Can I conditionally scale an image with graphicx

Question

In particular, when I include a graphic, I would like it to have width=\linewidth if it's width is greater than \linewidth, but I'd like it to have \scale=1 if it is smaller than the line width.

In other words, I'd like my images to only shrink if they wouldn't otherwise fit.

I know that generating a document generally involves iterating on the typesetting, but when creating internally-shared documents that aren't going to be published, I'm not too concerned about how exactly perfect the layout looks. I'd just like it to be decent the first time around and not have to worry about iterating on it.nally-share

Answer 1

\newcommand{\lwincludegraphics}[2][]{%
  \sbox{0}{\includegraphics[#1]{#2}}%
  \ifdim\wd0>\linewidth
    \resizebox{\linewidth}{!}{\box0 }%
  \else
    \leavevmode\box0
  \fi}

Use \lwincludegraphics as you would \includegraphics.

(The similarity with Werner's answer is evident, but having a proper command that allows for setting in the optional argument is better.)

Answer 2

You could use the following condition within your figures:

\documentclass{article}
\usepackage[showframe]{geometry}% http://ctan.org/pkg/geometry
\usepackage{graphicx}% http://ctan.org/pkg/graphicx
\usepackage{xifthen}% http://ctan.org/pkg/xifthen
\begin{document}
\begin{figure}
  \setbox0=\hbox{\includegraphics{tiger}}% Store image in box0
  \ifthenelse{\dimtest{\wd0}>{\linewidth}}%
    {\includegraphics[width=\linewidth]{tiger}}% Scale image to fit within \linewidth
    {\usebox0}% Use original (unaltered in width) image
  \caption{This is a tiger, rawr.}
\end{figure}
\end{document}

The geometry package was added merely to highlight the page dimension via the showframe package option. The actual image width of tiger is 550.68999pt > 430.004462pt = \linewidth.

You could also combine the above code in a macro. For example, consider the macro \maxwidth[<max hlen>]{<stuff>}:

\newcommand{\maxwidth}[2][\linewidth]{% \maxwidth[<max hlen>]{<stuff>}
  \setbox0=\hbox{#2}% Store image in box0
  \ifthenelse{\dimtest{\wd0}>{#1}}%
    {\resizebox{#1}{!}{#2}}% Scale object to fit within \linewidth
    {\usebox0}% Use original (unaltered in width) object
}

The first (optional) argument <max hlen> specifies the maximum horizontal length of the object <stuff> (the second, mandatory, argument). The default, if no <max hlen> is specified, is \linewidth. You would use it in the following way:

\maxwidth{\includegraphics{tiger}}

This would yield the same output as above