Web/API/ImageCapture/grabFrame

The grabFrame() method of the ImageCapture interface takes a snapshot of the live video in a MediaStreamTrack and returns a Promise that resolves with a ImageBitmap containing the snapshot.

Syntax

const bitmapPromise = imageCapture.grabFrame()

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 ImageCapture 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 CaptureThe definition of 'grabFrame()' in that specification.	Working Draft	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`grabFrame` Experimental'	Chrome Full support 59	Edge Full support ≤79	Firefox ?	IE No support No	Opera Full support 46	Safari ?	WebView Android Full support 59	Chrome Android Full support 59	Firefox Android ?	Opera Android Full support 43	Safari iOS ?	Samsung Internet Android Full support 7.0

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.

ImageCapture.grabFrame() by Mozilla Contributors is licensed under CC-BY-SA 2.5.