How to put a figure on the facing page of a chapter page with correct numbering?

Question

What's the best way to place a page-sized figure including the correct caption numbering on the facing page of a chapter opening page?

Correct numbering means: if I put the figure before the chapter, the numbering of the previous chapter is continued and the list of figures shows it belonging to the previous chapter. But I want to have it labeled 6.1 if the new chapter will be chapter 6.

Now I was thinking: Is there a way to use a caption(command) that will only be defined later? Is there a package that does something like this already?

In essence, something like this:

\cleartoevenpage{\thispagestyle{empty}}
\begin{figure}[p]
    \begin{sidecaption}{\theCaption}  % TODO: how?
        \includegraphics{image.jpg}
    \end{sidecaption}
\end{figure}

\chapter{Chapter Title}

\defineTheCaption

Or, if that is not possible, how can I manually label the figure as if belonging to the next chapter, with the correct entry in the lof file?

PS: I am using memoir. The kind of opposite thing seems possible with \newfixedcaption: it allows to place a caption on a page preceding a figure.

Answer 1

You can (and should) define a command doing the work, rather than explicitly set all those commands for each chapter.

My idea is to define a \chapterfigure command that has one optional argument and two mandatory ones; the optional argument and the first mandatory one are used for \includegraphics, while the final argument contains the caption.

The command steps the chapter counter, so the number for the figure will be correct; after the figure the counter is stepped back, so when \chapter is processed, the chapter number will be right; then we patch \memendofchapterhook so that it steps the figure counter (that would have been reset to zero by \chapter) and redefines itself to its previous value (usually nothing, but one never knows). Similarly, we issue \insertchapterspace, then redefine it to simply redefine itself to its previous value, so when the command is called by \chapter it does nothing else than putting us back to the original situation.

For a chapter without a facing figure, just issue \chapter by itself. A label for \chapterfigure should be in a trailing optional argument, to reflect the syntax of sidecaption; so

\chapterfigure[<options for includegraphics>] % optional
              {<graphic file name>}           % mandatory
              {<caption>}                     % mandatory
              [<label>]                       % optional

Here's a complete example

\documentclass{memoir}
\usepackage{xparse}
\usepackage[demo]{graphicx}

\NewDocumentCommand{\chapterfigure}{O{} m m o}{%
  \insertchapterspace
  \cleartoevenpage{\thispagestyle{empty}}
  \stepcounter{chapter}
  \begin{figure}[p]
  \IfNoValueTF{#4}
    {\begin{sidecaption}{#3}}
    {\begin{sidecaption}{#3}[#4]}
  \includegraphics[#1]{#2}
  \end{sidecaption}
  \end{figure}
  \addtocounter{chapter}{-1}
  \let\keptmemendofchapterhook\memendofchapterhook
  \renewcommand{\memendofchapterhook}{%
    \stepcounter{figure}%
    \keptmemendofchapterhook
    \let\memendofchapterhook\keptmemendofchapterhook}%
  \let\keptinsertchapterspace\insertchapterspace
  \renewcommand\insertchapterspace{%
    \let\insertchapterspace\keptinsertchapterspace}%
}

\begin{document}
\frontmatter
\tableofcontents
\listoffigures

\mainmatter

\chapterfigure[width=5cm,height=3cm]{somepic}
  {A caption for this figure}
% Here's how to call it if there's a label
%\chapterfigure[width=5cm,height=3cm]{somepic}
%  {A caption for this figure}[chapfig:one]

\chapter{A title for this chapter}

Some text

\begin{figure}[htp]
\centering
\includegraphics{xyz}
\caption{A caption to see it has the correct number}
\end{figure}

Some text

\end{document}

Answer 2

Here is a simple approach that I used (thanks to some hints here) to putting a landscape figure opposite a Chapter page, and numbering it as the first figure in that chapter:

% For viewing in Adobe Reader, don’t forget to set View> Page Display > Show Cover Page in Two-Page View 
\documentclass[draft,12pt,letterpaper,dvipsnames,svgnames,table,openright,twoside]{book} 
\usepackage{pdflscape} % Has landscape environment
\usepackage{graphicx}
\graphicspath{{./images/}}
\usepackage{caption}
\usepackage{lettrine}
\usepackage{calligra} 
\usepackage[nopar]{lipsum}

%
\begin{document} 
\renewcommand{\LettrineFontHook}{\calligra}
% PREFACE
\chapter*{Preface}
\lipsum[2-4]

% CHAPT 1
% \section[shortish TOC entry]{formatted chapter title} \sectionmark{short title for running headers}
\chapter{Dummy Chapter}
\lipsum[2-4]
%

% CHAPT 2
\makeatletter\@openrightfalse  %%%%
\newpage
\cleardoublepage\part[~STONE AGE]{STONE AGE}
%
% The following page is rotated 90-degrees clockwise in the pdf. 
% In the book it appears on the LHS, opposite the section “Chapter 16”
\stepcounter{chapter} 
\begin{landscape}
   \begin{figure}
      \captionsetup{width=1.20\textwidth}
      %\vspace{12pt} % To move picture further away from binding (odd page)
      \vspace{-36pt} % To move picture further away from binding (even page)
      \centering
      \includegraphics[width=6in]{US_Frequency_Allocations_Jan_2016_a.png}
      \caption[U.S. Electromagnetic Spectrum Frequency Allocations, October 2003]{U.S. Electromagnetic Spectrum usage from DC to 300 GHz}
      \scriptsize{\emph{Photo Credit: U.S. Government, Department of Commerce}}
      \label{figure:FCC_EM_Radio_Spectrum}
   \end{figure}
\end{landscape}
\addtocounter{chapter}{-1}
\newpage
% \section[shortish TOC entry]{formatted chapter title} \sectionmark{short title for running headers}
\chapter{2001: Welcome to Space \& Beyond!}
\label{section:DC2Daylight}
\@openrighttrue\makeatother 
% Body Text:
\lettrine[lines=3,lhang=0.33,lraise=0.0,loversize=0.30,slope=-16pt,findent=2.3em,nindent=-0.4em]{U}{\textbf{nknown Origins}} \lipsum[1-5] 
%
\end{document}
\endinput