1. A printing apparatus that performs printing on a print medium, comprising: a dot data generator that performs a halftone process on image data representing a tone value of each of pixels constituting an original image to determine a status of dot formation on each of print pixels of a print image to be formed on the print medium, for generating dot data representing the determined status of dot formation, and a print image generator that forms a dot on each of the print pixels for generating a print image according to the dot data, wherein the print image is formed by mutually combining print pixels belonging to each of a plurality of pixel position groups for which a physical difference is assumed at a formation of dots by the print image generator, in a common print area, and the halftone process is configured to generate the dot data, so that a pattern of dots belonging to each of the plurality of pixel position groups has either blue noise characteristics or green noise characteristics.