NTSC

NTSC stands for the National Television System Committee. It is an analog television standard that defined both the black-and-white transmission framework and the color-encoding system used in much of the Americas and parts of Asia. The format specifies 525 lines per frame and an interlaced structure, with a field rate of 59.94 Hz and a frame rate of 29.97 frames per second. About 480 of the 525 lines are typically visible, and the horizontal scanning frequency is 15.734 kHz. Color information is encoded with a color subcarrier at 3.579545 MHz, using luminance (Y) and chrominance components (I and Q). The system was designed to be backward compatible with monochrome receivers, so color broadcasts could still be viewed on black-and-white sets.

Development and adoption: The NTSC color standard was introduced in the early 1950s and was formalized to work with existing B&W infrastructure, enabling a smooth transition from monochrome to color television. Color broadcasts began in the United States in the mid-1950s, and the 29.97 fps rate was chosen to preserve compatibility with black-and-white signals and early studio practices.

Usage and legacy: NTSC was widely deployed in the United States, Canada, Mexico, and many countries in South America and parts of Asia. With the transition to digital television, many regions moved to digital standards such as ATSC in the United States, while NTSC remains a reference to the old analog 525-line system. The term is still used in discussions of standard-definition video, such as 480i/480p formats, to indicate the historical framing and line structure associated with NTSC.