• Journal of Korea Multimedia Society
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• v.16 no.6
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• pp.756-763
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• 2013

Bilateral filter (BF), functioning by two Gaussian filters, domain and range filter is a nonlinear filter for sharpness enhancement and noise removal. In infrared (IR) small target detection field, the BF is designed by background predictor for predicting background not including small target. For this, the standard deviations of the two Gaussian filters need to be changed adaptively in background and target region of an infrared image. In this paper, the proposed bilateral filter make the standard deviations changed adaptively, using variance feature of mean values of surrounding block neighboring local filter window. And, in case the variance of mean values for surrounding blocks is low for any processed pixel, the pixel is classified to flat background and target region for enhancing background prediction. On the other hand, any pixel with high variance for surrounding blocks is classified to edge region. Small target can be detected by subtracting predicted background from original image. In experimental results, we confirmed that the proposed bilateral filter has superior target detection rate, compared with existing methods.

• Journal of Korea Game Society
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• v.15 no.2
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• pp.159-168
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• 2015

This paper introduces effective noise removal method for medical ultrasound volume data. Ultrasound volume data need to be filtered because it has a lot of noise. Conventional 2d filtering methods ignore information of adjacent layers and conventional 3d filtering methods are slow or have simple filter that are not efficient for removing noise and also don't equally operate filtering because that don't take into account ultrasound' sampling character. To solve this problem, we introduce method that fast perform in parallel bilateral filtering that is known as good for noise removal and adjust proportionally window size depending on that's position. Experiments compare noise removal and loss of original data among average filtered or biliteral filtered or adaptive biliteral filtered ultrasound volume rendering images. In this way, we can more efficiently and correctly remove noise of ultrasound volume data.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9C
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• pp.863-870
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• 2009

Bilateral filter (BF) is a nonlinear filter for sharpness enhancement and noise removal. The BF performs the function by the two Gaussian filters, the domain filter and the range filter. To apply the BF to infrared (IR) small target detection, the standard deviation of the two Gaussian filters need to be changed adaptively between the background region and the target region. This paper presents a new BF with the adaptive standard deviation based on the analysis of the edge component of the local window, also having the variable filter size. This enables the BF to perform better and become more suitable in the field of small target detection Experimental results demonstrate that the proposed method is robust and efficient than the conventional methods.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.11-13
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• 2011

양방향 필터 (Bilateral filter)는 에지 보전 평활화 필터로써 디노이징, 반사 제거, 스테레오 매칭 등 다양한 분야에서 사용되고 있다. 이는 기존의 가우시안 필터에 사용되는 공간 도메인 커널 (spatial kernel)이외에 강도 도메인 커널 (range kernel)을 추가로 사용하여 비슷한 강도의 픽셀에 높은 가중치를 부여함으로써 에지를 보전하면서 평활화를 한다. 또한 양방향 필터는 비등방성 확산 필터 (Anisotropic diffusion filter)와 달리 항상 수렴을 보장한다. 따라서 본 논문에서는 고정점 반복 이론을 적용하여 양방향 필터의 수렴을 수학적으로 증명한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.134-137
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• 2014

화질의 개선을 위해 잡음을 제거하는 기술이 많이 개발되고 있으며 그 기술들 중에 효과적으로 사용되고 있는 것 하나가 양방향 필터이다. 양방향 필터는 거리에 대한 가중치와 화소 값에 대한 가중치를 모두 고려하기 때문에 경계 부분을 보존하면서 잡음을 제거하는 것이 가능하다. 필터를 적용함으로 잡음이 제거되지만 본 논문에서는 그보다 나은 결과를 위해서 경계 부분을 캐니 에지 검출기로 검출하고 강조함으로써 양방향 필터의 장점을 전보다 부각시켜 이전보다 효과적인 화질개선 방법을 제시하고자 하였다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.1
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• pp.60-64
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• 2011

In this paper, we propose a new post-processing technique that removes blocking and ringing artifacts in Block discrete cosine transformation (BDCT)-coded images using bilateral filtering. The selection of filter parameters is a key issue in the application of a bilateral filter because it significantly affects the result. An efficient method of selecting the bilateral filter parameters is presented. The experimental results show that the proposed approach alleviates the artifacts efficiently in terms of PSNR, MSDS, and SSIM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4C
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• pp.350-357
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• 2010

In this paper, we present an auto-range fast bilateral filter (FBF) for high-dynamic-range (HDR) images, which increases computation speed by using adaptive standard deviations for range filter (RF) of FBF in iCAM06. Many images that cover the entire dynamic range of the scene with different exposure times are fused into one High Dynamic Range (HDR) image. The representative algorithm for HDR image rendering is iCAM06, which is based on the iCAM framework, such as the local white point adaptation, chromatic adaptation, and the image processing transform (IPT) uniform color space. FBF in iCAM06 uses constant standard deviation in RF. So, it causes unnecessary FBF computation in high stimulus range with broad and low distribution. To solve this problem, the low stimulus image and high stimulus image of CIE tri-stimulus values (XYZ) divided by the threshold are respectively processed by adaptive standard deviation based on its histogram distribution. Experiment results show that the proposed method reduces computation time than the previous FBF.

• Journal of Korea Multimedia Society
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• v.16 no.6
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• pp.746-755
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• 2013

This paper presents a three dimensional bilateral filter detecting target trajectory, extracting spatial target information using two dimensional bilateral filter and temporal target information using one dimensional bilateral filter. In order to discriminate edge pixel with flat background and target region spatially and temporally, spatial and temporal variance are used for an image and temporal profile. With this procedure, background and background profile are predicted without original target through two dimensional and one dimensional bilateral filter. Finally, using spatially predicted background and temporally predicted background profile, small target can be detected. For comparison of existing target detection methods and the proposed method, the receiver operating characteristics (ROC) is used in experimental results. Experimental results show that the proposed method has superior target detection rate and lower false alarm rate.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.105-107
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• 2012

본 논문에서는 영상의 잡음제거에 주로 적용되어 왔던 양방향 필터(bilateral filter) 기법을 개량하여 에지 정보를 더 잘 살리게 하는 방법을 제안한다. 우선, 잡음 영상에서 에지의 위치를 파악하기 위한 방법으로, 이웃픽셀값들의 분산을 이용하는 방법을 제안한다. 또한 에지와의 거리를 기반으로 필터의 계수를 조정하는 방법을 제시한다. 따라서 제안하는 알고리즘을 적용하여 잡음 제거를 수행하면 기존의 잡음 제거율을 유지하면서도 에지정보를 보존한 결과를 얻을 수 있다.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.17-18
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• 2014

본 논문에서는 리튬이온 배터리 모델을 고려한 양방향 인터리브드 DC-DC 컨버터의 최적 수동소자 설계 기법을 제안한다. 제안하는 방법은 배터리 리플전류 제한값과 필터 커패시터의 전류정격을 만족시키는 최대 허용 리플전류를 설계함으로써 최소한의 인덕턴스값과 최적의 필터 커패시터를 구한다. 본 설계 기법을 하이브리드 ESS를 위한 100kW급 양방향 인터리브드 DC-DC 컨버터에 적용하여 설계하였다.