If you are on a release of Trisquel 9, Linux Mint 19.x or Ubuntu 18.04-Ubuntu 19.10 the scanner is not yet supported out of the box. See our directions on how to update SANE and related scanner drivers as they pertain to this scanner.
If you are on Ubuntu 20.04, Linux Mint 20, or any distribution based on Ubuntu 20.04 you may need to remove a package for the scanner to work properly. Despite being detected you will get an error when attempting to scan otherwise. A bug report has been filed with Ubuntu.
Open a terminal and run the following command:
sudo apt remove ippusbxd
scanimage
reboot
Or watch the complete setup video (missing the reboot part at the end, you may need do that as well):
Scanning Under Fedora 36
The TPE-CANSCR400 is picked up as a ESCL flatbed scanner which means it'll likely work under Fedora 36+ if ipp-usb is installed. We have not or not yet confirmed our directions below work as expected with the specific model scanner, TPE-CANSCR400, but if you try them before we've had a chance to test this please let us know how it went.
1. Open a terminal and run the following command:
sudo dnf -y install ipp-usb
2. Search for and open the Document Scanner from Activities search
3. Select the eSCL Canon scanner_name (USB) option from the list of found scanners and click the Scan button to initiate scanning