Brightness correcting circuit and method for efficiently correcting brightness at edge and corner of monitor screen

A brightness correcting circuit and method for efficiently correcting the brightness of the edges and the corners of a monitor screen are provided. The circuit for correcting the brightness of the monitor screen which operates according to the brightness correcting method includes a parabolic signal generator for generating a parabolic signal and a corrected video signal generator for controlling the gain of an input video signal in response to the parabolic signal and outputting a corrected video signal. The parabolic signal generator includes a horizontal parabolic signal generator for generating a horizontal parabolic signal, the waveform of which is variable in response to a plurality of control signals, using a horizontal flyback pulse as an input, a vertical parabolic signal generator for generating a vertical parabolic signal, the waveform of which is variable in response to other plurality of control signals, using a vertical flyback pulse as an input, and an adder for adding the horizontal parabolic signal to the vertical parabolic signal and outputting the addition result as the parabolic signal. It is possible to efficiently correct the brightness of the edges and the corners of the screen by varying the waveform of the parabolic signal by selectively controlling the control signals of the horizontal parabolic signal generator and the vertical parabolic signal generator.