PAM-face-authentication是一款能让webCam扫描脸部进而登录ubuntu的软件，确实很神奇，费话少说，直接体验更直接。

安装依赖工具包
sudo apt-get install cmake libcv-dev libcvaux-dev libhighgui2.1 libhighgui-dev libpam0g-dev checkinstall  build-essential libx11-dev libqt4-dev qt4-qmake(由于本机中已有QT开发环境，后两项就不装了)

下载安装
cd ~/Downloads
wget http://pam-face-authentication.googlecode.com/files/pam-face-authentication-0.3.tar.gz
tar zxf pam-face-authentication-0.3.tar.gz
cd pam-face-authentication-0.3
mkdir build
cd build
cmake -D CMAKE_INSTALL_PREFIX=/usr ..(这两点不可缺少)
make
sudo make install


配置
在终端运行
qt-facetrainer




编辑配置文件
cat << EOF | sudo tee /usr/share/pam-configs/face_authentication /dev/null
> Name: face_authentication
> profile
> Default: yes
> Priority: 900
> Auth-Type: Primary
> Auth:
> [success=end default=ignore]
> pam_face_authentication.so
> enableX
> EOF

让配置文件生效
sudo pam-auth-update --package face_authentication

备注
如果你的系统已经设置成自动登录了，请在System-->Administration-->Login Screen

勾选Show the screen for choosing who will log in

Reference
1、http://code.google.com/p/pam-face-authentication/