VISUAL INSPECTION APPARATUS AND VISUAL INSPECTION METHOD

A visual inspection apparatus detects a defect candidate for each of captured images of a crown surface of a piston that are captured at a plurality of posture angles different from one another, locates 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, applies 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, determines a feature amount regarding the defect candidate based on the two-dimensional position of the defect candidate for each of the captured images captured at the plurality of posture angles, and inspects the crown surface of the piston using the feature amount regarding the defect candidate.