"No particles were detected. The threshold (255-255) may not be correct"

Hi all,
I am trying to use the Analyse Particles tool to measure the area of vessels. I convert my image to 8-bit, then adjust the contrast and threshold accordingly. This usually works fine when I then go to use the Analyse Particles tool, however, every now and then I am having the error “No particles were detected. The threshold (255-255) may not be correct” come up, even though I am doing everything the same… I am just wondering if other people have ran into this issue before and could suggest possible reasons as to why it is occurring.

Thank you.

Could you describe your workflow more explicitly? Which OS do you use, etc?

The warning message simply indicates that the threshold interval is wrong.

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Hi Melissa,
have you found a solution to your problem by any chance? I have exactly the same issue, Puzzlingly, the issue seems to have appeared out of the blue in the midst of a repeated analysis that had been working ok just hours before. Restarting the software was of no help.
Briefly, I was counting cells in 8-bit images. All I was doing was 1) Setting the threshold (never, incidentally, at 255-255) 2) Process, Binary, Convert to mask; 3) Process, Binary, Watershed: 4) Analyze, Analyze Particles.

I am using FiJi in Ubuntu 16.04.

Any idea of what the problem might be?

Ok, my problem was a silly oversight. I didn’t realize I had the analysis set on inch^2 and I wasn’t getting any count.
Apologies for rushing to write a message on the board before doing a more thorough due diligence.


I have the same problem. I run morphological segmentation, produce watershed lines before running analyse particles. It throws the same error. any help please?

Hello @Maryam_Garba
the Analyze particles command has a minimum and maximum size for detection. Can you check it’s “0-Infinity”?

Hi, I had the same problem and realized that it would only work if I had “pixel units” selected; I just did all my work in pixel units and converted into real measurements later. Good luck to anyone with this problem, it’s annoying!

Please try to remove the radio button of “Include holes”.

What I noticed is that the Analyze Particles… works if the background is black and the particles white. If the background is white and the particles black, it will report “No particles were detected. The threshold (255-255) may not be correct”.