A MEASURE FOR STAIRSTEPPING IN DIGITIZED TEXT THAT CORRELATES WITH THE SUBJECTIVE IMPRESSION OF QUALITY

The electrophotographic printer/copier industry is being driven to pro duce digital equipment with ever higher addressability and bits per pi xel. One reason for this drive is to minimize the phenomenon of stairs tepping in the diagonal strokes of text. To assess improvements in tex t image quality, it is important to be able to measure the level of st airstepping to ascertain whether any changes are visually meaningful. This study describes a measure of stairstepping that has been shown to correlate with the subjective impression of text quality for a variet y of levels of addressability and bits per pixel. The assessment metho d has the distinct advantage of not requiring special targets but is s imply measured from the letter ''o.''