Placing subfig vertically
Your problem is different, as you don't have to measure anything.
In order to align the two parts at the top, you can use \raisebox{-\height}{...}
.
\documentclass{article}
\usepackage{graphicx,subfig}
\begin{document}
\begin{figure}[tbp]
\centering
\raisebox{-\height}{%
\subfloat[Image 1]{%
\includegraphics[height=5cm]{example-image-9x16}%
\label{image1}%
}%
}\qquad
\raisebox{-\height}{%
\begin{tabular}{@{}c@{}}
\subfloat[Image 2]{%
\includegraphics[width=0.4\textwidth]{example-image}%
\label{image2}%
} \\
\subfloat[Image 3]{%
\includegraphics[width=0.4\textwidth]{example-image}%
\label{image3}%
}
\end{tabular}%
}
\caption{Figure}
\label{figure}
\end{figure}
\end{document}
If you want to vertically center the left image:
\documentclass{article}
\usepackage{graphicx,subfig}
\begin{document}
\begin{figure}[tbp]
\centering
\begin{tabular}{@{}c@{}}
\subfloat[Image 1]{%
\includegraphics[height=5cm]{example-image-9x16}%
\label{image1}%
}%
\end{tabular}\qquad
\begin{tabular}{@{}c@{}}
\subfloat[Image 2]{%
\includegraphics[width=0.4\textwidth]{example-image}%
\label{image2}%
} \\
\subfloat[Image 3]{%
\includegraphics[width=0.4\textwidth]{example-image}%
\label{image3}%
}
\end{tabular}
\caption{Figure}
\label{figure}
\end{figure}
\end{document}
see if the following example can help you:
\documentclass{article}
\usepackage{multirow,tabularx}
\usepackage[export, demo]{adjustbox}
\usepackage{subfig}
\newsavebox\bigleftbox
\begin{document}
\begin{figure}[tb]
\centering
\begin{tabularx}{\linewidth}{XX}
\multirow[t]{2}{=}{\subfloat[Image 1 \label{image1}]%
{\includegraphics[height=5cm, valign=t]{images1}}%
}
& \subfloat[Image 2 \label{image2}]%
{\includegraphics[height=\dimexpr2.5 cm-\baselineskip, valign=t]{images1}} \\
& \subfloat[Image 3 \label{image3}]%
{\includegraphics[height=\dimexpr2.5 cm-\baselineskip, valign=b]{images1}} \\
\end{tabularx}
\caption{Figure}
\label{figure}
Here is a variant using minipages:
\documentclass{article}
\usepackage{graphicx,subfig}
\begin{document}
\begin{figure}
\centering
\begin{minipage}[c]{0.3\textwidth}
\subfloat[Image 1]{%
\includegraphics[height=5cm]{example-image-9x16}%
\label{image1}%
}
\end{minipage}
\begin{minipage}[c]{0.4\textwidth}
\subfloat[Image 2]{%
\includegraphics[width=\textwidth]{example-image}%
\label{image2}%
}
\subfloat[Image 3]{%
\includegraphics[width=\textwidth]{example-image}%
\label{image3}%
}
\end{minipage}
\caption{Figure}
\label{figure}
\end{figure}
\end{document}