How to Create AOI based on threshold area?

[sharinganez]

Hi guys,

Lets say i have a picture with symbol at the middle of the picture.

Symbol is filled with red color while background are in black color. (pls refer to pic)

Now that i want to measure the color within symbol , how do i define the AOI?

** i only want to include symbol area

Is there any way to do it in VBAI?

Thanks in advance for u guys opinion.

Edited June 22, 2010 by sharinganez

[Antoine Chalons]

Hi guys,

Lets say i have a picture with symbol at the middle of the picture.

Symbol is filled with red color while background are in black color. (pls refer to pic)

Now that i want to measure the color within symbol , how do i define the AOI?

** i only want to include symbol area

Is there any way to do it in VBAI?

Thanks in advance for u guys opinion.

Hello,

I don't think you can define your "free shape" AOI, it has to be rectangular or circular or any geometrical shaped available in the palette.

That said, if colour is homogeneous on the aera you can define a rectangular AOI that is smaller than the symbol, so you only have one colour in your AOI. Would that be ok?

[crelf]

You can define really complex ROIs, including free shapes. More info Image Aqcuitision and Processing with LabVIEW attached (sorry, no idea why the images are negatives ).

That said, Antoine put it, you might not actually want to make a complex ROI if all you want to do is find the rough colour of the symbol. I'd make a binary mask based on a B/W intensity threshold then look at the average colour.

ROIs.pdf