How can I name each LED?

[LV2010]

Hi all,

I am new to this vision. Could somebody please tell how can I name each LED in attached image.

After naming how can get intesity of marked LEDs.

Thanks,
Sashi

[Michael Noll-Hussong]

A good starting point are the pattern matching examples shipped with IMAQ Vision (search for "pattern matching example.vi" resp. "color matching example.vi"). Having then a ROI around the desired object (here: LED) it´s easy to get the intensities using the IMAQ Analysis VIs (under ). Mail again if you need further help ...

[LV2010]

Dear Michael,

Thank you for your message. I wanted help to complete below task.

"I am dealing with multiple ROIs in a single image to perform different functions, sometimes of dependence to one another. How do I label each ROI and call them?
How do I call the ROI after imaqLabel?"
I want mark 3 or 4 LEDs at once and I wanted to get Intesitiy of each LED?

Thanks,

Sashi

[Simon Tew]

Hi everyone,

Currently, I also dealing a LED inspection project using LV7.1 + IMAQ. I can extract LEDs RGB color plane and intensity value of each LED using Rectangle Light Meter VI. But found it was difficult to differentiate Green, Orange, Dim Green, Dim Orange LEDs. How to define a GOOD Green, GOOD Orange, Dim Green and Dim Orange LEDs? Any reference for me? Any good suggestion for me?

[Irene B]

Hi Simon,

From what I understand, you have the RGB and intensity values of your LEDs and you need to find a way to input these values in for color matching.  One method of doing this is to use the IMAQ ColorMatch to determine orange or green and then apply a IMAQ ColorThreshold to determine what intensity range you wish to detect (bright or dim LEDs).

Hope this helps,
Irene Chow
National Instruments
Applications Engineer

[Simon Tew]

Hi irene,

Thanks for your advise.

But some of LED are too DIM(my customer purposely make it dim to test the software's ability) even apply color match also could not find at first, therefore the following analysis seem not possible due to can't determine the actual XY coordinate.

By the way, do you think using Light Meter to extract RGB value is more straightforward method.

I also found extract XY coordinate always shifted by apply Color Pattern matching, and this make me to use these XY for the following analysis is alway not consistence. Anyway to improve it?

Somebody suggest to use HSL for LED will be better than RGB plane, Is correct?

[Simon Tew]

Sorry forget to tell your my application in detail.

The project need to inspect on boad LEDs which consist of many Green LED + Orange LED + Red LED.

The software must able to detect the wrong color of LED, dim color of LED, and totally "OFF" of LED.

The method I use will be, Color pattern matching act as first pass to find similiar LED (If " pass " XY coordinate will be generated) , secondly use the XY coordinate + ROI to input to Light meter to extract RGB value and then following analysis will determine how bright or dim of LED.

But some problems arise, first too dim LED can not be find during color pattern matching therefore Light meter can not extract RGB value due to NO XY coordinate. Second the actual XY always not consistence after color pattern matching therefore the extracted RGB value from Light meter will vary......

Thank in advance...

[Irene B]

Hi Simon,

Could you please clarify what you mean by the non-consistent XY values?  Do you mean that the LEDs actual vary in position from picture to picture or that the color pattern matching is finding different XY coordinates (I assume, the centroid) each time even though the LEDs do not move?  

Go ahead and post a zip file of several pictures, showing green, orange, and red LEDs in their various states.  (Are the states On, OFF, and dim?)  It will probably give us a better idea of how close the colors are.  

Thanks,
Irene Chow
National Instruments
Applications Engineer

[Simon Tew]

Hi Irene,

The actual XY coordinate in term of pixel will shift a bit even same image applied to color pattern matching every time.  Later I will attach some image for viewing...

Thanks in advance.