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14 pages, 5528 KiB

Open AccessArticle

From Google Earth Studio to Hologram: A Pipeline for Architectural Visualization

by Philippe Gentet, Tam Le Phuc Do, Jumamurod Farhod Ugli Aralov, Oybek Mirzaevich Narzulloev, Leehwan Hwang and Seunghyun Lee

Appl. Sci. 2025, 15(11), 6179; https://doi.org/10.3390/app15116179 - 30 May 2025

Viewed by 598

Abstract

High-resolution holographic visualization of built environments remains largely inaccessible due to the complexity and technical demands of traditional 3D data acquisition processes. This study proposes a workflow for producing high-quality full-color digital holographic stereograms of architectural landmarks using Google Earth Studio. By leveraging [...] Read more.

High-resolution holographic visualization of built environments remains largely inaccessible due to the complexity and technical demands of traditional 3D data acquisition processes. This study proposes a workflow for producing high-quality full-color digital holographic stereograms of architectural landmarks using Google Earth Studio. By leveraging photogrammetrically reconstructed three-dimensional (3D) city models and a controlled camera path, we generated perspective image sequences of two iconic monuments, that is, the Basílica de la Sagrada Família (Barcelona, Spain) and the Arc de Triomphe (Paris, France). A custom pipeline was implemented to compute keyframe coordinates, extract cinematic image sequences, and convert them into histogram data suitable for CHIMERA holographic printing. The holograms were recorded on Ultimate U04 silver halide plates and illuminated with RGB light-emitting diodes, yielding visually immersive reconstructions with strong parallax effects and color fidelity. This method circumvented the requirement for physical 3D scanning, thereby enabling scalable and cost-effective holography using publicly available 3D datasets. In conclusion, the findings indicate the potential of combining Earth Studio with digital holography for urban visualization, cultural heritage preservation, and educational displays. Full article

(This article belongs to the Topic 3D Documentation of Natural and Cultural Heritage)

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14 pages, 3918 KiB

Open AccessArticle

Transforming Monochromatic Images into 3D Holographic Stereograms Through Depth-Map Extraction

by Oybek Mirzaevich Narzulloev, Jinwon Choi, Jumamurod Farhod Ugli Aralov, Leehwan Hwang, Philippe Gentet and Seunghyun Lee

Appl. Sci. 2025, 15(10), 5699; https://doi.org/10.3390/app15105699 - 20 May 2025

Viewed by 523

Abstract

Traditional holographic printing techniques prove inadequate when only input data are available. Therefore, this paper proposes a new artificial-intelligence-based process for generating digital holographic stereograms from a single black-and-white photograph. This method eliminates the need for stereo cameras, photogrammetry, or 3D models. In [...] Read more.

Traditional holographic printing techniques prove inadequate when only input data are available. Therefore, this paper proposes a new artificial-intelligence-based process for generating digital holographic stereograms from a single black-and-white photograph. This method eliminates the need for stereo cameras, photogrammetry, or 3D models. In this approach, a convolutional neural network and deep convolutional neural field model are used for image colorization and a depth-map estimation, respectively. Subsequently, the colored image and depth map are used to generate the multiview images required for creating holographic stereograms. This method efficiently preserves the visual characteristics of the original black-and-white images in the final digital holographic portraits. This provides a new and accessible method for holographic reconstruction using limited data, enabling the generation of 3D holographic content from existing images. Experiments were conducted using black-and-photographs of two historical figures, and highly realistic holograms were obtained successfully. This study has significant implications for cultural preservation, personal archiving, and the generation of life-like holographic images with minimal input data. By bridging the gap between historical photographic sources and modern holographic techniques, our approach opens up new possibilities for memory preservation and visual storytelling. Full article

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12 pages, 15174 KiB

Open AccessArticle

A New Method for Detecting Weld Stability Based on Color Digital Holography

by Qian Li, Guangjun He, Haiting Xia, Ruijie Wang, Weifan Zhang, Jinbin Gui, Qiang Fang, Cong Ge and Qinghe Song

Appl. Sci. 2024, 14(11), 4582; https://doi.org/10.3390/app14114582 - 27 May 2024

Viewed by 1230

Abstract

Weld stability is directly related to the safety and reliability of engineering, and continuous improvement of its detection technology has great research significance. This paper presents a novel method for weld stability detection based on color digital holography. A color digital holography optical [...] Read more.

Weld stability is directly related to the safety and reliability of engineering, and continuous improvement of its detection technology has great research significance. This paper presents a novel method for weld stability detection based on color digital holography. A color digital holography optical path was designed to capture the holograms of welds under varying loads. Several common denoising algorithms were used to deal with speckle noise in the wrapped phase, among which the 4-f optical simulation integrated cycle-consistent generative adversarial network (4f-CycleGAN) denoising algorithm based on deep learning was more suitable for the color digital holographic detection system. The three-dimensional deformation fields of three samples (lap-jointed, butt-jointed, and defective butt-jointed aluminum alloy plates) under different loads were calculated. The center profile of the deformation field in the direction of load and holographic reconstruction images are used to determine the position of the weld. The coefficient of variation near the weld was used to evaluate the weld stability. The coefficient of variation for lap-jointed, butt-jointed and defective butt-jointed plates are 0.0335 (<0.36, good stability), 0.1240 (<0.36, good stability) and 0.3965 (>0.36, poor stability), respectively. The research results of this paper provide a new strategy for detecting weld stability. Full article

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12 pages, 5471 KiB

Open AccessArticle

Crosstalk-Free Multiplane Full-Color Holography Based on the Space Division Method

by Axiu Cao, Yingfei Pang and Qiling Deng

Photonics 2024, 11(3), 230; https://doi.org/10.3390/photonics11030230 - 2 Mar 2024

Cited by 1 | Viewed by 1571

Abstract

This paper has proposed a full-color holography based on the space division method to provide a new solution for three-dimensional color holographic display. The hologram is divided into three different regions for the R, G, and B trichromatic hologram components, which will be [...] Read more.

This paper has proposed a full-color holography based on the space division method to provide a new solution for three-dimensional color holographic display. The hologram is divided into three different regions for the R, G, and B trichromatic hologram components, which will be designed separately at the corresponding positions. The projection images at different projection depths are preprocessed to meet dimension matching and position matching conditions. Different color images are reconstructed on a single plane and 19 planes in simulations and experiments, respectively, which verify the feasibility of the method. The designed phase-only holograms were fabricated on the silica substrate to obtain the diffraction optical element (DOE). Expect for one DOE, three lasers, and one CCD, no additional optical components are required to prompt a compact and simple experimental setup, which is expected to be used to realize full-color display. Full article

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15 pages, 10544 KiB

Open AccessArticle

A Full-Color Holographic System Based on Taylor Rayleigh–Sommerfeld Diffraction Point Cloud Grid Algorithm

by Qinhui Yang, Yu Zhao, Wei Liu, Jingwen Bu and Jiahui Ji

Appl. Sci. 2023, 13(7), 4466; https://doi.org/10.3390/app13074466 - 31 Mar 2023

Cited by 7 | Viewed by 1829

Abstract

Real objects-based full-color holographic display systems usually collect data with a depth camera and then modulate the input light source to reconstruct the color three-dimensional scene of the real object. However, at present, the main problems of the real-time high quality full-color 3D [...] Read more.

Real objects-based full-color holographic display systems usually collect data with a depth camera and then modulate the input light source to reconstruct the color three-dimensional scene of the real object. However, at present, the main problems of the real-time high quality full-color 3D display are slow speed, low reconstruction quality, and high consumption of hardware resources caused by excessive computing. Based on the hybrid Taylor Rayleigh–Sommerfeld diffraction algorithm and previous studies on full-color holographic systems, our paper proposes Taylor Rayleigh–Sommerfeld diffraction point cloud grid algorithm (TR-PCG), which is to perform Taylor expansion on the radial value of Rayleigh–Sommerfeld diffraction in the hologram generation stage and modify the data type to effectively accelerate the calculation speed and ensure the reconstruction quality. Compared with the wave-front recording plane, traditional point cloud gridding (PCG), C-PCG, and Rayleigh–Sommerfeld PCG without Taylor expansion, the computational complexity is significantly reduced. We demonstrate the feasibility of the proposed method through experiments. Full article

(This article belongs to the Special Issue Digital Holography: Novel Techniques and Its Applications)

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13 pages, 4657 KiB

Open AccessArticle

Three-Channel Metasurfaces for Multi-Wavelength Holography and Nanoprinting

by Zuyu Li, Yuhang Zhang, Jiadong Yuan, Yuhan Hong, Hongzhan Liu, Jianping Guo, Qiaofeng Dai and Zhongchao Wei

Nanomaterials 2023, 13(1), 183; https://doi.org/10.3390/nano13010183 - 31 Dec 2022

Cited by 8 | Viewed by 2531

Abstract

Metasurfaces, employed to simultaneously generate nanoprinting and holographic images, have been extensively explored recently. Among them, multi-wavelength multiplexing in a single metasurface is often accompanied by dispersion and crosstalk, which hinder the display of multicolor patterns. Here, we propose an efficient phase method [...] Read more.

Metasurfaces, employed to simultaneously generate nanoprinting and holographic images, have been extensively explored recently. Among them, multi-wavelength multiplexing in a single metasurface is often accompanied by dispersion and crosstalk, which hinder the display of multicolor patterns. Here, we propose an efficient phase method to decouple the wavelength and realize a three-channel display operating at different wavelengths. Holographic images appear in the far field with the illumination of two different circularly polarized lights while a nanoprinting image is reconstructed by inserting an orthogonal optical path with the illumination of linear polarization light. The proposed metasurface is only composed of four types of unit cells, which significantly decreases the complexity of fabrication and improves the information capacity. Benefiting from its different decoding strategies and capability of multi-wavelength control, this approach may develop broad applications in information encryption, security, and color display. Full article

(This article belongs to the Special Issue Metasurfaces for Photonic Devices: Theory and Applications)

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12 pages, 13304 KiB

Open AccessArticle

Time-Division Color Holographic Projection in Large Size Using a Digital Micromirror Device

by Takayuki Takahashi, Tomoyoshi Shimobaba, Takashi Kakue and Tomoyoshi Ito

Appl. Sci. 2021, 11(14), 6277; https://doi.org/10.3390/app11146277 - 7 Jul 2021

Cited by 17 | Viewed by 2789

Abstract

Holographic projection is a simple projection as it enlarges or reduces reconstructed images without using a zoom lens. However, one major problem associated with this projection is the deterioration of image quality as the reconstructed image enlarges. In this paper, we propose a [...] Read more.

Holographic projection is a simple projection as it enlarges or reduces reconstructed images without using a zoom lens. However, one major problem associated with this projection is the deterioration of image quality as the reconstructed image enlarges. In this paper, we propose a time-division holographic projection, in which the original image is divided into blocks and the holograms of each block are calculated. Using a digital micromirror device (DMD), the holograms were projected at high speed to obtain the entire reconstructed image. However, the holograms on the DMD need to be binarized, thereby causing uneven brightness between the divided blocks. We correct this by controlling the displaying time of each hologram. Additionally, combining both the proposed and noise reduction methods, the image quality of the reconstructed image was improved. Results from the simulation and optical reconstructions show we obtained a full-color reconstruction image with reduced noise and uneven brightness. Full article

(This article belongs to the Special Issue Holography, 3D Imaging and 3D Display Volume II)

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10 pages, 6432 KiB

Open AccessArticle

Color Digital Holography Based on Generalized Phase-Shifting Algorithm with Monitoring Phase-Shift

by Minwoo Jung, Hosung Jeon, Sungjin Lim and Joonku Hahn

Photonics 2021, 8(7), 241; https://doi.org/10.3390/photonics8070241 - 28 Jun 2021

Cited by 4 | Viewed by 3259

Abstract

Color digital holography (DH) has been researched in various fields such as the holographic camera and holographic microscope because it acquires a realistic color object wave by measuring both amplitude and phase. Among the methods for color DH, the phase-shifting DH has an [...] Read more.

Color digital holography (DH) has been researched in various fields such as the holographic camera and holographic microscope because it acquires a realistic color object wave by measuring both amplitude and phase. Among the methods for color DH, the phase-shifting DH has an advantage of obtaining a signal wave of objects without the autocorrelation and conjugate noises. However, this method usually requires many interferograms to obtain signals for all wavelengths. In addition, the phase-shift algorithm is sensitive to the phase-shift error caused by the instability or hysteresis of the phase shifter. In this paper, we propose a new method of color phase-shifting digital holography with monitoring the phase-shift. The color interferograms are recorded by using a focal plane array (FPA) with a Bayer color filter. In order to obtain the color signal wave from the interferograms with unexpected phase-shift values, we devise a generalized phase-shifting DH algorithm. The proposed method enables the robust measurement in the interferograms. Experimentally, we demonstrate the proposed algorithm to reconstruct the object image with negligibly small conjugate noises. Full article

(This article belongs to the Special Issue Holography)

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13 pages, 4194 KiB

Open AccessArticle

Full-Color See-Through Three-Dimensional Display Method Based on Volume Holography

by Taihui Wu, Jianshe Ma, Chengchen Wang, Haibei Wang and Ping Su

Sensors 2021, 21(8), 2698; https://doi.org/10.3390/s21082698 - 11 Apr 2021

Cited by 8 | Viewed by 3461 | Correction

Abstract

We propose a full-color see-through three-dimensional (3D) display method based on volume holography. This method is based on real object interference, avoiding the device limitation of spatial light modulator (SLM). The volume holography has a slim and compact structure, which realizes 3D display [...] Read more.

We propose a full-color see-through three-dimensional (3D) display method based on volume holography. This method is based on real object interference, avoiding the device limitation of spatial light modulator (SLM). The volume holography has a slim and compact structure, which realizes 3D display through one single layer of photopolymer. We analyzed the recording mechanism of volume holographic gratings, diffraction characteristics, and influencing factors of refractive index modulation through Kogelnik’s coupled-wave theory and the monomer diffusion model of photopolymer. We built a multiplexing full-color reflective volume holographic recording optical system and conducted simultaneous exposure experiment. Under the illumination of white light, full-color 3D image can be reconstructed. Experimental results show that the average diffraction efficiency is about 53%, and the grating fringe pitch is less than 0.3 μm. The reconstructed image of volume holography has high diffraction efficiency, high resolution, strong stereo perception, and large observing angle, which provides a technical reference for augmented reality. Full article

(This article belongs to the Section Optical Sensors)

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13 pages, 3950 KiB

Open AccessArticle

Wavelength-Selective Phase-Shifting Digital Holography: Color Three-Dimensional Imaging Ability in Relation to Bit Depth of Wavelength-Multiplexed Holograms

by Tatsuki Tahara, Reo Otani and Yasuhiro Takaki

Appl. Sci. 2018, 8(12), 2410; https://doi.org/10.3390/app8122410 - 28 Nov 2018

Cited by 6 | Viewed by 4403

Abstract

The quality of reconstructed images in relation to the bit depth of holograms formed by wavelength-selective phase-shifting digital holography was investigated. Wavelength-selective phase-shifting digital holography is a technique to obtain multiwavelength three-dimensional (3D) images with a full space-bandwidth product of an image sensor [...] Read more.

The quality of reconstructed images in relation to the bit depth of holograms formed by wavelength-selective phase-shifting digital holography was investigated. Wavelength-selective phase-shifting digital holography is a technique to obtain multiwavelength three-dimensional (3D) images with a full space-bandwidth product of an image sensor from wavelength-multiplexed phase-shifted holograms and has been proposed since 2013. The bit resolution required to obtain a multiwavelength holographic image was quantitatively and experimentally evaluated, and the relationship between wavelength resolution and dynamic range of an image sensor was numerically simulated. The results indicate that two-bit resolution per wavelength is required to conduct color 3D imaging. Full article

(This article belongs to the Special Issue Holography, 3D Imaging and 3D Display)

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25 pages, 1614 KiB

Open AccessArticle

Holographic Spectroscopy: Wavelength-Dependent Analysis of Photosensitive Materials by Means of Holographic Techniques

by Kay-Michael Voit and Mirco Imlau

Materials 2013, 6(1), 334-358; https://doi.org/10.3390/ma6010334 - 23 Jan 2013

Cited by 10 | Viewed by 8677

Abstract

Holographic spectroscopy is highlighted as a powerful tool for the analysis of photosensitive materials with pronounced alterations of the complex permittivity over a broad range in the visible spectrum, due to the advances made both in the fields of advanced holographic media and [...] Read more.

Holographic spectroscopy is highlighted as a powerful tool for the analysis of photosensitive materials with pronounced alterations of the complex permittivity over a broad range in the visible spectrum, due to the advances made both in the fields of advanced holographic media and highly tunable lasers systems. To analytically discuss consequences for in- and off-Bragg reconstruction, we revised Kogelnik’s coupled wave theory strictly on the basis of complex permittivities. We extended it to comply with modern experimental parameters such as out-of-phase mixed holograms and highly modulated gratings. A spatially modulated, wavelength-dependent permittivity that superimposes a spatially homogeneous wavelength-dependent ground state spectrum is taken into account for signal wave reconstruction with bulky elementary mixed gratings as an example. The dispersion characteristics of the respective diffraction efficiency is modelled for color-center-absorption and absorption of strongly localized carriers. As an example for the theoretical possibilities of our newly derived set of equations, we present a quantitative analysis of the Borrmann effect connected to out-of-phase gratings, providing easier and more intuitive methods for the derivation of their grating parameters. Full article

(This article belongs to the Special Issue Advanced Materials for Modern Holographic Applications)

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