1. A method of generating ink drop correction parameters for ejectors in a plurality of printheads in an inkjet printer comprising: operating inkjet ejectors in a plurality of printheads to eject ink in a pattern of structured dashes on an image receiving member, the structured dashes corresponding to a predetermined image data pattern; generating image data corresponding to the pattern of structured dashes on the image receiving member; identifying a process direction correction parameter for each ejector in the plurality of printheads with reference to the generated image data; modifying image data to be printed by the plurality of printheads with reference to the process direction correction parameter identified for at least one of the ejectors; and operating the plurality of printheads with reference to the modified image data.