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 colormap.
YIQ = rgb2ntsc(RGB) converts the truecolor image RGB to the equivalent NTSC image YIQ.
yiqmap = rgb2ntsc(rgbmap) YIQ = rgb2ntsc(RGB)
You can give an example if you know one.