A Single Weighting Characteristic for Random Noise in Monochrome and NTSC Color Television

Previously there were specifications of separate noise-weighting characteristics for monochrome and color TV. A series of subjective tests was designed to study the effects of broadband random noise on 525-line monochrome and NTSC color TV. A single noise-weighting characteristic has been derived which satisfactorily weights broadband noise shapes (power density vs frequency curves) typical of those found in various TV transmission systems. Both color and monochrome pictures were generated from slides and viewed on 21-in studio monitors at a viewing distance of four times the picture height. A seven-point comment scale, ranging from “not perceptible” to “extremely objectionable,” was used to obtain the observer responses. The distributions obtained from the data describe the spread of observer opinion as a function of noise level for each of the classes.