ImageJ or Fiji for fibre length of bright field images

Hi! I am trying to conduct fibre length analysis on various regions of the hippocampus on images stained for dopamine-beta-hydroxylase to look and NE fibres. My images were taken in brightfield, so I am having trouble finds resources that aren’t for fluorescent images. I’ve tried both Fiji and ImageJ, along with a number of different plug-ins and I can’t seem to figure out how to do this analysis. Attached is an image of what I am trying to analyze. I am not trying to analyze the whole section, but rather a section to determine the length. DiameterJ seemed to be the most promising because it left me to convert to pixels/micron, but when I click “ok” I either get no output or an error in the code. Does anyone have any idea about whether I should be using ImageJ or Fiji and what plug-in? Also, detailed instructions would be great. Thanks!

Hi Maw222, Welcome.
Your attachment didn’t make it here…