NI VideoMASTER and NI AudioMASTER

[Roberto83]

Hello everybody,

I am trying to do a simple task yet I have been unable to complete it successfully.

I have an avi video and I want to extract a particular frame from it, then I want to subtract this frame to other frames in the video, this could be helpful for instance to remove the background from a video. The video corresponds to a bubble that grows and collapses in a few frames.

I am able to do the subtraction from operation (i.e.. Frame 2 - frame 1); I then convert the resulting image to a grayscale image (SSL) with the IMAQ cast image VI/ However, the resulting image is all black. I expected to see the difference between the two images as a dark ring that shows the growth of the bubble and not only a black image. 

Can somebody give me a hand with this problem?

I am attaching the VI and the video(Test.avi). 

Rob

[Vegemite]

Hi Roberto83

You probably have to allocate memory for both Frame A and B by using IMAQ Create.

See attached VI.

[Roberto83]

Thank you for your assistance Vegemite.

I was unabel to open the vi because I am using version 8.5, by any chance can you save it a an 8.5 version.

Thanks again

Rob 

[Vegemite]

Hi Rob

here is 8.5 version of VI.