SOURCE

document.addEventListener('paste', function(event) {
    var items = (event.clipboardData && event.clipboardData.items) || [];
    var file = null;
 
    if (items && items.length) {
        for (var i = 0; i < items.length; i++) {
            console.log(items)
            if (items[i].type.indexOf('image') !== -1) {
                file = items[i].getAsFile();
                console.log(file)
                break;
            }
        }
    }
});