{i} This page state about a scanner service in freedesktop. This document was started off a discussion at xdg mailing list : http://lists.freedesktop.org/archives/xdg/2007-January/009074.html

Goals

  • Monitor buttons
  • Share devices These feature imply that the software own the device handle, this is why the software expose acquisition API.

  • Acquire image

Achievement

This can be done through a dbus system wide daemon.

DBus API

This is a rough draft of an API -- ?EtienneBersac 2007-01-28 22:21:45

  • device_list ?GetDeviceList
  • string ?GetDeviceInfo (device)
  • option_list ?GetDeviceOptions (device)
  • ?ShareDevice (device, boolean)
  • job ?StartScan (device, settings)
  • ?StopScan (job)
  • ?GetImage (job) /!\ How to monitor ? How to get buttons events ? How should the image be transferred back to the client?

  • A file descriptor or device node might be one way for transferring the image quickly (sending it directly over D-BUS definitely wouldn't work). Signals :

  • device-plugged (device)

  • device-unplugged
  • button-pressed (device, button)
  • job-done (job)

Scanner access

Scanner access is done through the famous SANE library. Hope that HAL & SANE will work better together in the future in order to get devices from HAL.

Sharing

SANE has a net scanning protocol. However, it shows some limitation (basically, it's too slow for huge image). What to do ?

  • It would be nice to come up with a new protocol for this like the D-BUS one, maybe with some kind of compression, like bzip2. I wouldn't worry about breaking compatibility. -- ?DonaldStraney