Efficient gray tile storage

Abstract

A method building a tile of pixels usable by a marking routine in a raster output device to mark an output device pixel according to a sample value. The method includes the steps of receiving the sample value in a rendering process; deriving, from the sample value, a base value and a fractional tile of pixels; and building the pixels of the tile by adding the base value to the corresponding pixels of the fractional tile. The fractional tile may have a bit depth of one. The invention also features building a chunky color tile by deriving, from a sample color, one component base value for each color component; obtaining a component fractional tile for each color component of the sample color; and building each pixel in the chunky color tile as the composition of the sum of the component base values and the component fractional tile pixel values for the corresponding color components and pixel position. The component fractional tiles can be stored in a packed representation. The chunky color tile can have four color components. The invention also builds a pixel in chunky color tile by deriving, from a sample color, a base pixel in a device color space; obtaining a fractional tile for each component of the sample color; forming an addend from all the fractional tiles; and building the chunky color tile pixel by adding the addend to the base pixel.