Arrays of LED verification with monochrome image

[mini09]

Hi all, 

I have a set of LED arrays ON and I need to find if all the LED's are glowing? I have few methods in my mind since I haven't done much image processing I thought of collecting some ideas here, 

Method 1: Comparing the sample image with golden image.

Method 2: Invert the image and find the number of circles or search for patterns.

Kindly comment if there is any better way of analysis.

Thanks

[Hatef.fouladi]

I done such protect before
select appropriate ROI for any led and just check intensity average inside this ROI

[mini09]

Hi Hatef, 

Sure, but what if some of the other LEDs are OFF? This will not work out, right?

[Hatef.fouladi]

if you know the positions of led and just want find witch  leds are glowing  use this vi in bellow image

but if you want to find led itself you can use color pattern matching for this one 

[desalando]

Hello mini09 ( ),

Could you send/post some images?

[mini09]

Please find the image

[mini09]

Thanks, Hatef, I'll work on the same and will update you if I have any difficulties.

[SimonAldred]

Both your ideas are a promising starting point. A few things you might want to consider.

1. Improved image quality - better focussing, less blurring if possible

2. Before you can do any particle analysis you will need to threshold the image. There are a number of different thresholding techniques that you can look at in NI Vision. 

3. Look at equalising the image intensity.

4. Because of blurring you may need erode the thresholded image to ensure that LEDs are not touching as this would give you an erroneous count.

[mini09]

Hi Simon, 

Thanks, I'll work on your feedback by adjusting the fixture and lens.

FYI, I'm using ND filters between the LED and lens to get clear picture of the LEDs.

[SimonAldred]

I had a quick look last night at trying to process your image. The problem I had was the tail off in intensity across the image. Another option - if you took a reference image with all LEDs on then you could subtract subsequent images from this and look for a remaining LED. However, if the intensity of the LEDs varies in time this might be a problem.

Simon