POSITIONAL-DEVIATION CORRECTING DEVICE AND IMAGE FORMING APPARATUS INCLUDING POSITIONAL-DEVIATION CORRECTING DEVICE

A positional-deviation correcting device includes a reading device and control circuitry. The reading device reads recording media on which marks and each of adjustment charts having different image densities are formed in accordance with the image densities. The control circuitry acquires data on image formation positions of the marks on the recording media, based on a reading result of the marks; and corrects an image formation position of an image to be formed on a recording medium. The control circuitry calculates a correction value of the image formation position corresponding to an image density for each of the image densities corresponding to the adjustment charts on a one-on-one relationship, based on a reading result of the adjustment charts; interpolates correction values corresponding to the image densities on a one-on-one relationship; and calculates a correction value of the image formation position corresponding to another image density different from the image densities.