1. A multifocus digital image restoration method using an image integration technology, the method comprising the steps of: receiving a deteriorated image, and generating N restoration images by using a preset Point Spread Function (PSF) and an image restoration filter without computing a PSF of the input deteriorated image; dividing the N restoration images into window parts of a predetermined window size, computing absolute values of differences among peripheral pixels within the divided window parts, selecting only a high frequency part within the window part, and analyzing focus deterioration; determining weights of the N restoration images by using the analyzed focus deterioration; selecting window parts having high weights based on the determined weights; integrating the selected window parts into one image; comparing a degree of restoration of the integrated image with a preset degree of restoration, and outputting the integrated image as a resultant image when the degree of restoration of the integrated image is higher than the preset degree of restoration.