Saving table as PNG

Question

I'd like to save the following table as png. I've tried this and using the Linux program convert, but both saved the whole page instead of just the table. I want to save just the table as png.

How can I do this?

\documentclass[11pt]{article}
\usepackage[table]{xcolor}

\definecolor{myblue}{RGB}{78, 126, 222}
\usepackage{multirow}
\usepackage{geometry}
\usepackage{tabularx}
\usepackage{booktabs}
\usepackage{ragged2e}

\begin{document}

\begin{table}[ht]
    \centering\setlength{\extrarowheight}{3pt}
\rowcolors{1}{myblue}{}
        \begin{tabularx}{\textwidth}{>{\cellcolor{white}} c >{\cellcolor{white}}c>{\RaggedRight\arraybackslash}X>{\RaggedRight\arraybackslash}X}
            \toprule
            & Inner index 1.1 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \multirow{-2}{*}{Outer index 1} & Inner index 1.2 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \midrule
             & Inner index 2.1 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \multirow{-2}{*}{Outer index 2} & Inner index 2.2 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \midrule& Inner index 3.1 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            &Inner index 3.2 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            &Inner index 3.3 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            \multirow{-2}{*}{Outer index 3}&Inner index 3.4 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            &Inner index 3.5 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            &Inner index 3.6 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            \bottomrule
        \end{tabularx}
\end{table}

\end{document} 

Answer 1

You can get a page sized to the content using the standalone class something like

\documentclass[border={0pt 40pt 40pt 0pt}]{standalone}

\usepackage[table]{xcolor}

\definecolor{myblue}{RGB}{78, 126, 222}

\usepackage{multirow}
\usepackage{geometry}
\usepackage{tabularx}
\usepackage{booktabs}
\usepackage{ragged2e}


\begin{document}

\begin{tabularx}{\textwidth}{>{\cellcolor{white}} c >{\cellcolor{white}}c>{\RaggedRight\arraybackslash}X>{\RaggedRight\arraybackslash}X}
            \toprule
            & Inner index 1.1 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \multirow{-2}{*}{Outer index 1} & Inner index 1.2 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \midrule
             & Inner index 2.1 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \multirow{-2}{*}{Outer index 2} & Inner index 2.2 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            \midrule& Inner index 3.1 & Text data placeholder. May be long enough that it needs to be wrapped. & Text data placeholder. May be long enough that it needs to be wrapped.\\
            &Inner index 3.2 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            &Inner index 3.3 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            \multirow{-2}{*}{Outer index 3}&Inner index 3.4 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            &Inner index 3.5 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            &Inner index 3.6 & \multicolumn{2}{>{\hsize=\dimexpr2\hsize+2\tabcolsep+\arrayrulewidth\relax\RaggedRight\arraybackslash}X}{ Text data placeholder. May be long enough that it needs to be wrapped. Text data placeholder. May be long enough that it needs to be wrapped.}\\
            \bottomrule
        \end{tabularx}
\end{document}

If you add png:

\documentclass[border={0pt 40pt 40pt 0pt},png]{standalone}

and run pdflatex with --shell-escape then it will automatically use imagemagic convert in the background and directly produce a PNG image rather than PDF outpuput.