A feature value extraction device, method and program capable of extracting position-invariant local feature values, a location inference device mounted therewith, and a location inference method and program are provided. This location extraction device (10) performs location inference processing using position-invariant feature values extracted by a feature value extraction unit (11). The feature value extraction unit (11) is provided with a local feature value extraction means (21) which extracts local feature values from input images made up of continuously imaged images, a feature value matching means (22) which, for the extracted local feature values, makes matches between the continous input images, a corresponding feature value selection means (23) which selects, as corresponding feature values, the feature values which have been matched, and a position-invariant characteristic feature value extraction means (24) which calculates position-invariant feature values on the basis of the corresponding feature values. The position-invariant characteristic feature value extraction means (24) extracts, as position-invariant feature values, those corresponding feature values having a change in position less than or equal to a prescribed threshold value.
FEATURE VALUE EXTRACTION DEVICE AND LOCATION INFERENCE DEVICE