如何解决扫描仪权限问题

Question

我的电脑以前运行的是 Ubuntu 10.4。升级到 13.4 后，系统再也找不到我的 Epson 扫描仪了。根据文档，我发现以下内容：

$ sane-find-scanner

  # sane-find-scanner will now attempt to detect your scanner. If the 
  # result is different from what you expected, first make sure your
  # scanner is powered up and properly connected to your computer.

  # No SCSI scanners found. If you expected something different, make sure that
  # you have loaded a kernel SCSI driver for your SCSI adapter.

could not open USB device 0x046d/0x082b at 001:007: Access denied (insufficient permissions)
...
  # No USB scanners found. If you expected something different, make sure that
  # you have loaded a kernel driver for your USB host controller and have setup
  # the USB system correctly. See man sane-usb for details.
...

如果我改为运行 sudo sane-find-scanner，我会得到

$ sudo sane-find-scanner

  # sane-find-scanner will now attempt to detect your scanner. If the
  # result is different from what you expected, first make sure your
  # scanner is powered up and properly connected to your computer.

  # No SCSI scanners found. If you expected something different, make sure that
  # you have loaded a kernel SCSI driver for your SCSI adapter.

found USB scanner (vendor=0x04b8 [EPSON], product=0x0131 [EPSON Scanner]) at libusb:001:009
could not fetch string descriptor: Pipe error
could not fetch string descriptor: Pipe error
  # Your USB scanner was (probably) detected. It may or may not be supported by
  # SANE. Try scanimage -L and read the backend's manpage.

那我该怎么办？scanimage -L 对我没有任何作用，我不知道“后端的联机帮助页”可能是什么。这似乎是一个权限问题，因为可以以 root 身份找到扫描仪，但我不知道如何解决。有人可以帮忙吗？

更新： 我也尝试过简单扫描和 xsane。他们都找不到扫描仪。这就是促使我尝试 sane-find-scanner 的原因。

Answer 1

我的扫描仪（不支持 Epson Perfection V-300 Photo）。那么它在 Ubuntu 10.04 上是如何工作的呢？“Perfection V300 Photo USB 0x04b8/0x0131 不受 epkowa 后端和非免费解释器支持”。感谢Marc给我一个可以看的地方，这是我迈出的第一步为我提供了这些信息，这让我回想起如何才能让它在 Ubuntu 10.04 上运行。我下载了驱动程序，一切正常。

我想说的是 sane-find-scanner 中的错误消息没有它可能有的帮助。

而不仅仅是

  # Your USB scanner was (probably) detected. It may or may not be supported by
  # SANE. Try scanimage -L and read the backend's manpage.

他们可以轻松地包含一个指向http://www.sane-project.org/sane-mfgs.html的链接，从而节省了我浪费时间进行调查的时间。