Television measurements through psychophysics to subjective picture quality

The most important property of a television system is the quality of the received picture as judged by the user. An explanation is offered of the way in which human beings quantify picture quality and the apparent magnitude of picture impairments. Although the explanation is speculative, it is hoped it will prove intuitively attractive, and will assist both the interpretation of the results of visual subjective studies and their application in terms of objective measurements. The psychological scale of apparent magnitude turns out to be also the scale along which co-existing impairments may be simply summed to determine their total effect. It is thus closely related to the IMP scale which has already found practical application.