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
Dependencies
The following libraries are required to run Heartbeat:
They must be installed on the system such that headers and libraries are found on the compiler's standard search path.
Installation
For building a Makefile is available that works on macOS:
$ makeAlternative compilation for Ubuntu. Works with opencv 3.1:
$ g++ -std=c++11 Heartbeat.cpp opencv.cpp RPPG.cpp `pkg-config --cflags --libs opencv` -o HeartbeatSettings
After building, the app can be run via
$ ./Heartbeat
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