How to automatically mark a circle?

[OnlyOne]

 Hello,

i just installed NI Vision Assistant 8.5 for testing.

I have an image for simulation which contains an almost black background and one frayed, filled circle (~1cm radius).

This point can be in different colors. I write frayed because the point will be later a LED with i think no totally clear borders.

What i now want to do is:

1.) Mark the area of this point as ROI. I did this with "Image mask from ROI"= works

2.) The marked area now cointains only the circle and still a part of the background. What function do i have to use to only mark the circle?

3.) At the end i want the RGB-values to see what color the circle is.

My testing image is 32bit, do i first have to convert it that all functions can be used?

Thx

[OnlyOne]

Is it possible what i want to do? Or do i have to create a template and find this template in my ROI?

This is also possible, but then i dont have the rgb-values.

I think i need a function which autimatically finds the circle in my ROI. I saw that there is a functions which can find different forms but this function is not available for my 32bit-picture.

Thanks for any help / ideas.

[wbadry]

Hello OnlyOne,

          as a start, could you please post sample images as it is the most effective way to demonstrate your problem. Secondly, what language do you use for your implementation (.NET, LABVIEW) ?

          Will it make a difference if you convert your image to binary, this will make you deal with several gauging functions such as caliper, hydraulic radius to measure how good is the circle (in terms of score)

         Frankly, I write from PC other than my development machine, so I shall dig into it and inform you back asap.

        Again, posting pictures will do great deal of help.

[OnlyOne]

Currently i have no final-picture but i think it will look like that attached picture.

My idea is to test it first in the VisionBuilder and later everything should become a .Net-DLL created in C#.

Or do you think it is ebough if i lnly create a small rectangle-ROI instead of a circle?

The LED is always at the same position +/- 2mm.

Is there a function to get each RGB-value direct from a ROI?

And another question is: Will it be possible to use the IMAQ-functions in my .Net-program? Because i found this thread

http://forums.ni.com/ni/board/message?board.id=200&thread.id=18813

which says the driver works only in Labview and VA.

Thank you for the help