Part of 3DLife's major goal to bring the 3D media Internet to life, concerns the development and wide-spread distribution of online tele-immersive (TI) virtual environments. As the techniques powering challenging tasks for user reconstruction and activity tracking within a virtual environment are maturing, along with consumer-grade availability of specialized hardware, this paper focuses on the simple practices used to make real-time tele-immersion within a networked virtual world a reality.

We propose a method for segmentation of frontal human portraits from arbitrary unknown backgrounds. Semantic information is used to project the face into a normalized reference frame. A shape model learned from a set of manually segmented faces is used to compute a rough initial segmentation using a fast iterative algorithm. The rough initial cutout is refined with a boundary based algorithm called "Cluster Cutting". Cluster Cutting uses a cost function derived from clustering pixels along the normal of the initial segmentation path with a tree-building algorithm. The result can be refined by the user with an interactive variant of the same algorithm.

Acquisition of consistent multi-camera image data such as for time-slice sequences (widely known by their use as cinematic effects, e.g. in "The Matrix") is a challenging task, especially when using low-cost image sensors. Many different steps such as camera calibration and color conformation are involved, each of which poses individual problems. We have developed a complete and extendable setup for recording a time-slice image sequence displaying a rotation around the subject utilizing a circular camera array. Integrating all the aforementioned steps into a single environment, this setup includes geometrical and color calibration of the camera hardware utilizing a novel, multi-functional calibration target as well as a software color adaption to refine the calibration results. To obtain a steadily rotating animation, we have implemented an image rectification which compensates for inevitable mounting inaccuracies and creates a smooth viewpoint trajectory based on the geometrical calibration of the cameras.

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