[Tex/LaTex] Knowing how much \resizebox scales

graphicsscaling

Is it possible to know how much a \resizebox scales something for further use in a \scalebox?

To clarify, take this example:

\documentclass{article}
\usepackage[paperwidth=12cm]{geometry}
\usepackage{graphicx}
\begin{document}
\def\figurea{\includegraphics[width=5cm]{example-image-a}}
\def\figureb{\includegraphics[width=2.5cm]{example-image-b}}
This is \texttt{fig-a} with its natural size:

\figurea
\bigskip

This is \texttt{fig-b} with its natural size:

\figureb
\bigskip

This is \texttt{fig-a} scaled to fit the page width:

\resizebox{\textwidth}{!}{\figurea}
\bigskip

How do I rescale \texttt{fig-b} to keep its relative size compared to \texttt{fig-a} without knowing its actual size?
\bigskip

\texttt{Insert a nice piece of code here :)}

\end{document}

I want to have fig-b with the same relative size to fig-a without actually knowing the size of any of them.

Also, as in the example, there will be text in between the figures, so putting them in the same \resizebox is not an option.

Best Answer

\resizebox is just \scalebox with a scale factor being the number that you ask for. So you can just persuade it to expose that number rather than just use it in a local group and discard it.

\documentclass{article}
\usepackage[paperwidth=12cm]{geometry}
\usepackage{graphicx}
\makeatletter
\let\zz\Gscale@box
\long\def\Gscale@box#1{%
\xdef\thelastscalefactor{#1}%
\zz{#1}}

\makeatother
\begin{document}
\def\figurea{\includegraphics[width=5cm]{example-image-a}}
\def\figureb{\includegraphics[width=2.5cm]{example-image-b}}
This is \texttt{fig-a} with its natural size:

\figurea
\bigskip

This is \texttt{fig-b} with its natural size:

\figureb
\bigskip

This is \texttt{fig-a} scaled to fit the page width:

\noindent%you need this:-)
\resizebox{\textwidth}{!}{\figurea}
\let\savethis\thelastscalefactor
\bigskip

How do I rescale \texttt{fig-b} to keep its relative size compared to \texttt{fig-a} without knowing its actual size?
\bigskip

\noindent
\scalebox{\savethis}{\figureb}

\end{document}

Related Solutions

[Tex/LaTex] Scale (resize) large images (graphics) that exceed page margins

Using the adjustbox package with the export option which extends graphicx with several new keys you can now simply use the max width key which scales the image down to that width if it is larger but doesn't scale it at all if it is smaller the equal to it. There are also the related keys max height, max size (for both width and height) as well as min width, min height and min size.

In your case simply use the following code:

\includegraphics[max width=\linewidth]{<image file name>}

Note that you can't set max width etc. in a global way using \setkeys{Gin}{max width=...}. It is implemented in a different way as width. However, I'm planning to add a possibility for this as well.

[Tex/LaTex] Scalebox – knowing how much it scales

It is not true that \scalebox{0.5} of the graphics package scales a graph to 0.8 times of the original size. It scales it simply by this factor, as Ian Thompson already said in his answer.

Note that their is also \resizebox{<width>}{<height>}{<content>} which allows you to scale the image to a given size. This can be more useful for adjusting bigger graphics or pictures: \resizebox{\textwidth}{!}{<content>} scales the content directly to the size of the main text. The ! for the height states that it should scale with the width. See my answer to Quickest way to include graphics for more explanation about scale vs. direct width/height.

See the graphics/x manual for the other commands like \rotatebox. Note that if you want to resize images you can use the optional arguments of \includegraphics[height=<height>,width=<width>,angle=<angle>,keepaspectratio]{<filename>}.

For other things like diagrams drawn using TeX commands (pgf/tikz, pstricks, etc.) there is the adjustbox package which gives you \adjustbox{height=<height>,width=<width>,angle=<angle>,keepaspectratio}{<TeX content>} or the similar and very new gincltex which allows you to include .tex files like images using \includegraphics.

Best Answer

Related Solutions

[Tex/LaTex] Scale (resize) large images (graphics) that exceed page margins

[Tex/LaTex] Scalebox – knowing how much it scales

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