1. A computer implemented method of compositing multiple images, comprising: providing a plurality of graphics buffers representing a plurality of application windows rendered by an application, wherein the rendered application windows represent a plurality of graphic layers to be composited into a composite image; subdividing an image area of the composite image into a plurality of cells such that for each one of the cells, either none of the graphic layers overlap within a respective one of the cells or all of the graphic layers that overlap within the respective one of the cells overlap throughout the respective one of the cells; determining, for each one of the cells, a respective composition operation applicable to composite a set of the graphic layers that intersect the respective one of the cells; determining, for each one of the cells, which of a plurality of processors is to generate the respective one of the cells based on which of the processors is able to perform the type of the respective composition operation; on the graphic layers that intersect the respective one of the cells, the graphic layers representative of the rendered application windows; and compositing the rendered application windows by generating the cells with the processors, each respective one of the cells of the composite image generated from the set of the graphic layers that intersect the respective one of the cells by performing the respective composition operation with a processor determined to be one of the processors to generate the respective one of the cells.