// 压缩上传图片
export function translate(imgSrc, scale, callback) {
	let img = new Image();
	img.src = imgSrc;
	img.onload = function() {
		let that = this;
		let h = that.height; // 默认按比例压缩
		let w = that.width;
		let canvas = document.createElement('canvas');
		let ctx = canvas.getContext('2d');
		let width = document.createAttribute("width");
		width.nodeValue = w;
		let height = document.createAttribute("height");
		height.nodeValue = h;
		canvas.setAttributeNode(width);
		canvas.setAttributeNode(height);
		ctx.drawImage(that, 0, 0, w, h);
		var base64 = canvas.toDataURL('image/jpeg', scale); //压缩比例
		canvas = null;
		callback(base64);
	}
}