Bidirectional multi-pass printing with three or more passes prints a high-quality image with reduced time difference unevenness. To this end, an image in a unit region on a printing medium is printed by a print head performing 2N+1 bidirectional print scans (where N is a natural number). In this printing, a print permission rate for an even-numbered print scan of the 2N+1 times of the print scans is set lower than the print permission rate for an odd-numbered print scan of the 2N+1 times of the print scans.