I am looking to count tire rubber particles in jpeg images. I have FTIR images of the same scene (different image registration) and will want to analyze those with ImageJ later, also, and then compare the results (not just as comparison, but also as a kind of quality check). Alright, let’s talk about those jpegs. I made a clipping for illustration.
This image is of a filter with filter cake containing “stuff” and tire rubber, which is black or recognizable as black to a human eye in context.
All these blackish dots down to a few pixels are the particles I would like to count and know their particle size distribution and overall area. If I could get them all into a multi-selection in ImageJ, by now, I have figured out that I can just hit
m and the magic happens. Unfortunately, I don’t know how to get to that multi-selection I so long for.
In GIMP (I first tried in ImageJ, but alas with little success), I tried adjusting the curves to really emphasize the black and gray particles, like so:
and this gave me the following
The problem with this is that small particles don’t turn black, since, to a computer, they are not nearly black enough. The other problem is visible in the right part of the image, where a big blob is now black that should not be black at all. Unfortunately, it is so dark that it is caught by the curve manipulation. I told myself I need a function that will tell the machine vision to look for context, but I have no clue how to do this. I was setting my hopes on “Subtract Background…”
What I tried in ImageJ with the following TIF
run("Set Scale...", "distance=111 known=1 pixel=1 unit=mm global"); //run("Brightness/Contrast..."); run("Enhance Contrast", "saturated=0.35"); setMinAndMax(25, 230); run("Subtract Background...", "rolling=50 light");
but then I don’t know how to proceed. I tried color threshold, decomposing the image to R, G, and B channels and working on those individually, but I am loosing myself in functions over functions at it all just gets very complicated, inefficient and distorted.
Them daaamn particles, I see them, they’re right there, but how do I count them?