Decision whether an object is anomalous or not is based on the 19 Cityscapes evaluation classes. If an object can be assigned to one of these classes, it is labeled as not anomaly (white), otherwise as anomaly (orange) or void (black).
The road ahead is the region of interest, labeled as not obstacle (white). Every object placed on the road is labeled as obstacle (orange), everything besides the road is voided (black). We also void areas that could distract the model, such as wet spots on the road.