1. An image processing apparatus comprising: a point spread function (PSF) pattern generation unit that is configured to generate a PSF pattern in which a plurality of PSFs are located in a plurality of lines of the PSF pattern; a PSF estimation unit that is configured to estimate at least one of the plurality of PSFs of an out-of-focus input image from at least one of a plurality of step responses of respective ones of the plurality of lines of the PSF pattern with respect to an edge of the out-of-focus input image; and an image restoration unit that is configured to restore the out-of-focus input image to a focused restored image using the estimated PSF.