var img = new Image();
img.src = _tmp_img.src;
if (img.complete) {
	console.log(1738)
	console.log($(img)[0].naturalWidth)
} else {
	img.onload = function () {
		console.log(1987)
		console.log($(img)[0].naturalWidth)
		img.onload = null;
	};
};
实际使用的代码：

if (img1.complete) {
	console.log(3858)
	console.log($(img1)[0].naturalWidth)
	callback(img1);
} else {
	img1.onload = function () {
		console.log(1827)
		console.log($(img1)[0].naturalWidth)
		img1.onload = null;
		callback(img1);
	};
};