How to select the particles after using the Particle Analysis

[lshi]

Can I select the particles after the particle analysis directly, like chosing #1, #2 ..., or should I run the particle filter using the measured parameter?

[Torba]

Hello Ishi,

Thank you for contacting National Instruments.  Depending on the software environment that you are working in will determine how to process the detected particles.  Are you programming in Vision Builder for Automated Inspection (VBAI) or LabVIEW?  What version of the software are you using?

Regards,

Mike T

National Instruments

[lshi]

Hi, I am currently using the Labview with the Vision Assistant 8. The particle analysis and particle filter are the VIs in the package.

Thanks

[Torba]

Ishi,

I'm afraid that I don't quite understand the question that you are asking.  What do you mean by running the particle filter using the measured parameter?  Are you referring to the table of detected objects and the parameters?  What further processing do you have to perform after the particle filter?

Mike T
National Instruments

[lshi]

Yes, I am refering to the table of measured particles. I'd like to know if there's anyway to simply chose any one of those in the table, like just select #1or #4 particle. This can be done in Vision Assitant, but not in the labview, while neither of them seem to be able to export the select particle region, whose shape is what I want.

thanks

[Torba]

Hello Ishi,

I now have a much better idea on what you are trying to do.  If you run the IMAQ Particle Analysis Report VI on the thresholded image that contains particles, an array of clusters will be returned that will contain specific information for each particle including the area, number of holes, bounding rectangle coordinates, center of mass, orientation, and dimensions. 

To find out which particle is which in the image, index the Particle Reports (Pixels) output of this VI, unbundle the cluster to extract the Bounding Rectangle cluster, and then pass it to the Rectangle input of an IMAQ Overlay Rectangle VI.  This VI will overlay a bounding rectangle onto the image to show where the particle is located.  You can specify which particle you want highlighted by changing the array index of the Index Array VI that is responsible for extracting a specific cluster of particle information from the Particle Reports output of the IMAQ Particle Analysis Report VI.

Regards,

Mike T
National Instruments

[lshi]

But if I use the overlay, would it also extract some other paticles or part of them which might happen to be there?

[Torba]

Hello Ishi,

The rectangles generated represent the bounding rectangle that the particle analysis uses to associate particles.  This does not mean that the particle is defined as the bounding rectangle.  It is only a means to describe which particle is which.  Therefore if you have two particles close together but not touching, if one of the particles are coincidentally inside the bounding rectangle of the other particle, it will not be accounted for.

Regards,

Mike T

National Instruments

[lshi]

I see, thanks a lot, you are very helpful.