Image size getter

gistfile1.ts

function imageSizeGetter(image: HTMLImageElement, callback: (size:[number, number]) => any): void {
    if (image.width > 0 && image.height > 0) {
        callback([image.width, image.height]);
    } else {
        var observer = new MutationObserver(function (record) {
            observer.disconnect();
            callback([image.width, image.height]);
        });
        observer.observe(image, {
            attributes: true,
            attributeFilter: ["width", "height"]
        });
    }
}