Pixels from an image are sampled for auto white balance (AWB) statistics.
To avoid the effects of monochromatic regions, only pixels located at or
near edges between monochromatic regions and neighboring regions are
sampled for computation of the AWB gains. A sampling criteria is applied
to each pixel that automatically excludes pixels in monochromatic regions
of any size. As a result, white balancing is based only on portions at or
near edges of substantially monochromatic regions.