MG3500 doesn't need special image post processing
Canon PIXMA MG3500 Series is working
Pixma backend version 0.17.12
changelog for recent work
fujitsu backend v122

- add support for object_position halt
- call object_position halt in check_for_cancel when requested
new Canon scanners
  MAXIFY MB5000, MB5300, MB2000, MB2300
  PIXMA MG7500, MG6600, MG5600, MG2900, E460
  *all scanners need further testing*
Pixma backend version 0.17.13
changelog for recent work
Canon PIXMA MG2900 Series is working
added alternate PID for P-215
fujitsu backend v123

workaround Linux USB3 bugs by adding command counting code and
sending an even number of reads and writes during disconnect_fd
Remove firmware checking for HP5370c scanners