## 3 Results and Discussion
### Semantic Segmentation Maps  
Results for the semantic segmentation for the RD annotated dataset for FRNB are presented in Figure 17, showing the ground truth (Figure 17a,b) and the predicted outcome (Figure 17c-g) of the test bridge image after training. The output of the individual image blocks was combined to make a complete map for visualization without any further image processing. The probability outcome of the delamination detection was presented in a heat map to show the progress and gradient of delamination over the bridge deck area from \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Bridge**} & \multicolumn{2}{c}{**Global Accuracy**} & \multicolumn{1}{c}{**Bridge**} & \multicolumn{1}{c}{**Mean Acc**} & \multicolumn{1}{c}{**Bridge**} & \multicolumn{1}{c}{**Precision**} & \multicolumn{1}{c}{**Bridge**} & \multicolumn{1}{c}{**TPR**} & \multicolumn{1}{c}{**Bridge**} & \multicolumn{1}{c}{**TNR**} & \multicolumn{1}{c}{**Bridge**} & \multicolumn{1}{c}{**F1 Score**} \\ \hline \multirow{2}{*}{FRNB} & FN/R/D & 0.728 & FN/R/B & 0.650 & FN/R/B & 0.667 & FN/B/B & 0.532 & FN/R/B & 0.872 & FN/R/B & 0.427 \\ \cline{2-13}  & FN/M/AB & 0.506 & FN/M/AB & 0.494 & FN/M/D & 0.263 & FN/B/A & 0.250 & FN/M/AB & 0.669 & FN/B/A & 0.282 \\ \hline \multirow{2}{*}{FRSB} & FS/R/D & 0.736 & FS/B/B & 0.657 & FS/R/B & 0.716 & FS/B/B & 0.588 & FS/R/B & 0.895 & FS/R/B & 0.420 \\ \cline{2-13}  & FS/M/B & 0.491 & FS/M/Aa & 0.500 & FS/R/D & 0.247 & FS/B/Aa & 0.273 & FS/B/B & 0.671 & FS/R/D & 0.268 \\ \hline \multirow{2}{*}{PRMD} & PM/R/D & 0.719 & PM/R/A & 0.641 & PM/R/B & 0.672 & PM/B/B & 0.515 & PM/R/B & 0.876 & PM/R/B & 0.427 \\ \cline{2-13}  & PM/M/AB & 0.506 & PM/M/Aa & 0.496 & PM/M/Aa & 0.270 & PM/B/A & 0.265 & PM/B/A/B & 0.675 & PM/B/A & 0.273 \\ \cline{2-13}  & PN/R/D & 0.644 & FN/B/B & 0.603 & PN/R/B & 0.674 & FN/B/A & 0.504 & PM/R/B & 0.293 & PN/R/B & 0.362 \\ \hline \multirow{2}{*}{PRSB} & PN/R/B & 0.447 & FN/M/A & 0.504 & PN/B/A & 0.248 & PN/R/A & 0.243 & PN/B/AB & 0.529 & PN/R/A & 0.261 \\ \cline{2-13}  & PS/R/D & 0.723 & FS/R/B & 0.655 & FS/R/D & 0.239 & PS/B/B & 0.509 & PS/R/B & 0.899 & PS/M/AB & 0.401 \\ \hline \multirow{2}{*}{PRSB} & FS/M/AB & 0.485 & PS/M/A & 0.497 & FS/R/B & 0.605 & PS/B/D & 0.269 & PS/M/A & 0.685 & PS/R/D & 0.261 \\ \cline{2-13}  & Maximum & & & & & & & & & & \\ \cline{1-1} \cline{2-13}  & Minimum & & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Summary of minimum and maximum performance metrics. sound (zero) to severe delaminated (one) and mid-delamination level (0.5), represented by blue, red, and green colors on the map. The output for the CM, AM1, and AM2 models barely distinguished between sound and delaminated regions. The maps generated from the BM and ABM models, compared \begin{table}
\begin{tabular}{l l l l l l l} \hline \hline  & **Global Acc.** & **Mean Acc.** & **Precision** & **TPR** & **TNR** & **F1 Score** \\ \hline FN/R/D & _0.728_ & 0.560 & 0.269 & 0.326 & 0.813 & 0.295 \\ \hline FN/R/A & 0.720 & 0.553 & 0.264 & 0.311 & 0.810 & 0.285 \\ \hline FN/R/A2 & 0.713 & 0.555 & 0.282 & 0.306 & 0.811 & 0.294 \\ \hline FN/R/AB & 0.625 & 0.628 & 0.631 & 0.311 & 0.863 & 0.416 \\ \hline FN/R/B & 0.621 & 0.638 & _0.667_ & 0.314 & _0.872_ & _0.427_ \\ \hline FN/B/D & 0.697 & 0.648 & 0.325 & 0.268 & 0.844 & 0.294 \\ \hline FN/B/A & 0.693 & 0.645 & 0.318 & 0.282 & 0.829 & 0.299 \\ \hline FN/B/A2 & 0.688 & 0.636 & 0.322 & _0.250_ & 0.852 & _0.282_ \\ \hline FN/B/AB & 0.636 & 0.644 & 0.321 & 0.505 & 0.699 & 0.392 \\ \hline FN/B/B & 0.636 & _0.650_ & 0.324 & _0.532_ & 0.687 & 0.402 \\ \hline FN/M/D & 0.584 & 0.501 & _0.263_ & 0.329 & 0.674 & 0.292 \\ \hline FN/M/A & 0.570 & 0.499 & 0.296 & 0.326 & 0.673 & 0.310 \\ \hline FN/M/A2 & 0.577 & 0.501 & 0.282 & 0.328 & 0.674 & 0.304 \\ \hline FN/M/AB & _0.506_ & _0.494_ & 0.462 & 0.322 & _0.669_ & 0.379 \\ \hline FN/M/B & 0.508 & 0.499 & 0.472 & 0.326 & 0.672 & 0.385 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Performance metrics for FRNB models (Highest and lowest values in _italics_).