# Skin Lesion Segmentation Using Image Bit-Plane Multilayer Approach
## 6 Experimental Results
### Results  
For the experimental validation of the implemented method, a publicly available database of skin lesion dermoscopic images was used. Therefore, the system performance could be quantitatively compared with other segmentation procedures indicated in literature.  
The collection of skin lesion dermoscopic images of the PH\({}^{2}\) database was processed to assess the procedure performance. For comparative purpose, the results were analyzed in two different ways. The first one considered the whole dataset of images, and the next one two subsets of images, melanoma and benign lesions separated.  
Comparisons of the obtained performance with other methods indicated in literature which adopted the PH\({}^{2}\) database as test bench showed the procedure validity. In particular, in Table 1 results obtained adopting the whole PH\({}^{2}\) dataset are indicated while Table 2 contains the performance obtained differentiating the images with and without melanoma.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{5}{c}{**Performance [\%]**} \\ \cline{2-6}
**Paper** & \multicolumn{5}{c}{**Sp**} & **Ac** & **DI** & **JA** \\ \hline [PERSON] et al. ref. n. [19] & 95.2 & 92.5 & 96.4 & 94.6 & 89.9 \\ [PERSON] et al ref. n. [21] & 95.86 & - & 98.47 & 95.22 & - \\ [PERSON], et al. ref. n. [22] & 87 & 97 & 93 & 90 & 85 \\ [PERSON] et al. ref. n. [23] & - & - & - & 86.54 & - \\ [PERSON] et al., ref. n. [25] & 87.6 & 95.3 & 93.4 & - & - \\ [PERSON] et al., ref. n. [28] & 80.24 & 97.22 & 89.66 & - & - \\ [PERSON] et al. ref n. [30] & 96.67 & 98.74 & 97.5 & - & - \\ [PERSON] et al., ref. n. [32] & - & - & - & 91.5 & 85.3 \\ [PERSON] et al. ref. n. [33] & 94.89 & 93.98 & 94.24 & 90.66 & 83.99 \\ [PERSON] et al. ref. n. [34] & 96.23 & 94.52 & 95.30 & 92.10 & 85.90 \\ [PERSON] et al. ref. n. [35] & 83.63 & 94.02 & 92.99 & 88.13 & 79.54 \\ [PERSON] et al. ref. n. [38] & 91.04 & 89.73 & 90.39 & 89.18 & - \\ [PERSON] et al. ref. n. [39] & 95.50 & 98.40 & 96.02 & 92.24 & 85.25 \\ Proposed method & 93.60 & 98.77 & 95.37 & 95.32 & 91.05 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Performance comparison among some most recent segmentation procedures indicated in literature which adopted the PH\({}^{2}\) database.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{5}{c}{**a**} \\ \hline \hline  & \multicolumn{5}{c}{**Performance [\%]**} \\ \cline{2-6}
**Paper** & \multicolumn{5}{c}{**Se**} & **Sp** & **Ac** & **DI** & **JA** \\ \cline{2-6}
**[PERSON] et al. ref. n. [28]** & 86.78 & 97.46 & 93.74 & - & - \\ [PERSON] et al. ref. n. [33] & 95.64 & 95.12 & 95.61 & 90.77 & 84.15 \\ [PERSON] et al. ref. n. [34] & 97.11 & 95.85 & 96.61 & 92.26 & 86.05 \\ [PERSON] et al. ref n. [38] & 92.18 & 94.98 & 94.19 & 92.02 & - \\ Proposed method & 93.01 & 98.77 & 95.37 & 95.30 & 91.03 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Performance comparison for melanoma (**a**) and no-melanoma (**b**) PH\({}^{2}\) database images.  
In Figure 5, an example of segmentation obtained adopting the proposed procedure is presented which shows the performance in terms of FP (green area), FN (red area), and TP (yellow area).  
Figure 4: The violin plots of TN, TP, FN, and FP statistics for melanoma, atypical, and normal skin lesions.  
Figure 5: _Cont._