preloadImage: function(index, callback) {
      if(this.images[index]) {
        var image = this.images[index];
        if(!this.images[index].preloaded) {
          var img = $(new Image());
          img.attr('src', image.image);
          if(!this.isImageLoaded(img[0])) {
            this.preloads.append(img);
            var context = this;
            img.load(
              function() {
                image.preloaded = true;
                image.size = { width: this.width, height: this.height };
                context.fireCallback(callback);
              }
            ).error(
              function() {
                image.error = true;
                image.preloaded = false;
                image.size = false;
              }
            );
          } else {
            image.preloaded = true;
            image.size = { width: img[0].width, height: img[0].height };
            this.fireCallback(callback);
          };
        } else {
          this.fireCallback(callback);
        };
      };
    },
请问一下,我用jquery ad_gallery 插件时,图片加载时,出现小图片,界面刷新一下就正常了,是否是img.load有问题,有时候加载的图片正常,有时候就变成小图了?