Movement Difference filter

blackburst's picture

Can anybody please shed some light on whether there already is, or how to make a "difference" filter that only shows the moving parts of the image. I call it difference filter because that is what it was called in Isadora and it worked quite well. I want something to filter out static backgrounds from a moving foreground, I believe an apple isight app did something similar. Any suggestions/links?

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pixelnoizz's picture
Re: Movement Difference filter

i wrote a tutorial about that: http://pixelnoizz.wordpress.com/2011/04/26/what-a-difference-a-very-usel...

i copy paste the important part here:

Then lets work on the motion detection part. There are many solutions to do this(optical flow by Vade) , but i would like to use the simplest solution. Lets get the difference of two frames, for that lets use a ‘queue’ node (size 2) and a structure index member (index: 0). How does it works? I put my video signal in to the queue, so it will generate a structure of images, in this case a structure with two members (0 and 1), after i will choose the first image from the structure. Now i just need to compare with the original image, for this i will use a ‘different blend’. So i will put the original image as background and the structure index member output as the other image. Voila we have the motion image.

cybero's picture
Re: Movement Difference filter

LOL - I do love a sense of irony "super useless tutorial".

blackburst's picture
Re: Movement Difference filter

So helpful p/n thanks heaps, I've found a few pieces and tutorials from you very cool, thanks a lot.