How to measure the particle one by one?

[lenienter]

I am doing the particle analysis using Vision. I found it hard to solve one probelm recently. That is how can I make the ROI to be one particle (irregular) at a time? Then I can analysis the different area of the binary particles, so that i can get the area ration of the particle. I tried partilce labelling, but that would not give the exact information i need. I attached part of the image i am working.

Thanks in advance for the help and opinion.

[DOC-doc]

Hi lenienter,

It would be great if you give us more details : are you using vision assistant or are you using the vision tools in a LabVIEW custom development ?

In both cases there are solutions to your problem but they are not identical.

[DOC-doc]

It seems that you want to implement automatic granulometry analysis by camera, from the picture you send.

I have a lot of experience in this domain and I would suggest that you contact me at info@machinevision.ch.

Cheers

[Joel Khan]

Hi Lenienter,

I do not really understand your question completely but would like to let you know that there are IMAQ pixel functions in the Vision and motion» vision utilities>> pixel manipulation.

I am certain that there are better ways of detecting the rotation of a particle than going through a point by point pixel analysis. A lot of these methods will likely be driven by the vision assistant.

<Joel Khan | Applications Engineering | National Instruments | Rice University BSEE>  

[DOC-doc]

My understanding is that he wants to measure the area of sand or gravel particle and the area of black particle but the vision context is not good for me, the contrast in the image is not sufficient, he would need to change the lighting conditions.

That is why I asked with which soft he was working because it is not the same methodology with Vision Assistant and with LabVIEW

[lenienter]

Thank you very much for the help. I want to measure the area ratios of the different phases in one particle. some are 0, some are 1. so i want to output the individual area ratio one by one in the excel file. is it possible to remove one particle at a time or something like particles array that can rearrange the particles in the 2D image? I had this problem for about half a year.

The contrast is not a probelm. i can do color threshold to make the image into binary image, then i can do the analysis. the problem is how to select the ROI?

I am working with Labview with Vision and i am not using the machine vision. I got this offline image from SEM. I also tried Vision assistant for many times, but, unfortunately, it doesn't work.

[DOC-doc]

Hi Lenienter,

You don't need to make a specific ROI for each particle, you can get a "Particle Report" that gives the data for each particle in an array.

If you use LabVIEW :

1 - Threshold the image to make it binary;

2 - Get the particle report "IMAQ Particle Analysis": Analyse the particle using (here you can select which data you want to collect : for you area of each particle, further you can also get the bounding box of each roi, if you want to make some specific computation on each particle).

3 - Save the data in a text file

You are done.

Cheers

[lenienter]

I used the same method you mentioned to get the areas of the particles but not the area ratios. I also sent you an email. I am not sure whether you received it or not. That is the clear question I want to ask. The questions is not easy to explain using typing words.