Setting the alt text for code figure outputs in markdown output

I was wondering if anyone could help me. Is there a way to set the alt text for code cell figures when exporting a notebook as markdown? Whenever I try to export a notebook, the code cell figures are exported as:

![png](Testing_files/Testing_5_0.png)

Is there a way to get alt text description to say something other than png? So it would look like

![My interesting figure caption](Testing_files/Testing_5_0.png)

Further, in an idea world I would like to append a reference tag like {#fig:figRef} to the end of the figure line, e.g.

![My interesting figure caption](Testing_files/Testing_5_0.png){#fig:figRef}

All of the above is to support processing the output markdown file through pandoc, using pandoc-crossref, to get nicely referenced technical document.