1. A method for calibrating auto white balancing in an electronic camera, comprising: obtaining a plurality of first color values from a respective first plurality of images, of a respective plurality of real-life scenes, captured by the electronic camera under a first illuminant; invoking an assumption about a true color value of at least portions of the real-life scenes; and determining, based upon the difference between the true color value and the average of the first color values, a plurality of final auto white balance parameters for a respective plurality of illuminants including the first illuminant.