A11 Color Camera Processing

White balancing ensures that an object that is white will appear white in an image no matter what the light source is. In an ordinary digital camera, some of the white balance settings would include daylight, cloudy, fluorescent and incandescent.

In this activity, we investigate the two different white balancing algorithms: White Patch and Gray World.
This is the correctly balanced image.


The image below was taken under fluorescent light sources but was white balanced using incandescent.

For this case both algorithms work well.

Gray World

White Patch

For a sample with low variety of colors

The properly white balanced (fluorescent) image is
When wrongly balanced using incandescent
Whitebalancing it again results to

Gray World
White Patch

We can see that the gray world only works when the gray world assumption holds. That is when there are indeed comparable areas that have reds, greens and blues in the image.