ImageCapture.grabFrame()

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The grabFrame() property of the ImageCapture interface takes a snapshot of the live video in a MediaStreamTrack, returning an ImageBitmap, if successful.

Syntax

ImageCapture.grabFrame().then(function(imageBitmap) { ... })

Parameters

None.

Return value

A Promise that resolves to an ImageBitmap object.

Example

This example is extracted from this Simple Image Capture demo. It shows how to use the Promise returned by grabFrame() to copy the returned frame to a <canvas> element. For simplicy it does not show how to instantiate the image capture object.

var grabFrameButton = document.querySelector('button#grabFrame');
var canvas = document.querySelector('canvas');

grabFrameButton.onclick = grabFrame;

function grabFrame() {
  imageCapture.grabFrame()
  .then(function(imageBitmap) {
    console.log('Grabbed frame:', imageBitmap);
    canvas.width = imageBitmap.width;
    canvas.height = imageBitmap.height;
    canvas.getContext('2d').drawImage(imageBitmap, 0, 0);
    canvas.classList.remove('hidden');
  })
  .catch(function(error) {
    console.log('grabFrame() error: ', error);
  });
}

Specifications

Specification Status Comment
MediaStream Image Capture
The definition of 'grabFrame()' in that specification.
Working Draft Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support59 ? ? ?46 ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support5959 ? ?46 ?7.0

Document Tags and Contributors

Contributors to this page: fscholz, shaunlebron, jpmedley
Last updated by: fscholz,