face-detection-draw.js

startVideo()

video.addEventListener('play', () => {
  //create the canvas from video element as we have created above
  const canvas = faceapi.createCanvasFromMedia(video);
  //append canvas to body or the dom element where you want to append it
  document.body.append(canvas)
  // displaySize will help us to match the dimension with video screen and accordingly it will draw our detections
  // on the streaming video screen
  const displaySize = { width: video.width, height: video.height }
  faceapi.matchDimensions(canvas, displaySize)
  setInterval(async () => {
    const detections = await faceapi.detectAllFaces(video, new faceapi.TinyFaceDetectorOptions()).withFaceLandmarks().withFaceExpressions()
    const resizedDetections = faceapi.resizeResults(detections, displaySize)
    canvas.getContext('2d').clearRect(0, 0, canvas.width, canvas.height)
    faceapi.draw.drawDetections(canvas, resizedDetections)
    faceapi.draw.drawFaceLandmarks(canvas, resizedDetections)
    faceapi.draw.drawFaceExpressions(canvas, resizedDetections)
  }, 100)
})