My goal is to separate a full-color image into its luminance and chrominance ("color") components and display them as two images: 1) a black and white image (for the luminance) and 2) a color image (for the chrominance).
It would appear that the proper color space for this separation would be CMYK (cyan-magenta-yellow-black), as this separates the black from the others:
This gives me four component images. The last of which is the luminance (like a grayscale) image... half of what I need.
But how do I combine the first three channels to obtain a colored image that has no luminance component... i.e., appears in color but is of uniform lightness?