Picture Quality Judgments in a Digital Television System

Abstract

Digital communication systems distort their signals as a consequence of the digitization process. The distortions are related to the code length and sampling frequency of the system. The present study assessed viewers' responses to these variables by using simulated digital television. To do this, 24 subjects rated the quality of pictures distorted by several combinations of the variables. A response surface generated from the ratings showed that the ratings were affected by both variables, but most profoundly by code length. Interpretation of the surface's contours from the perspective of system costs revealed that costs should be considered solely from the standpoint of code length.