Deploy libfacedetection with OpenCV

Example to deploy libfacedetection with the OpenCV's FaceDetectorYN in both Python and C++.

Please note that OpenCV DNN does not support the latest version of YuNet with dynamic input shape. Please ensure you have the exact same input shape as the one in the ONNX model to run latest YuNet with OpenCV DNN.

Important Notes:

• Install OpenCV >= 4.5.4 to have the API FaceDetectorYN.
• Download the ONNX model from OpenCV Zoo.

Envrionment tested:

• System: Ubuntu 18.04 LTS / 20.04 LTS
• OpenCV >= 4.5.4
• Python >= 3.6

Python

1. Install numpy and opencv-python.

   pip install numpy
   pip install "opencv-python>=4.5.4.58"
2. Run demo. For more options, run python python/detect.py --help.

   # detect on an image
   python python/detect.py --model=/path/to/yunet.onnx --input=/path/to/example/image
   # detect on default camera
   python python/detect.py --model=/path/to/yunet.onnx

C++

1. Build the example with cmake:

   cd cpp
   mkdir build && cd build
   cmake .. # NOTE: if cmake failed finding OpenCV, add the option `-DCMAKE_PREFIX_PATH=/path/to/opencv/install`
   make
2. Run the example:

   # detect on an image
   ./detect -m/path/to/yunet.onnx -i=/path/to/image
   # detect on default camera
   ./detect -m/path/to/yunet.onnx