prouast / heartbeat-js

JavaScript implementation of Remote Photoplethysmography – Measuring pulse rate using facial video.

heartbeat-js: Video-based pulse rate monitoring in JavaScript

This is a simple JavaScript implementation of rPPG, a way to measure the pulse rate without skin contact. It uses a 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

Demo

Test the live demo directly in your browser: Demo

Currently, tracking is disabled. Works best if there is no subject motion.

See also my C++ implementation and YouTube Demo.

License

GPL-3.0

heartbeat-js's Issues

Adding your own video

This is great code, thanks! Is there anyway to add a local video file to be processed?

crash in detrend function

Thank you for also making this javascript version of your C++ code. It's awesome.

I ran your JS code successfully but am trying now to combine it with a handpose tracker in order to see if i can get a BPM from the palm of my hand.

I am using this opencv.js helper for my p5js project.
https://github.com/orgicus/p5.js-cv#installation

But the app crashes after running for a while at cv.split(a_signal, s); line.
Would you have any idea why that might be?
It's interesting that step variable in the console says "Exception: TypeError" when usually it is 2.

// Remove trend in a_signal
function detrend(a_signal, lambda) {
    let h = cv.Mat.zeros(a_signal.rows-2, a_signal.rows, cv.CV_32FC1);
    let i = cv.Mat.eye(a_signal.rows, a_signal.rows, cv.CV_32FC1);
    let t1 = cv.Mat.ones(a_signal.rows-2, 1, cv.CV_32FC1)
    let t2 = cv.matFromArray(a_signal.rows-2, 1, cv.CV_32FC1,
                             new Array(a_signal.rows-2).fill(-2));
    let t3 = new cv.Mat();
    t1.copyTo(h.diag(0)); t2.copyTo(h.diag(1)); t1.copyTo(h.diag(2));
    cv.gemm(h, h, lambda*lambda, t3, 0, h, cv.GEMM_1_T);
    cv.add(i, h, h, t3, -1);
    cv.invert(h, h, cv.DECOMP_LU);
    cv.subtract(i, h, h, t3, -1);
    let s = new cv.MatVector();
    console.log({a_signal});
    cv.split(a_signal, s); //crash here
     console.log({s});
    cv.gemm(h, s.get(0), 1, t3, 0, s.get(0), 0);
    cv.gemm(h, s.get(1), 1, t3, 0, s.get(1), 0);
    cv.gemm(h, s.get(2), 1, t3, 0, s.get(2), 0);
    cv.merge(s, a_signal);
    h.delete(); i.delete();
    t1.delete(); t2.delete(); t3.delete();
    s.delete();
}