• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1992.06a
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• pp.447-451
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• 1992

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.722-725
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• 2008

In this paper, we propose a new approach for fast generation of CGHs of a 3-D object by using the run-length encoding and N-LUT methods. In this approach, object points to be involved in calculation of the CGH pattern can be dramatically reduced and as a result a significant increase of computational speed can be obtained.

• Journal of Information Display
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• v.13 no.1
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• pp.21-30
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• 2012

Active-matrix electrophoretic display (AMEPD) is commonly used for the applications of smart handheld reading devices such as e-books and e-news. This paper presents a new reduced waveform lookup table storage method that reduces the associated lookup table by approximately 2n (n is the number of gray levels employed) times the conventional one. The paper also proposes a driving method for image display. The method provides high-speed performance for image display and also effectively eliminates the image residue, achieving high image quality. The prototyped controller was connected to a 6" AMEPD panel, whose excellent display quality demonstrated the effectiveness of the proposed controller design.

• Proceedings of the Korean Printing Society Conference
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• 2000.12b
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• pp.5-10
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• 2000

In case of outputting the image with color printer, image is occurred color distortion by characteristics of paper, effect by overlap between neighbor dots and the mechanical characteristics if printer. Color calibration is needed to reduce this color distrotion. To color calibration, we select the color sample in printer color gamut. The accuracy of color calibration is determined by the number of sample, distribution, and calibration method. Generally, color space is selected the color sample dividing equal interval. In this case, the range of gamut of printed color patches is reduced due to the effect of inks overlap. Therefore, error is occurred when color transformation relatively. In this paper, we have the color sampling based on equi-visual perception and then reproduce the color using the Neural-Network and interpolation by LUT.

• Proceedings of the Korean Printing Society Conference
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• 2000.12b
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• pp.17-28
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• 2000

Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. However, most of the digital proofing devices have lower resolutions than analog proofing systems and differ with actual color presses in the color gamuts. Therefore, proper color compensations are needed for digital color proofing in order to match color between the proofs and the press sheets. In this paper, we used 3-dimensional look-up table(LUT) and tetrahedral interpolation method for the color space conversion between the device independent color space(CIEXYZ or Lab) and the device dependent color space(CMY) to reduce the color differences between the original copy and digital color proofs and the press sheets.

• The Magazine of the IEIE
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• v.30 no.4
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• pp.422-422
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• 2003

본 논문에서는 기존의 기지국과 W-CDMA 시스템을 상호 연동하기 위한 SDR(Software Defined Radio) 기반의 멀티 밴드 디지털 IF 모듈 구현에 대해 소개한다. 하드웨어 플랫폼상에 테스트 및 시험 검증하기 위해서 크게 광대역 ADC, DAC, FPGA로 구성하였으며, FPGA 내에 디지털 필터 및 NCO 등의 응용 소프트웨어는 VHDL로 코딩하였다. 디지털 필터는 FPGA의 허용 자원을 고려하여 인터폴레이션 및 데시메이션을 위한 폴리페이즈 필터 뱅크로 구현하였다. 또한 송신단에서는 이미지 성분을 제거하기 위해 2단의 DCQM(Digital Complex Quadrature Modulation)을 적용하였으며, 이때 적용되는 NCO(Numerically Controlled Oscillator)는 1/4주기의 LUT를 사용하여 설계하였다. 수신단에서는 IF 단에 SAW 필터를 사용하지 않기 때문에 W-CDMA의 블록커 규약에 준하면서 근접 채널을 제거하기 위한 고출력의 감쇄 특성을 갖는 필터를 설계하였다. 본 논문에서는 컴퓨터 시뮬레이션 결과와 스펙트럼 분석기를 통해 측정된 결과를 비교 분석하였으며 이에 대한 디지털 IF 모듈의 성능을 검증하였다.

• Proceedings of the Korean Printing Society Conference
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• 2000.04a
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• pp.45-55
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• 2000

Recently, as the prepress mainstream is changed to the digital wolkflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. Generally, CRT monitors are also often used as a soft proofing device for hard-copy image output. However, displayed color image on CRT monitor does not match to the actual color printing sheets. Because, the color space of CRT monitor used RGB color space, and it is differ with printing device color space, CMY. Therefore, proper color compensations are needed to match the colors between hard-copy proofs on the printing device and soft copy proofs on the monitor. For the proper compensation, we used LUT and gamut mapping method for color space transformation between device dependent color space and device independent color space, vis a vis. This paper shows the application method and the usefulness of CRT monitor for the soft-copy proofing using the output characteristics of printing device.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06a
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• pp.125-131
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• 1999

In this paper, we address practical methods for calculating camera lens distortion for real time applications. Although the lens distortion problem can be easily ignored for constant-parameter lenses, in the field of real-time camera calibrations, for zoom lenses a large number of calculations are needed to calculate the distortion. However, if the distortion can be calculated independently of the other camera parameter, we can easily calibrate a camera without the need for a large number of calculations. Based on Tsai's camera model, we propose two different methods for calculating lens distortion. These methods are so simple and require so few calculations that the lens distortion can be rapidly calculated even in real-time applications. The first method is to refer to the focal length - lens distortion Look Up Table(LUT), which is constructed in the initialization process. The second method is to use the relationship between the feature points found in the image. Experiments were carried out for both methods, results of which show that the proposed methods are favorably comparable in performance with non-real full optimization method.