skahlert

I was wondering if or how it is possible to create an average of a video over a certain time.

My idea is to remove the moving parts of a video stream and emphasize the static parts.

So I guess I need to accumulate several frames into one matrix. I just don't know how to accomplish this.

By the way, how do I stop a bang message from traveling all the way down my patch?

I was wondering if or how it is possible to create an average of a video over a certain time.
My idea is to remove the moving parts of a video stream and emphasize the static parts.

averaging-multiple-frames

sounds like you're trying to do the reverse of background subtraction (foreground subtraction?)

search the forum for "background subtraction". plenty of examples. that will be a start.

please make sure you've done the max and jitter tutorials first, otherwise the patches won't make much sense.

sounds like you're trying to do the reverse of background subtraction (foreground subtraction?) 

search the forum for "background subtraction".  plenty of examples. that will be a start.

please make sure you've done the max and jitter tutorials first, otherwise the patches won't make much sense.


look to jit.op @op absdiff, this can be used with successive frames if you connect the same input to each inlet (in the correct order). it'll find any difference between the two current frames, so the output will be mostly a black video, with lighter sections representing anything that moved and how much. so then you can use the static part for whatever you want (run it through a threshold operator like jit.op @op > to extract only the black parts). Basically look to jit.op in general and then figure out the procedure to look at successive frames. There's also a way to collect a number of frames and average them, look also to jit.3m. Probably there are many other operations which will help down the road.

For the bang (as well as any other message): it will travel as far as it's allowed. You must determine where/when it stops based upon what objects it goes into and/or through. Anyplace it "finishes", like a storing inlet in a [pack] or a closed [gate], that'll be it for its lifetime, for that run. So unless you've closed a gate or something similar down the path before you start the bang, it'll go until it's stopped elsewhere.

Read up about [trigger] or [t] and use it everywhere you need more control over order of operations, it's an absolutely indispensable object and allows you to get around any right-to-left ordering issues. I use it liberally, probably in places it's not needed, but that's OK, it really helps you determine, organize, and understand the flow of things in your patches.

Averaging multiple frames