How to insert a background picture behind an IMAQ overlay?

[PULSE.Wannabe]

Hi, I'm new to machine vision, currently I'm making a project which I use a red object as a control. I use vision assistant to acquire red particles from the cam, then I use overlay rectangle to bound the red object. But now I want to put an image behind the rectangle overlay but I don't know how.

summary : I want my rectangle overlay to hover above an image

Any suggestions are welcome !
thanks in advance

[wiebe@CARYA · Accepted solution]

Change the input of IMAQ Rectangle Overlay to your background image... That would overlay the rectangle over the background image.

Although Vision Assistant should make things easier, in my experience it complicates things in the slightly longer run.

Why not simply convert your RGB grab to HSL and use a threshold on H to get red pixels with a threshold on L to remove blacks? IIRC, there's a multi color threshold for that.

IIRC, red is a bit more complicated as the red range wraps around 0 (e.g. from ~250-255 and from 0 to ~15)...

But at least you'd know exactly what you're doing... With VA things often remain a mystery with very little control over details.

[PULSE.Wannabe]

thanks so much, i will try