Efficient space-leaping method for volume rendering

Volume rendering is a technique that visualize 2D image of object from 3D volume data on image screen. Ray casting algorithm, one of popular volume rendering techniques, generate image with detail and high quality compared with other volume rendering algorithms but since this is a highly time consuming process given large number of voxels, many acceleration techniques have been developed. Here we introduce new acceleration technique, efficient space leaping method. Our new space leaping method traverse volume data and projects 3D location of voxel onto image screen to find pixels that have non-zero value in final volume image and locations of non-empty voxels that are closest to ray. During this process, adaptive run-length encoding and line drawing algorithm are used to traverse volume data and find pixels with non-zero value efficiently. Then we cast rays not through entire screen pixel but only through projected screen pixels and start rendering process from non-empty voxel location directly. This new method shows significant time savings applied to surface extraction without loss of image quality.