Disclosed are a holographic display method and a holographic display device. The holographic display method includes: acquiring an area of Nth diffraction order corresponding to an eye position; according to the area of Nth diffraction order, calculating a holographic complex amplitude distribution corresponding to a window of Nth diffraction order to obtain window hologram information, a function of the holographic complex amplitude distribution being expressed by C(m,n)=A(m,n)*exp[−iφ(m,n)/N]; encoding the window hologram information; and according to the encoded window hologram information, loading the encoded window hologram information in the area of Nth diffraction order to display a hologram.

A holographic display apparatus and a holographic display method are provided. The holographic display apparatus determines a representative depth from 3D image data; calculates a computer generated hologram (CGH) corresponding to the representative depth on the 3D image data; obtains the modulated CGH by modulating a phase of the CGH to increase an eye box; modulates a light according to the modulated CGH and generates a hologram image; and forms the generated hologram image at the representative depth.

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 holographic display apparatus capable of providing an expanded viewing window and a display method are provided. The holographic display apparatus includes an image processor configured to provide computer generated hologram (CGH) data to a spatial light modulator, wherein the image processor is further configured to generate a hologram data array comprising information of the holographic image to be reproduced at the first resolution or a resolution less than the first resolution, perform an off-axis phase computation on the hologram data array at the second resolution, and then, generate the CHG data at the first resolution.

A holographic optical apparatus includes a beam splitting component, a transmission assembly, a focal length modulation component and an optical element. The beam splitting component splits received light into reference light and signal light that are coherent light, and outputs the reference light and the signal light. The focal length modulation component includes a plurality of local length modulation regions with different focal lengths. The optical element includes a recording medium layer with a plurality of recording regions, and each recording region is located in a light-exit path of a focal length modulation region. The transmission assembly is disposed in a light-exit path of the beam splitting component, transmit the reference light to the plurality of recording regions and transmit the signal light to the plurality of focal length modulation regions.

A holographic display apparatus capable of providing an expanded viewing window and a display method are provided. The holographic display apparatus includes an image processor configured to provide computer generated hologram (CGH) data to a spatial light modulator, wherein the image processor is further configured to generate a hologram data array comprising information of the holographic image to be reproduced at the first resolution or a resolution less than the first resolution, perform an off-axis phase computation on the hologram data array at the second resolution, and then, generate the CHG data at the first resolution.

A method of generating a hologram includes receiving an input image representing a 3D object, defining a first phase value for a first pixel data such that spatio-temporally identical pixels with respect to the input image have the same phase, defining a second phase value for a second pixel data such that spatio-temporally identical pixels with respect to the input image have the same phase, and generating a multi-view hologram using the first phase value and the second phase value.

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.

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.

Provided is a hologram generation method including receiving a distribution of a polygon and generating an angular spectrum based on the distribution of the polygon, determining whether a rotation angle of the polygon is included in a first section determined based on a maximum diffraction angle of a spatial light modulator, and recording the angular spectrum if it is determined that the rotation angle is included in the first section.