An image recording apparatus 1 generates halftone image data regarding black, cyan, magenta, and yellow from a multi-tone color image. Magenta is a target color component that has a lower ink density than that of the other color components. In generating halftone image data regarding magenta, the sum of the sizes of black, cyan, and magenta dots formed at a target pixel position is made smaller than or equal to a threshold dot size. If the hue of the pixel of interest is within a hue range in which magenta coloration is strong, it is determined that the threshold dot size is a corrected threshold dot size larger than the reference threshold dot size. It is thus possible to suppress overlapping of dots of a plurality of color components and to thereby improve color reproduction of the target color component while suppressing poor color reproduction and cockling.