Abstract: Production and processing of data representing digitized images are disclosed. The disclosure addresses the problem of providing an image which simultaneously represents both high spatial resolution information and low spatial resolution information which pertains to the high spatial resolution information. Images may be produced which represent high spatial resolution information in the form of relative luminance contrasts, and represent low spatial resolution information in the form of color variance. Images representing high spatial resolution information may be altered to represent areas sharing a common trait (low spatial resolution information) by altering image data to make all pixels of those areas a common color, while scaling the luminance of each altered pixel by a uniform factor relative to its luminance in the original representation of the image.

Abstract: The rasterization process is separated into two modes, a test mode and a normal mode, to eliminate shading calculations associated with all-hidden triangles, thereby providing improved efficiency over prior rasterization schemes.