High quality rendering and physics-based modeling in volume graphics have been limited because intensity-based volumetric data do not represent surfaces well. High spatial frequencies due to abrupt intensity changes at object surfaces result in jagged or terraced surfaces in rendered images. Use of a distance-to-closest-surface function to encode object surfaces allows accurate reconstruction of objet surfaces for volumetric data. However, constructing the distance map for distance-based rendering requires a prior model of the object surface. Here we present a number of methods that can be used to estimate the distance map from a binary segmented volume, where no prior knowledge of object surfaces exists. |
