Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics. To help physicians fully understand deep seated human organs and focuses ( e.g. a tumour) as 3D structures, in this paper, we present a modified volume rendering algorithm to render volumetric data. Using this method, the projection images of structures of interest from different viewing directions can be obtained satisfactorily. By rotating the light source and the observer eyepoint, this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time. Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.
