Image capturing apparatus having a gamma-characteristic corrector and/or image geometric distortion correction

An image capturing apparatus capable of performing a suitable illuminance nonuniformity correction by setting a suitable gamma-characteristic every block even in the case that the size of a character image projected on a sensing surface changes according to an image capturing magnification, and capable of extracting a boundary area between a white board portion and a background portion and applying a suitable image processing to this boundary area during the illuminance nonuniformity correction for a picked image, and capable of image capturing a representation such as characters drawn on a white board in such a manner that an obtained image is clear and easy to see by suitably performing an illuminance nonuniformity correction even in the case of color image capturing, and capable of detecting a regularly reflected light with high accuracy and can thereby securely prevent an error of obtaining an image of low quality by image capturing, and capable of preventing an error in flash-image capturing a representation such as characters drawn on a white board under insufficient illumination light and effectively perform an illuminance nonuniformity correction.