Having identified the exact time frame when pits appear and their initial detected sizes, we sought to investigate whether the locations of their appearance could be predicted based on optical signatures associated solely with the formation of the passive layer. To achieve this, we employed a procedure conceptually similar to pit detection. In the first step, we collected normalized optical images corresponding to passive film formation (Fig. ), followed by per-pixel temporal decomposition (Fig. ). In contrast to the pitting detection results shown in Fig. , the evolution of normalized intensities in Fig. does not exhibit striking differences in behavior. Instead, all curves display a consistent trend of slight decrease, ranging from 98 % to 102 %.