\begin{picture}(0,0)%
\includegraphics{topologie.pdf}%
\end{picture}%
\setlength{\unitlength}{4144sp}%
%
\begingroup\makeatletter\ifx\SetFigFont\undefined%
\gdef\SetFigFont#1#2#3#4#5{%
  \reset@font\fontsize{#1}{#2pt}%
  \fontfamily{#3}\fontseries{#4}\fontshape{#5}%
  \selectfont}%
\fi\endgroup%
\begin{picture}(8572,8072)(3376,-10068)
\put(5221,-2221){\makebox(0,0)[lb]{\smash{{\SetFigFont{14}{16.8}{\sfdefault}{\mddefault}{\updefault}{\color[rgb]{1,1,1}8 tests positions around node $P_i$}%
}}}}
\put(5221,-2461){\makebox(0,0)[lb]{\smash{{\SetFigFont{14}{16.8}{\sfdefault}{\mddefault}{\updefault}{\color[rgb]{1,1,1}from $T_{i,0}$ to $T_{i,7}$ counterclockwise}%
}}}}
\put(10306,-3481){\makebox(0,0)[rb]{\smash{{\SetFigFont{14}{16.8}{\sfdefault}{\mddefault}{\updefault}{\color[rgb]{1,1,1}node $P_{i-1}$}%
}}}}
\put(4861,-9871){\makebox(0,0)[lb]{\smash{{\SetFigFont{14}{16.8}{\sfdefault}{\mddefault}{\updefault}{\color[rgb]{1,1,1}node $P_{i+1}$}%
}}}}
\end{picture}%