image improvement for circle detection

[SSJVegetto]

Hi all,

Can anyone help me to improve the following image so that i can detect the circles which you can see in the image. The filtered image i use still is not capable of detecting the correct circles. I really need some help with this.

Does someone know how to create a good high or lowpass filter? I'm confused about this all. But still i think i need to do different stuff in order to detect these circles. 

Kind regards,

Bob Rots

[ThiCop]

Hello Bob,

What Vision-related toolkits and/or modules do you have at your disposal?

Can you give an example of a VI that you used to create the filtered pictures below.

[Stephen_Joseph2]

The image you attached is not clear, How you took the image what camera what lighting need more info. Its always easy to work on lightings rather image processing

[SSJVegetto]

I use the following vi as a test. The lighting is done by the microscope webcam itself by 8 LEDs the link to a similar cam is (if not the same):

http://dx.com/p/portable-usb-2-0-25x-400x-cmos-digital-microscope-with-8-led-illumination-black-7070...

The image is from a transparent disc. 

[ThiCop]

Hello,

With this lighting you'll for sure need more than a simple low-pass or high-pass filter.

I was thinking about applying edge detection to detect the edges, but the edges of the 3 circles are not so clean.

The first one would be easy to detect, the other ones less easy. (not completely clean edges)

Have you ever tried to create a script with the vision assistant and exporting that script to LabVIEW?

Are the circles always at around the same place on the rectangular structure?

Is it your goal to detect the position of the circles relative to the rectangular structure or relative to the picture boundaries?

Can you give some more information about what your planning to do afterwards with the information about the circles?

[SSJVegetto]

Yes the edge detection i was thinking about to but its not clean at all so i was trying to get the picture more clean. 

No i have never created a script using vision assistant. Don't even know how to do it and what i can achieve by it?

The circles are always in that square/rectangular structure there are 6 positions for the circles and depending on where the circles are it can be given a number so that we know what channel of the disc we are looking at. This is necessary for me to know. 

Thank you for your help thus far.

Kind regards, 

Bob

[ThiCop]

hello Bob,

This post seems to be linked to http://forums.ni.com/t5/LabVIEW/Learn-Multiple-Geometric-Patterns/m-p/2241942/highlight/false#M71237...

Am I correctly assuming that this is the same issue.

To create script this way you just have to place a Vision Assistan Express VI in the Block Diagram and double click it.

A good thing to start with would be this tutorial about the Vision Assistant:

http://digital.ni.com/manuals.nsf/websearch/90F38BCB007B8194862578A900591706

Are you very familiar with LabVIEW on itself?

[SSJVegetto]

Where would you like to continue the discussion? Here?

I'm not very experienced but i usually manage. Only image processing is something i've very little experience with. 

Kind regards,

Bob Rots

[Aojha]

Have you tried thrsholding-Binary conversion and particle rejection.

[Aojha]

hi I was telling about this

http://forums.ni.com/t5/LabVIEW/blob-image-analysis/td-p/2241216