1. An image processing apparatus, comprising: an image acquisition unit that acquires a plurality of images from terminal devices of a plurality of users through a network for a predetermined period; an image analysis unit that analyzes contents of each of the plurality of images; an evaluation value calculation unit that calculates an analysis evaluation value of each of the images based on an analysis result of each of the images; an evaluation information acquisition unit that acquires evaluation information, which indicates evaluation for each of the images that is given by the plurality of users, from the terminal devices of the plurality of users through the network for the predetermined period; and a group forming unit that forms one or more groups, each of which includes a plurality of similar images, by specifying the plurality of similar images, among the plurality of images, based on the analysis result of each of the images after the predetermined period has passed, wherein the evaluation value calculation unit calculates an overall evaluation value by adding a value to an analysis evaluation value of each of the plurality of similar images based on evaluation information, which indicates high evaluation for the plurality of similar images, for each of the groups.