capture an image from usb camera

Hi.

I have a logitech quickcam communicate deluxe/s7500.

I tried to capture an image using the usb camera app in qtopia.

The Cam is on, but image is all black. And the snap image had 0Kb data.

The cam works fine on window7 and support the YUV422 format.

How can I figure out this?

hi i have logitech usb webcam and i have the capture programm took it form
this site but i couldnot able get picture instead i get blank screen.

any one can help me regarding the above query

i could able get  the image using usb webcam please anyone help me