Abstract: A method of compositing layers by grouping the layers into a foreground group and a background group; identifying independent instructions of compositing model for execution independently from the background group and dependent instructions requiring a compositing output of a background layer in order to composite foreground layers; executing the independent instructions on the foreground layers in parallel with compositing the background layers, a first independent instruction storing a corresponding result in a first buffer and a second independent instruction storing a corresponding result in a second buffer; executing a dependent instruction by updating the second buffer using the background compositing output; and determining a compositing output for the foreground group dependent upon contents of the first buffer and the updated second buffer.

Abstract: A method of compositing layers by grouping the layers into a foreground group and a background group; identifying independent instructions of compositing model for execution independently from the background group and dependent instructions requiring a compositing output of a background layer in order to composite foreground layers; executing the independent instructions on the foreground layers in parallel with compositing the background layers, a first independent instruction storing a corresponding result in a first buffer and a second independent instruction storing a corresponding result in a second buffer; executing a dependent instruction by updating the second buffer using the background compositing output; and determining a compositing output for the foreground group dependent upon contents of the first buffer and the updated second buffer.

Abstract: Disclosed is a method of processing a print job, the print job being received in a page description language format. The method identifies a number of print heads on a printer targeted for printing said print job. The method processes the print job in the page description language format to produce a plurality of intermediate jobs, in which a number of the intermediate jobs is determined by the number of print heads. The intermediate jobs have an intermediate format between the page description language format and a rasterized image format. The method renders each of a plurality of intermediate jobs to a rasterized image in a renderer associated with each of the print heads independently of one another and external input.