Canon printer driver: low DPI

My printer (Canon G7050) can print up to 4800 x 1200 dpi. However, the linux driver I got from Canon is set to 600 dpi only: *OpenUI *Resolution/Output Resolution: PickOne *de.Translation Resolution/Output Resolution: PickOne: "" *fr.Translation Resolution/Output Resolution: PickOne: "" *zh.Translation Resolution/Output Resolution: PickOne: "" *ja.Translation Resolution/Output Resolution: PickOne: "" *DefaultResolution: 600dpi *Resolution 600dpi/600 dpi: ">setpagedevice" *de.Resolution 600dpi/600 dpi: ">setpagedevice": "" *fr.Resolution 600dpi/600 dpi: ">setpagedevice": "" *zh.Resolution 600dpi/600 dpi: ">setpagedevice": "" *ja.Resolution 600dpi/600 dpi: ">setpagedevice": "" *CloseUI: *Resolution - Could you confirm that I lose potential printing quality with this PPD? - Can I manually add new DPI settings?