Quality rating of television pictures: comparison of results obtained by laboratories in different countries

The participation of five European countries in preliminary experiments with methods of television subjective testing, intended for application to a 2 Mbit/s codec, has provided the first opportunity for comparing results obtained by different organisations using a single-stimulus full-range quality-rating method under fairly well standardised conditions. The range in standards of subjective judgment was about 2 dB, as expressed in terms of the equivalent level of wideband random noise. This small range, coupled with simplicity, encourages the continued use of quality grading by the single-stimulus method for television subjective studies involving a substantial range of subjective magnitudes.