Detecting the vision target

[biojae]

What is the best way to detect the Vision target with the camera?

For last year, we were able to use the NIVision detect circle to find the posts.
So far, I have not been able to get the Vision Assistant to detect a rectangle.
Steps:

Acquire image -> extract Saturation plane -> binary threshold -> detect geometry (Rectangle, allow scaling, occlusion, and rotation)

What is the best way to detect the target?