Adding latex to existing pdf document?

Question

I would like to import a pdf document and add additional code on top of the image (the pdf). I can write over figures by the overpic package. The problem is that I would like my compiled latex file to have the same exact document size (geometric) as the imported graphic (pdf). Is this possible?

Answer 1

You can use the pagecommand option with includepdf to overlay the document with tikz.

\documentclass{article}
\usepackage{pdfpages}
\usepackage{tikz}
\begin{document}
    \includepdf[pagecommand={\begin{tikzpicture}[remember picture,overlay]
        \fill[red, opacity=0.3] (current page.south west) rectangle (current page.north east) ;
        \end{tikzpicture}\thispagestyle{empty}}]{test.pdf}
\end{document}