PURPOSE: To obtain a picture processor with an optional filter effect by revising a coefficient of a spatial filter in response to a luminance of an input picture to attain gradation correction matching a human visual characteristic.
CONSTITUTION: A coefficient signal suitable for gradation correction in a low luminance area is set to a register 7 and a coefficient signal suitable for gradation correction in a high luminance area is set to a register 8 from a CPU 10 as initial setting. A luminance signal of a picture signal from a camera 1 is given to a comparator 5 via an A/D converter 2, compared with a reference value and the result of discrimination of the high and low luminance is given to a selector 9. The selector 9 reads a coefficient signal from the register 7 when the result of comparison indicates a low luminance and reads a coefficient signal from the register 8 when the result of comparison indicates a high luminance to revise a coefficient of a spatial filter arithmetic operation section 6. Thus, gradation is corrected from a luminance signal at a low luminance part and a high luminance part of an input picture with a coefficient suitable for gradation correction respectively and a picture with a gradation suitable for a human visual characteristic is obtained.
SHIMIZU KAZUO
KOBAYASHI SHIGERU
