Now that we have presented how most of the image processing techniques met so far are translated for color images, it is time to give a very practical example mixing several of the methods. Red eye reduction is a common problem in amateur photography and has been addressed in several ways. The cause of red eyes in photographs (typically, the ones taken at night or in dark areas using flash), is the widening of our pupils. This has the effect of enlarging the area hit by the flash light, causing it to hit our retina, thus illuminating its red surface which is picked up by our camera lens.

In order to address the red eye issue after it has occurred (in the processing phase of our photograph), the most common way is to follow these two simple steps:

So, in order to see if this technique really works, we should tackle a real example.