<!DOCTYPE html>
<script>
fetch('./large_image.png')
.then(response => response.blob())
.then(blob => {
var reader = new FileReader();
reader.onloadend = () => {
download(reader.result);
}
reader.readAsDataURL(blob);
});
function download(url) {
var a = document.createElement("a");
a.href = url;
a.download = 'large.png';
document.body.appendChild(a);
a.click();
}
</script>