IMAQ image aquisition,basic query

[fringe]

Hello,
I m new to the Labview environment,so excuse me if this sounds stupid.
We plan to use LABVIEW with IMAQ vision.
I have read the maniual on IMaQ for LABVIEW and I have not been able to
figure out a waty to aquire a streaming image into
the VI's.I have been able see the stream thru MAX>>NI IMAQ devices.
But I would like to use it inside LABVIEW.The manual says...

'Acquire images continually through a grab acquisition. Grab functions
perform an acquisition that loops continually on one buffer. Use the
grab functions for high-speed image acquisition. Use the
IMAQ Grab Setup VI (Image Acquisition) to start the acquisition.
Use the IMAQ Grab Acquire VI (Image Acquisition) to return a copy
of the current image. Use the IMAQ Stop VI (Image Acquisition»
Low-Level Acquisition) to stop the acquisition.'

I have not been able to find IMAQ Grab Setup VI and the other two
fucntions.I can access all other tools and VI'S under Vision utilities etc.
Please tell me where to find these!

Also,I would like to know if two camera link camras with a NI 1429 can be
used simultaneusly using labview.(for stereo vision purposes)

Thank you in advance,
Dhananjay

[Bob_Y.]

The Snap or Grab is part of the image acquisition driver for the type of acquire to do. You can use 1394, an NI frame-grabber or a USB camera and each will have its own grab vi. Just make sure that you have the IMAQ driver for frame grabbers installed, and I think it should be the first sub-palette in the second row of the vision palette.

Hope that this helps,
Bob

[fringe]

Hello,
Thank you for your prompt reply.
I would like to add a few details.
I am using the NI 1429 framegrabber on a Windows XP machine.I installed the software after
the hardware.(noticing that the warning was for Win2k).Everything else seems to be working fine.

I reinstalled the driver,but I still do not see the grab,acquire etc.The search does not show it too,of course.
Is this a problem specific to 1429 or perhaps i have to install real time modules.I am quite cluesless.
Thank you,
Dhananjay

[nipun]

Hello Dhananjay,

Thank you for using our discussion forums. Once you do install NI-IMAQ you should see a Vision palette installed in LabVIEW under Functions>>NI Measurements. I've attached a screenshot of the palette as a reference for you. If this palette is present the you can find all the image acquisition functions required for the 1429 on it. Also, if you are looking for a simple grab I would recommend starting with the HLGrab example program included with NI-IMAQ. All the example are accessible through the Example Finder. Follow the instructions below to find IMAQ examples in the Example Finder:

1. Start the Example Finder by clicking on Help>>Find Examples...
2. Double click on Hardware Input & Output
3. Find and double click on IMAQ and then on High Level

This should get you started.

In case you don't see the Vision Palette one reason for this could be an older version of LabVIEW. Version 3.1.1 of NI-IMAQ installs support for versions of LabVIEW as far back as 6.1. I hope this helps you out. Let me know if you have any other questions.

Regards,
Nipun M
Applications Engineer
National Instruments

[fringe]

Hello Nipun,Bob,

Thank you!I think i figured it out.The complete install of IMAQ did not have support for LABVIEW chosen by default.(which is quite strange
when you consider the word complete)

I am using Labview 7.1 and IMAQ 3.1,but I cant see many IMAQ image processing functions.(like histogram,line analysis)
We need to develop a real time application using stereovision.
Would it be recommnended to write code in C using the funtions provided in IMAQ Vision?
I have now been able to aquire the image directly into Labview as i wanted.But I am still not sure if can do processing on this
stream as wring to the hard drive is not an option(real time)

Thank you in advance,
Dhananjay

[nipun]

Hello Dhananjay,

The vision analysis functions that you are looking for are a part of the Vision Development Module and are not included with the NI-IMAQ drivers. The IMAQ drivers allow you to acquire images and the vision functions are designed for further analysis of these images. Personally I would recommend using the Vision Assistant and LabVIEW for your application. Let me know if you are interested and I can point you to the appropriate product pages. Have a nice day!

Regards,
Nipun

[fringe]

Hi Nipun,
Thanks!
I think we chose IMAQ beacuse it can support Labview Real time on the Target.I
am not quite sure about the real time capabilties of Vision assitent.
I am sure I will have further queries for you 🙂
Thank you,
Dhananjay

[nipun]

You're very welcome Dhananjay. Let us know if you have any other questions.

Regards,
Nipun M