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