Counting dots/circles in an image

Question

I'm testing to see if I can count/draw circles around dots I drew on a piece of paper, this research is for my thesis as I want to count the amount of pinholes in a composite laminate. I tried several methods that were already given in several forums.

The code I use is:

img = Import["https://i.imgur.com/Wu7pSBY.jpg"];
i = GaussianFilter[FillingTransform[img], 15];
b = Binarize[i];
d = DistanceTransform[b, Padding -> 0];
m = MaxDetect[ImageAdjust[d, 0.2]];
w = WatershedComponents[GradientFilter[b, 3], m, Method -> "Rainfall"];
s = SelectComponents[w, "Count", 20 < # < 10000 &];
ms = ComponentMeasurements[
   s, {"Centroid", "EquivalentDiskRadius", "Label"}];
Show[seimg, 
 Graphics[{Blue, Circle @@ # & /@ (ms[[All, 2, 1 ;; 2]]), 
   MapThread[Text, {ms[[All, 2, 3]], ms[[All, 2, 1]]}]}]]

I have zero to none idea what this all does, but the results are this (click for full size):

The only thing I want it to do is draw circles around the dots and count them. Can anyone help out?

All you need is Binarize, ColorNegatve and ComponentMeasurements to find the centroids. Please read up on these. Using code you don't understand is not a good idea. — Szabolcs, Mar 16 '21 at 13:40
Possible duplicate of Count Elements in Image and Count flowers in an image (which is a duplicate of the first one) — Sumit, Mar 16 '21 at 14:06
Try studying each line of the code by remove the semi-colons one at a time on each. Just look at the first two, remove semi-colon on the GaussianFilter. See what the output is. Then study the help: Type GaussianFilter, place cursor on it, press the "i" icon and study the help. Do that slowly with each command, learn what's happening then have what I think is a good chance of not only understanding what's happening but improving it. :) — Dominic, Mar 16 '21 at 14:13
Thank you all so much for the respons, I'll experiment with the lines and will study the help. — Stan van der Tuuk, Mar 16 '21 at 14:40

score 6 · Answer 1 · edited Mar 16 '21 at 16:33

I think I have a solid way now to count them, my code is:

img = Import["https://i.imgur.com/Wu7pSBY.jpg"];
b = DeleteSmallComponents[ColorNegate[Binarize[img]], 50];
c = ComponentMeasurements[
   b, {"Centroid", "EquivalentDiskRadius", "Label"}];
Show[b, Graphics[{Red, Circle @@ # & /@ (c[[All, 2, 1 ;; 2]]), 
   MapThread[Text, {c[[All, 2, 3]], c[[All, 2, 1]]}]}]]
c // Length

This resulted in this:

Thanks for the help everyone!

Counting dots/circles in an image

1 Answers1