Wavelet Projections for Volume Rendering

We extended Gross's method of volume wavelet rendering by computing splats via an orthogonal projection operator. The method decomposes the volume data into a wavelet pyramid representation in the spline domain. The splats of the basis functions are approximated on a multiresolution grid. Using least-squares approximation ensures the smallest possible error for a given sampling step size. The approximation error on the grid is derived as a function of the sampling step h. The choice of the appropriate wavelet space and spatial resolution at each step produces the smallest possible filters. Our approach reduces the number of computations and allows full control of the image quality.