US Patent 7602528 Compositing pages from page components

Sets of pixel data defining parts of rasterized portions of an image are received. At least one of the parts of one of the rasterized portions of the image overlaps another part of that portion of the image. The pixel data that defines the overlapping part includes mask data that identifies pixels of the overlapping part that are to be included in the image. The sets of pixel data are decompressed. The decompressed data are used to generate a series of the rasterized portions of the image including the pixels identified in the mask data. While each of the rasterized portions of the image is being used by a print engine, another of the rasterized portions of the series is being generated.