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Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
black burst a TV black video signal containing horizontal and vertical sync, color burst, and setup (i.e., a composite video black signal). Black burst is also called "color black." A black burst signal is often used in the video studio to provide synchronizing pulses. black level the portion of the video signal pertaining to the lower luminance (brightness) levels. black start the task of re-starting an isolated power system which is completely de-energized. Most generating plants require substantial external electric power to start. Thus a black start may be initiated by hand-starting gas turbine generators or by opening the gates of a hydroelectric generator somewhere in the system. blackbody theoretically contrived object that gives rise to the so-called "black body radiation." One might imagine a closed surface object (say of metal) possessing one opening that connects the interior surface with the outside world. When the object is heated, the opening becomes a perfect "black" radiator. Such radiation depends on temperature only. blackout system. total loss of power to the entire power
Colour television
Published in John Watkinson, Television Fundamentals, 1996
It is a characteristic of AM that the presence of the carrier blots out interference. Thus less interference will be experienced when the modulator produces full carrier amplitude. However, in video signals, noise is more visible when it affects dark picture areas. The optimum solution is to invert the baseband video signal before it drives the modulator. In this way the carrier amplitude is maximum during the sync pulses and minimum at peak white. Black level or blanking corresponds to a significant carrier level which helps reduce noise in dark picture areas.
Measuring Video
Published in Peter Hodges, An Introduction to Video and Audio Measurement, 2013
We have now put in place all the background to make measurement possible. There is a voltmeter in the form of a waveform monitor, WFM, able to measure signal level in voltage. We have ascertained the parameters of a standard signal and its references. Black level is established as the reference from which to measure picture levels. Overall amplitude is measured from the tip of sync pulses to the maximum permissible, which is white, sometimes known as ‘peak white’, and we have a time scale.
Effect of black level and color gamut on display brightness
Published in Journal of Information Display, 2023
Garam Seong, Youngshin Kwak, Hyosun Kim
The black level affects the perceived brightness due to the simultaneous contrast effect. This effect is a color appearance phenomenon in which brightness is perceived differently depending on the background luminance. For example, a gray patch on a black background is perceived as brighter than a gray patch on a white background. Mantiuk et al. studied the relationship between the surrounding luminance and the stimuli’s brightness of a display [2]. They determined that the perceptually absolute black level, perceived as the darkest black, changed depending on the surrounding luminance. The absolute black level increased with the surrounding luminance. Baek et al. investigated the effect of the black level in complex images. They showed that people perceive an image with a lower black level as brighter as the dark area of an image increases [3].