An image forming apparatus, comprising: a light source configured to emit light beam for exposing a photosensitive member (14, 15, 16, 17) to light; deflecting means for deflecting the light beam so that the light beam scans the photosensitive member; optical means for guiding the light beam deflected by the deflecting means to the photosensitive member; data generating means for generating pixel data corresponding to each pixel included in an output image; outputting means for outputting correction data for correcting unevenness of a potential distribution of an electrostatic latent image centered at a target pixel formed on the photosensitive member by exposure of the photosensitive member to the light beam in a scanning direction in which the light beam scans the photosensitive member, the correction data corresponding to a position of the target pixel in the scanning direction, the outputting means outputting the correction data being indicative of an amount of change in potential at the position of the target pixel caused by exposure of a surrounding pixel located around the target pixel to the light beam; correcting means for correcting pixel data of the target pixel on the basis of the correction data; control means for controlling the light source on the basis of the pixel data of the target pixel corrected by the correcting means, to form the target pixel; storage means (2006, 2007, 2008) for storing a first variance value (σx) indicative of a potential distribution of the electrostatic latent image centered at the target pixel in the scanning direction, a second variance value (σy) indicative of a potential distribution of the electrostatic latent image centered at the target pixel in a rotation direction of the photosensitive member, and a third variance value (pxy) indicative of a potential distribution of the electrostatic latent image centered at the target pixel in both the scanning direction and the rotation direction; and correction-data generating means for generating the correction data on the basis of the first variance value, the second variance value, and the third variance value. a light source configured to emit light beam for exposing a photosensitive member (14, 15, 16, 17) to light; deflecting means for deflecting the light beam so that the light beam scans the photosensitive member; optical means for guiding the light beam deflected by the deflecting means to the photosensitive member; data generating means for generating pixel data corresponding to each pixel included in an output image; outputting means for outputting correction data for correcting unevenness of a potential distribution of an electrostatic latent image centered at a target pixel formed on the photosensitive member by exposure of the photosensitive member to the light beam in a scanning direction in which the light beam scans the photosensitive member, the correction data corresponding to a position of the target pixel in the scanning direction, the outputting means outputting the correction data being indicative of an amount of change in potential at the position of the target pixel caused by exposure of a surrounding pixel located around the target pixel to the light beam; correcting means for correcting pixel data of the target pixel on the basis of the correction data; control means for controlling the light source on the basis of the pixel data of the target pixel corrected by the correcting means, to form the target pixel; storage means (2006, 2007, 2008) for storing a first variance value (σx) indicative of a potential distribution of the electrostatic latent image centered at the target pixel in the scanning direction, a second variance value (σy) indicative of a potential distribution of the electrostatic latent image centered at the target pixel in a rotation direction of the photosensitive member, and a third variance value (pxy) indicative of a potential distribution of the electrostatic latent image centered at the target pixel in both the scanning direction and the rotation direction; and correction-data generating means for generating the correction data on the basis of the first variance value, the second variance value, and the third variance value.