1. A processor-implemented method of inputting information comprising the steps of: extracting an object located on a plane from an image that includes the plane and the object; determining whether the object is a writing implement; calculating , with at least one processor, a position of a contact point between the writing implement and the plane as information to be input if the object has been determined as the writing implement; and inputting the information representing a position on the plane indicated by the object, wherein when a plurality of objects are extracted from the image, one of the plurality of objects that satisfies a prescribed condition is determined as the writing implement, and the contact position of the writing implement is input as the information.