IEEE 205-2001 pdf download IEEE Standard on Television: Measurement of Luminance Signal Levels
1.Overview
1.1 Scope
This standard describes a method of measuring the amplitude levels of an SMPTE 170M-1994, NTSCcolor or monochrome television video signal. t is concerned with luminance measurements at variouspoints in transmission systems where the signals are at video frequencies. The methods described inthis standard are limited to the use of waveform monitors, software video processing for amplitudeassessment. or suitable oscilloscopes, and are primarily directed to specifying means of measuringtelevision signal levels for operating purposes.
1.2 Purpose
This standard provides a uniform method to measure the luminance portion of a video signal in thepossible presence of large chrominance portions. It also specifies a method of measuring video levels ina manner permitting ready correlation between measurements at different points of a system.regardless of the nominal voltages present.
1.3 Application
The significant levels of the luminance portion of the signal are shown in Figure 1. The peak amplitudeexcursion of a composite color signal may exceed, by substantial amounts, the peak amplitude of theuminance portion of the signal. Because subjective brightness is more nearly proportional to theuminance portion than to any other signal portion, it is desirable to maintain the luminance portionof the signal at a consistent level. The application of this standard will result in approximately the samebrightness and contrast when the signal is viewed on either color or monochrome monitors, withoutrequiring supplementary adjustments. Additionally, an improved LUM flter is introduced to approximate the luminance orY portion of the decoded signal, allowing better matching ofsubsequent composite-to-component conversions.
2.References
This standard shall be used in conjunction with the following publication.ANSI/SMPTE 170M-1994, Television Composite Analog Video Signal-NTSC for Studio Applica-tions.
3. Definitions
For the purposes of this standard, the following terms and definitions apply. The AuthoritativeDictionary of IEEE Standard Terms, Seventh Edition should be referenced for terms not defined inthis clause
The significant portions of a composite video signal are defined below, and shown in Figure l.
3.1 black peak: A maximum negative excursion of the luminance portion from reference white towardsblanking.
3.2 blanking leve: That level of a video signal which separates the luminance portion from thesynchronizing pulses.
IEEE 205-2001 pdf download
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