LaTeX-examples/tikz/convolution-linear/convolution-linear.tex

\documentclass{standalone}
\usepackage{amssymb}
\usepackage{tikz}
\usetikzlibrary{calc}

\begin{document}
\newcommand{\filtersize}{3}
\newcommand{\filterx}{8}
\newcommand{\filtery}{2.2}
\newcommand{\filteroffset}{1}

\newcommand{\imagesize}{7}
\newcommand{\imagex}{0}
\newcommand{\imagey}{0}
\newcommand{\imageoffset}{2}

\newcommand{\outx}{13}
\newcommand{\outy}{0}
\newcommand{\outoffset}{2}

\newcommand{\percx}{1}
\newcommand{\percy}{2}
\begin{tikzpicture}
% ,circle,thick,draw=black,fill=black,minimum width=4pt,minimum height=4pt
    \tikzstyle{point}=[draw=none,inner sep=0pt]


    % draw perceptive field
    \node (p1)[point] at (\imagex+\percx,
                          \imagey+\percy+\percx*\imageoffset/\imagesize) {};
    \node (p2)[point] at (\imagex+\percx+\filtersize,
                          \imagey+\percy+\percx*\imageoffset/\imagesize+\filtersize*\imageoffset/\imagesize) {};
    \node (p3)[point,blue] at (\imagex+\percx+\filtersize,
                          \imagey+\percy+\filtersize+\percx*\imageoffset/\imagesize+\filtersize*\imageoffset/\imagesize) {};
    \node (p4)[point] at (\imagex+\percx,
                          \imagey+\percy+\filtersize+\percx*\imageoffset/\imagesize) {};
    \draw[fill=gray] (p1.center) -- (p2.center) -- (p3.center) -- (p4.center) -- (p1.center);

    % draw output point
    \node (o1)[point] at (\outx+\percx+1,
                          \outy+\percy+\percx*\outoffset/\imagesize+1+1*\outoffset/\imagesize) {};
    \node (o2)[point] at (\outx+\percx+2,
                          \outy+\percy+\percx*\outoffset/\imagesize+1*\outoffset/\imagesize+1+1*\outoffset/\imagesize) {};
    \node (o3)[point,blue] at (\outx+\percx+2,
                          \outy+\percy+1+\percx*\outoffset/\imagesize+1*\outoffset/\imagesize+1+1*\outoffset/\imagesize) {};
    \node (o4)[point] at (\outx+\percx+1,
                          \outy+\percy+2+\percx*\outoffset/\imagesize+1*\outoffset/\imagesize) {};
    \draw[fill=black] (o1.center) -- (o2.center) -- (o3.center) -- (o4.center) -- (o1.center);

    % draw image
    \foreach \x in {0,...,\imagesize}
    {
    \draw (\imagex+\x, \imagey+\x*\imageoffset/\imagesize) -- (\imagex+\x, \imagey+\imagesize+\x*\imageoffset/\imagesize);
    \draw (\imagex, \imagey+\x) -- (\imagex+\imagesize, \imagey+\x+\imageoffset);
    }

    % draw filter
    \foreach \x in {0,...,\filtersize}
    {
    \draw (\filterx+\x, \filtery+\x*\filteroffset/\filtersize) -- (\filterx+\x, \filtery+\filtersize+\x*\filteroffset/\filtersize);
    \draw (\filterx, \filtery+\x) -- (\filterx+\filtersize, \filtery+\x+\filteroffset);
    }

    % draw out
    \foreach \x in {0,...,\imagesize}
    {
    \draw (\outx+\x, \outy+\x*\outoffset/\imagesize) -- (\outx+\x, \outy+\imagesize+\x*\outoffset/\imagesize);
    \draw (\outx, \outy+\x) -- (\outx+\imagesize, \outy+\x+\outoffset);
    }

    \node at (\imagex + \imagesize/2,\imagey + \imagesize + 2) {$I \in \mathbb{R}^{\imagesize \times \imagesize}$};
    \node at (\filterx + \filtersize/2,\filtery + \filtersize + 2) {$F \in \mathbb{R}^{\filtersize \times \filtersize}$};
    \node at (\outx + \imagesize/2,\outy + \imagesize + 2) {$I' \in \mathbb{R}^{\imagesize \times \imagesize}$};
    \node[draw,circle] (sumsymb) at (\filterx + \filtersize+1,\filtery + \filtersize/2 + \filteroffset-0.5) {$\sum$};

    \draw[dashed] (1.5, 2.9) -- (10.5, 2.9) -- (sumsymb.center);
    \draw[dashed] (1.5, 2.9+\filtersize-1) -- (10.5, 2.9+\filtersize-1) -- (sumsymb.center);
    \draw[dashed] (1.5+\filtersize-1, 2.9+\filtersize-1+2*\filteroffset/3) -- (10.5+\filtersize-1, 2.9+\filtersize-1+2*\filteroffset/3) -- (sumsymb.center);
    \draw[dashed] (1.5+\filtersize-1, 2.9+2*\filteroffset/3) -- (10.5+\filtersize-1, 2.9+2*\filteroffset/3) -- (sumsymb.center);
    \draw[dashed] (sumsymb.center) -- (15, 4);

    \node[draw,circle,fill=white] at (5.5, 2.9) {$+$};
    \node[draw,circle,fill=white] at (5.5+\filtersize-1, 2.9+2*\filteroffset/3) {$+$};
    \node[draw,circle,fill=white] at (5.5+\filtersize-1, 2.9+2*\filteroffset/3+\filtersize-1) {$+$};
    \node[draw,circle,fill=white] at (5.5, 2.9+\filtersize-1) {$+$};
    \node[draw,circle,fill=white] at (sumsymb.center) {$\sum$};
\end{tikzpicture}
\end{document}