How to combine real-time video with LabVIEW indicators so that video can be displayed and recorded with data overlay

[wildcatherder]

Assume for the moment that I can find a camera for which LabVIEW has the appropriate drivers.  Is it possible to combine the camera feed with numeric indicator fields so that there is a video output showing the data as an overlay upon the live image?

I'm talking about something like a point-and-shoot camera display where you see camera settings displayed on the image in the viewfinder.  Note that I a not talking about analyzing the video data in any way or actually reading camera settings from the camera.  Data would be temperatures, pressures, speeds, etc. acquired by separate instruments at the same time the video is captured and processed in some way by LabVIEW.

[Mellobuck]

I think the most processor-friendly method would be to make some kind of 'Taskbar' at the bottom of the image, so that you do not have controls over-layed, which causes a lot of extra work for LabVIEW. The next step would be to actually take the data or a picture of the indicator needed, and insert into the image "IMAQ Overlay Text" (for a numeric indication), or "IMAQ Overlay BMP" (for an actual slider etc.), seem like they might work to make the items you might want, but I have not used them

If you don't have the IMAQ tools, the picture controls might enable you to do this a little less elegantly (ie Draw Text in Rect.vi), and I don't know how fast they would be with respect to live feed.

Good Luck,

Mello

[wildcatherder]

I don't really care where on the video the data appears.  That is not the problem.  The problem is what tools are required to acquire the video, combine with the data display and OUTPUT so that results can be displayed in real-time and recorded for later analysis.

[Mellobuck]

Will "IMAQ Overlay Text" or "IMAQ Overlay BMP" Vis work for you then?

[wildcatherder]

I'm sorry if I gave the impression that I have any idea what I am talking about other than what was presented.

"I don't know what is in the LabVIEW library.  I do not currently have access to IMAQ VIs.  Similar VIs were suggested by NI engineering support but the descriptions of the VIs say "image" rather than video", so I have no idea if they are suitable.

I'm not asking for a lot of hand-holding, just a quick overview of the necessary tools:

Video acquisition hardware

Video/text combining software (VIs)

Video output hardware

Thanks for your continuing participation.

[Mellobuck · Accepted solution]

No problem Wildcatherder, let me give you an overview of the process.

When you get input from a video acquisition method, it will be an image format. Essentially, it is a bunch of images being updated at the video capture speed, just as in the hardware. There are express VIs (Wizard-like items) that streamline getting images from your video source. With the drivers and Measurement and Automation Explorer installed, you should be able to at least get the image.

If you had the IMAQ toolkit I mentioned, you could just wire the image reference (a squiggly purple wire) and a text input (say a temperature converted to string) into the Overlay Text VI and it would produce the effect you want. Without those, you will have to convert the Image to Picture (those are two separate data types in LabVIEW) and use the picture editing tools instead (essentially replacing pixels in the 2D picture data). You would then be updating a picture indicator with your altered picture, hopefully at the frame rate of the acquisition hardware. As I mentioned this is less elegant, and may take a certain amount of processor time. If you are not displaying these images at all, and are just routing them out, it should be slightly faster.

I am not sure about Video output hardware, I have mostly used Firewire or USB input, with the data going to the computer screen or to file. However, if the driver exists, it should be possible, but a cursory examination of the functions doesn't seem to come up with any output functions. Can't advise on hardware, but you can start with:http://sine.ni.com/np/app/main/p/bot/no/ap/vision/lang/en/pg/2/sn/n17:vision,n21:11600/?

Regards,

Mello

[wildcatherder]

Thanks for that overview.  I'll follow the reference you provided and see where it leads me.

[whatinthename]

what kind of applications are you looking for. maybe i can help you.

Bobby