Patent ID: 7198343

Claim:
An image printing apparatus which prints image data using a plurality of printheads, each of which includes a plurality of printing elements, and which are arranged side by side substantially along an array direction of the printing elements, said apparatus comprising: a density correction signal calculation unit which calculates a density correction signal based on a product of: (i) a correction parameter set in accordance with a printing element positional relationship between the plurality of printheads in the array direction, and (ii) a signal value of at least one pixel adjacent to a switching position of image data from a printing element of one printhead to a printing element of another printhead where the printheads are adjacent; a quantization unit which quantizes the density correction signal calculated by the density correction signal calculation unit into a quantized density correction signal having a signal level that can be input to one of the printheads; and a correction signal printing unit which forms at least one print dot adjacent to the switching position in one of a print line including said at least one pixel and a neighboring print line, based on the quantized density correction signal from the quantization unit.