问codeigniter图片上传水印和缩略图

EN

$this->do_thumb('file_name');
$this->watermark('file_name');

function watermark($filename){
        $image_cfg = array();
        $image_cfg['image_library'] = 'GD2';
        $image_cfg['source_image'] = 'upload/' . $filename;
        $image_cfg['wm_overlay_path'] = 'upload/watermark.png';
        $image_cfg['new_image'] = 'upload/mark_'.$filename;
        $image_cfg['wm_type'] = 'overlay';
        $image_cfg['wm_opacity'] = '10';
        $image_cfg['wm_vrt_alignment'] = 'bottom';
        $image_cfg['wm_hor_alignment'] = 'right';
        $image_cfg['create_thumb'] = FALSE;

        $this->image_lib->initialize($image_cfg);
        $this->image_lib->watermark();
        $this->image_lib->clear();

//        echo $this->image_lib->display_errors();
//        die();

    }

    function do_thumb($filename) {
        $image_cfg['image_library'] = 'GD2';
        $image_cfg['source_image'] = 'upload/' . $filename;
        $image_cfg['create_thumb'] = TRUE;
        $image_cfg['maintain_ratio'] = TRUE;
        $image_cfg['width'] = '200';
        $image_cfg['height'] = '175';
        $this->load->library('image_lib');
        $this->image_lib->initialize($image_cfg);
        $this->image_lib->resize();
        $this->image_lib->clear();
    }