Recent copying machines have higher image quality, and the halftone processing methods are diversifying. If automatic tone correction is applied in correspondence with the diversified halftone processing methods, a long operation time is required. Hence, a sample chart based on the sample data is formed by a printer. A reader acquires image data of the sample chart, and the tone correction characteristics of a density correction unit corresponding to the image processing are updated based on the image data of the sample chart. In this case, generation of sample charts and updating of the tone correction characteristics are controlled in accordance with a user instruction as to whether or not to execute batch update processing of the tone correction characteristics of the density correction unit corresponding to the plurality of halftone processing methods.