Rolling shutter using Pixelink camera?

[Steverino]

I am using a Pixelink PL-A781 camera. When I switch from Format 7 (2208 x 3000) to Mode 5 (640 x 480), it works fine. Switching back works fine, too, except the image "rolls" from right to left on a frame-by-frame basis. If I stop the grab then re-start it everything is fine.

I use the following commands to start the acquisition

• imaq1394SetupGrabCW to set up the acquisition
• imaq1394Grab2CW (for each frame I want to acquire)

When I stop, I use

• imaq1394Close

Any ideas of how I can get around start, stop, then re-start to avoid the rolling image?

Thanks!

[viksiv]

Hi,

Have you tried to perform same camera Mode switches in MAX? Try and see if the problem persists.

Some cameras do not like changing acquisition Mode while acquisition is in progress. In this case stopping the acquisition, changing to required Mode, and immediately re-starting the acquisition should help. This is different from changing acquisition parameters like Gain or Shutter, which usually can be changed "on the fly".

Regards

[Steverino]

Yes. The same thing happens. Except in MAX, I need to stop the grab, click on a different camera, then click back to the original camera in order to avoid this problem.

[viksiv]

I wonder what will happen when you try to control only one camera with MAX. Will you have the same problem?

The other thing to try is (that's for Labview. I assume there should be equivalent functions in LabWindows/CVI):

1. Call IMAQ1394 Clear Acquisition

2. Change VideoFormat, VideoMode and VideoRate as required using Property Node

3. Call IMAQ1394 Grab Setup again

4. Start acquiring

At least this procedure works for my Basler 102f camera where I can switch between Format 7, Mode 0 (1392x1040 @ 15 fps), Mono8 (1280x960 @ 15fps), and Mono16 (1280x960 @ 7.5fps).

If not, the only remaining option may be closing IMAQ1394 sesion and starting it again as described in my previous reply.

Regards