Opensource tool to create slowmotion videos from your footage

To find optical flow, you first pick out a collection of sample points in frame A. What constitutes a good sample point depends on your specific algorithm, although generally speaking you pick "corners". In OpenCV, you can easily do this by calling cvGoodFeaturesToTrack().

You then search for those same sample points in the successive frame B, and end up with a collection of vectors that probably represent the motion of each point. Using OpenCV, this is usually done with cvCalcOpticalFlowPyrLK().

Tweening is basically just interpolation.

Optical Flow is a method for determining the movement between two or more frames of video. This data is then used for morphing the frames into one another, or moving the underlying vertexes of the textures from one position to the next.

Sadly its only interpolating the motion between frames, so you don't get back any new information.

Also optical flow really doesn't handle occlusions very well, so if one thing obscures another you'll get lots of artifacts.

That makes me shudder. Security footage "compressed" this way wouldn't stand up in court (I hope); did the guy on the tape really do that, or did the algorithm just fill it in?