Image processing device and image processing method

An image processing device (100) includes an object detecting unit (103a) that detects objects each appearing in a corresponding one of pieces of image data; an object tracking unit (103b) that tracks the detected objects in a time direction; a descriptor generating unit (104) that generates feature descriptors of the respective objects on the basis of results of the detection and results of the tracking of the objects; a data recording control unit (105) that forms a database from the generated feature descriptors and the pieces of image data of the objects corresponding to the feature descriptors; an image retrieving unit (108a) that retrieves, from the database, object groups that match a retrieval condition and form a pair of object groups appearing in pieces of image data obtained by capturing different regions, each of the object groups corresponding to a corresponding one of the regions; a feature extracting unit (108b) that extracts a feature to be used for checking, from pieces of image data and feature descriptors of each of the retrieved object groups; and a determining unit (108c) that determines whether the object groups forming the pair of object groups are identical to each other, by checking the extracted features against each other.