Requirements for the optical marker. GOM Correlate 2D

[[Ma...]]

Hello all,

First of all I am glad that this forum exists.

I want to perform a 2D analysis (GOM Correlate) with respect to a distance. 
Also, the process is relatively fast, so I used a camera with around 240 fps. 

So let's move on to my question, what are the requirements for the optical marker.

I have some available here that are even self-reflecting (perhaps not GOM) whereas there are often problems detecting them. 

Thanks a lot!

Max

[[Iv...]]

Hi Maximilian,

i suggest you are talking about the reference point markers. 

You need nearly ideal round markers. With a white inside circle and a black one on the outside. We need a ideal circle for a better tracking of the coordinate because we going to fit a ellipse where the gray value gradient has the highest value. Approximately the middle point of the ellipse is the coordinate you are tracking. 

The requirements of the markers are: 

• ideal 10 pixels of the white area (inner circle)
• good contrast between white and black (if self created) - also influenced by the illumination
  • can be self-reflecting if you use tracking spots and measurement with a higher measurement frequency 
• other requirements based on the location you stick your points on. 
  • minimum 3 better 5 for a point component
  • not on curved or high deformation areas 
  • ...

I hope this helps. If you have further questions, feel free to ask.

Greetings, Ivan