1. A method, comprising: transferring a patterned structure into a microscope; acquiring a top-view image of the patterned structure by the microscope; transferring the patterned structure out of the microscope and exporting the top-view image to an image analysis processor; measuring a difference between a contour of the top-view image and a predetermined layout of the patterned structure by the image analysis processor; calculating an area ratio of the contour to the predetermined layout of the patterned structure; and adding rounding correction features to the predetermined layout of the patterned structure such that the area ratio of the contour to the predetermined layout of the patterned structure is not in a range of 0.95 to 1.05.