Finding Defects in Colored pixels

Question

Using NI Vision, I am trying to isolate and count and black and bright spots in the colored pixels
Problem 1)
I am current locating the pixels using shape dectection and using a mask smaller than the pixel size.  However, I would like to use the entire shape found(colored pixel) to mask the colored pixel.  Is it possible to mask the colored pixels based on the coordinates of the shape detection?
Problem 2)
If I mask the entire colored pixel the black/bright spots are difficult to find when thresolding the image because the center of the colored pixels are so much brighter than corners. If colored pixels are not uniform is there still a way to detect the defects?  Do I need to try extracting a different plane then threshold the image?
Any comments or suggestions would be greatly appreciated,
E
Attachments:
Find 4 Pixels3.vascr ‏6 KB
1.PNG ‏386 KB

Answer 1

Hi E,
1) I saw you posted a Vision Assistant script. Are you using Vision Assistant in conjunction with LabVIEW? If so, the easiest option for you is going to be to detect those pixel rectangles using Vision Assistant, and then you can use those rectangles to create ROIs with IMAQ VIs in LabVIEW. At that point, you can either do your processing in LabVIEW with those ROIs, or use them to create smaller images from your original image which you can then feed into a second Vision Assistant VI, which could accomplish what you want. I've attached an example of creating ROIs from those squares.
2) You could try extracting different planes. such as the HSV luminance plane. Also try applying different lookup tables, to see if that has any effect.
Best,
Dan N
Applications Engineer
National Instruments 
Attachments:
testROI.vi ‏118 KB