Restoration of shift variant blurred image estimating the parameter distribution of point-spread function

This paper describes a method of restoring a position-dependent (shift variant) blurred image by estimating the size of the blurred part and by adjusting the restoration proportionally to it. In this method, it is assumed that all blurred images are due to a defocussing of a lens system or accidental camera motion. If the point-spread function (PSF) of the blurred point is known, the estimation of the PSF can be replaced by the estimation of its parameter distribution (consisting of the diameter of a defocussed circle and the width of the motion caused by the accidental camera motions). Then a blind deconvolution of a shift-variant blurred image can be realized by locally applying a Wiener filter to the estimated distribution. The method was tested using computer simulated images and actual images taken by a CCD camera, both with blurred parts. The results confirm the effectiveness of the method.