video effect. december 2001.
as i found out later the timewarp effect is already pretty well established and has gone through many incarnations. for an excellent compilation of similar approaches see » golan levin’s » Informal Catalogue of Slit-Scan Video Artworks.
the effect allows you to see a video not in the traditional linear way but distorted (warped) through time. my goal was to allow arbitrary warpings through time. what you see in one frame is not only the information of one time slice but parts of several consecutive frames merged together. to specify which parts of the resulting image resemble which slice in time you have to provide a grayscale mask. where there is a white pixel in the mask a pixel of the most current image is taken for black pixels the oldest images are used and the gray scale accounts for time in between.
» eno used my timewarp effect in one of his works. he used a radial gradient like the following to postprocess a video.
i implemented a version of this effect as an external for max/nato for use in realtime scenarios. you can have it (with sources) on request as it has some weired bugs.