In the run-up to the computer generated image fair Siggraph 2021 starting on August 9th, as usual many interesting new projects are published - one of them is a method to animate parts of a photo (or video) in loops, which leads to very interesting image effects. The special thing is that you can not only view the resulting animated loops (aka cinemagraphs), but also create them yourself using an app (iOS/Android).
But how does the algorithm ( Endless Loops: Detecting and Animating Periodic Patterns in Still Images ) of the research team at Israel&s Interdisciplinary Center Herzliya work? It detects periodic structures, such as the windows of a building or the steps of a staircase, and generates a special displacement vector field that maps each segment of the structure to a neighboring segment along a main direction of motion chosen by the user or automatically.
This displacement field is used together with temporal and spatial smoothing to distort the image and create the frames of a continuous animation loop.
Lightricks& Motionleap app ( Android /iOS ), which implements the new algorithm and is partially paid for, generates such cinemagraphs on a smartphone in less than a second, allowing users to interactively try out different animations or even correct mistakes immediately.
Several image areas can also be animated at once in the app. The app also works with videos - even in a shaky video, selected parts of an image can be looped independently of the rest.
Users of the app can select which (structured) image components to animate and loop, and also specify the direction of movement. The results can be as realistic (such as water movement or smoke) as surreal animations, such as steps or other parts of a building moving unnaturally. Here we present the new method (which for once is not based on neural networks) of 2 Minute Papers:
The new method once again increases the arsenal of possibilities for animating images in a variety of ways - for example, the Deep Learning Algorithm Photo Wake-Up brought figures from images to life realistically.