Evolving Time Fronts: Spatio-Temporal Video Warping

Alex Rav-Acha,  Yael Pritch,  Dani Lischinski,  Shmuel Peleg 
Abstract

We propose 'evolving time fronts', a new framework for spatio-temporal warping of video. The proposed framework is simple yet general, allowing a large variety of spatio-temporal warps to be specified in an intuitive manner. Specifically, we manipulate the time flow of a video sequence by sweeping an evolving 'time front' surface through the video's aligned space-time volume. Specific strategies for time front evolution are demonstrated to produce a variety of interesting and useful operations on video, ranging from subtle timing changes to eye-catching special effects, creation of dynamic panoramic mosaics, and parallax effects. A technical report describing the Evolving Time Fronts video warping framework in more details Simple Evolving Time Fronts Select the winner in any race. By enabling time to flow differently at different locations in the video, we create new videos with any desired winner. Demolition: Customize the way you want the stadium to be blown: Starting at the sides or starting at the center? Dynamic Panoramas All water flows down simultaneously in a panoramic view, although each part was captured at a different time! Special Effects Watch the Dunks! The Magnifying Glass lets you focus on a single action in the video, slowed down and magnified. Drawing with Time: The "text over waves" is written merely by shifting time at designated locations. Parallax Effects Creating new movies as if taken from new viewpoints is just a special case of the spatio-temporal video warping