Just signed up to ask about this: I select my ROI in ImageJ and measure and I get a number for the area (say 114611.775). I then adjust the threshold to cover only the particles I’m interested in measuring, measure again and I get a different number for the area (say 91748.572). Shouldn’t the area stay the same as it’s the same ROI? IntDensity and GreyScale will change, but I don’t understand why the area changes.
Edit: On a different but related note: I am thinking of moving from ImageJ to photoshop for my analysis and doing some test images I noticed that the area doesn’t change when I make the measurements photoshop.