A method for reading optical indicia involving the application of different symmetrical transforms to each of a plurality of images of an optical indicia. Characteristic features are identified in the transformed frequency domain representation of each transformed image, the characteristic features corresponding to repetitive features found in the original non-transformed representation of each image. Modified images are created by subjecting the frequency-domain representation of each image to an inverse transformation. The modified images can be combined to create an improved representation of the optical indicia being read. Thus, the depth of field and efficiency of an optical indicia reader can be enhanced.