Getting a signal (boolean) if the camera ROI detects movements

[Kryno]

Introduction:

Hello, I'm pretty new to this camera acquisition thing and it really is easy to use and play with it, but I do not find a solution for this..

Project:

The project is for university, I need to do an automatic sorter so my idea was to take a photo from the conveyor, process it and use labview to control the motors and everything. I did almost everything from the acquisition image, but i can not find a way to get a boolean when something is entering in the ROI I made on a camera.
Problem:
How do I set a boolean true when the object is entering in the ROI?

Observations:

• Because I need to take that photo to process it for optimization I will make the program to take a photo every time the object is entering in the ROI, not a photo every milisecond. 
• I tried to use the color learn option, but I couldn't find a way to use this properly.
• I can't use the tracking from vision assistant, because the object is not always in the frame.

[Bob_Schor]

The "easiest" way to do this is to generate a TTL signal to trigger the "Snap" when the Object of Interest is in front of the camera.  Something like a photo-diode (what we used to call "an electric eye") watching the conveyer belt or a proximity sensor would do it.  You may have to play a bit with speed of the conveyor, size of the Object, size of the ROI, etc.

Bob Schor

[Kryno]

That's a very good idea and I will take it into consideration, but I wonder.. Can't I make something in the software? 

I really thought it will be so easy and there must be an option/method to detect if something is changed in the ROI and now I'm too surprised that I can't find a solution.

Thanks you!

Adrian Geantă

[Bob_Schor]

One of the most challenging LabVIEW "corner" is Image Processing -- not 1D, not 2D, but 3D data (two spatial dimensions, one intensity dimension which, if color, can be considered as RGB = 3 more dimensions).  I'm glad I had several years of LabVIEW experience before being "introduced" to LabVIEW Vision.

You could capture images with identified ROIs and figure out a "measure" to decide if is "sufficiently different".  Are you an IMAQdx expert?  Ready to spend a month or so learning?

Bob Schor