1. An information processing apparatus comprising: first generating means configured to generate, based on feature points detected on a cepstrum from an input image, a point spread function that represents the degree of blurring generated in said input image; second generating means configured to generate a structure that represents an image obtained by reducing said input image with a size based on said point spread function and enlarging said input image with said size, based on said point spread function; and updating means configured to execute an updating process to update at least either said point spread function or said structure such that said point spread function and said structure approximate to a true value; wherein said updating means repeatedly execute said updating process to set, of a structure component and a texture component making up said structure after updating by said updating process, said structure component as a new structure to be updated by said updating process, and set said point spread function after updating by said updating process as a new target to be updated by said updating process.