[Tex/LaTex] Thicken and widen curly braces around graphics

Question

I want to put curly braces around an image that is about 3.5 x 5 inches. When I do this using the following command, the braces are 5 inches tall but very skinny, so it looks bad.

 \newcommand{\bracedincludegraphics}[2][]{%
 \sbox0{$\vcenter{\hbox{\includegraphics[#1]{#2}}}$}%

   \left\lbrace

   \vphantom{\copy0}
   \right.\kern-\nulldelimiterspace

   \rbrace{\box0}}

How do I make the curly braces thicker and wider. By "wider," I mean that the horizontal length from the one point on the left of \lbrace to the two points on the top and bottom of \lbrace is too small (and the analogous situation for \rbrace). Basically I want it to be noticeable that a 3.5 x 5 inch graphic is between curly braces, instead of the braces looking scrawny. As an example of this, look at the TeX stack exchange logo. The thickness of those braces would be very nice, if not thicker. Thanks.

Answer 1

If you're prepared to load TikZ, here's a version using the calligraphy package.

\documentclass{article}
%\url{https://tex.stackexchange.com/q/373803/86}
\usepackage{graphicx}
\usepackage{tikz}
\usetikzlibrary{decorations.pathreplacing,calligraphy}


\begin{document}

\tikz {\node (a) {\includegraphics[width=.8\textwidth]{batman}}; \draw[decorate,line width=5mm,decoration={calligraphic brace, amplitude=1cm}] (a.north east) -- (a.south east); \draw[line width=5mm,decorate,decoration={calligraphic brace,amplitude=1cm}] (a.south west) -- (a.north west); }

\end{document}

Obviously, you could package all that into a command. I've picked the numbers to show the effect, you can vary them as you please.