In a printing system, a method is used for adjusting currents to LEDs in an LED printbar to achieve uniformity of the print. The line test pattern and halftone strips test pattern are printed. The test patterns are scanned. An LED line metric of each LED test pattern line and reflectance uniformity of each halftone test strip are measured. A line uniformity difference profile and a set of halftone strips uniformity difference profiles are concurrently calculated. A current value supplied to each LED associated with the test patterns is adjusted to simultaneously optimize the uniformity in the lines test pattern and the halftone strips test pattern.