Image forming apparatus and image forming method

An image forming apparatus comprising:

• an image forming device configured to form an image on a recording medium;
• a reading device configured to scan the recording medium having a position detection mark on the recording medium as the image and generate a scanned image;
• and
• circuitry configured to calculate a plurality of correction values to adjust a position of the image to be formed on the recording medium, based on the scanned image,
• the circuitry being configured to:
• calculate a first correction value of the plurality of correction values, based on a first scanned image generated from a first face of the recording medium;
• calculate a second correction value of the plurality of correction values, based on a second scanned image generated from a second face of the recording medium;
• and
• calculate a third correction value of the plurality of correction values to adjust a position of an image to be formed on the second face of the recording medium, based on the first scanned image generated from the first face of the recording medium on which the position detection mark is formed using the first correction value.