Thread Subject:

DV Image Acquisition

Hi ,
I am using Image Acquistion (trial software) with Matlab
to grab 60 frames (2 seconds) of DV video. My frame
trigger is set to default (instantaneous). I am able to
grab 60 frames of video, but it is not in realtime. i
find that there is a delay of 0.26 seconds between the
start of trigger and the first frame grabbed. Please note
that frames are grabbed into memory at the moment. The
computer has a core duo processor with 2 GB of memory. Are
there any other Mathwork solutions for realtime image
acquistion? Any help is greatly appreciated.
Thanks,
Sudha.

Sudha wrote:
> Hi ,
> I am using Image Acquistion (trial software) with Matlab
> to grab 60 frames (2 seconds) of DV video. My frame
> trigger is set to default (instantaneous). I am able to
> grab 60 frames of video, but it is not in realtime. i
> find that there is a delay of 0.26 seconds between the
> start of trigger and the first frame grabbed. Please note
> that frames are grabbed into memory at the moment. The
> computer has a core duo processor with 2 GB of memory. Are
> there any other Mathwork solutions for realtime image
> acquistion? Any help is greatly appreciated.
> Thanks,
> Sudha.

Sudha,

I'm confused by your use of the phrase "real time". What you are
describing sounds like an unacceptable latency, not a lack of real time
capabilities. When you call START on an a videoinput object, the
toolbox must connect to the hardware, configure it, and then wait for a
valid frame to come in. Depending on your hardware this can take
anywhere from a few milliseconds to almost a minute.

 From your description above, I think that using the manual trigger
option should alleviate your problem.

-Dave Tarkowski