webrtc snapshot from webcam

snapshot.js

function snapshot() {
  if (localMediaStream) {
    var img = document.querySelector('img');
    /* draws the image to the canvas */
    ctx.drawImage(video, 0, 0);
    /* loads the img to the hidden img tag */
    img.src = canvas.toDataURL('image/webp');
    img.style.display= "block";
  }
}