An image forming apparatus comprising: a conveying device configured to sequentially convey a plurality of successive recording media, the plurality of successive recording media including a preceding recording medium and a following recording medium conveyed after the preceding recording medium; an image forming device configured to form an image on each of a front surface and a back surface of the preceding recording medium conveyed by the conveying device; a reading device configured to read an outer shape of the preceding recording medium bearing the image formed by the image forming device; a deformation amount calculation unit configured to calculate an amount of deformation of the preceding recording medium based on the outer shape of the preceding recording medium read by the reading device; and an image correction unit configured to correct at least one of a front image and a back image based on the amount of deformation calculated by the deformation amount calculation unit, to cause the image forming device to form the front image and the back image on a front surface and a back surface, respectively, of the following recording medium, wherein the reading device is configured to read a first shape of the preceding recording medium having the image only on the front surface of the preceding recording medium, wherein the deformation amount calculation unit is configured to calculate, as the amount of deformation, a first-half magnification that is a magnification of the first shape to an initial shape of the preceding recording medium, and wherein the image correction unit is configured to scale the front image by a reciprocal of the first-half magnification or to scale the back image by the first-half magnification, characterized in that the deformation amount calculation unit is configured to calculate a magnification for each edge of the preceding recording medium, and wherein the image correction unit is configured to scale each edge of at least one of the front image and the back image at a different magnification. a conveying device configured to sequentially convey a plurality of successive recording media, the plurality of successive recording media including a preceding recording medium and a following recording medium conveyed after the preceding recording medium; an image forming device configured to form an image on each of a front surface and a back surface of the preceding recording medium conveyed by the conveying device; a reading device configured to read an outer shape of the preceding recording medium bearing the image formed by the image forming device; a deformation amount calculation unit configured to calculate an amount of deformation of the preceding recording medium based on the outer shape of the preceding recording medium read by the reading device; and an image correction unit configured to correct at least one of a front image and a back image based on the amount of deformation calculated by the deformation amount calculation unit, to cause the image forming device to form the front image and the back image on a front surface and a back surface, respectively, of the following recording medium, wherein the reading device is configured to read a first shape of the preceding recording medium having the image only on the front surface of the preceding recording medium, wherein the deformation amount calculation unit is configured to calculate, as the amount of deformation, a first-half magnification that is a magnification of the first shape to an initial shape of the preceding recording medium, and wherein the image correction unit is configured to scale the front image by a reciprocal of the first-half magnification or to scale the back image by the first-half magnification, characterized in that the deformation amount calculation unit is configured to calculate a magnification for each edge of the preceding recording medium, and wherein the image correction unit is configured to scale each edge of at least one of the front image and the back image at a different magnification.