At home we have an HP OfficeJet J6410 printer, which has worked brilliantly for years. Unlike every previous printer we’ve owned, this printer sits happily on our network and seems perfectly content to be used only very occasionally, whereon it willingly responds with decent quality prints and scans.

I have set up the printer with a static IP address and so the scanning is managed via the web interface http://192.168.0.100/webScan, whereon the scanned image opens a new tab in the browser, enabling you to save to wherever.

This printing and scanning Nirvana hit a road bump today, when it just instantly went to “Scan done” and failed to actually do anything. Rebooting the laptop, the printer and clearing temporary internet files all failed to resolve the problem, as did changing from Chrome to Firefox.

In desperation I tried running Ubuntu Simple Scan, but predictably enough it did not find the printer. A quick Internet search took me to this excellent Ubunutu community page.

I opened a terminal and typed:

$ hp-makeuri 192.168.0.100

CUPS URI: hp:/net/Officejet_J6400_series?ip=192.168.0.100
SANE URI: hpaio:/net/Officejet_J6400_series?ip=192.168.0.100
HP Fax URI: hpfax:/net/Officejet_J6400_series?ip=192.168.0.100

Done.

I then typed (taking the SANE URI from above):

$ simple-scan hpaio:/net/Officejet_J6400_series?ip=192.168.0.100

And it worked perfectly! Flushed with success I read on to see how to make this a permanent fixture, and it turned out that all I needed to do was configure the CUPS URI for the printer itself (it was previously set to something like socket://192.168.0.100):

$ vim /etc/cups/printers.com

DeviceURI hp:/net/Officejet_J6400_series?ip=192.168.0.100

And now simply running Ubuntu Simple Scan works perfectly.

Thank you Ubuntu community!

Before you start, you need to have sane installed, and you also need tesseract-ocr - both should be available in your distros repositories.

$ sudo apt-get install sane-utils tesseract-ocr

Next you need to find out what scanners you have available, and you do this with:

$ scanimage -L
device `v4l:/dev/video0' is a Noname Vimicro USB Camera (Altair) virtual device
device `plustek:libusb:004:002' is a Epson Perfection 1250/Photo flatbed scanner)

Obviously the latter is my scanner.

Assuming you have a working scanner, the following is a simple two liner to scan and OCR.

$ scanimage -d 'plustek:libusb:004:002' --mode Lineart \
--format tiff -x 215 -y 297 --resolution 200 > example.tif

And finally convert to text with tesseract:

$ tesseract /tmp/example.tif example

You should now have a file example.txt in your current directory, which you can open in any text editor.

Obviously this has limitations - it works for single-page A4 portrait typed documents - but it gives you the basics.

You could probably experiment with the resolution, 200 worked for me, so I didn’t bother trying anything else.  Traditionally the higher the resolution the better, but I seem to recall that tesseract works better on 300 and below.

On my Epson Perfection 1250 I found that I needed to add the sane switch --warmup-time 0 as otherwise it never finished warming up.

If you would prefer to OCR an existing PDF, which is another thing that I find myself doing from time to time, then first convert it to a tif:

$ convert -density 200 example.pdf -depth 8 /tmp/example.tif

And then run the above tesseract command.

Scanning with LTSP 5 in Debian Etch or Lenny

At the time of writing these instructions worked for Etch, but have not been completed for Lenny.

Introduction

This is a description for a scanner physically connected to a terminal (not to the server).

For LTSP scanning to work, you just need to remember that the roles are reversed - that is the client is the scanning server and the server is the scanning client. With the exception of the fact that you have to chroot to get at the client, the set-up is an ordinary Linux network scanning set-up.

Configure client

Install client packages

You have to be root in the chroot LTSP client environment for the next steps:

$ sudo chroot /opt/ltsp/i386
# mount -t proc /proc /proc
# mount -t sysfs sys /sys
# apt-get install libexif12 libgphoto2-2 libgphoto2-port0 libieee1284-3 libltdl3 libsane libsane-extras sane-utils
# umount sys
# umount /proc

User ‘saned’ needs an additional group:

Still in the chroot:

# usermod -a -G scanner saned

Modify /etc/inetd.conf (Etch)

Still in the chroot, open /etc/inetd.conf (e.g. with vi) and add at the end of the file (after ‘#:OTHER: Other services’) this line:

sane-port stream tcp nowait saned.saned /usr/sbin/saned saned

Modify /etc/default/saned (Lenny)

The problem with this is that it will run for all users, which seems a bit pointless, should be possible to use an ldm rc.d script, but this did not work correctly for me.

Still in the chroot, open /etc/default/saned and change RUN=no to RUN=yes.

On an upgraded server, this was not enough, I also needed to symlink:

# cd /etc/rc2.d
# ln -s ../init.d/saned S99saned

The initial openbsd-inetd links are wrong. (Etch)

Still in the chroot, Delete openbsd-inetd links with:

# rm /etc/rc*/*openbsd*

Create new one’s:

# ln -s ../init.d/openbsd-inetd /etc/rc2.d/S20openbsd-inetd
# ln -s ../init.d/openbsd-inetd /etc/rc3.d/S20openbsd-inetd
# ln -s ../init.d/openbsd-inetd /etc/rc4.d/S20openbsd-inetd
# ln -s ../init.d/openbsd-inetd /etc/rc5.d/S20openbsd-inetd
# ln -s ../init.d/openbsd-inetd /etc/rc0.d/K20openbsd-inetd
# ln -s ../init.d/openbsd-inetd /etc/rc1.d/K20openbsd-inetd
# ln -s ../init.d/openbsd-inetd /etc/rc6.d/K20openbsd-inetd

Check if everything is fine:

# ls -l /etc/rc*/*openbsd*

Leave chroot

# exit or [Ctrl]+[d]

Configure server

Install server packages

Thanks to the Debian package system it’s easy to get almost all software (as root):

# apt-get install libsane libsane-extras sane-utils

Set user grants

You have to set the saned group for every scanner user:

# usermod -a -G saned ~username~

saned.conf Configuration (client)

Modify the saned.conf file. Put the IP address of your server, e.g.:

/opt/ltsp/i386/etc/sane.d/saned.conf

#
# saned.conf
#
# The contents of the saned.conf  file  is  a  list  of  host  names,  IP
# addresses or IP subnets (CIDR notation) that are permitted to use local
# SANE devices. IPv6 addresses must be enclosed in brackets,  and  should
# always  be specified in their compressed form.
#
# The hostname matching is not case-sensitive.
#
~serverip~

net.conf Configuration (client)

Modify the net.conf file. Put the IP addresses & names of your server, scanner terminal; client and localhost here, e.g.:

/opt/ltsp/i386/etc/sane.d/net.conf

# This is the net config file.  Each line names a host to attach to.
# If you list "localhost" then your backends can be accessed either
# directly or through the net backend.  Going through the net backend
# may be necessary to access devices that need special privileges.

localhost
~server-ip~
~server-hostname~

Modify the dll.conf (client)

Enable only two lines, one with ‘net’ and the other one with the name of your (!) scanner backend (for me: snapscan -> works with Epson scanner).

/opt/ltsp/i386/etc/sane.d/dll.conf

# enable the next line if you want to allow access through the network:
net
snapscan
#abaton
#agfafocus
#apple
#avision
#artec
#artec_eplus48u
#as6e
...

Here you find an overview of supported backends:

• http://www.sane-project.org/sane-mfgs.html

Modify dll.conf (server)

Modify dll.conf. Enable only the line with ‘net’ (disable all others):

/etc/sane.d/dll.conf

# enable the next line if you want to allow access through the network:
net
#abaton
#agfafocus
#apple
#avision
#artec
#artec_eplus48u
#as6e
...

Modify net.conf (server)

Modify net.conf. Put the IP address of your scanner terminal client (!) here, e.g.:

/etc/sane.d/net.conf

# This is the net config file.  Each line names a host to attach to.
# If you list "localhost" then your backends can be accessed either
# directly or through the net backend.  Going through the net backend
# may be necessary to access devices that need special privileges.
~client-ip~

Alternatively (and better in my opinion) is to script the scanner program, so that it starts with:

SANE_NET_HOSTS=client-ip
export SANE_NET_HOSTS
scanimage > test.pnm

See Alternative Configuration.

Restart your client terminal

Restart hplip (Etch only)

$ sudo /etc/init.d/hplip restart
Stopping HP Linux Printing and Imaging System: hpiod hpssd.
Starting HP Linux Printing and Imaging System: hpiod hpssd.

Test

If it doesn’t work - take a look at your syslog.

Alternative configuration

If your client doesn’t have a static ip and hostname (as with the default ltsp set-up), then you can either configure /etc/dhcp3/dhcpd.conf to provide you with a static ip and hostname, or use this alternative scanner configuration.

Step 1: Remove all client references above

Work back through the above configurations, commenting out all references to your client-ip and client-hostname.

Step 2: Write a script

Here is a simple test script to determine your client, and list your connected scanner:

SANE_NET_HOSTS=`echo $SSH_CLIENT | cut -d " "  -f 1`
export SANE_NET_HOSTS
scanimage -L

You would need to modify this script to do something more useful with scanimage.

References

• http://wiki.ltsp.org/twiki/bin/view/Ltsp/Debian#Scanning_with_LTSP_5_in_Debian_E
• http://wiki.ltsp.org/twiki/bin/view/Ltsp/Scanners
• http://www.enterprisenetworkingplanet.com/nethub/article.php/%203637076
• http://www.jumako.de/cms/index.php?option=com_content&task=view&id=26&Itemid=31

Enable saned on terminal

• Edit /opt/ltsp/i386/etc/lts.conf and add XINETD_SERVICES = "saned" to the [default] or relevant terminal section
• Restart the terminal
• Run scanimage -L on workstation shell to verify that scanner has been detected

Usage

• Physically plug the scanner into the terminal using USB or parallel port.
• Edit /etc/sane.d/net.conf and add the hostname or address of client running saned
• Use xsane, OpenOffice.org, GIMP, or any other scanner-aware application, as they should now list the scanner.

Alternative to net.conf

If you do not wish to add the host to net.conf (as shown above) then you can run the following:

$ SANE_NET_HOSTS=`echo $DISPLAY | cut -d: -f1`
$ export SANE_NET_HOSTS

This will only work for the life of the terminal window - so you will need to run the application from the command line. Alternatively add this to a script that does the scanning.

Scanning from the command line

Check scanner detected

$ scanimage -L

Scan

$ scanimage -l 0 -t 0 -x 215 -y 297 --mode {Lineart|Gray|Color} --resolution {75..600} --format {pnm|tiff} --brightness {-100..100} --contrast {-100..100} >test.pnm

References

• http://wiki.ltsp.org/twiki/bin/view/Ltsp/Scanners

$ sudo apt-get install -t 'etch-backports' libwine-sane

This worked to a fashion for me; in that it brought up a rather poor scanner dialog, and triggered the scanner, but never completed the scan job. That said, I was using saned on LTSP (i.e. via network) which may be a step too far for libwine-sane!

Since upgrading to LTSP5, our scanning has ceased to work. I have created a Work in Progress page called LTSP5 Scanning. Having worked through the instructions contained on that page, scanning is still not working. The logs show that the request scanimage -L is being detected by the client and the client is confirming that the LTSP server has permission, but it is then failing with:

Jun 24 12:16:55 juno scanimage: unable to open /var/run/hplip/hpssd.port: No such file or directory: prnt/hpijs/hplip_api.c 94
Jun 24 12:16:55 juno scanimage: unable to connect hpssd socket 50002: Connection refused: prnt/hpijs/hplip_api.c 719

Not realising that HP had any involvement in scanning on Linux, I assumed that this was a port conflict with some utilities installed on our HP server, but reading into the matter further I believe that this is because the client has detected that the scanner is an HP model and has attempted to run an HP scan utility that is not installed on the client. Just guesses, if you have any ideas, please contact me. Any useful messages will be posted here!