PURPOSE: To reduce the size of a circuit by shortening the word length of a digital signal to be supplied to a multiplier circuit.

CONSTITUTION: This white balance circuit is constituted of a digital circuit, three primary color signals to be successively supplied to its input terminal 9a are supplied to one input terminal of the multiplier 15 through an input level conversion circuit 16 and prescribed coefficient signals are supplied to the other input terminal of the multiplier 15 through a coefficient level conversion circuit 17. The circuit 16 shifts the bits of the input signals in accordance with the levels of the input signals, i.e., red, green and blue signals and the circuit 17 shifts the bits of the coefficient signals in the reverse direction to that of the input signals.