Image output apparatus and image formation system for correcting density unevenness.

摘要

A test image is formed by performing overlap printing using a plurality of printing heads provided for a printing agent of one color. Density data attained by reading this test image is averaged. On the basis of this average value, a common correction is performed for drive signals for the printing heads. This makes it possible to perform head density unevenness correction at a high efficiency in performing overlap printing by using the plurality of printing heads. <IMAGE>