A method of computing a hologram by determining the wavefronts at the approximate observer eye position that would be generated by a real version of an object to be reconstructed. In normal computer generated holograms, one determines the wavefronts needed to reconstruct an object; this is not done directly in the present invention. Instead, one determines the wavefronts at an observer window that would be generated by a real object located at the same position of the reconstructed object. One can then back-transforms these wavefronts to the hologram to determine how the hologram needs to be encoded to generate these wavefronts. A suitably encoded hologram can then generate a reconstruction of the three-dimensional scene that can be observed by placing one's eyes at the plane of the observer window and looking through the observer window.

A method of generating a computer-generated hologram from a three-dimensional image comprising a plurality of two-dimensional image layers is provided. The method comprises generating hologram data for each layer of the image, and updating the hologram data of at least one layer of the image based on the hologram data of the other layers of the image.

A method for estimating a depth map associated with a hologram representing a scene, the method includes steps of: reconstruction of images of the scene, each image being associated with a depth; decomposition of each image into a plurality of thumbnails adjacent to each other, each thumbnail being associated with the depth and including a plurality of pixels; determination, for each thumbnail, of a focus map by supplying, at the input of a network of neurons, values associated with the pixels of the thumbnail, to obtain, at the output of the network, the focus map including a focus level associated with the pixel concerned; and determination of a depth value, for each point of a depth map, as a function of the focus levels obtained. The invention also relates to an estimation device and an associated computer program.

An apparatus which analyses a depth of a holographic image is provided. The apparatus includes an acquisition unit that acquires a hologram, a restoration unit that restores a three-dimensional holographic image by irradiating the hologram with a light source, an image sensing unit that senses a depth information image of the restored holographic image, and an analysis display unit that analyzes a depth quality of the holographic image, based on the sensed depth information image, and the image sensing unit uses a lensless type of photosensor.

The invention relates to a method for generating holograms for encoding in a spatial light modulation device for a holographic display for representing a two- and/or three-dimensional scene. The two- and/or three-dimensional scene is decomposed into object points and encoded in a hologram, which is subdivided into subholograms, in the spatial light modulation device. The object points of the scene are encoded into encoding regions on the spatial light modulation device. A size and/or shape of the encoding region is selected in relation to a size and/or shape of a subhologram, assigned to the encoding region, in such a way that crosstalk of higher diffraction orders in a virtual visibility region is reduced.

With regard to image data processing, a method of obtaining a focus term by using periodicity of the focus term is provided. The focus term may be used in a plurality of operation processes for processing image data.

Methods and apparatuses for encoding/decoding data content representative of a volumetric video are provided, wherein. the encoding/decoding comprises encoding in/decoding from a bitstream. an indicator specifying whether data content has information representative of at least one set of depth layers. the information representative of a set of depth layers specifying a number of depth layers and a depth value for each of the depth layers for a layer-based representation of the volumetric video. Methods and apparatuses for reconstructing Computer Generated Holograms from a reconstructed layered-based representation of the volumetric video are also provided.

A method and apparatus for processing a three-dimensional image are provided. The method includes receiving original color data and original depth data of a plurality of layers of an original holographic image, selecting reference layers from among the plurality of layers, mapping adjustment color data of a non-selected layer, which is determined based on using the original depth data of the non-selected layer and the reference layers, to each of the reference layers, and generating a computer generated hologram image by using the original color data of the reference layers and the adjustment color data that has been mapped to the reference layers.

A holographic display apparatus includes: a light source configured to emit light; a spatial light modulator configured to sequentially generate hologram patterns for modulating the light and to sequentially reproduce frames of hologram images based on the hologram patterns; and a controller configured to provide hologram data signals to the spatial light modulator, the hologram data signals being used to sequentially generate the hologram patterns. The controller is configured to further provide, to the spatial light modulator, diffraction pattern data signals for forming periodic diffraction patterns for adjusting locations of the hologram images to be reproduced on a hologram image plane, the diffraction pattern data signals being configured to move the periodic diffraction patterns on the spatial light modulator along a predetermined direction for each of the frames.

Provided are an apparatus and a method for displaying a holographic three-dimensional (3D) image. The apparatus includes an image segmenter configured to segment an original image into a plurality of segments, and a calculator configured to calculate diffraction fringe pattern information for displaying each of the plurality of segments as a 3D holographic image. The image segmenter adjusts the number of the plurality of segments.