Best way to give sources of images used in a beamer presentation

Question

What's the best style to cite the sources of images in beamer presentation. How to do it?

Since this question may not have a "best answer" I suggest to make it community wiki.

Answer 1

Either in print or in a presentation I think is best to add it below the image:

\documentclass[a4paper]{article}
\usepackage{graphicx,caption}
\parskip0pt
\begin{document}
\includegraphics[width=\linewidth]{pierced}
\hspace*{15pt}\hbox{\scriptsize Credit:\thinspace{\small\itshape Kathleen Gilje}}
  \captionof{figure}{Some description of the image.}
\end{document}

I prefer this approach as it takes less space and is also at the right place to "tell its story".

Answer 2

I prefer putting the source in the lower right corner of the slide (which allows me to put text and image references in the same place). For that, I use a small macro \source which is defined similar to this one:

\newcommand{\source}[1]{\begin{textblock*}{4cm}(8.7cm,8.6cm)
    \begin{beamercolorbox}[ht=0.5cm,right]{framesource}
        \usebeamerfont{framesource}\usebeamercolor[fg]{framesource} Source: {#1}
    \end{beamercolorbox}
\end{textblock*}}

(You probably need to fine-tune the positioning of the textblock in the first line to suit your template.)

In the actual beamer frame, just put it somewhere like this:

\begin{frame}
  \frametitle{Screenshot of Google.com}
  \includegraphics{…}
  \source{Google.com}
\end{frame}

There might be better ways to do it, but that is what works well for me.

EDIT: Forgot to mention that you need to include the definitions for the font and colors

In your beamer color theme, add a line like:

\setbeamercolor{framesource}{fg=gray}

In your beamer font theme, add a line like:

\setbeamerfont{framesource}{size=\tiny}

EDIT: Full MWE:

\documentclass{beamer}
\usepackage[absolute,overlay]{textpos}

\setbeamercolor{framesource}{fg=gray}
\setbeamerfont{framesource}{size=\tiny}

\newcommand{\source}[1]{\begin{textblock*}{4cm}(8.7cm,8.6cm)
    \begin{beamercolorbox}[ht=0.5cm,right]{framesource}
        \usebeamerfont{framesource}\usebeamercolor[fg]{framesource} Source: {#1}
    \end{beamercolorbox}
\end{textblock*}}


\begin{document}

\begin{frame}
  \frametitle{Screenshot of Google.com}
  \includegraphics{filename}
  \source{Google.com}
\end{frame}

\end{document}