Spread Image Pages in Chapter Opener

Chapter Opener Image is full page image. I have need to mask half page image and frond-end would like to put some text. I'm expecting the output (see screenshot). How do achieve this in LaTeX/XeLaTeX. I had searched and found only figure caption Unusual graphics and caption placement.

1. 
   

   1Half-Page Image is BackEnd.

   
   

   a) Put the Chapter Number and Chapter Title in Front End of the Half-Page Image.

   
   


2. 
   

   After Half-Page Image, Yellow Color box is back-end.

   
   


3. 
   

   2Half-Page Image is BackEnd.

   
   

   a) list text put in front of the second-half page in front-end text.

   
   

My MWE is:

\documentclass[11pt,twoside,openany,svgnames,x11names]{book}
\usepackage{wallpaper}
\usepackage{changepage}
\usepackage[explicit]{titlesec}
\usepackage{fancyhdr}
\usepackage{tikz}
\usetikzlibrary{shapes,positioning}
\usepackage{lipsum}
\usepackage{geometry}
\geometry{
   paperwidth=216mm, paperheight=303mm,
   left=23mm,
   right=18mm,
   top=23mm, bottom=23mm,
   headheight=\baselineskip,
   headsep=7mm,
   footskip=10mm
}
\definecolor{chapopcolor}{cmyk}{.18,0,1,0}

\newcommand\chapterillustration{}

\titleformat{\chapter}{}{}{0pt}{
\ThisULCornerWallPaper{1}{\chapterillustration}
\tikz[overlay,remember picture]
  \fill[chapopcolor,opacity=1]
  (current page.north west) rectangle 
  ([yshift=-3cm] current page.north east);
  \strictpagecheck\checkoddpage
  \ifoddpage{
    \begin{tikzpicture}[overlay,remember picture]
    \node[anchor=south west,
      xshift=20mm,yshift=-30mm,
      font=\sffamily\bfseries\huge] 
      at (current page.north west) 
      {\fontsize{16}{18}\selectfont\textcolor{white}{\chaptername}\     \thechapter};
    \node[text=blue,
      font=\fontsize{32}{34}\selectfont, 
      inner ysep=12pt, inner xsep=20pt,
      rounded rectangle,anchor=east, 
      xshift=-20mm,yshift=-30mm] 
      at (current page.north east) {#1};
    \end{tikzpicture}
  }
  \else {
    \ThisLLCornerWallPaper{.35}{fern_mo_01}
    \begin{tikzpicture}[overlay,remember picture]
    \node[anchor=south east,
      xshift=-20mm,yshift=-30mm,
      font=\sffamily\bfseries\huge] 
      at (current page.north east)
      {\chaptername\ \thechapter};
    \node[fill=Sienna!80!black,text=white,
      font=\Huge\bfseries,
      inner sep=12pt, inner xsep=20pt,
      rounded rectangle,anchor=west,
      xshift=20mm,yshift=-30mm] 
      at ( current page.north west) {#1};
    \end{tikzpicture}
  }
  \fi
}
\titlespacing*{\chapter}{0pt}{0pt}{135mm}





\begin{document}
\pagestyle{headings}

\renewcommand\chapterillustration{six-computers-chips-circuits}

\chapter{Chapter TeXt Here}

\section*{What you will learn}
\section*{Asian curriculum}

\begin{itemize}
\item[1A] Number Systems
\item[1B] Place value
\item[1C] Addition and subtraction
\item[1D] Addition and subtraction
\item[1E] Multiplication
\item[1F] Multiplying larger numbers
\item[1G] Division
\item[1I] Estimating and rounding Order of operations
\end{itemize}

\section*{Statistics and Probability}

\begin{itemize}
\item Data measures Determine mean, median, and range
and use these measures to compare
data sets explaining reasoning
\item Data investigation
Investigate questions involving the
collection of univariate and simple
bivariate data
\item Sample space
Construct sample spaces for single-
step experiments
\item Relative frequency
Calculate relative frequencies, and recognise variation between results
\end{itemize}

\end{document}