javascript 获取图片原始尺寸

javascript 获取图片原始尺寸

 function getImgInfo(url){
         var img = new Image(), loaded = false;
         var info = {};
         //对于预加载的情况,即没有把图片插入DOM树
         img.onload = function(){
             img.onload = null;
             loaded = true;  //标志当前已加载过，防止complete再运行
             info['width'] = img.width;
             info['height'] = img.height;
         }
         img.src = url;
         var orignInfo;
         //已经加载过的图片
         if(img.complete && !loaded){
             //safari,firefox,chrome,与opera10+中，有两个便捷的属性
             if(img.naturalWidth && img.naturalHeight){
                 info['width'] = img.naturalWidth;
                 info['height'] = img.naturalHeight;
             }else if(img.runtimeStyle){
                 //IE runtimeStyle不用同步style就能重绘原来的元素
                 orignInfo = {'width':img.width,'height':img.height};   //保存原来的尺寸
                 img.width = img.height = "auto";//重写
                 info['width'] = img.width;//获取原始尺寸
                 info['height'] = img.height;
                 img.width = orignInfo.width;  //还原尺寸
                 img.height = orignInfo.height;
             }else{
                 info['width'] = img.width;
                 info['height'] = img.height;
             }
         }
         return info;
     }

参考：http://www.cnblogs.com/rubylouvre/archive/2011/05/05/2037115.html