1. An image processing apparatus comprising: a storing unit that stores information on a feature area that indicates an area where a feature of a subject appears including a first data containing position information on the image and conversion coefficient value of the position information in association with each other and a second data includes the position information and a hierarchical level indicating variance of the conversion coefficient value in association with each other; and a subject determination unit that compares, when an input image is acquired, referring to the first data and the second data, the conversion coefficient value of the input image with the conversion coefficient value of the position information corresponding to the hierarchical level and determines whether the input image includes the subject based on the result of comparison and the hierarchical level corresponding to the result of comparison.