Automatic visual inspection apparatus automatic visual inspection method and recording medium having recorded an automatic visual inspection program

摘要

Image differential unit of the present invention is a differential reference image and a test image of the object to be inspected. An image dividing unit divides an image into a predetermined number of divisions. Aligned pixel accuracy location unit overlying the reference image and the test image by performing a position alignment accuracy of a pixel size, pixel accuracy. Function fitting unit may detect the edge, to obtain a distribution of the intensity profile of the absolute pixel value of the edge and the direction perpendicular to, and fitting a predetermined function, a single peak in the intensity profile. Calculating the sub-pixel accuracy, the position displacement unit calculates the difference between the edge positions corresponding to a sub-pixel displacement precision position. Adjusting the differential image forming unit forms an image by adjusting the differential rewriting the pixel values ​​to follow the single peak-shape function form of the two edges of the contrast profile of the pixel value of the direction perpendicular to the corresponding edge. Image comparison unit detects a defect in the object to be inspected by comparing based on the position displacement of the sub-pixel accuracy, the adjustment divided differential image of the test image and adjusting divided differential image of the reference image.