how to increase the size of acquisition window in C++ code

[zhiwei]

Hi,

I am using PCI 1405 to continuously acquire video images from vcr playback.

I tried to make use of the OnGrab function provided in the sample files, and included this function into my C++ application, without using LabView.

However I have difficulties increasing the size of the acquisition window (the maximum seems to be 640 by 480) using the api functions of the niimaq.h.

Thanks a lot.

Best regards

[jamrite]

Hi,

The size of the image depends on the source (like the camera or the VCR in your case). So there is no way of changing this size in software.

However, if you want to aquire and record only a part of the image, then you can use the imgGrabArea() function.

Thank You,

Jaidev Amrite

National Instruments

[zhiwei]

Hi,

Thanks for your reply.

I am using Panasonic VCR AG-7350.

So there is no resize function available to increase the image size?

How about the refresh rate? Is it possible to change the refresh rate. Currently the frame rate is 25 frames per second.

Thanks again.

Regards.

[jamrite]

Hi Zhiwei,

As with the frame size, frame rate also depends on the source. If your VCR can only generate 25 frames per second, your card cannot acquire any faster than that. And if you tried to acquire at a higher rate, you would just get duplicate frames.

Jaidev Amrite

National Instruments