Video Interpolation

You may have heard of video interpolation. Do you know what it is, though? Well, I have a pretty good understanding of it, and hopefully by the end of this post, so will you.

Interpolation is a way of creating slow motion video, using basic camera frame rates. All interpolation programs work basically the same way:
Let’s use a soccer ball as an example. In one frame, the ball is at the player’s foot. In the next frame, it is leaving the player’s foot. In the third frame, it is halfway to the goal. Then, in the fourth frame, it is in the goal. In order to be slowed down smoothly, that video would need more frames. That is exactly what interpolation does. It adds the ‘missing frames’ to the video, so that it can be slowed down smoothly. However, there are multiple issues with interpolation:

First,
Some of the action must actually exist in the original video. Interpolation would not work for filming a fire cracker going off at 30 fps (frames per second).

Second,
The software has to be very ‘intelligent’ to know what to do if there is, for example, a car passing behind a tree in one frame, and in the next frame it is out of the screen. How should the software display the added frames of the car? Should the car have part of a tree trunk attached to the middle of it? Should the be a missing space in the car where the tree was in the first frame? That decision is up to the computer program.

I took a video of flint and steel at 30 fps, and I added interpolation using a free program called SlowmoVideo. It really warped the video. Unfortunately, I can’t post if because I don’t have the video posting option, but maybe I can convert it to a .gif or something….I’ll see what I can do on that.

Despite these issues, interpolation works reasonably well at 60 fps. Here is a link to a video done using a $300 interpolation plug-in called Twixtor:
http://gizmodo.com/5863354/how-to-shoot-4000fps-footage-on-a-60fps-budget

Look for that video post, coming shortly!

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