN & **10.5485** & **103.3578** & **6.9186** & **32.7830** & 0.4926 & **6.7281** \\ \hline \multirow{4}{*}{5} & NSCT & 9.0230 & 74.8148 & 5.4163 & **36.7065** & 0.5333 & 5.7432 \\  & LatLRR & 7.9501 & 67.9433 & 6.5126 & 29.8936 & 0.4953 & 5.6478 \\ \cline{1-1}  & WT & 6.5029 & 55.1489 & 5.2648 & 31.4250 & 0.3038 & 5.0835 \\ \cline{1-1}  & LatLRR+NSCT & 9.1967 & 78.3693 & 6.5572 & 35.6572 & 0.5477 & 5.8475 \\ \cline{1-1}  & GANMcC & 6.2239 & 42.7345 & 5.6118 & 22.0594 & 0.3506 & 5.6745 \\ \cline{1-1}  & FusionGAN & 6.3612 & 44.9311 & 5.9115 & 24.4120 & 0.3017 & 5.0167 \\ \cline{1-1}  & LatLRR-GAN & **12.3573** & **119.3307** & **7.0015** & **36.1969** & 0.5078 & **6.8767** \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The results of fused images’ evaluation metric values of CT mediastinal window images and PET images. Method 1: NSCT; Method 2: LatLRR; Method 3: WT; Method 4: LatLRR+NSCT; Method 5: GANMcC; Method 6: FusionGAN; Method 7: LatLRR-GAN. The best evaluation metric values are represented in red; the second-best evaluation metric values are represented in blue. It can be seen from Table 2 and Figure 6 that compared with other methods, Method 7 proposed in this paper provides a great improvement in the evaluation metric values of AG and EI. In the evaluation metric values of SF, Method 7 shows little difference with Methods 1 and 4, but has obvious advantages compared with Methods 5 and 6. In the two evaluation metric values of IE and SD, Method 7 also has obvious advantages. In terms of the evaluation metric value of \(\mathcal{Q}^{\text{AB}/F}\), the value of Method 4 is improved compared with Method 7, because the background contrast of CT images is adjusted in Method 4 in order to highlight the lesion area of PET images.