I. Introduction
Product inspection has been implemented in different manufacturing steps to ensure the quality of products meets the production standard. In general, the inspection processes are performed by human inspectors. However, due to issues such as tiredness, tediousness, and fatigue, the performance of human inspectors is inadequate and unreliable. Besides, the working hours of human inspectors are relatively short compared to a machine [1]–[4]. Therefore, an automated visual inspection system is required to replace human inspectors in inspection tasks.