• 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.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.9-14
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• 2003

본 연구에서는 원격탐사 화상의 분류를 목적으로 분광정보와 공간적 상관성의 반복적 결합방법을 제안하였다. 퍼지이론을 기반으로 공간적 상관성을 분류 과정에 적용하기 위하여 초기단계에서 정의된 소속 함수에 대해서 주변영역에 대한 필터링을 적용하였고, 특정 수렴 조건을 만족하는 단계까지 반복적 결합을 수행하였다. Landsat TM 화상에 적용한 결과, 향상된 분류정확도와 분광정보만으로 분류가 애매한 화소의 공간적 분포 양상을 확인할 수 있었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.9
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• pp.1029-1039
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• 1992

This paper presents the filtering method which is processed on the frequency domain among Hangul character recognition methods. It is processed the Hangul character parrern with spatial positioning modulation and mapped the Hangul character element which have spatial position variant feature onto frequency domain, at this time, normalized spatial position and so normalized the character size in frequency domain. And it is grouped the Hangul character element according to the generating position and set the standard pattern, and used each standard character element pattern with character element filter and filtering the character pattern of Hangul character, it is derived the normalized cross correlation function and the coherence function led to the filtering results, and calculated classification threshold.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.207-209
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• 2021

In recent years, with the development of artificial intelligence and IoT technology, automation and unmanned technology are in progress in various fields, and the importance of image processing such as object tracking, medical images and object recognition, which are the basis of this, is increasing. In particular, in systems requiring detailed data processing, noise reduction is used as a pre-processing step, but the existing algorithm has a disadvantage that blurring occurs in the filtering process. Therefore, in this paper, we propose a filter algorithm using modified spatial weights to minimize information loss in the filtering process. The proposed algorithm uses mask matching to remove AWGN, and obtains the output of the filter by adding or subtracting the output of the modified spatial weight. The proposed algorithm has superior noise reduction characteristics compared to the existing method and reconstructs the image while minimizing the blurring phenomenon.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.21-25
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• 2008

최근 측량기술이 발전함에 따라 다양한 지형공간정보를 획득할 수 있게 되었다. 특히 레이저스캐닝 기술의 도입은 정밀한 지형과 식생 및 인공지물 등에 대한 정보를 신속하게 획득하여 원하는 최신 정보를 가공할 수 있게 되었다. 본 연구에서는 라이다의 식생 데이터에서 점의 밀도 분포를 통하여 정량적인 식생분포 분석을 실시하였다. 또한, 정밀한 지형 모델에 대하여 생성되는 라이다 등고선의 효율적인 활용을 위하여 단계별로 필터링을 실시하여 정확성은 유지하면서 저용량의 등고선을 생성하고 도로 및 엔지니어링 분야 활용을 높일 수 있도록 하였다. 이러한 지능적이고 과학적인 연구는 국내 라이다데이터의 적극적인 활용성을 높이고 누구나 쉽게 사용할 수 있도록 하는데 목적이 있으며, 건설 분야뿐만 아니라 생태지도 및 주제도, 재해 환경 분야, 홍수지도, 도시모델링 등 다양한 분야의 활용성을 가능하도록 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.300-303
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• 2005

본 논문에서는 디지털 멀티미디어 데이터의 저작권 보호를 위하여 웨이블릿 기반 인간 시각 시스템과 주파수 계수의 공간적 특성을 이용한 워터마킹 알고리즘을 제안하였다. 원영상을 1-Level 분해하여 HL1영역과 LH1영역을 4${\times}$4 영역으로 블록화하고 각 블록의 엔트로피와 텍스쳐 값이 가장 좋은 영역을 찾는다. 워터마크가 삽입될 영역은 상위 레벨 계수들의 상관도 특성에 따라서 3-Level 영역에 워터마크를 삽입하였다. 성능평가로 JPEG 압축, 필터링 등 워터마크된 영상에 외부공격을 가하여 워터마크 추출여부를 확인하였고, 실험결과 제안한 알고리즘은 JPEG 압축 50% 이상에서 90%이상의 상관도를 보였고, 샤프닝, 필터링 및 부분삭제 영상변형에 강인함을 보였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.745-746
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• 2009

오늘날 사람들의 의견을 제시하는 공간은 폐쇄적인 인쇄물이나 수동적인 답변 수준을 벗어나 무한의 공간을 가지는 웹에서 이루어지고 있다. 불특정 다수를 대상으로 하며 정형화된 틀을 없는, 더욱 유용한 의견을 많이 얻을 수 있는 특징을 가졌기 때문에, 이를 위해 오피니언 마이닝에 대한 연구가 활발히 진행되고 있다. 기본적으로 오피니언 마이닝은 해당 분야에 대한 정확한 정보를 찾는 것을 목적으로 하지만, 그러한 정보를 제외한 나머지 부분에 대해서도 충분히 유용하게 사용할 수 있다. 본 논문에서는 그 나머지 부분을 이용하여 무분별하게 등록되고 있는 스팸성 댓글을 효과적으로 필터링 할 수 있는 방법을 제안한다.

• Journal of Korea Spatial Information System Society
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• v.10 no.3
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• pp.55-65
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• 2008

For obtaining telematics traffic information(travel time or speed in an individual link), there are many kinds of devices to collect traffic data. Since the GPS satellite signals have been released to civil society, thank to the development of GPS technology, the GPS has become a very useful instrument for collecting traffic data. GPS can reduce the cost of installation and maintenance in contrast with existing traffic detectors which must be stationed on the ground. But. there are Problems when GPS data is applied to the existing filtering techniques used for analyzing the data collected by other detectors. This paper proposes a method to provide users with correct traffic information through filtering abnormal data caused by the unusual driving in collected data based on GPS. We have developed an algorithm that can be applied to real-time GPS data and create more reliable traffic information, by building patterns of past data and filtering abnormal data through selection of filtering areas using Quartile values. in order to verify the proposed algorithm, we experimented with actual traffic data that include probe cars equipped with a built-in GPS receiver which ran through Gangnam Street in Seoul. As a result of these experiments, it is shown that link travel speed data obtained from this algorithm is more accurate than those obtained by existing systems.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.3-10
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• 2012

The investigation of valley networks and their volume provide important information about past water activities on Mars. As an alternative of conventional image processing methods, terrain filtering algorithm using pointcloud data is suggested in this study. First, the topography of pointcloud is inverted so that the valleys become positive features and the algorithm is then applied to distinguish the valleys from the surface. Ground DEM and object DEM are generated from both the valleys and the surface pointcloud then the volume of valleys is estimated by multiplying the height difference between the surface with valleys and the area of valleys based on grid cellsize. In the test of valleys adjacent to Tuscaloosa crater, the total volume of valleys was estimated to be $1.41{\times}10^{11}m^3$ with the difference of 12% and 16% compared with the infill volume of Tuscaloosa crater and BTH result respectively.

• Journal of the Korea Society of Computer and Information
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• v.15 no.9
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• pp.25-33
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• 2010

We propose a retouching method that converts a general photography to a watercolor painting image using bilateral filtering and mean shift segmentation which are mostly used in image processing. The first step is to weaken high frequency components of the image, while preserving the edge of image using the bilateral filtering. And after that we perform DoG(Difference of Gradient) edge extraction and mean shift segmentation respectively from the bilateral filtered image. The DoG edge extraction is performed using luminance component of the image whose RGB color space is transformed into CIELAB space. Experimental result shows that our method can be applied to various types of image and bring better result, especially against the photo taken in daylight.