An inkjet printhead has a pair of adjacent printhead segments having overlapping ink ejection nozzles. A degree of overlap of the printhead segments is determined, and a half toning of a continuous tone image is provided. The half toning is provided by a dither matrix outputting a dither value to an adder, the adder having an overlap input signal which varies depending on the degree of overlap between the adjacent printhead segments. The half toning is adjusted in a region of overlap between the adjacent printhead segments to reduce artifacts between the adjacent printhead segments.