An image processing device extracts, in an image block selection section 226, a plurality of image block pairs from a degraded image and a provisional restored image, each of the image block pairs being formed by two image blocks at identical coordinates in the degraded image and the provisional restored image, and estimates a point spread function (PSF) for each of the image block pairs. From among the estimated PSFs, a PSF which is estimated to be close to a true PSF is selected as a candidate PSF. The estimation of the PSF is carried out on a block-by-block basis, whereby the amount of computation required for the estimation of the PSF can be reduced. Also, the estimation method used is not disturbed by an image block which includes noise, and therefore, a PSF which is close to the true PSF can be estimated.