PURPOSE: To easily control each correction control element and to secure faulty diagnosis by providing a picture memory between steps of a correction control circuit and supplies various data based on data stored in the memory to the correction control circuit.

CONSTITUTION: Registration correction operation as well as adjustment of a white balance are performed based on three primary color data fetched in picture memories 32∼34 from a signal line between an A/D conversion circuit 13 and a registration correction circuit 20. Where a CPU14 discriminates a relative position of a specimen point based on said color data to send out the correction data so as to eliminate the relative deviation to the circuit 20. In addition to the above operation, picture memories 31∼34 are utilized for faulty diagnosis. At this moment, output data when test data are inputted in each circuit are compared with reference data for faulty diagnosis.