System and method for flattening spans

摘要

A system and method for computing a run-length encoded raster in which spans are successively added to a raster or overlapping spans are flattened. Spans are temporarily expanded into a pixel array representing part of the raster, where entries in the pixel array are references to color values and other property data. Successive spans modify the pixel array. References in the array are then compared to run-length encode the partial raster. Remaining parts of the raster are processed similarly. In one embodiment, the array contains pointers referencing color and property information. In another embodiment, the array contains small indexes referencing a color palette.