Merge multiple EPS subfigures into a single figure using LaTeX Beamer

Some academic journals require all subfigures to be combined as one single file for submission. This may not be easy to do if you don't have a professional software (often proprietary) to edit vector maps, e.g., EPS and PDF.

I found a convenient way to deal with in LaTeX Beamer. The idea is to create a beamer slide and insert your subfigures with the command \includegraphics{} in the same figure environment. This beamer slide will then be the combined figure.

Suppose the figure you want to create has two panels, (A) and (B). A simple example would be

\documentclass[10pt]{beamer}
\geometry{papersize={8in, 6in}}  % slide size
\setbeamersize{text margin left=0.1in, text margin right=0.1in}
\mode<presentation>

\setbeamertemplate{navigation symbols}{}  % disable the navigation bar

\begin{document}
\title{}  % no title

\begin{frame}
\frametitle{}  % no frame title
\begin{figure}[h]
  \includegraphics[width=0.48\textwidth]{fig_1a.pdf}
  \includegraphics[width=0.48\textwidth]{fig_1b.pdf}
\end{figure}
\end{frame}
\end{document}

Some extra efforts may be needed to adjust the figure to a desirable layout, but hopefully it will be less laborious than redrawing the figure or editing it with an image processing software.