| 摘要 |
PURPOSE:To make low-speed processing possible with a picture processing device and to simplify the circuit by providing a memory which stores a signal obtained by reading a reference plane, operation processing means of the signal, and means for correcting a picture reading signal with an operation processed reference signal. CONSTITUTION:The output of an AD converter 11 is adjusted in timing at an FF 50 and corrected by an ROM 54 storing the calculated result of shading correction. The output of the FF 50 is stored in an RAM 52 which can store signals of one line quantity of a CCD. The image of a standard white plate 1 is stored in advance in the RAM 52 and the image is read out synchronously to the image of an original and given to the address signal line of the ROM 54. Then the calculated result of shading correction of the ROM 54 is read out and calculation for removing shading caused by uneven light emission, uneven density, uneven luminous intensity distribution, etc., is performed. A selector 57 switches to the horizontal address signal of a counter 58 when data of the standard white plate 1 are written in the RAM 52 and shading correction is performed, and switches to an address signal from a CPU 60 when the RAM 52 is read by the CPU 60. A timing control circuit 66 controls shading data sampling, shading correction, and the operation mode of the CPU 60.
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