reading a pdf, adding text/images to it and write the modified pdf in rails

I want to use PDF::writer to put some dates on a calendar sheet. The calendar sheet itself is prepared as a prerendered template in PDF format. How could I read this PDF as template to write text on it?

Is there an alternative? Fiddling with an H开发者_StackOverflow中文版TML-to-PDF converter (like HTMLDoc) is no option.

Maybe pdf-toolkit could help you

Edit: I remembered I played around with this a few years back and like it a lot.

If at all possible, try to get to the original text (i.e. calendar sheet) BEFORE it is transformed to PDF! It is not easy and sometimes not possible to reconstruct text (and your calendar's look and layout) from PDF.