OBJECT RETRIEVAL USING BACKGROUND IMAGE AND QUERY IMAGE

Each of a plurality of cameras is sequentially selected. An image that does not include a retrieval target object is acquired, as a background image, from an image group captured by a selected camera. An image including the retrieval target object is acquired as a query image. A discriminator being used for identifying the retrieval target object from the image captured by the selected camera is learned using the background image and the query image. The retrieval target object is retrieved from the image group captured by the selected camera using the learned discriminator.