Treffer: Semi-automatic modifications of video object trajectories for video compositing applications

This paper proposes a new approach allowing efficient and semi-automatic object-based manipulation for video editing or post-production applications, such as the modification of the trajectories of video objects in a natural scene. For that purpose, an image is seen as a superposition of video object planes (VOP) on an original image or a mosaic view of a fixed background. The method is based on the definition of an editing scenario which contains all the information required to create the edited sequence. A warping model is used to represent the location and the modification of the video object in the 2-D scene. Such an application is by nature semi-automatic since the operator has to specify the modifications that he wants to perform on the original sequence. The proposed method has been designed in order to reduce as much as possible the human workload by using the notion of key VOP and by calibrating in depth the fixed background area. Experimental results show that a high level of realism can be obtained on edited images in which the original trajectories of non-rigid video objects have been strongly modified.