如何在codeigniter中使用ImageMagick

i have a controller wich can upload images. Now gd2 library works perfectly except for big images. So i want to use ImageMagick for this. But i can't get it working. I use mamp for my localhost.

This is my code:

function voegfotostoe()
    {
        $config['upload_path'] = './uploads/';
        $config['allowed_types'] = 'gif|jpg|png';
        $config['max_size'] = '0';
        $config['max_width']  = '0';
        $config['max_height']  = '0';
        $this->load->library('upload', $config);    
        if ( ! $this->upload->do_upload())
        {
            $error = array('error' => $this->upload->display_errors());
        }   
        $datap = array('upload_data' => $this->upload->data());

        $id = $this->input->post('id');

        $gallery_path = realpath(APPPATH . '/../uploads');

        $upload_data = $this->upload->data();

        $this->load->library('image_lib');

        /* Size 350px x 300px */
        $config['image_library'] = 'ImageMagick';
        $config['library_path'] = '/usr/bin/';
        $config['source_image'] = $upload_data['full_path'];
        $config['new_image'] = $gallery_path . '/thumbs';
        $config['create_thumb'] = FALSE;
        $config['maintain_ratio'] = TRUE;
        $config['width'] = 350;
        $config['height'] = 300;

        $this->image_lib->clear();
        $this->image_lib->initialize($config);
        $this->upload->display_errors();
        $this->image_lib->resize();


        $config['image_library'] = 'ImageMagick';
        $config['library_path'] = '/usr/bin/';
        $config['source_image'] = $upload_data['file_path'] . 'thumbs/' . $upload_data['orig_name'];
        $config['new_image'] = $gallery_path . '/vierkant';
        $config['create_thumb'] = TRUE;
        $config['maintain_ratio'] = FALSE;
        $config['width'] = 200;
        $config['height'] = 200;

        $this->image_lib->clear();
        $this->image_lib->initialize($config);
        $this->image_lib->crop();


        $thumb = $this->upload->data();
        $thumbname = $thumb['raw_name'] . $thumb['file_ext'];

        /* Size 600px X 600px */

        $config['image_library'] = 'ImageMagick';
        $config['library_path'] = '/usr/bin/';
        $config['source_image'] = $upload_data['full_path'];
        $config['new_image'] = $gallery_path . '/medium';
        $config['thumb_marker'] = '_medium';
        $config['maintain_ratio'] = TRUE;
        $config['width'] = 500;
        $config['height'] = 500;

        $this->image_lib->clear();
        $this->image_lib->initialize($config);
        $this->image_lib->resize();
        $medium = $this->upload->data();
        $mediumname = $medium['raw_name'] . '_medium'. $medium['file_ext'];

    $data = array(
        'fk_land' => $this->input->post('landid'),
        'titel' => $this->input->post('titel'),
        'period' => $this->input->post('period'),
        'size' => $this->input->post('size'),
        'info' => $this->input->post('info'),
        'region' => $this->input->post('region'),
        'cat_id' => $this->input->post('catsculp'),
        'color' => $this->input->post('color'),
        'order' => $this->input->post('landtoevoegen'),
        'gallery_name' => $this->input->post('painter'),
        'thumb_img' => $thumbname,
        'medium_img' => $mediumname

    );

        if( $datap['upload_data']['orig_name'] != "" ) $data['gallery_img'] = $datap['upload_data']['orig_name'];
        $this->Cms_model->voegfototoe($data);
        redirect('home#toevoegen','refresh');   
    }

Replace these lines:

$config['source_image'] = site_url().'marcella-resources/front/img/M24CPP_x200/SBase1.jpg'; $config['new_image'] = site_url().'marcella-resources/front/test/SBase1_copy.jpg';

with these lines:

$config['source_image'] = 'marcella-resources/front/img/M24CPP_x200/SBase1.jpg'; $config['new_image'] = 'marcella-resources/front/test/SBase1_copy.jpg';