| 摘要 |
PROBLEM TO BE SOLVED: To generate an image signal always having high contrast in accordance with a distribution of luminance signals in a picked up image. SOLUTION: A digital image signal outputted from an A/D conversion circuit 5 is subjected to WB adjustment in a WB adjusting circuit 61 of a DSP (digital signal processor) 6, further subjected to gamma correction in a gamma correction circuit 62 and divided into a luminance signal and a color-difference signal. A histogram calculating circuit 63 sequentially detects a luminance signal level and calculates a histogram showing a distribution of each luminance signal level on an image pickup screen. A Y-gamma correction circuit 64 calculates an accumulated histogram from the calculated histogram, and performs characteristic correction by changing inclinations in a high luminance area of a correction straight line for correcting an input-output characteristic of the luminance signal level on the basis of the accumulated histogram. COPYRIGHT: (C)2003,JPO |
