You could host on something like dropbox …
let img, url = 'https://dl.dropboxusercontent.com/s/35drk9bes8j0ups/train.png?dl=0';
function preload() {
img = loadImage(url);
}
function setup() {
createCanvas(img.width * 0.25, img.height * 0.25);
img.resize(img.width * 0.25, img.height * 0.25);
}
function draw() {
image(img, 0, 0);
}