Patent ID: 7692651

Claim:
A method for image based rendering datasets, said method comprising: (a) providing a digitized volumetric comprising a plurality of intensities corresponding to a domain of voxels in a 3-dimensional space; (b) performing a pre-processing step, said preprocessing step comprising constructing a min-max Reduced Path Octree data structure and storing emptiness information for each node in the min-max Reduced Path Octree data structure in one memory byte, wherein the min-max Reduced Path Octree data structure comprises a plurality of levels and each of the memory byte includes emptiness state of a given node and the six immediate neighbors in the min-max Reduced Path Octree data structure, wherein bits 0 to 5 of the memory byte are used to store emptiness state information of the six immediate neighboring nodes, bit 6 of the memory byte is used to indicate whether the current node has been updated with useful information and bit 7 is used to store the emptiness state information of the given Reduced Path Octree node; (c) generating a 2-D image by casting a ray from each pixel of the image into the volume; (d) visiting each level of the Reduced Path Octree node and determining the emptiness of nodes at each level from the corresponding memory byte during the advancing of said ray; and (e) sampling along the ray inside only the non-empty nodes of the Reduced Path Octree data structure and skipping empty nodes associated with the min-max Reduced Path Octree data structure along the direction of the ray based on said memory byte included in each node.