| 摘要 |
PROBLEM TO BE SOLVED: To provide a sure shading correction method and an overhead projector by making shading of an area read actually by a camera shading correction pattern data. SOLUTION: A CPU 8 obtains a median of image data obtained from an A/D converter 6 by picking up a white paper sheet with a camera 5 at minimum 200ming magnification. The CPU 8 calculates a ratio of the median to a picture element of the image data with regard to each picture element to obtain M×N of shading correction pattern data, to store in a memory 7. A memory control part 12 reads out shading correction pattern data A of P×Q (P<=M, Q<=N) present in an actual visual field of the camera 5 from a magnification of a zoom lens detected by a magnification detector 11. An interpolation processing part 13 applies interpolation processing to the shading correction pattern data of P×Q to calculate shading correction pattern data B of M×N. A multiplier 14 multiplies image data of M×N obtained by picking up an original 1 with the camera 5 with the shading correction pattern data B of M×N for each corresponding picture element. |
