View-Dependent Octree Image Rendering

This paper considers view-dependent rendering method for 3D models represented as binary volumetric octree (BVO) together with reference images and corresponding cameras locations. This representation was proposed and accepted to MPEG-4 AFX (Animated Framework eXtension) as Octree Image Node in the Depth-Image Based Representations (DIBR) group. Originally DIBR-objects were assumed to be diffuse. In this paper we propose the techniques capable to represent and render such objects with dynamic lighting, semi-transparency and with imagebased view-dependent effects. The dynamic lighting is achieved by reconstruction of normals for each voxels of BVO with subsequent object relighting. The information of semitransparency is proposed to be stored as alpha channel of images. The correct transparency rendering is achieved by using BVO format capability to provide fast and correct back-to-front voxels traversal. Image-based view-dependence results from the images redundancy used in a special way in order to render voxels color.