Drawing label on figure (using tikz)
\begin{tikzpicture}
\node[anchor=south west,inner sep=0] at (0,0) {\includegraphics[trim={600px 200px 50px 200px},clip, width=1\linewidth]{images/DP_10150_simpleCombinedBasedOnDPlen.exe_scale1_blank/frm00001}};
%\draw[white,fill=white] (0.0,0.0) rectangle (0.5,0.5);
\node[minimum size=.6cm, fill=white,anchor=south west] at (0.0,0.0){а}; \end{tikzpicture}