Printing system, controller for printing apparatus, method of executing printing process, and program for flushing ejection

Abstract

For a low saturation and high density region in a printed sheet identified based on rasterized data, flushing ejection is executed, with landing positions dispersed in the region. For a region being low in saturation but not high in density, an edge portion of the region is determined as landing positions. During these processes, adjustment is made to the ejection from inkjet nozzels for color components which are not to be subjected to the flushing ejection, to maintian the original hue of the region. This achieves the flushing ejection minimizing the degradation of the quality of the printed sheet. Further, in the variable printing, necessity of the flushing ejection is judged based on details to be printed on a base page. This causes the evacution of the flushing ejection whenever individual printed sheets are produced. Therefore, the print quality is held uniform during the production of different printed sheets.