Patent ID: 8011586

Claim:
An image forming apparatus comprising: a decoding unit operable to decode a first two-dimensional code serving as a non-upright two-dimensional code in a manuscript image; a synthesis unit operable to create a second two-dimensional code serving as an upright two-dimensional code by using information obtained by the decoding unit, to synthesize the second two-dimensional code onto the printed image data; and a calculating unit operable to calculate a rotation angle of the first two-dimensional code, wherein the synthesis unit determines whether the rotation angle of the first two-dimensional code is greater than a rotation angle threshold value (θ) determined by a threshold length Z, and, if the rotation angle of the first two-dimensional code is greater than the rotation angle threshold value (θ), the synthesis unit synthesizes the second two-dimensional code onto the printed image data by rotating the second two-dimensional code by the rotation angle of the first two-dimensional code, and, if the rotation angle of the first two-dimensional code is less than or equal to the rotation angle threshold value (θ), the synthesis unit synthesizes the second two-dimensional code onto the printed image data without rotating the second two-dimensional code, and wherein the rotation angle threshold value (θ) satisfies an equation: A (sin θ+cos θ−1)≦ Z, A being a length of one side of the first two-dimensional code in millimeters and the threshold length Z being in millimeters.