1. An image estimation apparatus comprising: a forming unit that forms a reference frame with a size determined uniquely in accordance with a size of a recording region where an image is recorded; and an estimating unit that estimates a type of a single image based on a size of a bounding frame around the single image and the size of the reference frame formed by the forming unit, the single image being a target of type inference in an image contained in a designation region in a recording region image which is an image indicating the recording region where an image is recorded.