Apparatus and a corresponding method for processing image data are provided. The apparatus has compositing circuitry to generate a composite layer for a frame for display from image data representing plural layers of content within the frame. Plural latency buffers are provided to store at least a portion of the image data representing the plural layers. At least one of the plural latency buffers is larger than at least one other of the plural latency buffers. The compositing circuitry is responsive to at least one characteristic of the plural layers of content to allocate the plural layers to respective latency buffers of the plural latency buffers. Image data information for a layer allocated to the larger latency buffer is available for analysis earlier than that of the layers allocated to the smaller latency buffers and processing efficiencies can then result.