A display controller comprises an input stage 20 operable to read at least one input surface, a composition stage 28 operable to compose plural input surfaces to generate a composited output surface, an output stage 30 operable to provide the composited output surface to a display for display, a scaling engine 31 operable to scale a composited output surface generated by the composition stage 28, and a write-out stage 32 operable to write a composited and/or scaled output surface to external memory.