The disclosure provides a display system and a method for displaying a virtual image to a viewer An optical system of the disclosure includes a spatial light modulator, a light source, a Fourier transform lens, a viewing system and a processing system. The spatial light modulator is arranged to display holographic data in the Fourier domain, illuminated by the light source. The Fourier transform lens is arranged to produce a 2D holographic reconstruction in the spatial domain corresponding to the holographic data. The viewing system is arranged to produce a virtual image of the 2D holographic reconstruction. The processing system is arranged to combine the Fourier domain data representative of a 2D image with Fourier domain data representative of a phase only lens to produce first holographic data, and provide the first holographic data to the optical system to produce a virtual image.

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.

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[i(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 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 obtaining a focus term by using a periodicity of the focus term is provided. The focus term may be used in a plurality of operation processes for processing image data.

Provided are methods of processing a holographic image and apparatuses using the methods. A method includes obtaining image data with respect to a three-dimensional (3D) object, obtaining interference patterns in a computer-generated hologram (CGH) plane by performing a Fourier transform on the image data, and generating a CGH with respect to the 3D object based on the interference patterns, wherein the Fourier transform is performed based on a focal length of an eye lens of an observer.

A method for producing a hologram (1), (1) for security elements (1a) and/or security documents (1b). One or more virtual hologram planes (10) are arranged in front of and/or behind one or more virtual models (20) and/or one or more virtual hologram planes (10) are arranged such that they intersect one or more virtual models (20). One or more virtual light sources (30) are arranged on one or more partial regions of the surface (21) of one or more of the virtual models (20). One or more virtual electromagnetic fields (40) are calculated starting from at least one of the virtual light sources (30) in one or more zones (11) of the one or more virtual hologram planes (10). In the one or more zones (11), in each case, a virtual total electromagnetic field (41) is calculated on the basis of the sum of two or more, of the virtual electromagnetic fields (40) in the respective zone (11). One or more phase images (50) are calculated from the virtual total electromagnetic fields (41) in the one or more zones (11). A height profile (60) of the hologram (1) is calculated from the one or more phase images (50) and the height profile (60) of the hologram (1) is incorporated into a substrate (2) to provide the hologram (1).

An image processing method and apparatus are provided. The image processing apparatus includes a receiver configured to receive image data; and a processor configured to generate first data by performing a Fourier calculation on the received image data, generate second data by performing prism phase computation on the first data, generate third data by adding the first data and the second data, and perform encoding based on the third data.

A method for processing a three-dimensional holographic image includes obtaining depth images from depth data of a three-dimensional object, dividing each of the depth images into a predetermined number of sub-images, obtaining interference patterns of computer-generated hologram (CGH) patches corresponding to each of the sub-images by performing a Fourier transform to calculate an interference pattern in a CGH plane for object data included in each of the sub-images, and generating a CGH for the three-dimensional object using the obtained interference patterns of the CGH patches.

A holographic 3D display system is described that (1) always presents true-colored and true-orthoscopic 3D images regardless of whether the object is thin or thick, or the image is virtual or real and (2) accomplishes an effective data/signal compression apparatus that accommodates to both off-the-shelf detector and display arrays, of both amicable gross array dimensions and palpable individual pixel sizes. It provides a rectilinear-transforming digital holography (RTDH) system for recording and displaying virtual, real, or both virtual and real, orthoscopic three-dimensional images, the system comprising: (a) a focal-plane compression-domain digital holographic recording/data capturing (FPCD-DHR) sub-system; (b) a 3D distribution network for receiving, storage, processing and transmitting the digital-holographic complex wavefront data signals generated by the digital complex wavefront decoder (DCWD) to at least one location; and (c) a focal-plane compression-domain digital holographic display (FPCD-DHD) sub-system located at the at least one location.