Hello, I have a bunch of photos of frogs' back skins, and I'd like to count how many blisters are on the frog's back, or what percentage of the skin shows changes. I'm working with agile frog, which has a unique pattern with dots and stripes on the back.

I found ImageJ's PatternJ tools and MosaicSuite for ImageJ, but none of them appear to be useful to me. Maybe heat-mapping with automated detection will work for me. Can anyone assist me and recommend some software? Every piece of advice will be useful to me. Thanks.