1. An image recognition apparatus for recognizing a target object in an image by collation with dictionary data, comprising: an obtaining unit configured to obtain one or a plurality of images; a detection unit configured to detect a target object image from each of one or the plurality of images; a cutting unit configured to cut out one or a plurality of local regions from the target object image; a feature amount calculation unit configured to calculate, for each of one or the plurality of images, a feature amount from each of one or the plurality of local regions to recognize the target object; a similarity calculation unit configured to calculate, for each local region, a similarity between the feature amounts calculated for that region in respective images; and a registration unit configured to, for each local region, if there is a pair of feature amounts whose similarity is not less than a threshold in that region, register only one of the pair of feature amounts as dictionary data for the target object.