Canon ImageClass MF4450

I inherited one of these all-in-one machines and soon found a driver for the printer (linux-UFRII-drv-v520-usen). But I have had no luck discovering a linux driver for the scanner. All the candidates seem to return “scanner is busy” when I call on it from a scanning program.

Has anyone succeeded in using this scanner?

I have a Canon CanoScan Color Image Scanner - no similar issues. Although, I have a modern model with fresh drivers. Maybe the drivers are broken or are they just outdated? I do not even know.

Use Xsane:

xsane can be run as a stand-alone program or through the GIMP image
manipulation program. In stand-alone mode, xsane can save an image
to a file in a variety of image formats, serve as a frontend to a
fax program, or send an image to a printer.
SANE stands for “Scanner Access Now Easy” and is an application
programming interface (API) that provides standardized access to any
raster image scanner hardware (flatbed scanner, hand-held scanner,
video- and still-cameras, frame-grabbers, etc.). The SANE standard is
free and its discussion and development are open to everybody. The
current source code is written to support several operating systems,
including GNU/Linux, OS/2, Win32 and various Unices and is available
under the GNU General Public License (commercial applications and
backends are welcome, too, however).

Xsane will find your scanner as soon as you run it. I am using a Canon MG5400 series all-in-one. Best scanner software out there, IMO.

Thanks! Xsane does indeed work! The switchology on the MF4450 is a bit bizarre, but after trying a few combinations (Computer/Remote Scanner) and pushing some other buttons, I had a scanned image.
Many thanks, kgwoo!