Methods for Designing Differential Quantizers Based on Subjective Evaluations of Edge Busyness

Abstract

This is a study of the visibility of television noise and its dependence on the instantaneous rate of change of the video signal. Noise added to a picture tends to be least noticeable in regions where the brightness changes rapidly, but the relationship between visibility-of-noise and slope-of-the signal is dependent on the scene being displayed. Measurements are presented for four different scenes, and these data are used to design companding laws that minimize the visibility of noise from Differential Quantizers. The designs agree with those that have been satisfactory in practical applications.