Illumination power control for a computer-generated hologram display

A holographic display system comprising:

• an illumination source;
• a modulator configured to be illuminated by the illumination source;
• an input;
• and
• a controller configured to
• receive, via the input, source data representative of a scene to be displayed as a hologram;
• determine hologram data to display a computer-generated hologram representing the scene;
• determine a scene energy based on the source data and quantised using a scale which is non-linear and has a closer spacing between values in a mid-section of the scale than between values towards a minimum and a maximum of the scale;
• associate the scene energy with the hologram data;
• and
• control a holographic display according to the hologram data and simultaneously control an output power of an illumination source of the holographic display according to the scene energy.

A holographic display apparatus comprising:

• an illumination source;
• a modulator configured to be illuminated by the illumination source;
• an input;
• and
• a controller configured to:
• receive, via the input, hologram data and scene energy data associated with the hologram data, the scene energy data quantised using a scale which is non-linear and which has a closer spacing between values in a mid-section of the scale than between values towards a minimum and a maximum of the scale;
• operate the modulator to modulate the illumination source, thereby to generate a light field corresponding to a frame or sub-frame of the hologram data;
• and
• control an output optical power of the illumination source incident on the modulator according to scene energy data associated with the frame or sub-frame.