• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.205-209
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• 2012

To manufacture a real time digital holographic display system capable of being applied to next-generation television, it is important to rapidly generate a digital hologram. In this paper, we analyze digital hologram rendering based on a computer computation scheme. We analyze previous recursive methods to identify regularity between the depth-map image and the digital hologram.

• ETRI Journal
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• v.44 no.1
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• pp.85-93
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• 2022

We propose an efficient method for synthesizing mesh-based realistic computer-generated hologram (CGH). In a previous nonanalytic mesh-based CGH synthesis, the angular spectrum of the two-dimensional (2D) plane is calculated using the fast Fourier transform (FFT) with the same size as the resolution of the final hologram. Because FFT increases the computation time as the size of the input matrix increases, the previous method has a problem: The higher the resolution of the hologram, the greater the computational load, thereby delaying synthesis time. In this study, when calculating the angular spectrum of the 2D plane in mesh-based CGH synthesis, we propose a method to calculate the angular spectrum by defining the 2D plane with an arbitrary size smaller than the resolution of the final hologram. The resolution adjustment method reduces the computation time and can be applied to occlusion culling and texturing for the realistic effect of mesh-based CGH. We describe the principle, error analysis, application of realistic effect, and experimental results of the proposed method.

• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.149-154
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• 2017

The purpose of this study is to investigate the possibility of Hologram media as Advertising media in terms of comsumer communication. First, Motivation and Personality Traits was set variables that drive consumer media experience and, also examined the impact on eWOM and Purchase Intention structurally. As the result, it Found that Intrinsic and Social motivation of consumers have a positive impact on the media experience, eWOM and PI. In the case of Personality Triats, Openness to the motivation, Openness and Extraversion had an impact of positive to the degree of eWOM. Furthermore, eWOM influence on PI positively. This result can be considered the need for the Media MIX Strategy or IMC.

• Journal of Korea Game Society
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• v.15 no.1
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• pp.27-34
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• 2015

This paper proposes a user interface for enhancing immersiveness and usability by combining hologram and haptic device with common Leap Motion. While Leap Motion delivers physical motion of user hand to control virtual environment, it is limited to handle virtual hands on screen and interact with virtual environment in one way. In our system, hologram is coupled with Leap Motion to improve user immersiveness by arranging real and virtual hands in the same place. Moreover, we provide a interaction prototype of sense by designing a haptic device to convey touch sense in virtual environment to user's hand.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.242-245
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• 2009

This paper proposes an algorithm that increases the speed of generating a Fresnel hologram using a recursive addition operation covering the whole coordinate array of a digital hologram. The 3D object designed to calculate the digital hologram used the depth-map image produced by computer graphics (CG). The proposed algorithm is a technique that performs CGH (computer generated hologram) operation with only the recursive addition from the hologram's whole coordinates by analyzing the regularity between the 3D object and the digital hologram coordinates. The experimental results showed that the proposed algorithm increased operation speed by 30% over the technique using the conventional CGH equation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.603-610
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• 2008

In this paper, we propose an efficient noise reduction algorithm for digital hologram during acquisition and transmission. The proposed algorithm segment a digital hologram with object region and background region after DCT. Then, we adopt a histogram transition method for object region and zero-value change method for background region. The experimental results show that our algorithm has beuer performance than a natural image denoising algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1267-1274
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• 2007

In this paper, we propose a digital watermarking algorithm for digital hologram generated by computer generated hologram(CGH) method. Digital hologram generated by a computer calculation(CGH) is one of the most expensive contents and its usage is being expanded. Thus, it is highly necessary to protect the ownership of digital hologram. In this paper two digital watermarking schemes are introduced hologram-domain and global 2DDCT-domain scheme. Proposed watermarking scheme showed very high imperceptibility and quite high robustness against the attacks. The purpose of this paper is to introduce these global 2DDCT based watermarking schemes. Thus, we expect that these and the contents in this paper can be very useful bases for the further digital watermarking schemes of the digital holograms.

• Journal of Digital Contents Society
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• v.19 no.9
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• pp.1625-1630
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• 2018

Image presentation ways have recently been growing, and hologram, which is one of the next generation image presentation methods, has been developed through a lot of researches, but it is difficult to embody. Therefore, a similar hologram method has been used for different multimedia contents to present the hologram-like effects. This paper intends to investigate ways to effectively use a floating hologram method as one of the pseudo hologram methods to apply to interactive multimedia contents. It also aims to produce works applying a motion sensor to contents of a boxed form using the floating hologram method while studying real-time interaction between sound and image presented from audience's participation to provide researches on advantages and disadvantages of utilizing hologram and the technology while suggesting complementary methods on them.

• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.3-20
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• 2023

A computer-generated hologram (CGH) is a digitally calculated and recorded hologram in which the amplitude and phase information of an image is transmitted in free space. The CGH is in the form of a complex hologram, but it is converted into a phase-only hologram to display through a phase-only spatial light modulator (SLM). In this paper, in the process of including the amplitude information of an object in the phase information, when a technique that includes subsampling such as DPAC is used, we showed experimentally that the bandwidth of the phase-only hologram increases, and as a result, aliasing that was not present in the complex hologram can occur. In addition, it was experimentally shown that it is possible to generate a high-quality phase-only hologram by restricting the spatial frequency range even at a distance where the numerical reconstruction performance is degraded by aliasing.

• Broadcasting and Media Magazine
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• v.16 no.2
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• pp.93-108
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• 2011