1. A method of operating a printhead of an imaging device, the method comprising: actuating a plurality of ink jets of a printhead of an imaging device to emit drops of ink onto an image receiving surface in accordance with a test pattern, the test pattern including full pixel density areas and half pixel density areas that alternate in a process direction along the image receiving surface; measuring distances in a process direction between drops of the full pixel density areas and drops of the half pixel density areas in transition regions between the full pixel density areas and the half pixel density areas; and correlating the measured distances to a graininess level for the printhead.