## 6 Case Study
### Case-1: Sample with Rain, Windshield Disturbances, and Runway Water  
This sample contains 638 frames and elements that hamper extracting runway edges by the presence of windscreen, rain, and water noises in the runway, as shown in Figure 26. In this case, the buffers played an essential role in keeping tracking stable even with the high stress of the algorithm and in a segmented band situation. The noise removal was appropriate for not compromising the identification of the tracks. The analysis of the algorithm output for the left band is shown in Figure 27. It can be noticed that the increase in the error threshold directly influenced the result of the PPL and PPF, and there was a significant variation in the threshold indexes for all the ROIs. However, the modification of the ROIs had little influence on the PPL indices and none on the PPF indices. For all analyses, the MAD and SD remained stable with few variations. Figure 26: _Cont._  
Figure 25: Precision per frame flowchart. Figure 27: Performance analysis by PPL and PPF: **(a)** PPL for road left lane marking, **(b)** PPF for road right lane marking, **(c)** PPL for road left lane marking, and **(d)** PPF for road right lane marking. Figure 26: Road images under different weather conditions, according to table I: **(a)** Case-1, **(b)** Case-2, **(c)** Case-3, **(d)** Case-4, **(e)** Case-5, and **(f)** Case-6. The error threshold increase influenced only the PPL result, and the PPF index remained stable in all the analyses. The change in ROIs had little influence on the indexes. For all analyses, the MAD and SD remained stable with few variations. Case-2: The Band of the Left Was Continuous White, and the Right Band Was Continuous White, with a Small Segment Being Segmented  
In this case, the sample is formed by 493 frames and contains no elements that are hampered to extracting edges of the track, as shown in Figure 26b. Therefore, identifying the bands was performed with less stress of the algorithm regarding identifying the bands in case-1. The increase in the error threshold directly influenced the PPL and PPF results, and there was a significant variation in all the ROIs. For all analyses, the MAD and SD remained stable with few variations. The highest PPL and PPF values were 69.53% and 75.86%, respectively, even in a more favorable situation to identify the bands in this sample. This phenomenon is due to the ground truth metric marking the bands' optimal coordinates as the inner edges. However, through the qualitative analysis, it was identified that the algorithm performed the recognition and marking of the outer border of the left band, compromising the quantitative indexes of PPL and PPF. The increase in the error threshold influenced the PPF and PPL indices. The change in ROIs had little influence on the indexes. For all analyses, the MAD and SD remained stable with slight variations. Case 3: The Left Lane Was Continuous, a Short Continuous Double, and at the End of the Double Segmented Video, Yellow throughout the Sample, and the Right Lane Was Continuous White  
The sample is formed by 810 frames and contains no elements that are hampered to extract edges of the track or interference of noise from other vehicles, as shown in Figure 26c. Therefore, identifying the bands was performed with less stress of the algorithm regarding identifying the bands in case 2. The increase in the error threshold directly influences the PPL and PPF, causing a significant variation in these indexes in all the ROIs. For all analyses, the MAD and SD remained stable with few variations. However, even in a more favorable situation for identifying the bands in this sample, the highest PPL and PPF values were 31.35% and 32.66%, respectively. The reason is that the ground thrush metric is used to mark the optimal coordinates of the bands to be the inner edges. However, through the qualitative analysis, it was identified that the algorithm performed the recognition and marking of the outer border of the left band, compromising the quantitative indexes of PPL and PPF.