The HiQPdf software is able to load external PDF documents and to add new objects over the existing content.
Edit PDF Demo
In this demo you can learn how to load a PDF document from a file and layout various PDF objects on top of the existing content.
The demo will make two changes to the PDF document to edit: will create an orange border for each PDF page of the loaded document and will create a canvas whose content is automatically repeated on each PDF page.
The content from a HTML document will be laid out in the repeated canvas.
The HTML document does not have a background which makes visible the existing content from PDF and even more, the PNG image used in HTML is also transparent to create a very special effect.