\documentclass{article}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{spy,calc}
\usepackage{hyperref}
\newif\ifblackandwhitecycle
\gdef\patternnumber{0}
\pgfkeys{/tikz/.cd,
zoombox paths/.style={
draw=orange,
very thick
},
black and white/.is choice,
black and white/.default=static,
black and white/static/.style={
draw=white,
zoombox paths/.append style={
draw=white,
postaction={
draw=black,
loosely dashed
}
}
},
black and white/static/.code={
\gdef\patternnumber{1}
},
black and white/cycle/.code={
\blackandwhitecycletrue
\gdef\patternnumber{1}
},
black and white pattern/.is choice,
black and white pattern/0/.style={},
black and white pattern/1/.style={
draw=white,
postaction={
draw=black,
dash pattern=on 2pt off 2pt
}
},
black and white pattern/2/.style={
draw=white,
postaction={
draw=black,
dash pattern=on 4pt off 4pt
}
},
black and white pattern/3/.style={
draw=white,
postaction={
draw=black,
dash pattern=on 4pt off 4pt on 1pt off 4pt
}
},
black and white pattern/4/.style={
draw=white,
postaction={
draw=black,
dash pattern=on 4pt off 2pt on 2 pt off 2pt on 2 pt off 2pt
}
},
zoomboxarray inner gap/.initial=5pt,
zoomboxarray columns/.initial=2,
zoomboxarray rows/.initial=2,
subfigurename/.initial={},
figurename/.initial={zoombox},
zoomboxarray/.style={
execute at begin picture={
\begin{scope}[
spy using outlines={%
zoombox paths,
width=\imagewidth / \pgfkeysvalueof{/tikz/zoomboxarray columns} - (\pgfkeysvalueof{/tikz/zoomboxarray columns} - 1) / \pgfkeysvalueof{/tikz/zoomboxarray columns} * \pgfkeysvalueof{/tikz/zoomboxarray inner gap} -\pgflinewidth,
height=\imageheight / \pgfkeysvalueof{/tikz/zoomboxarray rows} - (\pgfkeysvalueof{/tikz/zoomboxarray rows} - 1) / \pgfkeysvalueof{/tikz/zoomboxarray rows} * \pgfkeysvalueof{/tikz/zoomboxarray inner gap}-\pgflinewidth,
magnification=3,
every spy on node/.style={
zoombox paths
},
every spy in node/.style={
zoombox paths
}
}
]
},
execute at end picture={
\end{scope}
\node at (image.north) [anchor=north,inner sep=0pt] {\subcaptionbox{\label{\pgfkeysvalueof{/tikz/figurename}-image}}{\phantomimage}};
\node at (zoomboxes container.north) [anchor=north,inner sep=0pt] {\subcaptionbox{\label{\pgfkeysvalueof{/tikz/figurename}-zoom}}{\phantomimage}};
\gdef\patternnumber{0}
},
spymargin/.initial=0.5em,
zoomboxes xshift/.initial=1,
zoomboxes right/.code=\pgfkeys{/tikz/zoomboxes xshift=1},
zoomboxes left/.code=\pgfkeys{/tikz/zoomboxes xshift=-1},
zoomboxes yshift/.initial=0,
zoomboxes above/.code={
\pgfkeys{/tikz/zoomboxes yshift=1},
\pgfkeys{/tikz/zoomboxes xshift=0}
},
zoomboxes below/.code={
\pgfkeys{/tikz/zoomboxes yshift=-1},
\pgfkeys{/tikz/zoomboxes xshift=0}
},
caption margin/.initial=4ex,
},
adjust caption spacing/.code={},
image container/.style={
inner sep=0pt,
at=(image.north),
anchor=north,
adjust caption spacing
},
zoomboxes container/.style={
inner sep=0pt,
at=(image.north),
anchor=north,
name=zoomboxes container,
xshift=\pgfkeysvalueof{/tikz/zoomboxes xshift}*(\imagewidth+\pgfkeysvalueof{/tikz/spymargin}),
yshift=\pgfkeysvalueof{/tikz/zoomboxes yshift}*(\imageheight+\pgfkeysvalueof{/tikz/spymargin}+\pgfkeysvalueof{/tikz/caption margin}),
adjust caption spacing
},
calculate dimensions/.code={
\pgfpointdiff{\pgfpointanchor{image}{south west} }{\pgfpointanchor{image}{north east} }
\pgfgetlastxy{\imagewidth}{\imageheight}
\global\let\imagewidth=\imagewidth
\global\let\imageheight=\imageheight
\gdef\columncount{1}
\gdef\rowcount{1}
\gdef\zoomboxcount{1}
},
image node/.style={
inner sep=0pt,
name=image,
anchor=south west,
append after command={
[calculate dimensions]
node [image container,subfigurename=\pgfkeysvalueof{/tikz/figurename}-image] {\phantomimage}
node [zoomboxes container,subfigurename=\pgfkeysvalueof{/tikz/figurename}-zoom] {\phantomimage}
}
},
color code/.style={
zoombox paths/.append style={draw=#1}
},
connect zoomboxes/.style={
spy connection path={\draw[draw=none,zoombox paths] (tikzspyonnode) -- (tikzspyinnode);}
},
help grid code/.code={
\begin{scope}[
x={(image.south east)},
y={(image.north west)},
font=\footnotesize,
help lines,
overlay
]
\foreach \x in {0,1,...,9} {
\draw(\x/10,0) -- (\x/10,1);
\node [anchor=north] at (\x/10,0) {0.\x};
}
\foreach \y in {0,1,...,9} {
\draw(0,\y/10) -- (1,\y/10); \node [anchor=east] at (0,\y/10) {0.\y};
}
\end{scope}
},
help grid/.style={
append after command={
[help grid code]
}
},
}
\newcommand\phantomimage{%
\phantom{%
\rule{\imagewidth}{\imageheight}%
}%
}
\newcommand\zoombox[2][]{
\begin{scope}[zoombox paths]
\pgfmathsetmacro\xpos{
(\columncount-1)*(\imagewidth / \pgfkeysvalueof{/tikz/zoomboxarray columns} + \pgfkeysvalueof{/tikz/zoomboxarray inner gap} / \pgfkeysvalueof{/tikz/zoomboxarray columns} ) + \pgflinewidth
}
\pgfmathsetmacro\ypos{
(\rowcount-1)*( \imageheight / \pgfkeysvalueof{/tikz/zoomboxarray rows} + \pgfkeysvalueof{/tikz/zoomboxarray inner gap} / \pgfkeysvalueof{/tikz/zoomboxarray rows} ) + 0.5*\pgflinewidth
}
\edef\dospy{\noexpand\spy [
#1,
zoombox paths/.append style={
black and white pattern=\patternnumber
},
every spy on node/.append style={#1},
x=\imagewidth,
y=\imageheight
] on (#2) in node [anchor=north west] at ($(zoomboxes container.north west)+(\xpos pt,-\ypos pt)$);}
\dospy
\pgfmathtruncatemacro\pgfmathresult{ifthenelse(\columncount==\pgfkeysvalueof{/tikz/zoomboxarray columns},\rowcount+1,\rowcount)}
\global\let\rowcount=\pgfmathresult
\pgfmathtruncatemacro\pgfmathresult{ifthenelse(\columncount==\pgfkeysvalueof{/tikz/zoomboxarray columns},1,\columncount+1)}
\global\let\columncount=\pgfmathresult
\ifblackandwhitecycle
\pgfmathtruncatemacro{\newpatternnumber}{\patternnumber+1}
\global\edef\patternnumber{\newpatternnumber}
\fi
\end{scope}
}
\begin{document}
\begin{figure}[ht]\centering
\begin{tikzpicture}[
zoomboxarray,black and white=cycle,
]
\node [image node] { \includegraphics[width=0.45\textwidth]{gallery} };
\zoombox{0.27,0.9}
\zoombox[color code=red,magnification=6]{0.4,0.83}
\zoombox{0.42,0.45}
\zoombox[magnification=5]{0.95,0.52}
\end{tikzpicture}
\caption{The National Gallery of Canada}
\end{figure}
\begin{figure}[ht]\centering
\begin{tikzpicture}[
zoomboxarray
]
\node [image node] { \includegraphics[width=0.45\textwidth]{gallery} };
\zoombox{0.27,0.9}
\zoombox[color code=red,magnification=6]{0.4,0.83}
\zoombox{0.42,0.45}
\zoombox[magnification=5]{0.95,0.52}
\end{tikzpicture}
\caption{The National Gallery of Canada}
\end{figure}
\end{document}
Here’s an example of using the spy library. I’ve written a couple of styles that can be used to create an array of magnficiations, with an arbitrary number of rows and columns, placed on any side of the original image, with specifiable gaps. The magnifications will take up the same space as the original image.
The image itself and the magnifications are subcaptionboxes, which requires the subcaption package. They are assigned labels of the form <figurename>-image and <figurename>-zoom, and can be referenced using \ref and \subref. If no figurename is supplied as an option to the tikzpicture, a default name of zoombox will be assumed.
The center points of the magnifications are specified in relative coordinates: \zoombox{0,0} would zoom in on the lower left corner, \zoombox{1,1} on the upper right.
You can specify the zoom factor for the individual zoomboxes using the optional argument: \zoombox[magnification=5]{0.5,0.5} would zoom in on the middle of the image, magnifiying 5x.
Boxes and magnifications can be drawn with a coloured frame using the optional argument [color code=<color>].
To display a grid over the original image to aid in placing the zoom points, use the option help grid in the image node.
Instead of using colors, black and white dash patterns can be used with the option black and white. This overrides color code options. To automatically use a different dash pattern for every box, use black and white=cycle.