Usb Webcam Light Led Activation

[Mic_Scale]

Hi All,

I possed Labview 7.1 including the Imaq Vision.

I would like to have an usb webcam set in a completely dark place (inside a machine) and then acquire pictures whenever an internal view point is needed. For this purpose I'm going to need a webcam which has light leds to light up the dark.

My question is, does Labview support this feature of light led activation in a usb webcam ? If not, maybe there is another way ?

Another thing I would like to ask is this. We are very limited with space for the webcam inside the machine. Therefore we need to find a camera which is both as small as possible, has light (and if possible zoomable via software). Does anyone know where I can find these kind of requirements ?  During my search I've encountered a pretty limited design variety of webcams.

The closes thing I could find is a camera which has 6 light leds, not zoomable and not a convenient design.

I'm attaching the picture.

Any kind of help would be highly appreciated.

[alipio]

Hi Mic.
Probably, you will get info about webcams for your needs.
You can try Hercules DeLuxe one ( http://www.hercules.com/showpage.php?swcty=UK&p=130&b=0&f=0).
Its size is very good and it has 4 leds for illumination and it is not zoomable.
You can try ...

Cheers
Alipio

[Irene B]

Hi Mic,

From what I understand you're trying to use LabVIEW to control the LEDs on a USB webcams and acquire images from it.  If you take a look the KnowledgeBase article Acquiring Images in LabVIEW Using a USB or an IEEE1394 (Firewire) Camera, it lists several ways to at least acquire images from the USB camera.  If you choose to use the NI-IMAQ for USB Cameras driver (which is currently not supported by NI Applications Engineers), make sure that the camera uses Direct Show filters. 

As for controlling the LEDs, your best bet will probably be to try Options 3 or 4 of that KnowledgeBase article I linked above.  Most likely, the camera will have a driver provided by the manufacturer, which may have functions that allow you to control the LEDs.  If this is true, then you can access the driver DLL using the Call Library Function Node in LabVIEW.  The last option would be to use direct USB commands to the camera using USB VISA VIs in LabVIEW, but it's quite possible that the camera company will not give you the USB commands to use.

Hope this helps,
Irene Chow
National Instruments
Applications Engineer