function resize() {
if (
body.clientWidth * window.devicePixelRatio < img.naturalWidth
|| body.clientHeight * window.devicePixelRatio < img.naturalHeight
) {
body.style.imageRendering = 'auto';
} else {
body.removeAttribute('style');
}
}
let body = document.body;
let img = document.getElementsByTagName('img')[0];
(new ResizeObserver(resize)).observe(body);