Instagram recently released its new Hyperlapse app for creating silky smooth timelapses in a hurry, and now we know how the technology behind the app actually works.
In the past, creating moving timelapses has been an expensive process that required camera rigs for video stabilisation. But by using the gyroscopes already inside your smartphone, Instagram’s Hyperlapse app is able to eliminate the jitters usually found in smartphone videos.
You can see a few examples of timelapses created using the Hyperlapse app above.
The video stabilisation algorithm is called Cinema, and it basically smooths out the orientation of each frame using your smartphone’s gyroscopes to counteract the motion of your hand.
Cinema then crops the video, finding an optimal camera motion that stays within the section that’s kept steady. Notice how the black border, or “empty space,” never dips into the frame.
Another nifty feature of Cinema lets the Hyperlapse app only apply its magic to the frames being used to create your timelapse. Instagram’s engineering team says this allows the app to “output a smooth camera motion even when the unstabilized input video becomes increasingly shaky at higher time lapse amounts.”
Since Hyperlapse needs to zoom in to find an optimal shake-free section, there’s a tradeoff between resolution and stability.
Instagram says its zoom is intelligent and responds to the amount of shake in a video, so you’re better off trying to hold your phone a little more steady if you’re worried about seeing a big dip in resolution. The less shaking the Cinema algorithm detects, the less it has to zoom in to find an unaffected section.
Here, for example, you can see how Cinema can use more of the steadier video on the left than the shakier video on the right.
You can read the full in-depth explanation of the technology behind Hyperlapse over at the Instagram Engineering blog.