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.
A Promise that resolves to an ImageBitmap object.
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 simplicity it does not show how to instantiate the ImageCapture object.
let grabFrameButton = document.querySelector("button#grabFrame");
let canvas = document.querySelector("canvas");
grabFrameButton.onclick = grabFrame;
function grabFrame() {
imageCapture
.grabFrame()
.then((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((error) => {
console.error("grabFrame() error: ", error);
});
}