1. A defacement degree determination apparatus comprising: a alignment unit configured to align positions of an input image from one printed material printed using a plurality of printing plates with registered images registered in advance; a plate separation processing unit configured to separate the input image into a plurality of printed components corresponding to the plurality of printing plates, and extract defacement features from the respective printed components; and a defacement degree determination unit configured to determine a defacement degree of the printed material based on the defacement features extracted from the respective printed components.