Every color image processing task presented so far used the RGB color space, which is probably the most popular one, especially due to its broad usage in computer screens. The main disadvantage of this color space, however, is the correlation of its color channels, which makes it almost infeasible to segment specific colors just by using one of the color channels. Furthermore, the RGB color space is susceptible to shadows and illumination changes, which cause a very significant distortion in colors.

To tackle these disadvantages, different color spaces, such as HSV or CIE-L*a*b* have been proposed. These color spaces are modeled more closely to the way humans perceive colors, they are less sensitive to illumination changes and they are also more appropriate for color segmentation purposes. MATLAB provides a set of transformations between different color spaces, based on the functions pair of makecform and applycform. The combination of these two functions can convert seven different color spaces. Furthermore, MATLAB also provides three more pairs of functions for color space transformations, between RGB and HSV, NTSC, and YCbCr. Let's examine the way we can transform RGB to different color spaces, through an example.