[Tex/LaTex] Using LaTeX to generate .png images of an equation

math-modepdftexpng

I am familiar with using LaTeX on online websites (like MathOverflow or Physicsforums). My input is rendered using MathJax. However, I do not understand the LaTeX environment in its native OS form. I have downloaded MacTeX, and all I would like to do is make tiny little .png or .jpg files that each contain one equation.

After some Googling, I have tried something along the lines of:

\documentclass[preview]{standalone}
\begin{document}
\begin{equation}
\frac{1}{2} = 0.5
\end{equation}
\end{document}

followed by

pdflatex equation.tex
convert -density 300 equation.pdf -quality 95 equation.png

(using ImageMagick's convert program), but the output contains a number next to my equation that I can't seem to get rid of. Also, this seems like a lot of work, and I don't need a whole documentclass just for one equation. Not to mention pdflatex produces a bunch of other auxiliary files that clutter up my directory during the conversion process. Is there some way I can just easily go from a file containing

\frac{1}{2} = 0.5

to equation.png? Better yet, is there a simple way I can take a file containing a list of equations and have each of them converted into their own little .png image?

Best Answer

standalone class is sufficient. You can enable the multi option, so that the contents of each (math) environment is cropped to its own page in a PDF file. Then you can either save each page directly as a .png image (Acrobat Pro, and perhaps Adobe Reader, allows you to do it in one go), or you can use the convert functionality (need Image Magick) provided with standalone. For the latter method, see Section 4.6 of the standalone documentation.

In the example below I define a new environment mymath, which is basically inline math with display style.

MWE

\documentclass[multi={mymath},border=1pt]{standalone}
% \usepackage{amsmath}
\newenvironment{mymath}{$\displaystyle}{$}

\begin{document}

\begin{mymath}
  \frac{1}{2}=0.5
\end{mymath}

\begin{mymath}
  a^2 + b^2 = c^2
\end{mymath}

\end{document}

Output

enter image description here

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