Method and apparatus for automatically adjusting white balance

Abstract

An automatic white balance adjusting method is disclosed in which color difference signals (E.sub.R -E.sub.y) and (E.sub.B -E.sub.y) are respectively integrated over the entire screen and the gains of red and blue signals are controlled so that the respective integration average values of these two color difference signals can coincide with their respective predetermined reference levels. In the integration of the above color difference signals, integration of the color difference signals of chromatic colors is prohibited. In the automatic white balance adjusting method, in order to check whether the respective color difference signals are chromatic colors or not, the respective color difference signals are added together and subtracted from each other to thereby generate color signals (E.sub.R +E.sub.B -2E.sub.y) and (E.sub.R -E.sub.B) and it may be checked whether at least one of these color signals goes beyond threshold levels for removal of chromatic colors respectively set correspondingly to the respective color signals.