PDF Digital Signature


I 'm not familiar with the concepts of implementing digital signature in PDF doc. I went through the sample code given by PDFTron. I could see they digitally sign the document and place an image in the placeholder. Is there a way that I can just display the digital signature as it is without hiding it behind an image. 'm looking for more of code example to display the digital signature.I tried setting the field value with signature obtained from the store, but it is not working. kindly help.
Your help is highly appreciated.

A digital signature has no default appearance, you have to make one your self.

The sample shows the simplest way, adding an image.

These posts provide info on how to do a custom appearance.