Method of restoring degraded image, apparatus for restoring degraded image, and computer program product

A degraded-image restoring apparatus comprising:

• an image input unit that inputs a degraded image degraded by a predetermined degradation process;
• a storage unit that stores a filter coefficient in a filtering process of restoring the degraded image, in which an iteration formula for minimizing a square error between the degraded image and an image obtained by degrading a restored image by the degradation process is expanded corresponding to a predetermined number of iterations;
• and
• a restored-image obtaining unit that obtains the restored image of the degraded image by performing the filtering process using the filter coefficient with respect to the degraded image.

A computer program product having a computer readable medium including programmed instructions for restoring a degraded image, wherein the instructions, when executed by a computer, cause the computer to perform:

• inputting a degraded image degraded by a predetermined degradation process;
• reading from a storage unit a filter coefficient in a filtering process of restoring the degraded image, in which an iteration formula for minimizing a square error between the degraded image and an image obtained by degrading a restored image by the degradation process is expanded corresponding to a predetermined number of iterations;
• and
• performing the filtering process using the filter coefficient with respect to the degraded image to obtain a restored image of the degraded image.