There’s no such thing as a color camera

If you’re familiar with how a CCD or CMOS sensor detects light you’ll agree with my title statement. Our silicon-based sensors develop electrical charge in response to the arrival of photons of light. Photon arrives, charge generated. The silicon has no knowledge of the wavelength of the incoming light.

So how do we get color images, and are there benefits in staying with monochrome? Rather than fudge an answer, let me refer you to a fascinating paper by Francois Marçeau of Clemex Technologies entitled “Image Analysis in Black & White,” (Advanced Imaging, May 2009.) Francois does a terrific job of explaining why monochrome can give better fidelity to the actual scene being imaged than can color. His paper should be required reading for anyone who believes they need a color machine vision system.