| 摘要 |
<p>The invention relates to a method for rendering of a volume data set on a two dimensional display. According to the method of the invention gradient vectors of voxel values are computed and are replaced by an index into a gradient look up table, thereby reducing the amount of required memory as well as the number of memory accesses during rendering. For each point on a two-dimensional view plane a ray is cast into the volume. Then the volume data is sampled at discrete sample points along each individual ray. During rendering eight gradient vectors of the neighboring voxels at each sample location are retrieved from the look up table. The invention proposes to apply dithering to the gradients before selecting the appropriate index. Recovery of the true gradient value is achieved because of the interpolation. Thus image artifacts, such as intensity bands caused by the discretization of the gradients, are avoided.</p> |
