Abstract: A method is described of compositing graphic elements in a pixel-based renderer (18). A first graphic element is received (step 2601) having a first colour and a first opacity and a second graphic element is received (step 2602) having a second colour and a second opacity. A blend output is obtained from a blend function dependent on the first colour and the second colour; and a resultant colour is determined (step 2603) of a compositing operation on the first and second graphic elements, the resultant colour being dependent on the blend output and otherwise being independent of the second colour.

Abstract: A method (1000) of compositing a group of graphical objects (B). The method (1000) forms the group of objects (B) in a temporary buffer (W). For each object (C, D) in the group of objects (B), a corresponding clipping path is provided. A resultant clipping path (Z) defined by a union of the clipping paths is calculated. The group of objects from the temporary buffer (W) is composited to a main buffer (V) through the resultant clipping path (Z).