colorsys: RGB to YIQ transform matrix

[David Berry]

Edward C. Jones wrote:
> In colorsys.rgb_to_yiq, the matrix of the linear transformation used is
> 
>     .30  .59  .11
>     .60 -.28 -.32
>     .21 -.52  .31
> 
> The places I checked on the Internet use
> 
>     .299  .587  .114
>     .596 -.275 -.321
>     .2.1 -.523  .311
> 
> Why does colorsys use a 2 decimal place wersion of the array?

Pass

> What is 
> the actual definition of the RGB to YIQ transform?

A good place to start is here,

http://www.poynton.com/ColorFAQ.html

which used to contains details of RGB->YIQ and much much more on color
space transforms.

Dave