Counting objects in an image

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subrajeet on 7 Jan 2013
Edited: John Kelly on 8 Nov 2017
Dear Researchers, I have a problem of counting objects in an image. Suppose I have the below image (below link)
which i got after segmentation.
how can I count the small circles in the middle of the image. Kindly suggest
Subrajeet

Image Analyst on 7 Jan 2013
Edited: Image Analyst on 7 Jan 2013
1. Binarize the image so that it's logical. binaryImage = grayImage > 128
2. Call binaryImage = imclearborder(binaryImage) to get rid of the single line around the perimeter.
3. Invert the image: binaryImage = ~binaryImage, so now black circles are white
4. Call binaryImage = imclearborder(binaryImage) to get rid of the large (now white) background
5. Call bwlabel: [labeledImage, numberOfCircles] = bwlabel(binaryImage). This gives you the count.
6. Call measurements = regionprops(labeledImage) if you want other measurements
See my Image Segmentation Tutorial in my File Exchange if you want an example.

subrajeet on 7 Jan 2013
@Image Analyst from core of my heart I want to thankyou. Really I could not do it from yesterday. But one one thing can you tell me using which image processing technique this was achieved.
Thanks a lot again.
Image Analyst on 7 Jan 2013
It's just basic, elementary image segmentation via intensity thresholding. Nothing fancy at all. See updated instructions above.

Thomas on 7 Jan 2013
Edited: John Kelly on 8 Nov 2017
You could use techniques shown in many MATLAB image processing demos.

1 Comment

subrajeet on 7 Jan 2013
Thomas U can see in my image the circular objects in the centre have immideate neighbors as white pixels. But again beyond white pixels I have black pixels. So i could not understand how can I have the access over the center circles. I desire if by some means I can assign the outer black pixels as 1 or make them white then I can count the circles. But I am unable to do that.

SANAHA PATHAN on 25 Jul 2016
i want to count number of silkworm eggs from this figure, i used L=Count(binaryfig) this command for counting number of objects ,this command works but i actually dont know what actually this command count,and result of this command is different every time

Image Analyst on 25 Jul 2016
SANAHA, take a look at this link and then if you still have questions, post a new Question (not here) and upload your code and image(s). We actually don't know what your Count() function does either so be sure that's included in the code you upload.
anna on 5 Oct 2016
hey I segmented blue nuclei from a blood smear image using k means color segmentation. how can i count the number of segmented blue nuclei. could u please help me with the code for counting [ cant use imfindcircle because the segmented nuclei are not exactly cirlce in shape ]
Image Analyst on 8 Oct 2016