Before installing the OpenCV package, you need to install the dependencies.

sudo apt update
sudo apt install python3 python3-dev python3-numpy cmake libgtk2.0-dev

Get the OpenCV package and install it.

wget https://dl.khadas.com/development/opencv-4.7-2.deb
sudo dpkg -i opencv-4.7-2.deb

Get the example repository from OpenCV_NPU_Demo.

cd ~
git clone https://github.com/khadas/OpenCV_NPU_Demo.git

Compile with cmake tool.

cd ~/OpenCV_NPU_Demo/cpp_demo
mkdir build && cd build
cmake ..
make

After the operation is successful, you can see that the camera has captured the face.

cd ~/OpenCV_NPU_Demo/cpp_demo/build
./detect-camera 1 ../../model/yunet_int8.onnx # My cam is /dev/video1, so there is 1