Patent ID: 8537439

Claim:
A print calibration processing apparatus comprising: a test image output section configured to output a plurality of patches for gradation characteristic generation, as two-sided test images to be printed on both sides of a print sheet, to an image forming section; a gradation characteristic data generation section configured to use, as a read object, a test chart obtained by printing the test images on both the sides of the print sheet by the image forming section while shifting print positions of the test images on a front side and a back side, to read the images on a first side of the test chart and on a second side opposite to the first side, and to generate gradation characteristic data of front test images on the first side and the second side and gradation characteristic data of show-through test images on the first side and the second side; a gradation correction data generation section configured to determine a correction value of maximum gradation based on gradation characteristics of the front test images and gradation characteristics of the show-through test images generated by the gradation characteristic data generation section: a gradation correction data storage section configured to store the gradation correction data generated by the gradation correction data generation section; and a gradation correction section configured to correct gradation of image data outputted from the image forming section based on the gradation correction data stored in the gradation correction data storage section.