如何在Codeigniter中创建图像水印wm_type overlay？

Question

I am trying to put an image over another image (watermark) like so:

class Water_mark extends CI_Controller {

    function __construct() {
        parent::__construct();
    }

    function index() {
        $this->load->library('image_lib');
        $config['image_library'] = 'GD2';
        $config['source_image'] = '/assets/images/tv-share.jpg';
        $config['new_image'] = '/assets/images/tv-share-done.jpg';
        $config['wm_type'] = 'overlay';
        $config['wm_overlay_path'] = '/assets/images/share_en.jpg';
        $config['wm_opacity'] = '50';
        $config['wm_vrt_alignment'] = 'top'; 
        $config['wm_hor_alignment'] = 'left';
        $config['wm_hor_offset'] = '10';
        $config['wm_vrt_offset'] = '10';

        $data = $config;
        $this->image_lib->initialize($config);

        if (!$this->image_lib->watermark()) {
            echo $this->image_lib->display_errors();
        }
        $this->image_lib->clear();

        $this->load->view('water_mark_view', $data);
    }

}

but I keep getting errors:

A PHP Error was encountered
Severity: Warning
Message: imagecolorat() expects parameter 1 to be resource, boolean given
Filename: libraries/Image_lib.php
Line Number: 941
A PHP Error was encountered
Severity: Warning
Message: imagecolorat() expects parameter 1 to be resource, boolean given
Filename: libraries/Image_lib.php
Line Number: 953
A PHP Error was encountered
Severity: Warning
Message: imagecolortransparent() expects parameter 1 to be resource, boolean given
Filename: libraries/Image_lib.php
Line Number: 953
A PHP Error was encountered
Severity: Warning
Message: imagecopymerge() expects parameter 1 to be resource, boolean given
Filename: libraries/Image_lib.php
Line Number: 954
The path to the image is not correct.
The path to the image is not correct.
The path to the image is not correct.
Your server does not support the GD function required to process this type of image.
Your server does not support the GD function required to process this type of image.
Your server does not support the GD function required to process this type of image.

What am I missing?

Answer 1

The issue was as simple as removing the forward slash (although in the documentation example the forward slash exists) at he beginning like so:

$config['source_image'] = 'assets/images/tv-share.jpg';
$config['new_image'] = 'assets/images/tv-share-done.jpg';
$config['wm_overlay_path'] = 'assets/images/share_en.jpg';

what got me confused this error:

Your server does not support the GD function required to process this type of image.

I never thought it was only a path issue when I saw the error above.