er une image
<form accept="image/*">
<input type="file" id="img" name="img" accept="image/*" />
</form>
... ementById('img').onchange = function (e) {
// file -> file
var b5 = Blitz.create()
b5({
source: e.srcElement.files[0],
// image will be up... .then(download => {
console.log('Resize using file successful')
// output is a download function