如何使用Yii2 kartik-mpdf添加水印

How can I add watermark image on pdf using kartik-pdf?

Here is the line I added:

'options' => [
    'title' => 'Title',
    'showWatermarkText' => true,
    'showWatermarkImage' => true,
],
// call mPDF methods on the fly
'methods' => [ 
    'SetHeader' => ['Title'], 
    'SetFooter' => ['{PAGENO}'],
    'SetWatermarkText' => ['DRAFT'],
    'SetWatermarkImage' => $basepath . '/images/imgbox1.jpg',
]

Only the text watermark display.

Is there something wrong on how I used watermarkImage?

use kartik mpdf library to create object of mpdf; The following code will create simple pdf using kartik widget

use mPDF;
class SiteController extends Controller
{
public funtion createpdf() 
{
    $HTML='your html content';
    $mpdf = new \Mpdf\Mpdf(); //please use your kartik mpdf object here 
    $mpdf->SetWatermarkImage('../images/background.jpg');
    $mpdf->showWatermarkImage = true;

    $mpdf->WriteHTML($HTML);
   // Saves file on the server as 'filename.pdf'
   $mpdf->Output('filename.pdf', \Mpdf\Output\Destination::FILE);
}
}