Measure length and width of an oval

[AscoGirl]

Greetings,

I'm measuring the length and width of a fungal spore in ImageJ and it is currently done as a (very time consuming) manual process.  The image is a microscope photo and the spore is an elongated oval. Is there a plugin that could be used to automate this process?

One issue I foresee is possibly needing to define the boundary of the spore - sometimes the photo is less clear and there is a halo effect around the spore (see attached image).

I'm quite new to ImageJ and not at all skilled with writing macros, so any help would be greatly appreciated.

Thanks,
Sara (AscoGirl)