This backend provides two devices called 0 and 1. No configuration required. The static library implementing this backend. If the library was compiled with debug support enabled, this environment variable controls the debug level for this backend. E.g., a value of 128 requests all debug output to be printed.
Smaller levels reduce verbosity.
If the pnm backend is installed and saned is used to allow users on remote computers to scan on the local machine, pnm files can be read by the remote user. All pnm files can be read if saned runs as root which isn't recommended anyway. The pnm backend is disabled by default. Be sure that only trusted users can access the pnm backend over saned.