1. A method for watermarking an image utilizing a computer, said method comprising utilizing the computer to: step through multipixel blocks of a digitized image having regions of a plurality of different densities; analyze the multipixel blocks of the digitized image to determine whether the multipixel blocks of the digitized image are replaceable with coded blocks indicative of a watermark code, said replaceable multipixel blocks thereby being codable blocks; and substitute coded blocks indicative of a watermark for codable blocks of the digitized image.