An image processing apparatus for generating image data for recording in a recording apparatus including a recording unit having a plurality of nozzles discharging ink, includes a converting unit which converts, based on characteristic information according to a characteristic of each nozzle included in the recording unit, image data corresponding to an input print job into image data to be used for recording by the recording unit and a control unit which executes one of a plurality of correction processes based on image data obtained by reading an image recorded by the recording unit. The plurality of correction processes include first correction processing that is performed after the recording of the image according to the print job is stopped, and second correction processing that is performed without stopping the recording of the image according to the print job.

A method of ink jet printing using an ink jet imaging device including a plurality of nozzles arranged for expelling droplets of an ink by actuation of an ink channel includes the steps of: a) providing a bit map of a spit pattern comprising an arrangement of refresh dots to be printed by each of the plurality of nozzles; and d) printing the bitmap of the spit pattern. The spit pattern includes a plurality of clusters of refresh dots, each cluster including at least two sequential refresh dots expelled from a single nozzle. A spit pattern for use in such a method is disclosed.