An image correction processing apparatus for correcting a pixel value of each pixel constituting image data obtained from an original image affected by the peripheral light-off is disclosed. The apparatus includes a pixel coordinate transforming unit for converting a distance between each pixel of a group of pixels which have an equal amount of peripheral light amount reduction and which are located on a common contour line of an oval about a predetermined reference pixel located at the center thereof and said predetermined reference pixel into a radius of a true circle having a diameter corresponding to the major axis of the oval; a cos.sup.4 calculating unit for obtaining, for each pixel, an angle value thereof in proportion to the radius obtained by the conversion and then obtaining a cos.sup.4 value of the angle value; and a correction calculating unit for multiplying an inverse of said cos.sup.4 value obtained for each pixel by a pixel value of this pixel, thereby to obtain a corrected pixel value for the pixel.