$filename ='F:/wamp/www/connection/style/theme/article-bottom-orig.png';
        $processor = new Varien_Image($filename);
        
        $processor->keepAspectRatio(false);//保持高宽比
        $processor->keepFrame(false);//保持帧
        $processor->keepTransparency(true);//保持透明度
        $processor->constrainOnly(false);//保持图片制约
        $processor->backgroundColor(array(255, 255, 255));//设置图片背景
        $processor->quality(100);//图片质量
        
        $processor->resize(840);//重设置宽度，高度
        $save = $processor->save('F:/wamp/www/connection/style/theme','new-article-bottom.png');