“Spatio-Temporal Video Warping”

While spatial image warping is extensively used in image and video editing applications for creating a wide variety of interesting special effects, there are only very primitive tools for manipulating the temporal flow in a video. For example, we can compare temporal speeding up (slowing down) of the video to image resizing, or the “in-out” video selection to image cropping. But there are currently no tools that implement the spatio-temporal analogues of more general image warps, such as the various image distortion effects found in common image editing applications.
In this sketch we outline evolving time fronts, a new framework for spatio-temporal warping of video, which provides much more general time flow manipulation capabilities. The proposed framework is simple yet general, allowing a large variety of warps to be specified in an intuitive manner, resulting in many interesting and useful operations on video, ranging from subtle timing changes to eye-catching special effects. In this sketch we mainly focus on one novel effect: the spatio-temporal magnifying glass, which appears to be particularly well-suited for instant replays in sports broad- casts. Additional effects are discussed in [Rav-Acha et al. 2005a] and [Rav-Acha et al. 2005b], and the reader is referred to the following URLs: http://www.vision.huji.ac.il/dynmos and http://www.vision.huji.ac.il/videowarping.

CARPENDALE, M. S. T., LIGHT, J., AND PATTISON, E. 2004. Achieving higher magnification in context. In Proceedings of the 17th annual ACM Symposium on User Interface Software and Technology, ACM, vol. 6, 71–80.
RAV-ACHA, A., PRITCH, Y., LISCHINSKI, D., AND PELEG, S. 2005. Dynamosaics: Video mosaics with non-chronological time. In Proceedings of CVPR 2005.
RAV-ACHA, A., PRITCH, Y., LISCHINSKI, D., AND PELEG, S. 2005. Evolving time fronts: Spatio-temporal video warping. Tech. Rep. 2005-10, The Hebrew University of Jerusalem.