Crop equations with preview package

Question

Is it possible to avoid left space from equations previewed with preview package?

\documentclass{minimal}
\usepackage{amsmath}
\usepackage[active,tightpage,displaymath]{preview}
\setlength\PreviewBorder{5pt}%

\begin{document}
\[x=3+y^2\]
\end{document}

The result is:

I would like a clipped (cropped?) equation. Is it possible?

Do you know a better solution to extract equations as images?

Answer 1

You can use the pdfcrop Perl script.

Answer 2

The left space is caused by the display style. You could use in-text style ($ ... $ or \( ... \)) instead and use \displaystyle in it to get the same result without the space. You need to wrap the equation manually in a preview environment:

\documentclass{minimal}
\usepackage{amsmath}
\usepackage[active,tightpage]{preview}
\setlength\PreviewBorder{5pt}%

\begin{document}
\begin{preview}
$\displaystyle x=3+y^2$
\end{preview}
\end{document}

Even shorter would be the use of the standalone class which uses preview internally. Note that the border option is only available since v0.4 2011/02/28. Before that you would need to set \PreviewBorder manually.

\documentclass[border=5pt]{standalone}
\begin{document}
$\displaystyle x=3+y^2$
\end{document}