A method of modulating a depth of a hologram, the method includes: obtaining hologram data; determining a scale factor based on a hardware specification of a holographic display to display a three-dimensional (3D) hologram image in a space by using the hologram data; and modulating depth information of the hologram data based on the scale factor.

Provided is a holographic image processing apparatus including a memory configured to store at least one instruction, and a processor configured to execute the at least one instruction stored in the memory to generate a corrected holographic image by correcting an original holographic image captured by a holographic camera based on a neural network configured to learn hologram correction in advance.

A head-up display is described. A spatial light modulator is arranged to display a diffractive pattern of first picture content and/or second picture content. A screen assembly has first and second diffusers arranged in a stepped configuration so that the first diffuser is spatially offset from the second diffuser by a perpendicular distance. A light source is arranged to illuminate the diffractive pattern such that the first picture content is formed on the first diffuser and/or the second picture content is formed on the second diffuser. An optical system comprising at least one optical element having optical power is arranged so that the first and second diffusers have different object distances to the optical system.

A holographic projection system includes a SLM that receives a light beam and generates a modulated beam projected at an eyebox, where: the modulated beam includes multiple versions of a test image; and the test image includes bright objects and transparent regions, which are selected dark areas of interest for measuring luminance. A control module runs a test to characterize contrast in each of multiple virtual image planes including: controlling the SLM to generate the modulated beam; measuring luminance levels of each of the versions of the test image displayed in the virtual image planes; calculating contrast ratios based on the luminance levels of each of the versions of the test image; determining whether the contrast ratios are within predetermined ranges of predetermined contrast ratios; and adjusting operation of the SLM in response to one of the contrast ratios not being within a corresponding one of the predetermined ranges.

A holographic sporting/combat optic may be mounted to weapon. The holographic sporting/combat optic includes a laser diode, a holographic recording element and one or more optical components arranged in a housing. In response to a light beam incident thereon, the holographic recording element projects a composite, multidimensional reticle image into the optical viewing window. Of note, the holographic recording element has two or more reticle elements recorded thereon which form the composite reticle image. Each of the two or more reticle elements is captured at a different distance from the weapon during different exposures of the holographic recording element.

The invention relates to a method for authenticating a diffractive element, e.g., a hologram, on an object or document (2), wherein at least two images of the diffractive element are recorded by means of a portable device (1). The recordings are taken in different spatial orientations of the portable device in relation to the diffractive element. Recording data are created from the images and the associated spatial orientations. The recording data are electronically compared with reference data. The comparison can be performed locally or in a server-based manner.

There is disclosed herein a method of light detection and ranging. The method comprises a first step of illuminating a scene with a first light pattern and monitoring for first light return from the scene with an array of detection elements. The method comprises a second step of obtaining first point cloud data from first parts of the scene where the first light return exceeds a first threshold value. The method comprises a third step of determining a second light pattern by reducing, such as substantially zeroing, the intensity of the first light pattern in the areas wherein first point cloud data was obtained. The method comprises a fourth step of illuminating the scene with the second light pattern and monitoring for second light return from the scene with the array of detection elements.

Disclosed is an apparatus of analyzing a depth of a holographic image according to the present disclosure, which 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.

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 optical element and a manufacturing method thereof, an image reconstruction method, and augmented reality glasses are disclosed. The holographic optical element includes a substrate, and a recording material layer in which at least two groups of interference fringes are recorded; each group includes a first interference fringe formed by a first signal light and a first reference light respectively incident from opposite sides of the recording material layer, and a second interference fringe formed by a second signal light and a second reference light respectively incident from opposite sides of the recording material layer; the second signal light passes through a lens before incidence; incident angles of the first signal light and the second reference light are equal; incident directions of the first signal light corresponding to respective groups are different, and focal lengths of the lenses are not equal.