Lighting effects for digital video effects system.

摘要

Lighting effects for a digital video effects system are provided by means of a write-side process. An array of pixels values from an source video image is mapped onto an object surface to produce an output image by storing the input image pixels in a memory 13 and then selectively addressing the memory in accordance with a function defining the object surface to form output pixels representative of the source video image mapped onto the object surface. Before storage in the memory, however, the intensity of the source pixels are modified by write side lighting processor 19. In order to achieve this, the source images are logically divided into tiles, a mapping of the corners of which onto the object surface is calculated (bY 32) and the mapped corner points are used (by 33) to compute normals for individual pixels using interpolation. The dot product of the interpolated normals are computed and mathematically combined with other factors to generate lighting intensity modification factors for each of the pixels of the source image. These factors are used to control the lighting processor. The pixels output by the lighting processor can be selectively filtered (by 12) before storage in the memory to mitigate aliasing effects. <IMAGE>