custom overlay histogram

[pallen]

Greetings,

I finally got around to playing with my NI 1456 CVS.  Currently using VBIA 3.0.1 

When setting up the Measure Colors step, I notice that it gives me a nice histogram. 

 

I'd like to place a historam as an Overlay.  So far, the only way I think I might be able to do this would be to pass the inspected values as Globals to a LabVIEW VI that would create and save the image of a histogram from those values.  Then use the Custom Overlay function to open that image and display it on the screen.  

I'm not sure yet if this would work or not.  But I'm wondering if there isn't a simpler way to do this.  Also curious about displaying other graphs as overlays.

Message Edited by pallen on 10-28-2008 04:41 PM

[chris.b]

I think the best approach would be to send the acquired image to a Run Lab VI step, and using the IMAQ ColorHistograph function.

[pallen]

Thanks Chris.  I'll look into that.

While thinking about this problem again this morning, I realized that the solution I mused about likely would not work unless I had some way of dynmically loading a new image file into the memory of the 1456 CVS.  

VBAI  prompts me to "save" to target if I want to use an image as an overlay.  I had been thinking I could just put a new file under the same name and my RT target would just update the information.  But I wasn't thinking about how I would transfer that new image file to the RT system.  I'm not sure; but I don't think I can do that programatically. 

[chris.b]

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But I wasn't thinking about how I would transfer that new image file to the RT system.  I'm not sure; but I don't think I can do that programatically. 

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I'm a little confused now.  Are you talking about transfering files from VBAI to LabVIEW (all on the CVS), or transfering from the from the CVS to another system?

[pallen]

Sorry for the confusion there.  I think I'm suffering from a little myself.

Ideally I'd like to run entirely from the CVS.  But I'm not sure I can do things like update a graphic on the screen programatically.  It's only been a few days that I've been playing around with this piece of hardware, so I'm still learning all the differences between a PC based vision application and an RT one.

Basically I was thinking of displaying a "live" histogram graph on the CVS display.  I'm starting to think that this may not be possible though.    

[chris.b]

You can definitely do this all onboard the CVS. All need is two VBAI steps: Acquire Image, and Run LabVIEW VI. In your LabVIEW VI, use an image control to take in the image from VBAI, then run the histogram and overlay.

[chris.b]

Note: You will have to FTP into the CVS to place the VI (in a LLB with all of its dependencies) on the target.