php生成水印，包括位置和透明度(2)

                return $this;

        }

        // imageInfo

        public function getImageInfo($img){

                $info = @getimagesize($img);

                if(isset($this->types[$info[2]])){

                        $info['ext'] = $info['type'] = $this->types[$info[2]];

                } else{

                        $info['ext'] = $info['type'] = 'jpg';

                }

                $info['type'] == 'jpg' && $info['type'] = 'jpeg';

                $info['size'] = @filesize($img);

                return $info;

        }

        // thumb(新图地址, 宽, 高, 裁剪, 允许放大)

        public function thumb($filename,$new_w=160,$new_h=120,$cut=0,$big=0){

        // 获取原图信息

        $info  = $this->getImageInfo($this->img);

        if(!empty($info[0])) {

            $old_w  = $info[0];

            $old_h  = $info[1];

            $type   = $info['type'];

            $ext    = $info['ext'];

            unset($info);

            // 如果原图比缩略图小 并且不允许放大

            if($old_w < $new_h && $old_h < $new_w && !$big){