pam_face_authentication with Ubuntu 9.10(Karmic Koala) + GDM + Speedlink Webcam

repat — Sun, 02 May 2010 23:56:09 +0000

I'll write this in English because I couldn't find a lot of articles about this topic, so everybody can understand what this is about. Found a lot of Spanish/Portuguese sites though o0.

There are probably several ways to install OpenCV. I decided to compile it by myself, because the .deb-package(found here) collided with lib-something and that was definitely necessary for pam_face_authentication, though that happened on my Toshiba M10 with Lucid Lynx 10.04 and not on the Karmic Laptop.
Anyway, even if it works for you, this is definitely not wrong to do:
Download the latest version of OpenCV(2.1.0 at the time) here and follow the very same Installation Guide:
(DO NOT COPY PASTE THIS! THINK FIRST!)

cd ~/projects/OpenCV-2.1.0
mkdir release
cd release
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D BUILD_PYTHON_SUPPORT=ON ..
make
make install
export LD_LIBRARY_PATH=~/projects/OpenCV-2.1.0/release/lib:$LD_LIBRARY_PATH
sudo ldconfig

This should work without any error messages, which - of course - it didn't. For example, I had to install libqt4-dev and qt4-make or something, just have a look at synaptic or apt-cache. Just try to google the error message. Also took quite a while. Go and have a coffee;)

Now download the source code from http://code.google.com/p/pam-face-authentication/ , my version is 0.3. Then follow the video instructions, if you can't watch it or whatorever:

cd pam_face_authentication-0.3
mkdir build
cd build
cmake -D CMAKE_INSTALL_PREFIX=/usr ..
make
sudo make install

Same thing, should work perfectly fine. Try to google any error messages, if you get any. On my Toshiba with Lucid I got shit loads of error messages, don't know what went wrong, but the cmake command just doesn't work. On Karmic however no worries at all.

Next thing was nearly more difficult...installing a webcam. As I posted before, my Speedlink SL-6810 worked out of the box with camorama, but somehow I couldn't get it to work-.- Turns out you need sudo(root privilege) to open /dev/video0. Same thing with cheese or other programs for webcams. These programs are designed to use libv4l drivers and stuff. qt-facetrainer, the program you need to capture a couple of sets for the recognition of your face, however has to be told to use these for this specific webcam.
Try

sudo LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so qt-facetrainer

(Thanks to rohan.anil and mystercoco)

So once you got your camera working, we'll try to implement the whole thing into GDM, which I thought is pretty complicated but is actually quite easy. Thanks again to Rohan's Blog:
Just add this line:

auth sufficient pam_face_authentication.so enableX

to /etc/pam.d/gdm, as it is said in his blog. Works fine for Karmic, can't say anything about Lucid.
For my webcam, you'll also need the libv4l for login, so create a /etc/ld.so.preload and just write

/usr/lib/libv4l/v4l1compat.so

in it. This will provide GDM with any information required to login by face authentication.

That's it. Leave comments if there are any questions:)

Weblinks

repats blog » pam_face_authentication karmic 9.10

pam_face_authentication with Ubuntu 9.10(Karmic Koala) + GDM + Speedlink Webcam