Patent ID: 7327503

Claim:
An image correction method for an inkjet recording apparatus for recording images by ejecting ink on a recording medium using a recording head having a plurality of nozzles for ejecting ink arranged on the recording head, the image correction method comprising the steps of: outputting a pattern for measuring recording characteristics of the recording head; determining a nonejecting nozzle from the plurality of nozzles and obtaining a density distribution corresponding to each nozzle based on the measured density of the output pattern; determining a complementary table for each nozzle from a reference preset value of the density distribution corresponding to the nonejecting nozzle in a state that the sizes and density of ink drops ejected from nozzles in the vicinity of the nonejecting nozzle are constant and there is no deviation in a landing position, by comparing the obtained density distribution thereof with reference preset value, the complementary table complementing with a color different from the color corresponding to the nonejecting nozzle; and converting image data corresponding to the nonejecting nozzle into different-color image data for ejection by another nozzle using the determined complementary table, wherein one of a table and a function showing a complementary amount with the different color in the state for each gradation value of input images is prepared for each number of consecutive nonejecting nozzles as a reference different-color complementary table, and wherein from a magnitude relation between density distribution in a portion of a target nonejecting nozzle and the reference preset value for each number of consecutive nonejecting nozzles, a different-color complementary table for each nozzle is determined by referring to the reference different-color complementary table for each number of consecutive nonejecting nozzles.