Fallacy and Fact of Sampled Imagery Displays

Abstract

Factors long considered to be of primary importance to the visual performance of observers of displays of sampled imagery have been shown to be dependent upon, subordinate to, or no more important than other factors largely overlooked. In TV displays, for example, sharp raster lines, thought by many to be the hallmark of a good display, have been shown to interfere with the true image to form false images, and “shades of gray” and “resolution”, often treated as independent variables, have been shown to depend directly upon the signal-to-noise ratio in the imagery as a function of spatial frequency. Experimental and theoretical work in the area is briefly reviewed, and some implications for system design criteria are pointed out.