Pandoc image sizing when converting from Jupyter notebook to LaTeX

I am attempting to use pandoc to convert a Jupyter Notebook into a readable pdf. I have read the pandoc manual section regarding images. Unfortunately the ipynb to pdf does not appear to be working as expected.

pandoc --version

gives

pandoc 2.12
Compiled with pandoc-types 1.22, texmath 0.12.1.1, skylighting 0.10.4,
citeproc 0.3.0.8, ipynb 0.1.0.1

Here is an image, where I would like to specify the width

{ width=1cm }

![Image Caption](test_image.png){ width=1cm }

Running:

pandoc -s -o README.tex README.md
xelatex README.tex

gives:

\begin{figure}
\centering
\includegraphics[width=1cm,height=\textheight]{test_image.png}
\caption{Image Caption}
\end{figure}

And, if I put

![Image Caption](test_image.png){ width=1cm }

in a markdown cell in a notebook, and run

pandoc --from ipynb+link_attributes -s -o Pandoc_problems.tex Pandoc_problems.ipynb
xelatex Pandoc_problems.tex

I get:

\includegraphics[width=1cm,height=\textheight]{test_image.png}