PURPOSE: To apply shading correction to a data inputted to a picture read means through a transparent original section by allowing a light to radiate to a transparency reference section and an original member having a transparency original section and using a data inputted to the picture read means through the transparency reference section.

CONSTITUTION: A light radiating from a light source unit 8 passes through a transparency reference section 11 of an original member 9 and a transparency original section 12 and radiates from a projector lens 4 and the light is reflected in a mirror 5 and the image is formed on a picture read face 6 and a correction data read image 13 from the transparency reference section 11 of the original member 9 is formed to a standby position P of a carriage 7 and a picture read image 14 from the transparency original section 12 of the original member 9 is formed to the lens 4. The carriage 7 is moved toward a direction of the arrow X from its standby position P and reads at first the correction data read image 13 and a shading correction data is stored in a memory. Then the carriage 7 reads the picture read image 14. After the picture data signal is processed, the result is subject to shading correction based on the correction data inputted from the memory by a shading correction section.