YIQ

YIQ, like YUV, is a color space used in television signals. YIQ is used predominantly by the NTSC television standard for encoding color information. The Y component, like in YUV, is used to encode luminance information, and is the only component used by black-and-white television receivers. The I and Q signals contain the actual color information. The YIQ color space is actually exactly the same as YUV, except the I-Q plane differs from the U-V plane by a simple 33-degree rotation. This rotation puts one of the two color axes in the orange region of the color space, which is where flesh tones are found. This axis is known as the "I" axis, which stands for in-phase, while the other color axis is known as "Q", meaning quadrature.

A formula exists for converting colors from the RGB color space to YIQ. This formula, where R, G, and B are defined on a scale from zero to one, is shown below.

Y = 0.299*R + 0.587*G + 0.114*B
I = 0.596*R - 0.275*G - 0.321*B
Q = 0.212*R - 0.523*G + 0.311*B