Chroma Subsampling - History

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:

    The disadvantage of men not knowing the past is that they do not know the present. History is a hill or high point of vantage, from which alone men see the town in which they live or the age in which they are living.
    Gilbert Keith Chesterton (1874–1936)

    The myth of independence from the mother is abandoned in mid- life as women learn new routes around the mother—both the mother without and the mother within. A mid-life daughter may reengage with a mother or put new controls on care and set limits to love. But whatever she does, her child’s history is never finished.
    Terri Apter (20th century)

    The history of the world is none other than the progress of the consciousness of freedom.
    Georg Wilhelm Friedrich Hegel (1770–1831)