Abstract: An algorithm named enhancing operator for restoring digitized images with degraded convex is introduced.The principle of the enhancing operator for enhancing and restoring digitized images with convex bright-dots perturbed by additive Gaussian noise is discussed. The computer simulation show that the algorithm has good functions for noise reduction,restoration and enhancement of convex image spots in digitized images. The enhancing operator has been previously used to process the digitized high-resolution electron microscopic (HREM) images of Al-Mn-Si quasicrystal and discovered the periodic characteristics in the HREM images.