Vision Assistant 8.2: dynamic overlay

[professor_rumsdiegeige]

Hello!

Is it possible to generate a dynamic overlay?

The background is the following: assume that you have measured sth. using "Caliper", e.g. the diameter of a circle. Now assume you would like to see how this diameter changes while continuously acquiring new images from a camera and moving the target object a bit.

My idea was to go to "batch processing" in acquisition mode, but it is not possible to look at the "Caliper" results there (you can open the parameter interface with each acquisition, but that is not comfortable).

So I thought one can perhaps convert this measurement to a string and display it using the overlay function.

Thank you for your help!

Regards

Sabine Lorentz

[Neville D]

QUOTE (professor_rumsdiegeige @ Oct 28 2008, 04:31 AM)

Is it possible to generate a dynamic overlay?

The background is the following: assume that you have measured sth. using "Caliper", e.g. the diameter of a circle. Now assume you would like to see how this diameter changes while continuously acquiring new images from a camera and moving the target object a bit.

My idea was to go to "batch processing" in acquisition mode, but it is not possible to look at the "Caliper" results there (you can open the parameter interface with each acquisition, but that is not comfortable).

So I thought one can perhaps convert this measurement to a string and display it using the overlay function.

Yes, you should be able to do it. Just clear the previous overlay using IMAQ Clear Overlay.vi, and write the new data (whatever it is, text or a graphic). You can use IMAQ Overlay text.vi for writing text onto your overlay.

With the new overlay functions in Vision 8.6.x (released Aug 2008), you can group overlays and then clear only the group that has changed, leaving other overlays untouched.

N.

[cookjr]

QUOTE (Neville D @ Oct 29 2008, 11:33 AM)

With the new overlay functions in Vision 8.6.x (released Aug 2008), you can group overlays and then clear only the group that has changed, leaving other overlays untouched.

Anybody know of an easy way to shift an overlay group by some offset x or y? I have done this by adding the overlay group to a blank image, then shifting the image using IMAQ Shift, then using IMAQ Copy Overlay to copy the shifted overlay from the blank image to the destination image. It just seems like there should be an easier way...

I would like to use this to dynamically move an overlay around on an image. The reason I'm attempting to do this with the Vision utilities instead of pictures is that I would like to use the IMAQ WindNonTearing function, which seems to work very well, by the way. Using pictures, I wasn't able to implement any non-tearing functionality.

Thanks.

[Neville D]

QUOTE (JimCo @ Feb 16 2009, 06:46 AM)

Anybody know of an easy way to shift an overlay group by some offset x or y? I have done this by adding the overlay group to a blank image, then shifting the image using IMAQ Shift, then using IMAQ Copy Overlay to copy the shifted overlay from the blank image to the destination image. It just seems like there should be an easier way...

I think your doing it the right way. The reason is most use cases need the overlay to stay with the image and transform as the image is transformed. But your case is the exact opposite, so you have to transform the image and then copy that overlay to your image.

Thats fine. I do that all the time. I maintain overlays in separate image buffers and only copy them over just before displaying. This allows me to maintain multiple overlays displaying the results of different processes, all of which may not be needed at display time. It doesn't seem to be very processor or memory intensive when used to display a few circles and lines and 4-5 lines of short text.

What are you overlaying? text alone? In that case, shift the text and copy over the overlay at the last instant.

N.