Beamer Custom theme with logo and custom background

Question

I just created a custom theme in beamer for our lab that has 2 pdf files for the backgrounds, 1 for the title page and another for the frames.

I've placed the style files in an appropriate place (I used $TEXINPUTS) and this is good.

Where do I place these pdf's so that texlive can find it? As of now, I'm adding them to the folder of each presentation, which is not exactly ideal.

Here's my theme style file:

\mode<presentation>

% Requirement
\RequirePackage{graphicx}
\RequirePackage{tikz}

% Settings
\useinnertheme{tmd}
\useoutertheme{tmd}
\usecolortheme{tmd}

\setbeamertemplate{navigation symbols}{}
\setbeamertemplate{blocks}[tmd][shadow=true]
\setbeamertemplate{background canvas}{ \includegraphics[width=\paperwidth,
  height=\paperheight, keepaspectratio]{TMD_frames} }

% Title Font
\setbeamerfont*{title}{size=\Huge,series=\bfseries}

% Frame Title
\setbeamerfont*{frametitle}{size=\LARGE,series=\bfseries}
\setbeamerfont*{framesubtitle}{size=\large,series=\bfseries}

% Footlines
\setbeamerfont*{author in head/foot}{series=\bfseries}
\setbeamerfont*{title in head/foot}{series=\bfseries}
\setbeamerfont*{date in head/foot}{series=\bfseries}

% Thanks
\def\makethanks{%
  \usebackgroundtemplate{\includegraphics[width=\paperwidth]{TMD_Title.pdf}}  
  \begin{frame}
    \frametitle{\vspace{0.5em}\@thankstitle}
    \begin{columns}[T]
      \begin{column}{0.5\textwidth}
        \centering\@thanksmessage
      \end{column}
      \begin{column}{0.5\textwidth}
        \centering\@thanksgraphic
      \end{column}    
    \end{columns}
  \end{frame}
  \usebackgroundtemplate{\includegraphics[width=\paperwidth]{TMD_frames.pdf}}  
}
\providecommand\makethanks{}
\def\thankstitle#1{\def\@thankstitle{#1}}
\def\thanksmessage#1{\def\@thanksmessage{#1}}
\def\thanksgraphic#1{\def\@thanksgraphic{#1}}

% Title page
\def\maketitle{%
  \usebackgroundtemplate{\includegraphics[width=\paperwidth]{TMD_Title.pdf}}
  \begin{frame}
    \titlepage
  \end{frame}
  \usebackgroundtemplate{\includegraphics[width=\paperwidth]{TMD_frames.pdf}}  
}

\mode<all>

TMD_Title.pdf and TMD_frames.pdf are the background pdf's that I am referring to.