An improved image processing method for generating an image from a hard copy document includes the following steps: scanning the hard copy document multiple times using a scanner to generate a plurality of images; performing deskewing for each image; performing translational compensation for each image; selecting two images (first and second) among the plurality of images that have the highest similarity to each other; dilating the first image; converting the dilated first image into a binary form; eroding the converted first image to generate a first processed image; eroding the second image; converting the eroded second image into a binary form; dilating the converted second image to generate a second processed image; and extracting common portions of the first and second processed images to generate a final image. This method can be used to generate high quality scanned images of hard copy documents for purposes of document authentication.