Imaging algorithm for volumetric display based on double-helicoid scanning screen

We present an imaging algorithm for a volumetric display using double-helicoid scanning screen. Swept-volume approach is employed to display 3-D image that occupies a volume of real 3-D space. We use 3-D discrete volumetric data as image source, and subdivide the array of voxels into a number of layers by the double-helicoid rotating screen, and then we render each layer of the voxel into an image frame respectively. Finally, the series of frames are projected on to the synchronous rotating screen by a high-frame-rate projector in time sequence, so the whole spatial image can be scanned out by the screen layer by layer. The software of image rendering and display control has been designed and tested on the volumetric display system. Volume visualization in actual physical space is realized; viewers can watch the spatial images directly from omni-directions and change views directly by changing viewing position, just as observing real physical object.