2 METHODS FOR WAVELET-BASED VOLUME RENDERING

This paper describes two methods for wavelet domain rendering of volum e data sets, which are based on entirely different paradigms for the a pproximation of the underlying volume rendering equation. The first ap proach comprises a ray-tracing algorithm for cardinal B-spline wavelet representations of both color and opacity values and generates high q uality images. We especially propose elaborated integration and evalua tion schemes, where the computation of shading is also performed in wa velet space. The second approach proposes a fast intensity integration method based on wavelet splats. This scheme takes advantage of the se lf-similarity of the basis functions and computes the required splats by Fourier projection slicing. At this point, it unifies the advantage s coming along with Fourier domain and with wavelet domain rendering a nd it avoids some of the major artifacts the first one is prone to. Du e to the computational efficiency, the splatting method allows the com putation of coarse approximations at interactive rates and refines the picture progressively. (C) 1997 Elsevier Science Ltd.