An image correcting method includes: (a) acquiring original image information to be corrected; (b) setting a confirmation range for confirming an effect of a correction; (c) producing corrected image information; and (d) displaying, on an image display section, an original image based on the original image information and a corrected image based on the corrected image information. The confirmation range is set based on the original image information. The corrected image information is produced by correcting the original image information within the confirmation range.