Frequently asked questions for IVision


General Questions:



1.            What is IVision LabVIEW toolkit at all?

IVision LabVIEW toolkit is a developer SDK for LabVIEW language. It has over 380vis, covers functions of video capturing, image processing, avi/media file read and write, video blending etc. The video capturing devices can be USB webcam, firewire/IEEE cameras, DV camcorder and TV tuner etc. It’s based on DirectX/DirectShow for video capturing and OpenCV for image processing, work on Windows platform.

2.          Do the vi icons mean anything?

For image processing functions, a vi icon with yellow background means they work on color images. With gray background means they only work on single channel image. With half yellow and half gray background means they work on both color and single channel image. Other vi icon backgrounds are for either examples or high level vis


3.            Where can I get help document of your IVision vis?

For controls and vi descriptions, you can use LabVIEW context help window (ctrl+H) and move the mouse over the controls and vi icons to see the descriptions. There are also some comments on the example’s front panels and in the block diagram. You can also find html format documents in our website, but they are not always updated. In future version, we will compile into help file.

4.            I download the Ivision LabVIEW toolkit, but when I try to open the IVision_All_vis.llb, it says “missing d3d9.dll” and I’m not able to open any vis. Why?

You need to upgrade your computer system to directx 9.0 runtime. Please go here to get it:

5.            What is development license, what is runtime license for IVision LabVIEW toolkit?

The development license for IVision LabVIEW toolkit is needed when you design LabVIEW code, which means you need to load IVision into LabVIEW. The runtime license is needed when you distribute your standalone application that does not need LabVIEW design environment, but only LabVIEW runtime engine. Users always need to first purchase development license before they can order runtime licenses.

6.            I got error at the end of IVision installation when it tries to use” regsvr32.exe” to register the directshow filters.

Most computers would register the filters just fine, but there are exceptions. In case the filter registration failed, do the following, this works for WinXP, vista or Windows 7, both 32bit and 64bit:

Reboot the computer and press F8 to go to Safe Mode, then manually register the .ax (directshow filter file) by going to Start->Run…, in command window, type in following:

C:/windows/System32/regsvr32  --- this is for 32bit

C:/windows/System32/regsvr32  --- this is for 32bit



C:/windows/SysWOW64/regsvr32  --- this is for 64bit

C:/windows/SysWOW64/regsvr32  --- this is for 64bit


When both filter registrations succeed, reboot the computer and go back to normal mode.


7.            How do I get started quickly with IVision?

The best and quick way to start is by looking at the examples in IVision. The first vi to load is “”, it’s block diagram organizes all IVision vis into different groups. There are many examples and usually you just need to run it, you should see the results. For camera/video capture devices, the best example to start with is Browsing through all the vis description will also give you some ideas of what IVision’s capabilities are.

8.            I have installed IVision older version, should I delete it?

Yes, it’s recommended that you uninstall or delete or backup the previous IVision toolkit to avoid confusing of maintaining multiple copies of vis. It’s always good practice to save your vis in different names if you modify some of the IVision vis, so that the upgraded version will not overwrite your modified vis.



Video Questions:

9.            Does IVision work with USB webcam?

Yes, as long as you have installed the WDM or VFW driver provided by the camera vendors.

10.    Does IVision work with firewire/IEEE1394 cameras?

Yes, as long as you have installed the WDM or VFW driver provided by the camera vendors.

11.   Does IVision work with DV camcorder?

Yes, luckily you don’t need any driver for DV camcorder.

12.   Does IVision work with TV tuner?

Yes, as long as you have installed the WDM driver provided by the device vendors.

13.   Does IVision work with frame grabber?

Maybe, as long as you have installed the WDM or VFW driver provided by the card vendors.

14.   Does IVision work with ATI All In Wonder (with TV tuner)?

Yes, as long as you have the proper driver installed. ATI All In Wonder can be used as TV tuner or as frame grabber.

15.    I got an error saying “A system resource is being used by another program” when I try to open the ATI TV tuner session, why?

Either the device is in use by other WebTV program or sometimes even you just click on an avi file in the windows explore, it also uses the ATI hardware resource. You just need to click on any other file such as txt file and it’ll fix the problem.

16.    Can I access the image frame from live video?

Yes, you can use the “snap” functions to grab one image at one time, or you can use callback vi to process the image continuously while video is streaming.

17.    Can I play back AVI file, mpeg, DV format or asf file?

Yes, there are two ways to playback avi file, using the legacy VFW based AVI functions or media file functions in IVision, VFW based AVI functions can only play uncompressed or certain compression format avi files while media file functions can play almost any modern format avi files.

18.    Can I record live video into avi files?

There are two ways to record video into avi files. The first way is using the legacy VFW based AVI functions, you can snap an image, and write to avi file frame by frame. The second and better way to record video into avi file is using the media file functions, it’ll record continuously, you can record audio along with video too. Both methods provide selectable compressions.

19.    I want to show two camera’s live video side by side or picture in picture, can I do that with IVision LabVIEW toolkit?

Yes, see the example You can adjust alpha channel for each video as well as position and size of each video.

20.    I want to playback two avi files side by side or picture in picture, can I do that with IVision LabVIEW toolkit?

Yes, see the example You can adjust alpha channel for each video as well as position and size of each video.

21.   How can I distinguish two cameras with the same model?

Using the

22.   Can I control the camera settings and video format?

Yes, there are always functions to bring out dialog window for settings, but there are also many camera functions in IVision to set these settings programmatically. Check the video capture device function group in Ivision_All_Vis.llb.

23.    Why my camera is listed under the ni-imaq for 1394, not in “Imaging devices” in the device manager and IVision does not work?

The problem is if you have ni1394 driver installed, some IEEE1394/firewire camera will be forced to be listed under the ni-imaq 1394 camera rather than normally under the “Imaging devices” group in the device manager. This will prevent any applications that use DirectShow to work for these cameras. So you need to change the configuration in the MAX to let cameras registered as it’s original name rather than ni1394 camera.. Important is making sure your 1394 cameras are listed under the “Imaging devices” group in the device manager.

24.   Where can I get the WDM driver for Basler IEEE1394 camera?

Many camera vendors today provide their own DirectShow compliant WDM drivers. But Basler does not provide this for their firewire cameras. A third party software “fire-i software” from Unibrain provide this WDM drivers for the Basler cameras. It seems that this WDM driver also works for other vendors such as Unibrain®, ADS®, AVT®, Basler®, Hamamatsu®, JVC®, MicroPix®, OrangeMicro®, PointGrey®, Sony®, Teli®, Victor®. Check out the link:

25.   Why my second camera does not work when I unplugged the first one and plug in my second one?

You need to first call the “” to erase the record of existing cameras in the system, then you can try your program again. Because once you call the “” once, it will keep the records of the existing cameras, so when you unplug and plug in a new one, it won’t auto detect the changes until you call the “” to erase the memory, then call the “” again to initialize the camera system.



Image Processing Questions:

26.    I prefer to use IMAQ-Vision for image processing, can I convert IVision image format to IMAQ?

Yes, you can. We have functions in IVision can do that. Try out the example "Acquire Camera" in IVisionToIMAQ.llb.

27.    I got a memory access error when I exit LabVIEW while there is still an image window not closed?

You should close down all IVision image windows before exit LabVIEW to avoid error message. can be used.

28.    LabVIEW crashes when I try to use some image processing functions, why?

Please make sure the image type is correct. Some image functions work for both color and gray, some only work for color or gray image and some functions require binary image. Please use the right type image. Besides the vi description, there are controls descriptions for image functions. Please move your mouse over these controls  and see the document in LabVIEW context window.