Subjective assessment of cable impairments on television picture quality

The subjective assessment of NTSC television pictures that have been subjected to a number of levels of commonly encountered cable-system impairments is discussed. The impairments included random noise, phase noise, microreflections, composite triple beat, and chroma/luma or group delay. The evaluations were performed in controlled-viewing experiments using psychological test methods with both expert and nonexpert viewers. The tests evaluated picture impairments, using the CCIR impairment scale with terms describing a continuum of annoyance. A comparison of the random noise test results with data from earlier similar studies in 1958 and 1983 demonstrates a continuing rise in view expectations for improved picture quality. >