Image acquisition using video capture card

[viji]

I am developing an application for Single fiber fusion splicer...my application basically has to capture the picture from the splicer using a Video capture card...Is it possible to use IMAQ session to get the picture from the card,store it a file and display the same using labview??or is there any other suitable way instead of IMAQ???

[mhaag]

Hello,

We have a few options that we might be able to use depending on what video capture card you have. If you are using a National Instruments frame grabber to acquire the images, then this will integrate easily into LabVIEW. You can use any number of shipping examples and VIs to acquire the images or video and then save and display them.

If you are using a 3rd party capture card, then, unless that company has provided VIs or DLLs that allow you to acquire and save the images, then most likely it will be difficult to create a program to acquire the images from this card into LabVIEW. The best way to do this may be to use the software or functions that came with your video card to save the images to file. Once you have saved them, you can use LabVIEW to
open the images, display them, and (if you have Vision) do all types of processing of the image.

Again, the hardware you have and the software/functions provided with it will dictate how easy it will be to incorporate it into LabVIEW and develop a single application to acquire, save, and display these images.

I hope this helps and gives you a few ideas of what can be done and what you need to look into. If you still have any questions on what the IMAQ functions in LabVIEW can do, then let us know and we will see what else we can do.

Regards,
Michael
Applications Engineer
National Instruments

[viji]

Hello Michael,
Thanx for your sugession.We have not yet decided on the video card.Does video card and video cature card mean the same?We only have a RC jack port (similar to the Linein for sound card on the PC) on the splicing machine and I am using LabVIEW 6.1 on Linux.

Viji

[mhaag]

Viji,

The video capture card will be the device that you connect your image source to and that is responsible for acquiring the image that you want. Unfortunately National Instruments does not develop any image acquisition device that will acquire from a basic RC jack. We do have a board that will acquire images from an S-Video connection, so some customers can acquire images from high-end, commercial VCRs to our image acquisition board through an S-Video connection.

Also, currently our IMAQ and Vision products are only supported and developed on the Windows platform, and we do not have IMAQ/Vision support for Linux. Because of this, you will not be able to use the IMAQ or Vision functions on a Linus machine, unless you can find or create
a 3rd party driver that interfaces properly.

Regards,
Michael
Applications Engineer

[rolfk]

viji wrote:
> Hello Michael,
> Thanx for your sugession.We have not yet decided on the video
> card.Does video card and video cature card mean the same?We only have
> a RC jack port (similar to the Linein for sound card on the PC) on the
> splicing machine and I am using LabVIEW 6.1 on Linux.

The NI cards are industrial image acquisition cards. As such they do
have a much broader range in video timing ranges than normal video
acquisition cards but they are also more expensive. They do not have
standard TV jacks but some of them could in principle be configured to
acquire standard video images. However that configuration can get very
tricky if you don't know exactly what you are doing.

One big problem with National Instruments cards will be L
inux support.
As NI is using their own chips on those cards there is little chance to
find actually a Linux driver which could work with such a card. I'm not
even sure if NI has a register level programmer reference manual for
those cards but even then someone would first have to bother to develop
such a driver.

Your best bet for standard video signals is probably to go for a
Bt848/849/878/879 compatible card which has native Linux support. You
will however have to get an interface to the Video4Linux API from
LabVIEW. Not sure if there is a finished VI library to interface to
Video4Linux though and creating one yourself would certainly not work
without some C programming.

If you need to interface to industrial cameras with other image
geometries than standard TV, you will have to look for an industrial
grade frame grabber card with Linux drivers which might be not so easy
to find.

Rolf Kalbermatter

[viji]

Thanx. The video output from the splicing machine is of NTSC standard and comes from a RCA jack. So can I use TV tuner card to save the picture on PC and Display it in LabVIEW? If I can't use IMAQ/Vision how can I see any picture in LabVIEW (linux)?

Viji

[Greg_McKaskle2]

> Thanx. The video output from the splicing machine is of NTSC standard
> and comes from a RCA jack. So can I use TV tuner card to save the
> picture on PC and Display it in LabVIEW? If I can't use IMAQ/Vision
> how can I see any picture in LabVIEW (linux)?
>

If you have the full version, you can use the picture control. If you
have base, you can sacrifice some color information and use the
intensity graph.

Greg McKaskle

[Cyril_P]

Dear Michael,

While looking for informations on NI website, I found on the forum your answers concerning the acquisition of video images using Labview.
Few words about me, I am a current user of Labview (7.0) (for teaching and practical work applications in a french engineering school).
Recently, I wanted to improve a used image acquisition software. This software has been first bought for the acquisition and real time treatment (on few pixels ...) of video frames (electronic diffraction on monocristals). BUT, this software is absolutly overaged, un-reliable, and so on ...
So, we decided trying to upgrade this measurment system, using Labview.
The video system consists in the following : - a domino maxi video card
                                                                         - a VHR-1000 video camera (768*572).
                                                                           - OS windows millenium (but may be converted in XP if necessary).

Thus, what I need. In few words, I need to command the video card using labview (get access to frames grabber, video parameters (gain , ..)).
But, as I am used to command instruments (IEEE, RS232, ...), I have never proceed to such operation. I imagine, I have to import DLL data from the video card, and be able to use them for the acquisition (but never done that in the past !!).
Can you indicate me if you have any information concerning this topic, where I will be able to find some.

Regards,

Dr Cyril Paranthoen
Professor assistant INSA-Rennes (FRANCE)

[Luke H]

Cyril,

A typical image acquisition system consists of the following components:

Camera » Framegrabber board » Image Acquisition Software » Image Processing Software

The software in this application is of course LabVIEW.  The ease of integration of it with your camera and framegrabber board is dependent on a number of variables and I discuss that further in the rest of this post.

1. Camera
   
   It looks like you already have a camera picked out, but I could not find any information on the VHR-1000 on the internet.  Who is the manufacturer?  Can you provide a link to information available about it online?  NI does not actually make cameras; we simply connect with third party cameras.  We have a list of the various cameras that are tested and supported by our hardware available at http://www.ni.com/cameras
   
   Here are two more documents that will discuss camera options in more detail:
   
   Choosing A Camera
   http://zone.ni.com/devzone/cda/tut/p/id/3087
   
   Image Acquisition
   http://zone.ni.com/devzone/cda/tut/p/id/2808
   
   
2. Framegrabber board
   
   The framegrabber board is what will be responsible for taking the signals from your camera, either digital or analog, manipulating them appropriately, and storing them in computer memory.
   
   The framegrabber board you choose will largely depend on the camera you choose and the interface it uses. (Interfaces are discussed in the Image Acquistion document mentioned earlier)
   
   It looks like you already have a Domino Maxi framegrabber board, which LabVIEW may or may not be able to interface with.  Could you please provide more information and possibly a link to some info on this framegrabber board?
   
   Choose NI Vision Hardware
   http://www.ni.com/vision/hardware.htm
   
   
3. Image Acquisition Software
   
   The Image Acquisition software is the software responsible for bringing images into the computer in conjunction with the framegrabber board or IEEE-1394 bus.  Depending on your interface, you will need either NI-IMAQ (framegrabber) or NI-IMAQdx (IEEE-1394).
   
   
4. Image Processing Software
   
   For image processing in LabVIEW, you will need the Vision Development Module.  It’s product page can be found here:
   
   Vision Development Module
   http://www.ni.com/vision/vdm.htm
   
   This software will enable you to do any type of image processing that your application may require.

Those are the basic components of an image acquisition system.  Hopefully you will be able to follow those links and gain a better understanding of what exactly you need to be able to setup the kind of system you are looking for.  This presentation provides a great deal of general information and may be able to answer some more specific questions you have: Imaging Fundamentals

http://www.ni.com/vision/vdm.htm

It also discusses camera and lens selection with respect to the image size and detail that you need.  Please let us know if you have any further questions related to this. Regards,
Luke H