Adjust the caption to figures on minipage

Question

Using minipage, is posible to split the (a) (b) letters above any figures, in order to perfectly center them?

\begin{figure}[tpb]
            \subfloat[]{
               \begin{minipage}{0.45\linewidth}   %tamaño
                   \includegraphics[width=1\columnwidth,keepaspectratio]{matlab/pdr_12345_p.pdf}
                \end{minipage}}  
            \subfloat[]{
            \hspace{5mm}    \begin{minipage}{0.45\linewidth}
                    \includegraphics[width=1\columnwidth,keepaspectratio]{matlab/pdr_11111_p.pdf}

                \end{minipage}} 
    \end{figure}

thanks in advance!

Answer 1

You could use the subcaption package to induce an automatic line break between the caption's "number" (letter, actually) and text. The subcaption package also provides the environment subfigure (plus subtable); using it allows you to combine \subfloat directive and minipage environment into a single environment.

The following MWE shows how this may done. (Note that I haven't provided a caption for the overall figure float as your example didn't seem to require one.)

\documentclass[a4paper,twoside]{report}
\usepackage{subcaption}
\captionsetup[sub]{labelsep=newline}
\usepackage[demo]{graphicx} % remove '[demo]' for real version
\begin{document}
\begin{figure}
   \begin{subfigure}{0.45\linewidth}   
      \includegraphics[width=\columnwidth,keepaspectratio]{matlab/pdr_12345_p.pdf}
      \caption{First Subfigure}
   \end{subfigure}
   \hspace{\fill}   % separate the two subfigures as much as possible
   \begin{subfigure}{0.45\linewidth}
      \includegraphics[width=\columnwidth,keepaspectratio]{matlab/pdr_11111_p.pdf}
      \caption{Second Subfigure}
   \end{subfigure} 
\end{figure}

\end{document}