#Color lines on tv generator
#Color lines on tv tv

The pluge pulse aids in adjusting the bottom of the luminance range to avoid either washing out the black tones into grays or collapsing picture information into the signal clipping that occurs a small distance below the black level (known as crushing the blacks). It comprises three small vertical bars, a rightmost one with intensity 4% above black level (11.5 IRE), a middle one with intensity exactly equal to black (7.5 IRE), and a leftmost one with intensity 4% below black (super-black or blacker than black, 3.5 IRE). The pluge (short for picture line-up generation equipment) pulse is positioned within the black rectangle, below the red bar (it is present in the illustration but may be hard to see). The white square lines up so that it is below the yellow and cyan bars, on a waveform monitor this will show up with the white bar overlapping the peak of the yellow and cyan chroma at 100 IRE units. More modern versions of the pattern feature a PLUGE pulse. The bottom section contains a square of 100% intensity white and a rectangle of 7.5% intensity black, for use in setting the luminance range. When a television receiver is set to filter out all colors except for blue, these castellations, combined with the main set of color bars, are used to adjust the color controls they appear as four solid blue bars, with no visible distinction between the bars and the castellations if the color controls are properly adjusted. The graticule of a vectorscope is etched with boxes showing the permissible regions where the traces from these seven bars are supposed to fall if the signal is properly adjusted.īelow the main set of seven bars is a strip of blue, magenta, cyan, and white or gray castellations. Because green contributes the largest share of luminance, followed by red, then blue, this sequence of bars thus appears on a waveform monitor in luminance mode as a downward staircase from left to right. This sequence runs through all seven possible combinations that use at least one of the three basic color components of green, red, and blue, with blue cycling on and off between every bar, red cycling on and off every two bars, and green on for the leftmost four bars and off for the rightmost three. The choice of white or gray depends on whether that bar's luminance is 100% or not. In order from left to right, the colors are white or gray, yellow, cyan, green, magenta, red, and blue. In a SMPTE color bar image, the top two-thirds of the television picture contain seven vertical bars of 75% intensity. Rendition of ECR-1-1978 color bars with 1kHz sine wave tone. CBS did not file a patent application on the test signal, thereby putting it into the public domain for general use by the industry. Its development by CBS was awarded a Technology & Engineering Emmy Award in 2002. This improved test signal was published as the standard SMPTE ECR 1-1978.

#Color lines on tv tv

Goldberg, of the CBS Technology Center, described an improved color bar test signal developed at the center by Hank Mahler that was then submitted to the SMPTE TV Video Technology Committee for consideration as a SMPTE recommended practice. Later, the EIA published a standard, RS-189A, which in 1976 became EIA-189A, which described a Standard Color Bar Signal, intended for use as a test signal for adjustment of color monitors, adjustment of encoders, and rapid checks of color television transmission systems.

#Color lines on tv generator

patent 2,742,525 Color Test Pattern Generator (now expired) was awarded on April 17, 1956, to Larky and Holmes.

Holmes (1926–2006) of RCA Laboratories and first published in RCA Licensee Bulletin LB-819 on February 7, 1951. It is also used for setting a television monitor or receiver to reproduce NTSC chrominance and luminance information correctly.Ī precursor to the SMPTE test pattern was conceived by Norbert D. Comparing it as received to the known standard gives video engineers an indication of how an NTSC video signal has been altered by recording or transmission and what adjustments must be made to bring it back to specification. Its components are a known standard, and created by test pattern generators. The Society of Motion Picture and Television Engineers (SMPTE) refers to the pattern as Engineering Guideline (EG) 1-1990. SMPTE color bars are a television test pattern used where the NTSC video standard is utilized, including countries in North America. Colors are only approximate due to different transfers and color spaces used on web pages ( sRGB) and video ( BT.601 or BT.709)