A method of producing a Computer Generated Hologram (CGH) for producing a 3 dimensional (3D) holographic image, including receiving data describing a 3D scene, producing a first CGH for producing a 2D image of the 3D scene as viewed from a specific viewing direction, the 2D image perpendicular to the viewing direction, decomposing the 2D image to a plurality of slices at different depths along the viewing direction, adjusting the first CGH by making, for at least one of the plurality of slices, a correction to the CGH associated with a depth of the slice along the viewing direction, thereby producing a corrected CGH for producing a 3D holographic image of the 3D scene. Related apparatus and methods are also described.

Provided are a hologram image representation method and a hologram image representation device. A hologram image representation method comprising: receiving a three-dimensional input image including depth information; obtaining a plurality of input image layers from the three-dimensional input image based on the depth information; generating a plurality of Computer Generated Hologram (CGH) image layers by performing CGH processing on each of the plurality of input image layers; and representing a hologram image using the plurality of CGH image layers.

A holographic display panel, a holographic display device, and a holographic display method are disclosed. The holographic display panel includes a plurality of sub-pixels arranged in an array and a phase plate disposed on a light exit side of the plurality of sub-pixels; and a blocking member disposed between the plurality of sub-pixels and the phase plate; an orthogonal projection of the blocking member on a plane where the plurality of sub-pixels are located is arranged between adjacent sub-pixels for blocking an edge portion of a light beam diffracted by the sub-pixel.

A method of producing a Computer Generated Hologram (CGH) for producing a 3 dimensional (3D) holographic image, including receiving data describing a 3D scene, producing a first CGH for producing a 2D image of the 3D scene as viewed from a specific viewing direction, the 2D image perpendicular to the viewing direction, decomposing the 2D image to a plurality of slices at different depths along the viewing direction, adjusting the first CGH by making, for at least one of the plurality of slices, a correction to the CGH associated with a depth of the slice along the viewing direction, thereby producing a corrected CGH for producing a 3D holographic image of the 3D scene. Related apparatus and methods are also described.

Provided is a holographic display apparatus including 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.

A three-dimensional (3D) image display apparatus includes a processor configured to determine, from image data of a 3D image to be displayed, a representative depth value based on a current frame of the 3D image and a previous frame of the 3D image, and an imaging optical system configured to generate the 3D image in a predetermined space by modulating light based on the representative depth value.

A holographic image display system comprising a processor receiving image data at an input and producing output hologram data based on the image data. The image data comprises three-dimensional image data that is separable into a plurality of two-dimensional image layers at different image planes. The processor is configured to: a) perform a space-frequency transform on each image layer to provide a transformed image layer, b) apply a focus factor to each transformed image layer, c) apply a pseudo-random phase factor to each transformed image layer, and d) sum the transformed image layers to form a holographic sub-frame, e) repeat steps (c) and (d) for a plurality of iterations, applying a different pseudo-random phase factor to the transformed image layers in each iteration to form a plurality of holographic sub-frames; and f) drive a spatial light modulator with the holographic sub-frames in rapid temporal succession to generate a holographic image.

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 for digitally generating a hologram plane from a three-dimensional scene, cut into a plurality of planes parallel to the hologram plane. The method includes for a current plane: counting a number of points of the non-zero amplitude scene; choosing a first or second technique for propagating a light wave emitted by the current plane as a function of a number of points of non-zero amplitude included in the current plane and with a preset threshold value, the first, point-based technique calculating the propagation of a sum of light waves emitted by point sources constituted by the points of the scene portion of a non-zero amplitude of the current plane on a following plane, and the second, field-based technique, globally calculating a light wave emitted by the scene portion situated in the current plane on a given plane; and processing the current plane according to the chosen propagation technique.

Provided is a holographic display apparatus including: a spatial light modulator that modulates a wavefront of a reference beam to form a hologram image; an optical element arranged to change a position of a viewing window of the hologram image off-axis by a first angle; and an image processor that generates hologram data according to the position of the viewing window of the hologram image and a hologram image to be reproduced, and provides the hologram data to the spatial light modulator. The hologram image formed by the spatial light modulator is viewable from a side of the spatial light modulator.