How do I define the spacing between two figures, when using \subbottom ? My code looks like the following:
\begin{figure}
\centerfloat
\subbottom[Manual segmentation of colon and liver. The two green segmentations are colon and the red is liver.]{%
\includegraphics[width=0.6\textwidth]{img/selection_colon_liver_thin.pdf}}
\subbottom[Histogram of the two segmentations of colon and liver made with 200 bins.]{%
\includegraphics[width=0.8\textwidth]{img/histogram_colon_liver.pdf}}
\caption{Needs caption}
\end{figure}
The captions are two long, so they get "merged" together. How do I separate them?

\quadbetween the subbottoms, they do not provide any horizontal padding. – daleif Mar 31 '14 at 09:37