pip install pandoc-shortcaption

python setup.py install

![This is a long image caption](img.png "Image Short Caption")

pandoc -f markdown -t latex --filter pandoc-shortcaption test.md

![long caption again](img.png "short caption"){#fig:myfig2}

Here is a reference to @fig:myfig2.

![long caption again](img.png "short caption"){#fig:myfig2 width=60%}

pandoc -f markdown -t latex --filter pandoc-shortcaption --filter pandoc-crossref test.md