The image signal processing method according to the present invention includes a video signal, a first signal including a contrast component signal, and a second signal including a component signal other than the component signal included in the first signal among the component signals of the video signal. A division step for dividing the input signal into components, a brightness adjustment step for performing a brightness adjustment process on the second signal among the component signals divided in the division step, the first signal divided in the division step, and the brightness And a synthesis step of synthesizing the second signal after the brightness adjustment in the height adjustment step.本発明にかかる画像信号処理方法は、映像信号を、コントラスト成分信号を含む第１の信号、および映像信号の成分信号のうち第１の信号が含む成分信号以外の成分信号を含む第２の信号に分割する分割ステップと、分割ステップで分割された成分信号のうち、第２の信号に対して明るさ調整処理を施す明るさ調整ステップと、分割ステップで分割された第１の信号、および明るさ調整ステップで明るさ調整された後の第２の信号を合成する合成ステップと、を含む。
