Gamma correction circuit

A gamma correction circuit, comprising:

• output-picture luminance signal generating means including
• first conversion means for converting supplied color picture signals into first luminance signals, and
• first gamma correction means for gamma correcting said first luminance signals from said first conversion means and outputting an output-picture luminance signal;
• a low-pass filter for transmitting low-frequency band components of said supplied color picture signals;
• luminance correction signal generating means including
• second gamma correction means for gamma correcting said low-frequency band components of said supplied color picture signals transmitted by said low-pass filter,
• second conversion means for converting gamma-corrected color picture signals from said second gamma correction means into second luminance signals,
• third conversion means for converting said low-frequency band components of said supplied color picture signals transmitted by said low-pass filter into third luminance signals,
• third gamma correction means for gamma correcting said third luminance signals, and
• a luminance correction signal generator for generating a luminance correction signal from said second luminance signals from said second conversion means and an output signal of said third gamma correction means;
• output-picture luminance signal correction means for correcting said output-picture luminance signal from said output-picture luminance signal generating means in response to said luminance correction signal from said luminance correction signal generator and outputting a corrected luminance signal;
• and
• color difference matrix means for generating color difference signals from said gamma corrected color picture signals from said second gamma correction means.