Development of Defect Iinspection Method with Function to Determine Concavity and Convexity Using Patterned Panel Illumination

Abstract

Effectiveness of a patterned panel illumination in an inspection of a small defect of an industrial product has been indicated by some researches. This study deals with an image processing method to remove pattern on an image, which is barrier to extract information of a small defect. Hough transformation is used as the main method in the sequence of the proposed image processing because of the linearity that the edge of the pattern has. Moreover, a function to determine concavity and convexity of the defect are mentioned. The function is achieved with checking the shift value of the center of gravity obtained by using triangle check pattern.