In an image processing apparatus, an image acquiring section acquires one or more images. An image analysis information acquiring section acquires image analysis information on each of the one or more images. A theme determining section determines a main theme representing a theme of each group of images related to each other among the one or more images and a subtheme representing a theme of each of the one or more images based on information on photography tendencies of images associated with each of one or more themes and the image analysis information on each of the one or more images. A theme information output section outputs information on the main theme and information on the subtheme.