[Tex/LaTex] how to make the same image size for 3×3 subplots

Question

In the code below,I produced each image separately in matlab and saved it as .eps.Then ,I used this code to put all nine images together as 3×3. However, their sizes looked different in height and width!. How can I fix such a problem.I can not manipulate .eps images in powerpoint !!!.Also, I wanted this set of subplots to fill the whole page but it did fill only half of the page, I really like them to look bigger.Any help is appreciated.
thanks in advance.

 \begin{figure}
        \centering
        \subfloat\[\]\[\emph{caption pic. 1}.\]
        {\includegraphics\[width=.3\textwidth\]{10t10w125x300y}} \quad
        \subfloat\[\]\[\emph{caption pic. 2}.\]
        {\includegraphics\[width=.3\textwidth\]{10t40w250x400y}} \quad
        \subfloat\[\]\[\emph{caption pic. 3}.\]
        {\includegraphics\[width=.3\textwidth\]{10t100w340x500y}} \\
        \subfloat\[\]\[\emph{caption pic. 4}.\]
        {\includegraphics\[width=.3\textwidth\]{30t10w200x400y}} \quad
        \subfloat\[\]\[\emph{caption pic. 5}.\]
        {\includegraphics\[width=.3\textwidth\]{30t40w350x750y}} \quad
        \subfloat\[\]\[\emph{caption pic. 6}.\]
        {\includegraphics\[width=.3\textwidth\]{30t100w550x1200y}} \\
        \subfloat\[\]\[\emph{caption pic. 7}.\]
        {\includegraphics\[width=.3\textwidth\]{50t10w300x600y}} \quad
        \subfloat\[\]\[\emph{caption pic. 8}.\]
        {\includegraphics\[width=.3\textwidth\]{50t40w600x1100y}} \quad
        \subfloat\[\]\[\emph{caption pic. 9}.\]
        {\includegraphics\[width=.3\textwidth\]{50t100w600x1500y}}
        \caption{Insert caption.}
        \label{fig:subfig}
        \end{figure}][1]

Answer 1

Measure the height of one of the images and use that on the rest.

\documentclass{article}
\usepackage{graphicx}
\usepackage{subfig}

\newlength{\common}

\begin{document}
\noindent\rule{\textwidth}{1pt}
\begin{figure}[htp]
\settoheight{\common}{\includegraphics[width=.3\textwidth]{example-image}}% get height
\subfloat[picture 1]{\includegraphics[width=.3\textwidth,height=\common]{example-image}}\hfill
\subfloat[picture 2]{\includegraphics[width=.3\textwidth,height=\common]{euclid-1.jpg}}\hfill
\subfloat[picture 3]{\includegraphics[width=.3\textwidth,height=\common]{images/supper.png}}
\end{figure}
\end{document}