1. An image printing method for completing a print process of each pixel by making a plurality of main scans of a print head, which prints dots on a print medium, with respect to the print medium, comprising: a step of assigning, to a pixel of interest, a pattern used to determine which of the plurality of main scans is used to print a dot to be printed for the pixel of interest; and a printing step of printing a dot on the pixel of interest in the main scan determined by the assigned pattern, and wherein the assignment step includes a step of selecting one pattern from a plurality of patterns corresponding to each of density levels on the basis of a density level of the pixel of interest, and assigning the selected pattern to the pixel of interest.