Visual inspection apparatus and visual inspection method

A visual inspection method of inspecting a surface of an inspection target by an imaging portion configured to image the surface of the inspection target, a posture control portion configured to change a posture of the inspection target relative to the imaging portion, and a computer, the visual inspection method comprising:

• a first step of detecting a defect candidate for each of captured images of the surface of the inspection target that are captured at a plurality of posture angles different from one another;
• a second step of locating a three-dimensional position of the defect candidate based on a two-dimensional position of the defect candidate detected from at least one captured image among the captured images captured at the plurality of posture angles:
• a third step of applying a perspective projection transformation on the three-dimensional position of the defect candidate to acquire a two-dimensional position of the defect candidate for each of the captured images captured at the plurality of posture angles;
• and
• a fourth step of inspecting the surface of the inspection target using a feature amount regarding the defect candidate, the feature amount being determined based on the two-dimensional position of the defect candidate for each of the captured images captured at the plurality of posture angles.