1. A method for electronically processing an undecoded electronic document image, comprising the steps of: automatically segmenting the document image into image units having information content without decoding the document image, each of the image units comprising one of an undecoded word and an undecoded group of words; identifying significant ones of said image units in accordance with selected morphological image characteristics without decoding the document image; and modifying said document image to emphasize the identified significant image units such that the significant image units are visually distinguishable from non-significant image units remaining in the document image.