History
Chroma subsampling was developed in the 1950s by Alda Bedford for the development of color television by RCA, which developed into the NTSC standard; luma-chroma separation was developed earlier, in 1938 by Georges Valensi.
Through studies, he showed that the human eye has high resolution only for black and white, somewhat less for "mid-range" colors like yellows and greens, and much less for colors on the end of the spectrum, reds and blues. Using this knowledge allowed RCA to develop a system in which they discarded most of the blue signal after it comes from the camera, keeping most of the green and only some of the red; this is chroma subsampling in the YIQ color space, and is roughly analogous to 4:2:1 subsampling, in that it has decreasing resolution for luma, yellow/green, and red/blue.
Read more about this topic: Chroma Subsampling
Famous quotes containing the word history:
“We aspire to be something more than stupid and timid chattels, pretending to read history and our Bibles, but desecrating every house and every day we breathe in.”
—Henry David Thoreau (1817–1862)
“Spain is an overflow of sombreness ... a strong and threatening tide of history meets you at the frontier.”
—Wyndham Lewis (1882–1957)
“... all big changes in human history have been arrived at slowly and through many compromises.”
—Eleanor Roosevelt (1884–1962)