Hello,
We have replied to your message with the following information:
We have tested it and it's working correctly, please test the included sample DigitalSignature/signPDF/sample_2.php. Could you try using a PNG image?
If you send us the PDF and image you are using we'll test them. What program are you using to open the signed PDF?
Please, use a single way to request support to avoid duplicated messages.
Regards.