The National Television Standards Committee or NTSC is an organization that was formed in the United States during the early years of broadcast television. The main function of the organization was to define the standards that would apply to the quality of the transmission and the equipment that would be able to receive the transmission. The work of the National Television Standards Committee is paralleled in the efforts of other similar organizations around the globe, most notably the Phase Alternation Line (PAL) and the Sequential Couleur avec Memoire or SECAM.
Originally formed in 1953, the original standards for broadcast television remained more or less constant for the remainder of the 20th century. Broadcast protocol set during this time was adaptable enough to handle the advent of color television broadcasts as they become increasingly common during the 1960’s and eventually replaced black and white transmissions. The basic protocols still held up as cable television became an increasingly common service during the 1980’s and beyond. Currently, those same standards still set the pattern for any type of analog broadcast signal from any TV station and tower.
Essentially, the National Television Standards Committee established a minimum of 525 horizontal lines per complete screen image. The lines are scanned from top to bottom as well as left to right in an alternating fashion. Essentially, the process requires two complete scans in order to fully resolve the image projection. This dual scan is known as interlacing, and is completed within a fraction of a second. For the TV viewer, this resolution process provides continuing images that provide a clear picture.
The guidelines put in place by the National Television Standards Committee work very well with broadcast television, but are not compatible with computer imaging. This means that conversion equipment is necessary to convert the standard television signal into a digital signal that will work well with computer generated video. The reason for the discrepancy is that the traditional television receiver has a lower rate of resolution than a computer monitor. However, with the full conversion in the United States to digital broadcasts in the near future, this discrepancy will cease to be an issue in many situations and render the original guidelines drafted by the National Television Standards Committee to be obsolete.
By Malcolm Tatum