Machine Vision

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Particle Detection - Location of Detected Particle XY Pixels

I am attempting to perform spot tracking for a beam aiming system. I need help with the "IMAQ Particle Analysis' function. I reviewed the examples, and none seem to demonstrate extracting the XY pixel location [Centroid] for a detected particle.


I coded an still image of my beam - and the particle analysis reporting does not correlate to the clearly 'seen' location of the beam - i.e. the only singular particle of the sample image. Some of the reporting seems correct - Hydraulic diameter - but the XY boundary - keep returning the entire image field boundaries?.


I have attached my test VI, a BMP of the captured image. Any help is appreciated. My Vision Acquisition, Analysis license is activated.

Particle TEST vi.png


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Message 1 of 8

if it's reasonable to convert the image into a binary, easy to filter  out outliers, and use the same tool to find the center of mass of the particle. 


Does this make sense?

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Message 2 of 8

If the particle detection function worked at all...I would invest the time.

Looking at the image, it's pretty much binary now. 

There has to be something wrong in how I am using the function.


This is the help I am looking for.


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Message 3 of 8

The image has to be binary.

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Message 4 of 8

Thanks! Yes I figured that out. Odd...there is not error returned from the function, and odder still it reports 'detecting' one particle...


I will upload the vi I posted with the binary conversion..


Thanks, Jack

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Message 5 of 8

I wrote a more detailed explanation, but the system decided to kick me out, and I'm too tired to write it agin.  But I have attached a VI that does a fair job of locating the center of mass..


Oh, Calibrated values will always be the same as pixel values, unless you have a calibrated image.







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Message 6 of 8


Thanks!....I've had the same issue with writing a long Forum reply to be booted off a refresh.



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Message 7 of 8

I hope the code makes sense. .Feel free to bug me if you have more questions.




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Message 8 of 8