The systems and methods presented herein provide for calibrating a print engine of a printing system. The printing system prints image data on a print medium and scans the printed image data. Color values of the scanned image data are then measured and various tints of color values and their transition locations are identified. A calibration module estimates the original optical densities of the identified color value tints and generates a target optical density for each of the identified color value tints using the estimated original optical densities to determine print irregularities in the color values of the scanned image data. The calibration module then generates a halftone screen based on the mean optical densities and applies the generated halftone screen to the print engine to calibrate the print engine.