pca3.tex

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{positioning}

\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[scale=.9,every node/.style={minimum size=1cm},on grid]
	
    \begin{scope}[
            yshift=-40,every node/.append style={
            yslant=0.5,xslant=-1},yslant=0.5,xslant=-1
            ]
        \fill[white,fill opacity=0.7] (0,0) rectangle (5,5);
        \draw[step=5mm, blue] (0,0) grid (5,5); 
        \draw[blue,very thick] (0,0) rectangle (5,5);
        \fill[blue] (0,5) rectangle (0.5,4.5);
    \end{scope}
    	
    \begin{scope}[
    	yshift=0,every node/.append style={
    	    yslant=0.5,xslant=-1},yslant=0.5,xslant=-1
    	             ]
        \fill[white,fill opacity=.7] (0,0) rectangle (5,5);
        \draw[green,very thick] (0,0) rectangle (5,5);
        \draw[step=5mm, green] (0,0) grid (5,5);
        \fill[green] (0,5) rectangle (0.5,4.5);
    \end{scope}
    	
    \begin{scope}[
    	yshift=40,every node/.append style={
    	    yslant=0.5,xslant=-1},yslant=0.5,xslant=-1
    	             ]
        \fill[white,fill opacity=.7] (0,0) rectangle (5,5);
        \draw[red,very thick] (0,0) rectangle (5,5);
        \draw[step=5mm, red] (0,0) grid (5,5);
        \fill[red] (0,5) rectangle (0.5,4.5);
    \end{scope}
    	
    % arrows and labels:
    \draw[-latex,thick] (6.2,3.4) node[right]{Red channel}
         to[out=180,in=90] (4,3.4);	
         
    \draw[-latex,thick] (6.2,2) node[right]{Green channel}
         to[out=180,in=90] (4,2);
         
    \draw[-latex,thick] (6.2,0.6) node[right]{Blue channel}
         to[out=180,in=90] (4,0.6);
        
    \draw[-latex,thick] (-6.2,3.4) node[left]{1st Pixel}
         to[out=0,in=90] (-4.5,3.8);
          
    \draw[-latex] (0,-2) -- (4.5,0.28) node at (2.5, -1.5) {$x$};
    \draw[-latex] (0,-2) -- (-4.5,0.28) node at (-2.5, -1.5) {$y$};
    \draw[-latex] (0,-2) -- (0,2) node[above] {$\lambda$};
    
        
\end{tikzpicture}
\end{document}