A holographic projector comprises an image processing engine arranged to, a hologram engine and a display engine. The image processing engine is arranged to receive a source image for projection. The source image comprises a first colour component and a second colour component. The image processing engine is further arranged to form a first colour secondary image from the first colour component by nulling alternate pixel values of the first colour component in accordance with a first checkerboard pattern. The image processing engine is further arranged to form a second colour secondary image from the second colour component by nulling alternate pixel values of the second colour component in accordance with a second checkerboard pattern. The first checkerboard pattern is opposite to the second checkerboard pattern. The hologram engine is arranged to determine a first colour hologram corresponding to the first colour secondary image and a second colour hologram corresponding to the second colour secondary image. The display engine is arranged to form a first colour holographic reconstruction from the first colour hologram and a second colour holographic reconstruction from the second colour hologram.

Apparatus for detecting a 3D structure of an object, comprising at least three laser emitters and a beam splitter that splits the laser radiation of the laser emitters into a reference radiation and an illumination radiation. The illumination radiation strikes the object to be measured, is reflected by the object as object radiation and interferes with the reference radiation. A detector receives the interference patterns formed from the interference of the reference and object radiation and an analysis unit analyzes the interference patterns. At least two of the laser emitters emit laser radiation in the invisible range and the analysis unit detects the object in three dimensions based on the interference patterns of the invisible laser radiation. At least one of the laser emitters emits colored laser radiation and the analysis unit deduces the object's color based on the intensity of the colored object radiation reflected by the object.

Briefly stated, technologies are generally described for providing a computer-generated holography (CGH). Example devices/systems described herein may use one or more of a server device and/or a client device. The server device may be configured to provide CGH data to a client device including a holographic image display unit. The server device may receive information on the holographic image display unit from the client device, calculate the CGH data from three-dimensional image data and the information on the holographic image display unit, and/or transmit the CGH data to the client device. The client device may be configured to provide a holographic image. The client device may reconstruct the holographic image on the holographic image display unit using CGH data and a reconstruction beam, transmit information on the holographic image display unit to the server device, and/or receive the CGH data from the server device.

The present invention provides a light-guiding plate which is applicable to incident rays over a wide ray angular range and wide wavelength rage, and is able to suppress a decrease in optical efficiency. A light-guiding plate 200 having a light diffracting portion 1200 for diffracting incident light by a multiple-recorded hologram is configured such that, in the light diffracting portion, when light 1210 of a single wavelength having a certain angular range is incident, at least two or more outgoing rays 1220 are discretely emitted with a first angular space θs, and the emitted rays each have a second angular range θa, and the first angular space θs is equal to or larger than the second angular range θa.

A method of generating a color image of a sample includes obtaining a plurality of low resolution holographic images of the sample using a color image sensor, the sample illuminated simultaneously by light from three or more distinct colors, wherein the illuminated sample casts sample holograms on the image sensor and wherein the plurality of low resolution holographic images are obtained by relative x, y, and z directional shifts between sample holograms and the image sensor. Pixel super-resolved holograms of the sample are generated at each of the three or more distinct colors. De-multiplexed holograms are generated from the pixel super-resolved holograms. Phase information is retrieved from the de-multiplexed holograms using a phase retrieval algorithm to obtain complex holograms. The complex hologram for the three or more distinct colors is digitally combined and back-propagated to a sample plane to generate the color image.

A method for performing color image reconstruction of a single super-resolved holographic sample image includes obtaining a plurality of sub-pixel shifted lower resolution hologram images of the sample using an image sensor by simultaneous illumination at multiple color channels. Super-resolved hologram intensity images for each color channel are digitally generated based on the lower resolution hologram images. The super-resolved hologram intensity images for each color channel are back propagated to an object plane with image processing software to generate a real and imaginary input images of the sample for each color channel. A trained deep neural network is provided and is executed by image processing software using one or more processors of a computing device and configured to receive the real input image and the imaginary input image of the sample for each color channel and generate a color output image of the sample.

An image-sensing device includes photoelectric elements for receiving incident light. The photoelectric elements are arranged into unit cells, and each of the unit cells includes a first, a second, a third and a fourth photoelectric element. The first, the second, the third and the fourth photoelectric elements in each of the unit cells are formed of pillar structures, and the first, the second, the third and the fourth photoelectric elements are different sizes. The first photoelectric element captures a first image in a first phase, the second photoelectric element captures a second image in a second phase, the third photoelectric element captures a third image in a third phase, and the fourth photoelectric element captures a fourth image in a fourth phase. The first phase, the second phase, the third phase, and the fourth phase are different.

There is provided a holographic optical element including: a hologram portion including a plurality of groups of unit regions, each group of unit regions of the hologram portion being configured to produce a respective holographic image under a respective light illumination having a respective predetermined wavelength; and a colour filter portion formed on the hologram portion, the colour filter portion including a plurality of groups of unit regions, each group of unit regions of the colour filter portion being arranged on a corresponding group of the plurality of groups of unit regions of the hologram portion, whereby the plurality of groups of unit regions of the colour filter portion is spatially arranged to form a predetermined colour image. There is also provided a method of forming the holographic optical element. There is further provided an article having optical security incorporated therein.

The present disclosure provides a method and apparatus for generating a full-color holographic image. The method of generating a full-color holographic image includes forming images for each color channel based on complex hologram data extracted from rays propagating from a target object, and combining the formed images into one color image, wherein the images for each color channel are formed at reconstruction points for each color channel derived based on the complex hologram data.

The present disclosure relates to a system and method for designating, for a hologram, a color to be implemented, by forming a certain pattern on a dithering mask, such that a hologram structure may express a particular structural color. To this end, the present disclosure may include an image obtaining unit configured to obtain an original image; an encryption unit configured to convert original colors of respective pixels included in the original image into encrypted colors, according to a predefined standard; a pattern data generation unit configured to generate, based on the encrypted colors, pattern data including dithering patterns corresponding to the respective pixels; and a pattern forming unit configured to form, based on the pattern data, a mask pattern on a dithering mask.