About the NI Vision Assistant problem.

[Jerry1024]

 Hello,

I have encountered some problem with "Geometric matching"  when I use the NI Vision Assistant tool . The problem description is shown below:

1. Here is my "Template image".

 

2. When I load the target image in NI Vision Assistant. It can't found any match pattern.

3. But when I disable the "Occluded", the pattern can be found with "Occlusion" 0%.

If my understanding for "Occuled" is correct, the occluded setting 0~60% means that the NI vision Assistant should find the matched pattern with occlusion 0% ~60%

Why cancel "Occluded" the result can't be found?

[b.ploetzeneder]

The underlying algorithms are subtly different.. and there can also be different rounding.

I would not use geometric pattern matching to find this pattern.

If there is even a subtle change in illumination, an edge border can change 1-2 pixels, and because you have a rather low resolution (total size of the shape), it can result in a shape that is hard to find.

Although it's already pretty good, clean up the image a bit first:

(I used the Median Filter and then adjusted brightness/contrast/gamma) Your initial image quality is nice, so you get almost pure signal vs background.

Then use Pattern Matching (eventually with subpixel accuracy if you need it). This should be much more robust than Geometric Pattern Matching.

Cheers Birgit