%User Variables
\usetikzlibrary{calc,trees,positioning,arrows,chains,shapes.geometric}
\usetikzlibrary{decorations.pathreplacing,decorations.pathmorphing,shapes}
\usetikzlibrary{matrix,shapes.symbols,plotmarks,decorations.markings,shadows}

\newcommand{\block}{1cm}
\newcommand{\scale}{0.7}

\begin{tikzpicture}[scale=\scale,every node/.style={minimum size=0.6*\scale*\block}, inner sep=0pt,on grid]
	
	\definecolor{lightgray}{rgb}{0.80,0.80,0.80};
	\definecolor{darkgray}{rgb}{0.40,0.40,0.40};

	\tikzstyle{arrow}=[draw, <->,shorten <=1pt,shorten >=1pt,>=stealth',thick]
	\tikzstyle{pel}=[circle, rounded corners ,draw=lightgray!80, fill=lightgray!80, thick,  scale=0.5]
	\tikzstyle{outerpel}=[pel, fill=gray, draw=gray!90, thick]
	\tikzstyle{innerpel}=[pel, fill=black!90, draw=black!90, thick]

	% Image pixels
	\foreach \x in {-2,...,9}
	\foreach \y in {-2,...,9}
	{
		\node at (\x+0.5,\y+0.5) [pel]() {};
	}


	% outer boundary
	\foreach \x in {0,...,7}
	\foreach \y in {-1,8}
	{
		\node at (\x+0.5,\y+0.5)  [outerpel](ref_tp)  {};
	}
	\foreach \x in {-1,8}
	\foreach \y in {0,...,7}
	{
		\node at (\x+0.5,\y+0.5)  [outerpel](ref_tp)  {};
	}

	% inner boundary
	\foreach \x in {0,...,7}
	\foreach \y in {0,7}
	{
		\node at (\x+0.5,\y+0.5)  [innerpel](ref_tp)  {};
	}
	\foreach \x in {0,7}
	\foreach \y in {1,...,6}
	{
		\node at (\x+0.5,\y+0.5)  [innerpel](ref_tp)  {};
	}


% 	\foreach \x in {0,8}
% 	\foreach \y in {1,...,2,4,5,...,7}
% 	{
% 		\node at (\x+0.5,\y+0.5) [pel](ref_lft) {};
% 	}


	% Center
%	\draw[draw=black,thick, opacity=1]  (\block,\block) rectangle ++(7*\block,7*\block);
	\node[anchor=center,scale=\scale, text centered] at (4,4) {Lost Block};

	\draw[draw=black, thick] (0*\block,-1) -- ++(0,10*\block);
	\draw[draw=black, thick] (8*\block,-1) -- ++(0,10*\block);
	\draw[draw=black, thick] (-1*\block,0*\block) -- ++(10*\block,0);
	\draw[draw=black, thick] (-1*\block,8*\block) -- ++(10*\block,0);

%	\draw[draw=black, thick] (8*\block-8+4,-1) -- (8*\block-8+4,10);

	% Lost pixel
	%\node at (4*\block+\block/2, 3*\block+\block/2) [pel, fill=black, draw=black, thick](lostpel)  [label=north east: $lp$] {};


	% Reference pixels
	%\node at (4*\block+\block/2, 8*\block+\block/2)  [pel, fill=black, draw=black, thick](ref_tp)  [label=north west: $p_1$] {};
	%\node at (0*\block+\block/2, 3*\block+\block/2)  [pel, fill=black, draw=black, thick](ref_lft)  [label=north west: $p_2$] {};
	%\node at (4*\block+\block/2, 0*\block+\block/2)  [pel, fill=black, draw=black, thick](ref_bottm)  [label=south east: $p_3$] {};
	%\node at (8*\block+\block/2, 3*\block+\block/2)  [pel, fill=black, draw=black, thick](ref_rght)  [label=north east: $p_4$] {} ;

	%\path [arrow] (lostpel) -- node[left] { $d_1$} (ref_tp);
	%\path [arrow] (lostpel) -- node[above] { $d_2$} (ref_lft);
	%\path [arrow] (lostpel) -- node[left] { $d_3$} (ref_bottm);
	%\path [arrow] (lostpel) -- node[above] { $d_4$} (ref_rght);



	\node[anchor=west,scale=\scale] at (-1,10.1) (pixel_label) {Pixel};
	\node at (-1.6,8.35) (pel) {};
	\path [-latex,anchor=center] (pixel_label) edge (pel);

	\node[anchor=west,scale=\scale, text centered] at (1,-2.2) (inner_pixel_label) {Internal Boundary};
	\node at (4-0.4,0.6) (inner_pel) {};
	\path [-latex,anchor=center] (inner_pixel_label) edge (inner_pel);



	\node[anchor=west,scale=\scale, text centered] at (4.5,10.2) (outer_pixel_label) {External Boundary};
	\node at (6-0.5,8.4) (outer_pel) {};
	\path [-latex,anchor=center] (outer_pixel_label) edge (outer_pel);

	\node[anchor=west,scale=\scale, text centered] at (1.7,9.1) (ref_pixel_label) { \Large $f_{(x,y,t)}$ };
	\node at (1.4,7.4) (ref_pel) {};
	\path [-latex,anchor=center] (ref_pixel_label) edge (ref_pel);

	\node[anchor=center,scale=\scale, text centered] at (4,9) (ref_pixel_label) { \Large T };
	\node[anchor=center,scale=\scale, text centered] at (4,-1) (ref_pixel_label) { \Large B };
	\node[anchor=center,scale=\scale, text centered] at (-1,4) (ref_pixel_label) { \Large L };
	\node[anchor=center,scale=\scale, text centered] at (9,4) (ref_pixel_label) { \Large R };



	%\node[anchor=west,scale=\scale] at (5.8,6.0) (edge_label) {Contour};
	%\path [-latex] (edge_label.south) edge (7.15,5.2);

%\node at (6.5,-1.3) (edge_start) {};
%\node at (10.3,8.1) (edge_end) {};
 %\path [-,thick] (edge_start.north) edge[out=80, in=190] (edge_end.west);


\end{tikzpicture}