An image processing method performs reduction processing on an input image to acquire a reduced image, extracts a feature point from a group of images including the input image and one or more of the reduced images, determines as a matched feature point the feature point extracted from a matching position in each of two or more images in the group of images, calculates a local feature quantity of the matched feature point determined by the determination unit, and registers the calculated local feature quantity as a local feature quantity of the input image.