yiqmap = rgb2ntsc(rgbmap) converts
the m-by-3 RGB values in rgbmap to
NTSC color space. yiqmap is an m-by-3
matrix that contains the NTSC luminance (Y) and
chrominance (I and Q) color
components as columns that are equivalent to the colors in the RGB
YIQ = rgb2ntsc(RGB) converts
the truecolor image RGB to the equivalent NTSC
RGB can be of class uint8, uint16, int16, single,
or double. RGBMAP can be double.
The output is double.