DEFECT INSPECTION APPARATUS FOR INSPECTING SHEET-LIKE INSPECTION OBJECT, COMPUTER-IMPLEMENTED METHOD FOR INSPECTING SHEET-LIKE INSPECTION OBJECT, AND DEFECT INSPECTION SYSTEM FOR INSPECTING SHEET-LIKE INSPECTION OBJECT

摘要

An apparatus divides a photographed image of a sheet-like inspection object into blocks each of which has a size of a predetermined number of pixels by a predetermined number of pixels, calculates a longitudinal variance based on pixel values in a longitudinal direction in each block and a lateral variance based on pixel values in a lateral direction in the block, determines whether the block is a defect candidate using the longitudinal variance and the lateral variance as sheet-like inspection object defect determination evaluation values, and determines, based on one of a length and an area of the blocks determined as the defect candidates, whether the sheet-like inspection object has defect.