SMPTE color bars

SMPTE color bars are a television test pattern used where the NTSC video standard is utilized, including countries in North America. The Society of Motion Picture and Television Engineers (SMPTE) refers to the pattern as Engineering Guideline (EG) 1-1990.^[1] Its components are a known standard, and created by test pattern generators.^[2][3][4] 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. It is also used for setting a television monitor or receiver to reproduce NTSC chrominance and luminance information correctly.

A precursor to the SMPTE test pattern was conceived by Norbert D. Larky (1927–2018)^[5][6] and David D. Holmes (1926–2006)^[7][8] of RCA Laboratories and first published in RCA Licensee Bulletin LB-819 on February 7, 1951. U.S. patent 2,742,525 Color Test Pattern Generator (now expired) was awarded on April 17, 1956, to Larky and Holmes.^[9] 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.^[10] In 1977, A. A. Goldberg, of the CBS Technology Center, described an improved color bar test signal developed at the center by Hank Mahler (1936–2021)^[11][12] that was then submitted to the SMPTE TV Video Technology Committee for consideration as a SMPTE recommended practice.^[13] This improved test signal was published as the standard SMPTE ECR 1-1978. Its development by CBS was awarded a Technology & Engineering Emmy Award in 2002.^[14] CBS did not file a patent application on the test signal, thereby putting it into the public domain for general use by the industry.

An extended version of the SMPTE color bars, SMPTE RP 219:2002^[15] was introduced to test HDTV signals (see subsection).^[16]

Although color bars were originally designed to calibrate analog NTSC equipment, they remain widely used in transmission and within modern digital television facilities. In the current context color bars are used to maintain accurate chroma and luminance levels in CRT, LCD, LED, plasma, and other video displays, as well as duplication, satellite, fiber-optic and microwave transmission, and television and webcast equipment.

In a survey of the top standards of the organizations' first 100 years, SMPTE EG-1 was voted as the 5th-most important SMPTE standard.^[17]