Density correction method capable of performing density correction at high speed with high precision. In a printing apparatus adopting this method, a predetermined test pattern image is printed on a printing medium, the printed test pattern image is optically read by a sensor at first resolution, the quality of the read image is evaluated, based on the evaluation result the printed test pattern image is optically read by the sensor at second resolution higher than the first resolution, and correction data is generated based on the read test pattern image.