1. An interest graph collection system that is a search system using image information containing various objects and subjects as input means, instead of using input means using ideographical characters such as a keyword, metadata, or writing, the system comprising: a network terminal on which a user selects, from among a large number of images existing on the Internet or on a dedicated network or images uploaded on the Internet by the user via the network terminal, an entire image or a specific region of an image in which the user has an interest; an image recognition engine on the server side, when queried by the user about the selected image via the network, extracting and recognizing in real time various objects such as a generic object, a specific object, a person, a face, a scene, characters, a sign, an illustration, a logo, and a favicon contained in the selected entire image or the specified image region; and a relevance search engine on the server side, when notified of image components contained in the recognized input image via the image recognition engine, determining other related elements directly or indirectly related to the individual image components to a certain degree or more, extracting the related elements based on multidimensional feature vectors describing direct relationships between elements held on a relevance knowledge database in the relevance search engine in a learnable manner, and visually representing the image components recognized by the image recognition engine and the related elements extracted by the relevance search engine as nodes in a relevance graph together with the depths of relationships between the nodes on the network terminal of the user as a two-dimensional image, or a three-dimensional image with depth, or a four-dimensional spatiotemporal image to which a time axis variable as observation time of the relevance graph is added.