color systems

• RGB is the most common as our eyes use something similar, but keep in mind that the OpenCV display system uses BGR colors.
• the HSV and HLS decompose colors into their hue, saturation and value/luminance components, which is a more natural way for us to describe colors. you might, for example, dismiss the value component, making your algorithm less sensitive to the light conditions of the input image.
• YCrCb is used by the popular JPEG format
• CIE L*a*b is a perceptually uniform color space, which comes handy if you need to measure the distance of a given color to another color.