The cartridges for this printer are of the combined sponge and print head variety. They can be refilled, although it is more difficult than refilling the single ink tanks from the more expensive Canon printer models. Like with the single ink tank printers the ink level monitoring can be disabled to allow printing with refilled cartridges.
Here is a German refill instruction from druckerchannel.de and here is a Google translation to English. These cartridges are older and the capacities might be different from the cartridges used in the MX479, but the principles and the refill method are the same.