Patent ID: 8419151

Claim:
An inkjet printer comprising: a recording head having a plurality of recording elements arranged at a prescribed pitch in a first direction, the recording head being movable in a second direction perpendicular to the first direction, the recording head being capable of forming dots on a recording medium a distance shorter than the prescribed pitch between two adjacent recording elements of the recording head; a conveying unit configured to convey the recording medium in the first direction past the recording head; a scanning unit configured to move the recording head back and forth in the second direction; a setting unit configured to set process pixels in an input image by rendering at least one of the plurality of recording elements disabled so as not to form dots and at least another one of the plurality of recording elements enabled to allow dots to be formed in each of a plurality of columns of the recording medium, the process pixel having density data representing a gradation level of the process pixel, row positions of the process pixels being determined depending upon the prescribed pitch between two adjacent recording elements of the recording head, wherein the setting unit sets the process pixels in the input image by applying one process pixel pattern to one plurality of pixel rows adjacent to each other that includes one pixel row of the input image corresponding to one recording element in the recording elements, and applying another process pixel pattern to another plurality of pixel rows adjacent to each other that includes another pixel row of the input image corresponding to another recording element in the recording elements in a single scan of the recording head in the second direction, the one process pixel pattern being different from the another process pixel pattern; and a dot data generating unit configured to generate dot data by applying a weight matrix to the density data of the process pixel, weights set in the weight matrix being allocated based on an arrangement of the process pixels depending on the one process pixel pattern or the another process pixel pattern, the dot data being applied to the recording head to form dots on the recording medium.