To use instant white balance correction press Ctrl + RightMouse button over neutral gray area of the
output image. I.e. you need to press Ctrl keyboard key and click with Right Mouse button over some
"would be" gray area of the picture.
In example above we know that asphalt on the road must have a neutral gray color. It's not gray at the
original photo because of wrong white level settings of the camera. To correct camera's error we need
just to Ctrl + RightMouse click over asphalt road and we get proper colors.
As soon as we did this correction white balance checkbox will be checked. Uncheck it to view original
image, or to try click over another neutral color area to get better results.