[Tex/LaTex] Metropolis theme [beamer], changing the background of logo in the title page

Question

I'm using the metropolis theme for beamer presentation and i have some problems with logo. In fact, I want to change the white background of my eps logo to the transparent one, so that only the colors of the letters are visible (red, blue, gray and not white).

The eps file is here and i donwload the png version to see what the figure looks like.

Thanks

Below you find my MWE and the screen of my document:

   \documentclass[10pt]{beamer}
   \usetheme[subsectionpage=progressbar,background=light]{metropolis}
   \usepackage{appendixnumberbeamer}
   \usepackage{booktabs}
   \usepackage[scale=2]{ccicons}
   \usepackage{xspace}
   \newcommand{\themename}{\textbf{\textsc{metropolis}}\xspace}



   \titlegraphic{%
      \includegraphics[width=.2\textwidth]{example-image-a}\hfill
      \includegraphics[width=3cm,height=1.6cm]{logo.eps}\hfill
      \includegraphics[width=.2\textwidth]{example-image-b}

   }

   \makeatletter
   \setbeamertemplate{title page}{
     \begin{minipage}[b][\paperheight]{\textwidth}

       \vfill%
       \ifx\inserttitlegraphic\@empty\else\inserttitlegraphic\fi
        \centering
        \vfill%
       \ifx\inserttitle\@empty\else\usebeamertemplate*{title}\fi
       \ifx\insertsubtitle\@empty\else\usebeamertemplate*{subtitle}\fi
       \usebeamertemplate*{title separator}
       \ifx\beamer@shortauthor\@empty\else\usebeamertemplate*{author}\fi
       \ifx\insertinstitute\@empty\else\usebeamertemplate*{institute}\fi
       \ifx\insertdate\@empty\else\usebeamertemplate*{date}\fi
       \vfill
        \vspace*{1cm}
     \end{minipage}
   }

   \setbeamertemplate{title}{
   %  \raggedright%
     \linespread{1.0}%
     \inserttitle%
     \par%
     \vspace*{0.15em}
   }
   \setbeamertemplate{subtitle}{
   %  \raggedright%
      \insertsubtitle%
      \par%
      \vspace*{0.5em}
   }
   \makeatother


   \title{My long long long long long long long long long long Title  }
   \subtitle{My subtitle}
   \author{FirstName LastName \\ Supervisor: My supervisor}
   \institute{My Institute}
   \date{\today}


   \begin{document}
   \begin{frame}
       \titlepage
   \end{frame}
   \end{document}

Secondly I would like to know how to create a command for a supervisor information (like \author, \institute, \date, …) instead of putting his name in the author command ? and how to place it just under the author name ?

Answer 1

The .eps file you linked to is no true vector graphic but simply has an image included. Thus the quality will not get any worse if you simply remove the white background from the logo, e.g. with gimp. The resulting image:

This logo can be included as usual (I added keepaspectratio to not distort the image):

\documentclass[10pt]{beamer}
\usetheme[subsectionpage=progressbar,background=light]{metropolis}

\titlegraphic{%
  \includegraphics[width=.2\textwidth]{example-image-a}\hfill
  \includegraphics[width=3cm,height=1.6cm,keepaspectratio]{mJeal}\hfill
  \includegraphics[width=.2\textwidth]{example-image-b}

}

\begin{document}
\begin{frame}
   \titlepage
\end{frame}
\end{document}