1. An image inspection method executed by an image inspection apparatus, the method comprising: acquiring an inspection target object image obtained by capturing an image of an inspection target object; reading, from a storage device that stores inspection region defining information created via an interactive setting tool that accepts one or more parameters for inspecting the target object while showing the image of the target object and a contour thereof in advance, the inspection region defining information; extracting, as an inspection region image, a portion to be an inspection region from the inspection target object image, based on the inspection region defining information; and performing inspection on the inspection target object by analyzing the inspection region image, wherein the inspection region defining information comprises information defining an initial contour of the inspection region and information defining a range based on the initial contour as a search range for searching a contour of the inspection region, wherein the range based on the initial contour as the search range includes distances both inside and outside of the initial contour, and wherein the extracting comprises: setting a plurality of base points on the initial contour; performing edge search processing on a line that passes through each base point and intersects with the initial contour, within an region of the search range of the inspection target object image, to determine an edge point corresponding to each base point; and connecting or approximating a plurality of the edge points respectively corresponding to the plurality of base points to generate the contour of the inspection region of the inspection target object image.