PyNGL Home > Functions > Color routines

Ngl.rgbyiq

Converts from the RGB color space to YIQ.

Prototype

y, i, q = Ngl.rgbyiq(r, g, b)

Arguments

r, g, b

Intensity values for red, green, blue in the range [0.1.].

Return values

y

Y component (luminance) values in the range [0.,1.].

i

I component (chrominance orange-blue) values in the range [-0.6, 0.6].

q

Q component (chrominance purple-green) values in the range [-0.52, 0.52].

Description

This function converts from the RGB (Red, Green, Blue) color space to YIQ (the TV standard). In the YIQ color space the Y (luminance) component is the only component transmitted to black and white TVs; the I (in-phase, or orange-blue) and Q (quadrature, or purple-green) components carry the color, or chrominance, information.

The conversion equations are:

   Y    = 0.299000R + 0.587000G + 0.114000B
   I    = 0.595716R - 0.274453G - 0.321263B
   Q    = 0.211456R - 0.522591G + 0.311135B

See Also

Ngl.yiqrgb, Ngl.hlsrgb, Ngl.hsvrgb, Ngl.rgbhls, Ngl.rgbhsv

Examples

See color3.py.