<?php
//Specify path to image. The image must have a 96 DPI resolution.
$watermark = new PDFWatermark('C:myimage.png');
//Set the position
$watermark->setPosition('bottomleft');
//Place watermark behind original PDF content. Default behavior places it over the content.
$watermark->setAsBackground();
//Specify the path to the existing pdf, the path to the new pdf file, and the watermark object
$watermarker = new PDFWatermarker('C: est.pdf','C:output.pdf',$watermark);
//Set page range. Use 1-based index.
$watermarker->setPageRange(1,5);
//Save the new PDF to its specified location
$watermarker->savePdf();
?>