var img = $("#j-preview-img"); var relratio, twidth, theight; $("<img/>").attr("src", $(img).attr("src")).load(function() { twidth = this.width; theight = this.height; relratio = (twidth/theight).toFixed(2); //获取图片比例 })
原文：http://www.cnblogs.com/snowbaby-kang/p/4463003.html