Fast digital perspective shell rendering

Volume visualization methods usually require extensive storage and time-intensive computations. To make them viable in many applications, researchers have proposed various types of hardware-based and software-based solutions. In most of these solutions, the rendering is based on orthographic parallel projection. However, in applications such as virtual endoscopy, perspective projection is necessary to allow the observer to travel inside the structures. In this paper, we extend one of these software-based solutions, called shell rendering, to provide fast digital perspective projection. The main idea in digital perspective is that each voxel should be rendered using an integer number of pixels which is inversely proportional to the distance between the voxel and the observer and that that distance can be discretized. We show that the new method, called digital perspective shell rendering, provides the same image quality as orthographic parallel projection.