Includegraphics maximum width

Question

With \includegraphics I can give the width of the resulting image (which would be scaled).

How can I give a maximum width of the image? That is, if the original is smaller than X, I'd like to keep the smaller image, if the image is larger than X, then the image width should be X.

Using pdflatex/graphicx.

Answer 1

For more exotic requirements adjustbox or resizebox are useful but you don't really need any additional commands for this (other than a local command just to access @ commands more easily)

\documentclass{article}

\usepackage{graphicx}
\makeatletter
\def\maxwidth#1{\ifdim\Gin@nat@width>#1 #1\else\Gin@nat@width\fi}
\makeatother

\begin{document}

\includegraphics[width=\maxwidth{1in}]{image}

\includegraphics[width=\maxwidth{1cm}]{image}

\end{document}

Answer 2

The adjustbox provides a max width key just for this purpose. If the package is loaded with the export option this key and most others can also be used for \includegraphics.

Here the content is only resized if its current size is larger than the given width. It works basically the same way as the code in David Carlisle's answer. If the \adjincludegraphics macro is used the original width can directly be accessed as \width. Note that this feature is not enabled for \includegraphics by the export option. However this can be done by making \includegraphics using \adjincludegraphics instead using \let\includegraphics\adjincludegraphics after loading adjustbox.

\documentclass{article}

\usepackage{mwe}% just for the example images
\setlength{\parindent}{0pt}

\usepackage[export]{adjustbox}% 'export' allows adjustbox keys in \includegraphics

\begin{document}

\hrule% to see \linewidth

\includegraphics[max width=\linewidth]{example-image-1x1}

\includegraphics[max width=\linewidth]{example-image-a4}

% With \adjincludegraphics (or \adjustimage) you can also use the original width as \width:
\adjincludegraphics[width=\ifdim\width>\linewidth \linewidth\else\width\fi]{example-image}

\end{document}

Answer 3

\documentclass{article}
\usepackage[demo]{graphicx}
\newlength\MaxWidth \newsavebox\IBox
\MaxWidth=100pt

\newcommand*\IncludeGraphics[2][]{%
  \sbox\IBox{\includegraphics[#1]{#2}}%
  \ifdim\wd\IBox>\MaxWidth \resizebox{\MaxWidth}{!}{\usebox\IBox}%
  \else\usebox\IBox\fi}

\begin{document}

\includegraphics{image}

\IncludeGraphics{image}

\IncludeGraphics[width=50pt]{image}

\end{document}