1. A printing apparatus comprising: a print head that has a plurality of nozzles including lower-end portion nozzles, center-portion nozzles, and upper-end portion nozzles; a medium transport unit that transports a medium that becomes a printing target; an edge detecting unit that detects an edge included in image data; and a print control unit that forms a pixel pattern on the medium by driving the print head together with relatively moving the print head and the medium that becomes the printing target, forms an overlapping pixel pattern on the medium by using nozzles, the number of which is a first number in a case where the edge is not detected by the edge detecting unit for the overlapping pixel pattern that can be formed by the upper-end portion nozzle and the lower-end portion nozzle, and forms the overlapping pixel pattern on the medium by using nozzles, the number of which is a second number smaller than the first number in a case where the edge is detected by the edge detecting unit.