Note that upgrades to cups-filters were not released for some platforms (e.g. Raspbian Stretch on the Raspberry Pi) until mid-June 2019, so if this did not work in the past try sudo apt update && sudo apt upgrade again.
Note that upgrades to cups-filters were not released for some platforms (e.g. Raspbian Stretch on the Raspberry Pi) until mid-June 2019, so if this did not work in the past try sudo apt update && sudo apt upgrade again.