A method of wastewater treatment is described. The fuel cell system also includes a recirculation device that recirculates anode exhaust gas to the anode input, which includes a discharge line for discharging liquid andor gas from the region of the recirculation device, and an air conveying device for supplying the cathode chamber with a supply air flow. The CPU executes image quality adjustment with regard to the multiple objective image data allocated to the plural layout locations and pastes the quality-adjusted image data on the ornamental image data according to layout control information, so as to generate resulting output image data.