Abstract: A method for adjusting the apparent brightness of a computer-generated hologram display is disclosed. The method comprises: receiving source data representative of a scene to be displayed as a hologram; determining hologram data to display a computer-generated hologram representing the scene; determining a scene energy based on the source data, the scene energy being 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; associating the scene energy with the hologram data; controlling a holographic display according to the hologram data and simultaneously controlling an output power of an illumination source of the holographic display according to the scene energy. A holographic display apparatus implementing the method is also disclosed.

Abstract: A method and display apparatus for reducing holographic speckle when displaying holographic images are described. A target image (10) is decomposed into input images (11). A first input image includes higher spatial frequency components of the target image and is imaged using a first display method (12) to generate a first holographic display image. The second input image includes lower spatial frequency components of the target image and is imaged using a second display method (12) to generate a second display image. The first and second display images are combined for display to a user. The second display method (12) is adapted to reduce holographic speckle or include no holographic speckle compared to the first holographic display method (12) thereby reducing holographic speckle in the combined display image (13).