• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.376-381
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• 2009

The image data compression, recognition, restoration, etc. are parts of the digital image processing technology. In the process by various devices, noises would be made. Because the noise could damage the image, we use the image filter to preserve the original image from the noise. The image filter used in digital image process basically has a two-dimensional structure. There an two methods of creating the filter - One is reiterating one dimension and the other is using an indivisible two-dimension image filter. The image filter is being widely used along with one-dimension filter according to each noise, and various median filters are being used to remove the impulse noise. In this paper, I suggested a powerful modified median filter, and compared with conventional filters for objective verification.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.281-284
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• 2015

Digital image processing is utilized in various application fields by rapid development of memory cell. However, the noise occurs with various causes in the process of data processing process and various methods have been studied in order to remove such noises. In general, the image is damaged by the mixed noise which has different characteristics each other. This paper proposed a filter algorithm which processes the data according to shape of noise in order to mitigate the impact of the mixed noise added to the image. In addition, this paper compared this filter algorithm with the current methods and used PSNR(peak signal to noise ratio) as a criterion of judgment.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10b
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• pp.44-48
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• 2006

디지털 카메라 기술의 발전과 보급으로 공공건물의 보안 카메라부터 개인 휴대 단말기의 카메라까지 동영상 데이터를 수집할 수 있는 수단이 크게 늘었으며, 그 활용 또한 매우 일반화되었다. 동영상 데이터는 문서나 음성 등의 다른 데이터보다 훨씬 구체적이고 사실적인 정보를 포함하므로 과거의 기억을 정리하고 복원하기 위한 유용한 방법이 될 수 있다. 동영상 데이터의 증가와 함께 동영상 요약에 대한 연구가 최근에 활발히 진행되고 있는데, 이들 연구의 대부분은 하나의 동영상을 요약하고 분석하기 위한 것이다. 본 논문에서는 사무실에 여러 대의 카메라를 설치하여 데이터를 저장하며, 이렇게 수집된 동영상 데이터를 효과적으로 요약하고 검색하는 시스템을 구축한다. 동일한 이벤트를 여러 방향에서 바라보고, 그 상황을 가장 잘 설명한 카메라를 선택 할 수 있다는 점에서 멀티 카메라의 사용은 장점을 갖는다. 사전에 정의된 이벤트에 따라 전문가가 어노테이션을 부여하도록 하였으며, 전문가가 설정한 유틸리티에 따라 카메라 선택 및 요약이 이루어진다. 다양한 옵션에 따라 요약된 결과로 사용자 평가를 수행하였다.

• The Journal of the Korea Contents Association
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• v.5 no.2
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• pp.87-94
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• 2005

In this paper, we present a new watermarking algorithm in which a watermark is created based on the energy of the original image and embedded into the image by replacement. The watermark is adjusted to have a certain proportional amount of energy based on one of the original image and embedded into the DFT magnitude component replacing original coefficients. This scheme reduces degree of quality degradation in a watermarked image by maintaining energy and strengthen robustness against attacks by embedding a strong watermark. From the result of experiment, we confirmed that the proposed algorithm had high invisibility of 47.6dB of PSNR and could reconstruct 98.9% of message on average.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.300-303
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• 2015

Digital imaging process has been put to practical use in various application sectors due to a rapid advancement such as memory devices, etc. However, noises are being generated due to various reasons during the image processing and a variety of methods are being studied in order to eliminate these noises. Generally, images are damaged due to a mixed noise having different characteristics. In this paper, a filter algorithm which switches according to the noise types was proposed in order to mitigate the influence of mixed noise included in the image. And using the PSNR as the standard for objective decision making of the improvement effect, it was compared with the existing methods.

• Journal of Broadcast Engineering
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• v.24 no.3
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• pp.452-462
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• 2019

A digital hologram, which is one of the next generation visual systems, can be generated and displayed in various formats, and a digital hologram is created in accordance with the characteristics of the system for display. Diffraction efficiency can be used as a measure of the characteristics of digital holograms generaged under various conditions in various display environments. In this paper, diffraction efficiency for computer-generated hologram (CGH) under various conditions was measured. This paper discusses the generation conditions that should be considered in hologram display. We compared each condition by measuring the intensity of the first order diffraction pattern of the fringe generated under the Fresnel condition for the phase hologram. Through this paper, we showed the tend about characteristics of the diffraction efficiency according to object point, reconstruction distance, laser and SLM.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.61-67
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• 2011

Stereoscopic 3D video can be transmitted by frame-compatible packing format to fulfill the compatibility requirement with the existing digital TV. Then, the reduced stereo image needs to be expanded to the original size at the receiver. This paper proposes an adaptive interpolation method for the discarded image lines. The horizontal line-based linear filter and NEDI6 filter are used selectively for the interpolation of each pixel. Experimental results show that the NEDI6 combined with the horizontal line-based linear filter yields better image quality than the bilinear method by around 0.6dB.

• Journal of Korea Multimedia Society
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• v.8 no.4
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• pp.516-524
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• 2005

In this paper, a new watermarking scheme based on the POCS theory and human visual system is proposed. Using the POCS theory, watermarks are embedded into imperceptible image regions such as edge and strong texture area in the spatial domain. Also it is inserted into middle frequency band in the transform domain to achieve the robustness against compression and filtering, etc. In addition, different gain factors are employed into blocks classified by considering texture masking effect. By doing so, the proposed method has a novel property of having both the imperceptibility and the robustness simultaneously. Simulation results show that the proposed method has an excellent performance better than conventional approaches.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.795-797
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• 2014

Image treatment has grown in its necessity in many fields due to the development of display technology used in smart phones and tablet computers. In digital imaging technology, noise is created by many causes during the process of acquiring, transmitting and treating image data. Therefore, this paper suggests a median filter that is more competent in removing noise by taking into account the direction when restoring noisy images that have been damaged by impulse noise. In order to verify the noise removal characteristics, PSNR(peak signal to noise ratio) was used for comparison against existing methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2717-2723
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• 2015

Recently, digital image processing is being applied in various areas of broadcasting, communication, computer graphic and medical science. But, degradation of images occurs in the process of digital image acquisition, processing and transmission. Therefore, in order to remove the mixed noise, this paper suggested the image restoration algorithm to process salt and pepper noise with weighted filters according to 4 direction pixel changes after judging the noise and to process AWGN with weighted filters which have individually different characteristics. Regarding the processed results by applying Boat images which were corrupted by salt and pepper noise(P=40%), suggested algorithm showed the improvement by 1.33[dB], 1.41[dB], 0.51[dB] respectively compared with the existing CWMF, AWMF, MMF.