aliushn/heartbeat

Desktop implementation of Remote Photoplethysmography – Measuring heart rate using facial video.

Heartbeat: Measuring heart rate using remote photoplethysmography (rPPG)

This is a simple implementation of rPPG, a way to measure heart rate without skin contact. It uses a video recording or live feed of the face to analyse subtle changes in skin color.

Here's how it works:

• The face is detected and continuously tracked
• Signal series is obtained by determining the facial color in every frame
• Heart rate is estimated using frequency analysis and filtering of the series

If you are interested in the specifics, feel free to have a read of my publications on the topic:

• Remote Photoplethysmography: Evaluation of Contactless Heart Rate Measurement in an Information Systems Setting
• Using Contactless Heart Rate Measurements for Real-Time Assessment of Affective States
• Remote heart rate measurement using low-cost RGB face video: A technical literature review

See also my minimal JavaScript implementation and Browser Demo.

Demo

• Real-time rPPG in action
• Offline rPPG With physiological baseline measurements

Dependencies

The following libraries are required to run Heartbeat:

• OpenCV

They must be installed on the system such that headers and libraries are found on the compiler's standard search path.

Installation

UPDATE: With current changes in Mojave, compiling via g++ was complicated. After following this advice, the following works for me with macOS 10.14.2 and opencv 4.0.1 installed via Homebrew:

g++ -std=c++11 -I/usr/local/Cellar/opencv/4.0.1/include/opencv4 -lopencv_core -lopencv_dnn -lopencv_highgui -lopencv_imgcodecs -lopencv_imgproc -lopencv_objdetect -lopencv_video -lopencv_videoio Heartbeat.cpp opencv.cpp RPPG.cpp Baseline.cpp -o Heartbeat

Compile the source code for your system, providing a number of required linker flags. This works with opencv 3.4.1 on macOS:

$ g++ -std=c++11 -lopencv_core -lopencv_dnn -lopencv_highgui -lopencv_imgcodecs -lopencv_imgproc -lopencv_objdetect -lopencv_video -lopencv_videoio Heartbeat.cpp opencv.cpp RPPG.cpp Baseline.cpp -o Heartbeat

Alternative compilation for Ubuntu. Works with opencv 3.1:

$ g++ -std=c++11 Heartbeat.cpp opencv.cpp RPPG.cpp Baseline.cpp `pkg-config --cflags --libs opencv` -o Heartbeat

Settings

Several command line arguments are available:

Argument	Options	Description
-i	Filepath to input video	Omit flag to use webcam
-rppg	g, pca (default: g)	Specify rPPG algorithm variant - only green channel or rgb channels with pca
-facedet	haar, deep (default: haar)	Specify face detection classifier - Haar cascade or deep neural network
-r	Re-detection interval (default: 1 s)	Interval for face re-detection; tracking is used frame-to-frame
-f	Sampling frequency (default: 1 Hz)	Frequency for heart rate estimation
-max	default: 5	Maximum size of signal sliding window
-min	default: 5	Minimum size of signal sliding window
-gui	true, false (default: true)	Display the GUI
-log	true, false (default: false)	Detailed logging
-ds	default: 1	If using video from file: Downsample by using every ith frame

License

GPL-3.0