Tikz, absolute image position, and text wrapping
Like this:
\documentclass[a4paper,10pt]{article}
\usepackage[T1]{fontenc}
\usepackage{lipsum}
\usepackage[margin=15pt]{geometry}
\usepackage{graphicx}
\usepackage{tikz}
\usepackage{wrapfig}
\begin{document}
%Image A:
\begin{tikzpicture}[remember picture,overlay]
\node[anchor=north west, inner sep=0pt] at (current page.north west)
{\includegraphics[width=21cm,height=12.6cm]{example-image-a}};
\end{tikzpicture}
\vspace{12.6cm}
\section{Title}
%Image B:
\begin{wrapfigure}{r}{0.43\textwidth}
\vspace{-\baselineskip}
\begin{tikzpicture}
\node {\includegraphics[width=\linewidth,height=12.6cm]{example-image-b}};
\end{tikzpicture}
\end{wrapfigure}
\lipsum[1-4]
\end{document}