Coherent image-based rendering of real-world objects

Abstract

Many mixed reality systems require the real-time capture and re-rendering of the real world to integrate real objects more closely with the virtual graphics. This includes novel view-point synthesis for virtual mirror or telepresence applications. For real-time performance, the latency between capturing the real world and producing the virtual output needs to be as little as possible. Image-based visual hull (IBVH) rendering is capable of rendering novel views from segmented images in real time. We improve upon existing IBVH implementations in terms of robustness and performance by reformulating the tasks of major components. Moreover, we enable high resolutions and little latency by exploiting view- and frame coherence. The suggested algorithm includes image warping between successive frames under the constraint of redraw volumes. These volumes form a boundary of the motion and deformation in the scene, and can be constructed efficiently by describing them as the visual hull of a set of bounding rectangles which are cast around silhouette differences in image-space. As a result, our method can handle arbitrarily moving and deforming foreground objects and free viewpoint motion at the same time, while still being able to reduce workload by reusing previous rendering results.