Image acquisition with 3 USB cameras causing too much memory/cpu usages

[hart]

Dear experts,

I am trying to capture images with 3 USB cameras located at 3 different positions. I have to initialize each USB cameras using enumerate camera vi when switching among cameras. I realize that by doing that method causing too much memory/cpu usages and might cause CPU to hang up. If I stop the program, the memory/cpu meter are going down.

Do you know how to minimize this problems. 

Thanks,

hart

[K_Bull]

Hi,

Do you mind posting your VI to show me how you are doing this? I will see what I can do for you.

Regards, 

[muks]

Hi hart,

            IS it a parallel capture that u r attempting?Is any one camera waiting for a trigger?As kabul mentioned posing your vi or a screen shot will defenitely help

[wbadry]

hi hart,

         USB cameras consumed tremendous amount of memory. New USB 2.0 cameras has much more bandwidth to consume rather than 1.0 and 1.1 counterparts which made it less CPU power consumer. Here is a tip, if you want to use mutiple cheap cameras with LABVIEW, you can buy a cheap analog camera (30 $) and a TV tuner (about 20 $ ). LABVIEW USB driver deals with any directshow cameras. these include video streaming from TV tuners.

It soved a problem with students of mine once, and we got rid of memory leak.

[pallen]

Here is a tip, if you want to use mutiple cheap cameras with LABVIEW, you can buy a cheap analog camera (30 $) and a TV tuner (about 20 $ ). LABVIEW USB driver deals with any directshow cameras. these include video streaming from TV tuners.

---

So, you connect multiple analog cameras to a single TV Tuner card and then use the directshow drivers to pull in a single stream from the tuner card?  

This sounds interesting.   

[wbadry]

You can buy TV tuners with multiple inputs, even old ones has:

• One port for A/V in
• One Port for Composite Video in

the third can then be utilized using USB port (only one USB camera is to be hooked up and thus the CPU load will vanish for good).

It is worthy to say that TV tuner is better to be PCI (we don't want to return back to USB latency 🙂 )

[Michelle_N]

hart,

Thank you for using our forums! The IMAQ for USB driver has a known memory leak. Please read the known issues section on that link. But it all depends on how you are calling the cameras. Please post you code.

[hart]

Dear Kabul M,

I would like to post the vi, but I made a lot of sub vi and are located in different folder, do you know how to merge all the vi? So that none of the sub vi missing when sending to you. 

Thanks.

Regards,

hart

[muks]

Hi hart,

You  can post the vi after converting it into llbs.

[muks]

Click save as and choose new llb.

Message Edited by muks on 08-28-2008 06:22 AM