| 摘要 |
PURPOSE: To set the detection of an abnormal picture element at the time of shading correction to be precise and to improve correction precision by reading data of a white reference board, obtaining a difference between respective pieces of picture element data and judging it. CONSTITUTION: The threshold of the detection of the abnormal picture element is set in an adder 8. White data in the first line on the white reference board is read, the abnormal picture element on respective pieces of picture element data is detected, and an abnormal picture element flag on the respective pieces of picture element data is stored in RAM 12 after the peak value of white data is detecetd. Then, the next line is similarly inspected. When the abnormal picture element flag is not abnormal, data is inputted to a previous picture element register 5. CPU 13 calculates shading correction data based on data on a present picture element register 4 and a subsequent picture element register 3, stores data in a calculated result register 9 and uses data as a correction value. |
