• Title/Summary/Keyword: digital holography

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Extremely High-Definition Computer Generated Hologram Calculation Algorithm with Concave Lens Function (오목 렌즈 함수를 이용한 초 고해상도 Computer generated hologram 생성 기법)

  • Lee, Chang-Joo;Choi, Woo-Young;Oh, Kwan-Jung;Hong, Keehoon;Choi, Kihong;Cheon, Sang-Hoon;Park, Joongki;Lee, Seung-Yeol
    • Journal of Broadcast Engineering
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    • v.25 no.6
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    • pp.836-844
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    • 2020
  • A very large number of pixels is required to generate a computer generated hologram (CGH) with a large-size and wide viewing angle equivalent to that of an analog hologram, which incurs a very large amount of computation. For this reason, a high-performance computing device and long computation time were required to generate high-definition CGH. To solve these problems, in this paper, we propose a technique for generating high-definition CGH by arraying the pre-calculated low-definition CGH and multiplying the appropriately-shifted concave lens function. Using the proposed technique, 0.1 Gigapixel CGH recorded by the point cloud method can be used to calculate 2.5 Gigapixels CGH at a very high speed, and the recorded hologram image was successfully reconstructed through the experiment.

Speckle Noise Reduction and Image Quality Improvement in U-net-based Phase Holograms in BL-ASM (BL-ASM에서 U-net 기반 위상 홀로그램의 스펙클 노이즈 감소와 이미지 품질 향상)

  • Oh-Seung Nam;Ki-Chul Kwon;Jong-Rae Jeong;Kwon-Yeon Lee;Nam Kim
    • Korean Journal of Optics and Photonics
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    • v.34 no.5
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    • pp.192-201
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    • 2023
  • The band-limited angular spectrum method (BL-ASM) causes aliasing errors due to spatial frequency control problems. In this paper, a sampling interval adjustment technique for phase holograms and a technique for reducing speckle noise and improving image quality using a deep-learningbased U-net model are proposed. With the proposed technique, speckle noise is reduced by first calculating the sampling factor and controlling the spatial frequency by adjusting the sampling interval so that aliasing errors can be removed in a wide range of propagation. The next step is to improve the quality of the reconstructed image by learning the phase hologram to which the deep learning model is applied. In the S/W simulation of various sample images, it was confirmed that the peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM) were improved by 5% and 0.14% on average, compared with the existing BL-ASM.

A Study on Analysis of Color characteristic of On-line of Game Play Image of according to the Users (온라인 게임 플레이영상의 이용자에 따른 색채 특성 분석 연구)

  • Jang, Hyun-Joo;Jung, Hyung-Won
    • Journal of Digital Convergence
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    • v.15 no.10
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    • pp.399-404
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    • 2017
  • If game images use colors improper for certain ages, the characteristics of games disappear, and the efficiency of image expression drops. thus a study in color is very important. Nevertheless, there is a lack of research on this subject. In this study, we investigated the difference of color of game images according to users. User group is divided into all users and users over 18 years old. Among the rank of games,10 each from games for all ages and games for non-teen-rated are selected, and the game-playing images are taken as snapshots to have 100 each images each, A total of 2000 images were extracted and the mean values of RGB and HSB of each game were obtained and independent sample t test was performed. The results showed that the RGB color values between the two users were significantly significant. In the future, it is expected that it will be helpful in color selection when developing psychotherapy games and emotional games using color psychology. Furthermore, we will use color image scales to express colors as adjectives, analyze colors in a variety of ways, and investigate the difference in color of game images in each country.

An Analysis of Influential Factors from Continuous Use by Mobil Game Users : Lifestyle under Gender and Nationality (모바일게임 이용자의 지속사용 영향요인분석: 성별과 국적에 따른 라이프스타일을 중심으로)

  • Shim, Sun-Ae;Jung, Hyung-Won
    • Journal of Digital Convergence
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    • v.15 no.5
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    • pp.381-390
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    • 2017
  • Lifestyle is an important variable to understand consumer behavior because it is a lifestyle that is common to all members of society or some members of society. so In this study, the survey has been performed on adult mobile game users over the age of 20 in Korea and China to evaluate the correlation between lifestyle and will of continuous use of game by mobile game users, and the hierarchical multiple regression analysis has been performed on the collected data by using the statistical package program SPSS 20.0. There were total 212 respondents with the gender ratio of 50:50, and 107 respondents were Korean, and 105 respondents were Chinese. As a result of study, first, regardless of lifestyle, more male and more Chinese respondents showed higher will of continuous use. Second, among mobile game user lifestyles, the challenge-oriented, trend-oriented, conservative, and ostentatious lifestyles could become significant causal variables for the will of continuous use of game. Yet, the influence of such lifestyle was not correlated with individual genders or nationalities. The result of this study will be provided as the basic data to establish the strategic solution for companies and government policies for entrance into the mobile game market of China in the future.

Leadership Experience through Guild Activities on Online Games : A Phenomenological Analysis (온라인 게임의 길드 활동을 통한 리더십 경험 : 현상학적 분석)

  • Kim, Ki-Suk;Jung, Hyung-Won
    • Journal of Digital Convergence
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    • v.14 no.6
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    • pp.415-423
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    • 2016
  • Numerous studies have been made on the negative effects of online games, as the negatives effects of the usage of online games have been recognized as social issues. However, this is a study on the positive functions of online gaming; more specifically, on how the guild activities on online games affect the user's leadership. This study has conducted in-depth interviews with online games, and drew the result using Giorgi's phenomenological analysis as for the methodology. 3 people participated in the research - a high school student, a university student, and an adult office worker - all of whom with experiences of guild leading on online games. To achieve the goal of this study, this study based the subjects' experience to analyze how online game guild activities have affected leadership on the subjects' real lives. As a result, timidity turned into initiation; not only leadership, but also decision making ability and coworking ability, as well as problem solving ability have shown improvement. Through this study, one can see that among the elements of online game, experience in guild activities is providing opportunities for enhancing leadership and possibilities for improving various other abilities. I hope more researchers continue studying interesting and diverse powers of online games based on this study.

Augmented Presentation Framework Design and System Implementation for Immersive Information Visualization and Delivery (몰입적 정보 표현과 전달을 위한 증강 프레젠테이션 디자인 및 시스템 구현)

  • Kim, Minju;Wohn, Kwangyun
    • Journal of the HCI Society of Korea
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    • v.12 no.1
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    • pp.5-13
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    • 2017
  • Interactive intervention of the human presenter is one of the important factors that make the visualization more effective. Rather than just showing the content, the presenter enhances the process of the information delivery by providing the context of visualization. In this paper, we define this as an augmented presentation. In augmented presentation concept, the presenter can facilitate presentation more actively by being fully immersed in the visualization space and reaching and interacting into digital information. In order to concrete the concept, we design presentation space that enables the presenter to be seamlessly immersed in the visualization. Also we increase the presenter's roles as a storyteller, controller and augmenter allowing the presenter to fully support communicative process between the audience and the visualization. Then, we present an augmented presentation system to verify the proposed concept. We rendered 3D visualization through a half-mirror film and a wall projection screen that are place in parallel and applied with stereoscopic images, then, spatially align the presenter inside the virtual visualization space. After that, we conduct a controlled experiment to investigate the subjective level of immersion and engagement of the audience to HoloStation compared to traditional presentation system. Our initial investigation suggests that the newly conceived augmented presentation has potential not only to enhance the information presentation but also to supports the delivery of visualization.