• Title/Summary/Keyword: digital image

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Twin-Image Elimination in In-line Digital Holography Microscope (In-line 디지털 홀로그래피 현미경에서 쌍둥이 상 제거연구)

  • Cho, Hyung-Jun;Yu, Young-Hun
    • Korean Journal of Optics and Photonics
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    • v.18 no.2
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    • pp.117-121
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    • 2007
  • A fundamental problem in the in-line digital holography microscope is that the real image and virtual image and zero-order image are not separated spatially. In this paper, we have eliminated the zero-order noise by an averaging method and the twin image is divided using a geometrical set-up in an in-line digital holographic microscope. The size of the virtual image depends on the distance between the objective lens and the hologram plane and on the distance between the hologram plane and the image plane. We found that the virtual image size is smallest when the distance between the objective lens and the hologram plane is equal to the back focal length of the objective lens. We could divide the virtual image and real image by controlling the distance between the hologram plane and the objective lens.

Application Study on the View Points Analysis for National Roads Route using Digital Elevation Data

  • Yeon, Sang-Ho;Hong, Ill-Hwa
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.292-296
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    • 2002
  • This study has been accomplished as a experimental study for field application of 3D Perspective Image Map creation using Digital Topographical Map and based on the Ortho-Projection Image which is generated from Satellite Overlay Images and the precise Relative Coordinates of longitude, latitude and altitude which is corrected by GCP(Ground Control Point). AS to Contour Lines Map which is created by Coordinate conversion of 1:5,000 Topographical Map, we firstly made Satellite Image Map to substitute for Digital Topographical Map through overlapping the original images on top of each Ortho-Projection Image created and checking the accuracy. In addition to 3D Image Map creation for 3D Terrain analysis of a target district, Slope Gradient Analysis, Aspect Analysis and Terrain Elevation Model generation, multidirectional 3D Image generation by DEM can be carried out through this study. This study is to develop a mapping technology with which we can generate 3D Satellite Images of a target district through the composition of Digital Maps and Facility Blueprint and arbitrarily create 3D Perspective Images of the target district from any view point.

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Pseudo 480-Hz Driving Method for Digital Mode Grayscale Displays

  • Ryeom, Jeongduk
    • Journal of Electrical Engineering and Technology
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    • v.8 no.6
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    • pp.1462-1467
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    • 2013
  • A pseudo 480-Hz drive method has been proposed to reduce the dynamic false contour noise that occurs on flat panel displays with displaying grayscale image in the digital mode, such as plasma display panels. The proposed method makes the image movements nearly continuous by rearranging the 8-bit image data displayed for 1 TV field into 8 subfields. The position of the image data rearranged in subfields has been optimized on the basis of the speed of the moving image by computer simulations for the dynamic false contour noise. It is verified that a significant reduction in the dynamic false contour noise is achieved with the proposed method as compared to the conventional noise reduction technologies. Moreover, to reduce the noise in digital mode displays, the proposed technology requires only 8 subfields. Therefore, there is no reduction in the brightness of the image.

Study on the Improvement of Indirect Intra-Oral Dental Digital X-ray Image Sensor with Optical Coupling

  • Whang, Joo-Ho;Chung, Jin-Bum;Kim, Tae-Woo
    • Nuclear Engineering and Technology
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    • v.33 no.5
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    • pp.514-525
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    • 2001
  • Optimum characteristics of digital X-ray sensor components were analyzed to develop intra- oral dental digital X-ray image sensor using indirect method. Parametric analysis was carried out to optimize the phosphor thickness and the fiber optic plate (FOP) coupling to charge coupled device (CCD). X-ray absorption and light diffusion in the phosphor layer were analyzed by the Monte Carlo method. Real time X-ray image was obtained with prototype X- ray image sensor using general CCD camera with 1∼10 Ip/mm resolution. It has been previously shown that large resolution degradation in X-ray images was caused by miss alignment of FOP to CCD and optical adhesive selection. In this study, we reported that X-ray image quality was greatly improved by using optimized characteristics of alignment device and phosphor thickness.

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Evaluation System for Color Filter Array (CFA) in Digital Camera (디지털 카메라에서 컬러 필터 어레이를 위한 평가 시스템)

  • Bae, Tae Wuk
    • Journal of Korea Multimedia Society
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    • v.20 no.11
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    • pp.1741-1749
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    • 2017
  • In commercial digital-cameras, color-filter filters light according to wavelength range of color filter array (CFA) and the filtered intensities contain color information of light. Then, output data of CFA is transformed to final rendered image through demosaicing process. In image processing of digital-camera, the quality of the final rendered image is affected by optical cross talk of CFA, kind of CFA pattern etc. Basically, pattern of CFA plays important role in image quality of final image rendered by digital-camera. Therefore, an evaluation system capable of quantitatively evaluating CFA is needed. This paper proposes a novel evaluation system using existing and proposed image metrics for evaluating CFAs of digital-camera. Proposed CFA evaluation system consist of color difference in CIELAB and S-CIELAB, Structure SImilarity (SSIM), MTF50, moire starting point (MSP), and subjective preference (SP). MSP and SP are newly designed for the proposed evaluation system. Proposed evaluation system is expressed in polar coordinates to analyze the characteristics of CFA objectively and intuitively. Through simulations, we confirmed that proposed CFA evaluation system can objectively assess performance of developed CFAs.

Stereo Sequence Transmission using Concealment of Disparity Information on Color Channels (변이 정보의 칼라채널별 은닉을 통한 스테레오 동영상 전송 기법)

  • 이호근;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.2
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    • pp.29-36
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    • 2003
  • This paper proposes a new 3D image transmission technique using digital watermarking for compatibility with conventional 2D digital TV. To transmit 3D images effectively, generally, we use image sequence transmission using temporal-spatial redundancy between stereo images. It is difficult for users with conventional digital TV to watch the transmitted 3D image sequence because of effectivity of 3D image compression. To improve such problem, in this paper, we perceive the concealment of new information of digital watermarking and conceal information of the other stereo image into three channels of the reference image. So we can watch the image with 3D TV as well as conventional digital TV when it is decoded.

A Study on the Characteristics and Artistic Application of the Image in Post-Internet Art (포스트-인터넷 아트에서의 이미지 특징과 예술적 적용에 관한 연구)

  • Noh, A Young;Lee, Jung Eun
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.4
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    • pp.347-357
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    • 2020
  • This study intended to examine the nature of image which uses the network as the medium in the context of 'post-internet art' and categorize and analyze the cases of applications within art images. In the post-internet art which embraces the background of Web 2.0 and extended digital and network environment, image is transformed and re-mediated into various formats beyond fixed forms. Hito Steyerl defined the image, copied, downloaded, and reedited digitally in low quality as 'poor image.' Young artists, the digital native generation, capture and re-contextualize the changed network environment and depict it in various images. In this context, the application of image in post-internet art can be categorized and analyzed into the 'Image Collected as Material' produced by collecting and recomposing images found in social media, operating system, and website, 'Image Processed through Work' which is newly processed and re-contextualized by using editing programs, and 'Combined Digital-Reality Image' which represents the section of the digital society as the film and image that combine virtuality and reality.

Arbitrary Viewpoint/Disparity Stereoscopic Image Generation from a Digital Hologram (디지털 홀로그램으로부터 임의시점/임의시차 스테레오스코픽 영상 생성)

  • Lee, Yoon-Hyuk;Choi, Hyun-Jun;Kim, Dong-Wook;Seo, Young-Ho
    • Journal of Broadcast Engineering
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    • v.19 no.6
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    • pp.854-865
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    • 2014
  • This paper proposes a method to generate a stereoscopic image pair from a digital hologram by considering the situation that digital hologram data is serviced but the end-user does not have the proper display equipment, etc. We use Fresnel transform as the method to convert a digital hologram into an image. Each image of the stereoscopic image pair uses a part of the given digital hologram and the sizes of the two partial digital holograms for the two images are chosen to be the same. Here, the size of the image is adjusted by the size of the partial digital hologram and the disparity between the pair images is adjusted by the distance between the centers of the two partial hologram. This paper also deals with how to adjust the size and the disparity of the images. In this paper the generated stereoscopic images are implemented as an anaglyphic display type to confirm the feeling of distance by wearing the red-blue glasses.

Implementation of High-definition Digital Signage Reality Image Using Chroma Key Technique (크로마키 기법을 이용한 고해상도 디지털 사이니지 실감 영상 구현)

  • Moon, Dae-Hyuk
    • Journal of Industrial Convergence
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    • v.19 no.6
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    • pp.49-57
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    • 2021
  • Digital Signage and multi-view image system are used as the 4th media to deliver stories and information due to their strong immersion. A content image displayed on large Digital Signage is produced with the use of computer graphics, rather than reality image. That is because the images shot for content making have an extremely limited range of production and their limitation to high resolution, and thereby have difficulty being displayed in a large and wide Digital Signage screen. In case of Screen X and Escape that employ the left and right walls of in the center a movie theater as a screen, images are shot with three cameras for Digital Cinema, and are screened in a cinema with multi-view image system after stitching work is applied. Such realistic images help viewers experience real-life content. This research will be able to display high-resolution images on Digital Signage without quality degradation by using the multi-view image making technique of Screen X and Chroma key technique are showed the high-resolution Digital Signage content making method.

Tamper Detection of Digital Images using Hash Functions (해쉬 함수를 이용한 디지털 영상의 위변조 검출)

  • Woo, Chan-Il;Lee, Seung-Dae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4516-4521
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    • 2014
  • Digital watermarking for digital image authentication and integrity schemes are based on fragile watermarking and can detect any modifications in a watermark embedded image by comparing the embedded watermark with the regenerated watermark. Therefore, the digital watermark for image authentication and integrity should be erased easily when the image is changed by digital image processing, such as scaling or filtering etc. This paper proposes an effective tamper detection scheme for digital images. In the proposed scheme, the original image was divided into many non-overlapping $2{\times}2$ blocks. The digital watermark was divided into two LSB of each block and the image distortion was imperceptible to the human eye. The watermark extraction process can be used to determine if the watermarked image has been tampered. The experimental results successfully revealed the effectiveness of the proposed scheme.