Local feature descriptor extracting apparatus, local feature descriptor extracting method, and program

Abstract

An object of the present invention is to reduce a size of a feature descriptor while maintaining accuracy of object identification. A local feature descriptor extracting apparatus includes: a feature point detecting unit which detects a plurality of feature points in an image and which outputs feature point information that is information regarding each feature point; a feature point selecting unit which selects a prescribed number of feature points in an order of importance from the plurality of detected feature points, based on the feature point information; a local region acquiring unit which acquires a local region corresponding to each selected feature point; a subregion dividing unit which divides each local region into a plurality of subregions; a subregion feature vector generating unit which generates a feature vector of a plurality of dimensions for each subregion in each local region; and a dimension selecting unit which selects a dimension from the feature vector for each subregion so that a correlation between neighboring subregions is lowered, based on a positional relationship between subregions in each local region and which outputs an element of the selected dimension as a feature descriptor of the local region.