Optimizing Cost, Design, and Human Visual Performance Tradeoffs in a Digital Television Encoding System

摘要

Tradeoff relationships among human visual performance, electronic design parameters, and system cost were determined for a digital television transmission system. These relationships were investigated by measuring subjects' minimum perceptible acuities for various length lines and spatial orientations. Variations in sampling frequency and binary code length were simulated for a differential pulse code modulation encoding system by changing bandwidths and signal-to-noise ratios of pictures displayed on the monitor of a closed television system. Noise level, bandwidth, line length, spatial orientation, and the length by orientation interaction all significantly affected the perception of image detail. Visual performance was determined for points along four noise-bandwidth tradeoff curves representing different information capacities and system costs. Perception was profoundly affected by bandwidth and very little affected by system cost relative to the curves tested. Optimum system performance was achieved by maximizing the sampling frequency of the encoder. (Author)