1. A method performed under control of one or more processors, the method comprising: identifying a subject of an image, wherein the subject of the image includes one of: a portrait, a landscape, and a particular object; determining a resolution value for the image based on one of a resolution usage history database and a user setting database, wherein the resolution usage history database includes resolution usage history data that corresponds to the identified subject, and wherein the user setting database includes a particular resolution value that corresponds to the identified subject; and modifying a resolution of the image based on the determined resolution value.