Distances between a query image and registered images are calculated for respective feature amounts, and weight values for the calculated distances are calculated on the basis of statistical amount of the feature amounts of the query image (S507). Similarities between the registered images and query image are calculated on the basis of the results obtained by weighting the distances for respective feature amounts by the calculated weight values (S508). Images similar to the query image are displayed as a list on the basis of the calculated similarities (S510).