Title:
PICTURE SIGNAL CORRECTION METHOD AND PICTURE READER
Document Type and Number:
Japanese Patent JP3184286
Kind Code:
B2
Abstract:
PURPOSE: To correct the nonlinearity and the dispersion of a sensor with high accuracy.
CONSTITUTION: A white color reference board is read by a CCD line sensor 1, an A/D converter 2 applies A/D conversion to the data and the result is stored in a white reference memory 3. Then a sensor output with respect to a median exposure of a required exposure range is obtained and it is led to subtractors 4, 5. An output of the subtractor 5 is stored in a correction value memory 6. When a picture is read, the A/D-converted signal is inputted to a subtractor 7, in which the signal is subtracted from a value read from the correction value memory 6 and corrected.
Inventors:
Norihiro Yamamoto
Application Number:
JP4789892A
Publication Date:
July 09, 2001
Filing Date:
February 03, 1992
Export Citation:
Assignee:
株式会社リコー
International Classes:
H04N1/401; H04N1/40; H04N1/407; (IPC1-7): H04N1/401
Domestic Patent References:
| JP6362473A | ||||
| JP1106184A | ||||
| JP3201773A | ||||
| JP3192965A |
Attorney, Agent or Firm:
Akichika Takano