An apparatus for correcting a scanned image includes a delay circuit configured to delay first image data by a delay amount corresponding to an integer multiple of a line interval, an interpolation circuit configured to perform an interpolation computation responsive to interpolation coefficients with respect to two or more lines included in the first image data delayed by the delay circuit, and a control circuit configured to set the delay amount to the delay circuit and the interpolation coefficients to the interpolation circuit, wherein the control circuit is configured to set the delay amount to an amount corresponding to integer m smaller than integer n and set the interpolation coefficients such that the interpolation computation becomes equivalent to a computation introducing a delay equal to n−m lines if an interval between the first image data and second image data is n times the line interval.