dlib_installation.md

The installation guide of dlib

If you meet performance problem with face recognition, you should consider compile dlib by yourself and reinstall it. As the website said, the compilation of dlib is simple. However, I found it quiet annoying compiling on portable computer device like Raspberry Pi due to the insufficient capacity of physical memory. Here's solution that I've found.

On Usual *nix device

cd examples
mkdir build
cd build
cmake ..
cmake --build . --config Release
cd ../../
python setup.py install

On Portable Computer (like Raspberry Pi)

You should run the same code like above. Before that, however, you should change your swap size setting:

sudo vi /etc/dphys-swapfile

change the CONF_SWAPSIZE from 100 to 2048. If you don't have 2048 MBytes, then 1024 also should work, just for in case.

Then, make sure you have enough space on your hard drive.

cd /var
sudo dd if=/dev/zero of=./swap2 bs=1024 count=2048000  # Will write 2G of zeros to file swap2, change the size if you want
sudo mkswap ./swap2
sudo swapon ./swap2
sudo /etc/init.d/dphys-swapfile restart

Now you can start building and leave for your coffee or something, it will take about 2 hours (at lease in my case).

☕ ☕ ☕

If you finish the compilation procedure and you want to change your swap size back:

sudo vi /etc/dphys-swapfile

and change CONF_SWAPSIZE to whatever you need, default is 100 then

sudo swapoff /var/swap2
sudo rm /var/swap2
sudo /etc/init.d/dphys-swapfile restart