There is disclosed an image data correction method for correcting image data picked up from an original image photographed in an exposure frame on a photographic film through a taking lens while holding the exposure frame curved along a lengthwise direction of the exposure frame to be concave toward the taking lens, so as to eliminate image distortion in the original image. An actual location of each pixel of the original image is calculated on the basis of an ideal location that corresponds to an ideal image point of that pixel formed on a flat exposure frame through an ideal taking lens having no distortion, and correction parameters predetermined in accordance with the distortion of the taking lens and the curvature of the exposure frame at the exposure. Then, the image data are rearranging by transforming each pixel from its actual location to its ideal location in accordance with a correlation between actual locations and ideal locations of respective pixels of the original image.