Re: what gives a clear scan with Linux?

> man sane-usb
> This is a short HOWTO-like section. For the full details, read the fol‐
>        lowing  sections.  The  goal  of  this  section  is  to get the
> scanner
>        detected by sane-find-scanner(1).

>        Run sane-find-scanner. If it lists your scanner with the correct
> vendor
>        and  product  ids, you are done. See section SANE ISSUES for
> details on
>        how to go on.

>        sane-find-scanner doesn't list your scanner? Does it work as
>  root?  If
>        yes, there is a permission issue. See the LIBUSB section for
> details.

>        Nothing  is found even as root? Check that your kernel supports USB
> and
>        that libusb is installed (see section LIBUSB).

> <edit>
> LIBUSB
>        SANE  can  only  use libusb 0.1.6 or newer. It needs to be
> installed at
>        build-time. Modern Linux distributions and other operating systems
> come
>        with libusb.

>        Libusb  can  only access your scanner if it's not claimed by the
> kernel
>        scanner driver. If you want to use libusb,  unload  the  kernel
>  driver
>        (e.g. rmmod scanner under Linux) or disable the driver when
> compiling a
>        new kernel. For Linux, your kernel needs support for the USB
> filesystem
>        (usbfs). For kernels older than 2.4.19, replace "usbfs" with
> "usbdevfs"
>        because the name has changed. This filesystem must be  mounted.
> That's
>        done  automatically  at  boot  time, if /etc/fstab contains a line
> like
>        this:

>               none /proc/bus/usb usbfs defaults  0  0

>        The permissions for the device files used by libusb  must  be
>  adjusted
>        for  user  access. Otherwise only root can use SANE devices. For
> Linux,
>        the devices are located in /proc/bus/usb/ or in  /dev/bus/usb,  if
>  you
>        use  udev.  There  are directories named e.g. "001" (the bus name)
> con‐
>        taining files "001", "002" etc. (the device files).  The  right
>  device
>        files can be found out by running scanimage -L as root. Setting
> permis‐
>        sions with "chmod" is not permanent, however. They will be reset
>  after
>        reboot or replugging the scanner.

>                 none /proc/bus/usb usbfs defaults  6   6