Float page always *before* reference and without page break

Question

I'm trying to create a layout where images are *always without exception* displayed before their reference, and on a page by themselves without any text above or below the image. I've tried a number of different approaches, but have not been successful.

The text needs to "flow" around the images on the alternate side, so using \FloatBarrier to force a new page is not an option.

The example below is as close as I've been able to get, but I (a) want to get rid of the text underneath the image on page 1, (b) want to move the leftover text on page 4 to page 5 (leaving the image on a page by itself).

The section that references the image will not always be at the top of the page - because of how I'd like to lay this out, there may be some leftover bits of the previous section(s) that have flowed over. An alternate way of thinking of this would be that the image is inserted as an entire page on the page before the reference would appear, pushing the contents of the book one page out.

\documentclass[]{book}
\usepackage{lipsum}
\usepackage[pagestyles]{titlesec}
\usepackage{float}
\usepackage{placeins}
\usepackage[demo]{graphicx}

\renewcommand{\thesection}{\arabic{section}}

\begin{document}

\begin{figure}[H]
  \includegraphics[width=\textwidth,height=0.8\textheight]{dummy}
\end{figure} % must appear before the section on a line below (1)
\section{}
\lipsum[1-2]
\section{}
\lipsum[1]
\section{}
\lipsum[1-6]
\begin{figure}[H]
  \includegraphics[width=\textwidth,height=0.8\textheight]{dummy}
\end{figure} % must appear before the section on the line below (4)
\section{}
\lipsum[1-2]

\end{document}

Answer 1

p figures will not drift into the document and will always be placed at the next page break if they are larger than \floatpagefraction

\documentclass[]{book}
\usepackage{lipsum}
\usepackage[pagestyles]{titlesec}
\usepackage{float}
\usepackage{placeins}
\usepackage[demo]{graphicx}

\renewcommand{\thesection}{\arabic{section}}
\renewcommand\floatpagefraction{.1}
\begin{document}

\begin{figure}[p]
  \includegraphics[width=\textwidth,height=0.8\textheight]{dummy}
\end{figure} % must appear before the section on a line below (1)
\clearpage
\section{}
\lipsum[1-2]
\section{}
\lipsum[1]
\section{}

\lipsum[1-4]
\begin{figure}[p]
  \includegraphics[width=\textwidth,height=0.8\textheight]{dummy}
\end{figure} % must appear before the section on the line below (4)
\lipsum[5-6]
\section{}
\lipsum[1-2]

\end{document}