Patent ID: 8057007

Claim:
An image recording apparatus which records an image on a recording medium, the image recording apparatus comprising: a recording head which has a plurality of recording elements; a conveyance device which conveys at least one of the recording head and the recording medium so that the recording head and the recording medium move relatively to each other; a characteristics information acquisition device which acquires information that indicates recording characteristics of the plurality of recording elements; a correction object determination device which selects from the plurality of recording elements a correction object recording element to be corrected, the correction object recording element having the recording characteristics that cause density non-uniformity in the image; a correction range setting device which selects from the plurality of recording elements N correction recording elements to be used for correcting an output density, N being an integer not less than 2; a virtual dot setting device which sets a virtual dot to be arranged at an overlapping portion where an overlap occurs between mutually adjacent dots recorded by the selected correction recording elements, the virtual dot being set for calculation purposes to correct the output density at the overlapping portion and not actually recorded on the recording medium, the virtual dot setting device also determining a virtual density of the virtual dot for the calculation purposes; a correction coefficient determination device which calculates the density non-uniformity caused by the virtual dot and the recording characteristics of the correction object recording element and which determines density correction coefficients for the N correction recording elements in accordance with correction conditions that reduce a low-frequency component of a power spectrum representing spatial frequency characteristics of the calculated density non-uniformity; a correction processing device which performs calculation for correcting the output density by using the density correction coefficients determined by the correction coefficient determination device; and a drive control device which controls the plurality of recording elements in accordance with the output density corrected by the correction processing device.