Hologram calculation

A light engine arranged to reconstruct an image from a hologram, wherein the light engine comprises:

• an image processor arranged to receive an image for display within a display area and determine a first image component of the image, wherein the display area is viewable from a viewing area spatially separated therefrom;
• a hologram engine arranged to calculate an angularly-channelized hologram of the image, wherein when illuminated, the angularly-channelized hologram produces spatially modulated light divided into a plurality of hologram channels, and wherein each hologram channel is defined by a range of light ray angles corresponding to a respective continuous region of the image;
• a display device arranged to display the angularly-channelized hologram and spatially modulate light in accordance with the displayed angularly-channelized hologram;
• and
• a pupil expander arranged to receive the spatially modulated light from the display device and propagate the spatially modulated light therethrough to provide a plurality of different light propagation paths for the spatially modulated light from the display device to the viewing area, wherein each light propagation path corresponds to a respective continuous region of the image based on the hologram channels produced by the angularly-channelized hologram,
• wherein the light engine is arranged to allocate more data processing resources to calculation of the angularly-channelized hologram with respect to the first image component than a second image component of the image, and wherein the first image component corresponds to a first sub-area of the image within a foveal vision area of a viewer, and wherein and the second image component corresponds to a second sub-area of the image within a peripheral vision area of the viewer.