• Proceedings of the Korea Multimedia Society Conference
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• 2002.05c
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• pp.215-218
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• 2002

영상 내에 존재하는 객체를 배경에서 분리해내는 영상분할에 대한 연구는 일반적으로 픽셀중심, 에지기반, 영역기반 그리고 모델기반의 영역에서 이루어져왔다. Active Contour 모델은 객체를 영상에서 분리하는 에지기반의 영상분할 방식이다. 전통적인 의미의 Active Contour 모델에서 사용한 그라디언트 함수 기반의 영상추출은 잡영이 많고 객체와 배경간 뚜렷한 경계가 없는 객체를 검출하는데는 그 한계를 보이고 있다. 이런 한계를 극복하고자 제안된 방법이 Mumford-Shah equation과 Lipshitz 함수를 이용한 Chan과 Vese의 Active Contour Model이다. 그런데 이 모델은 잡영이 많고 경계선이 뚜렷하지 않은 영상을 분할하는데는 효과적이나, 불균형적 조명이 있는 영상에서 객체를 분리해 내는데는 한계를 보이고 있다. 본 논문은 이러한 단점을 극복하기 위해 불균형적인 영상을 균일화하는 방법을 Chan과 Vese의 Active Contour 방식을 적용하기 전에 적용 시켜 영상 내 객체를 보다 효과적으로 추출하는 방법을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.874-878
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• 2000

본 논문에서는 내용 기반 영상 검색 방법 중 "외각선 영역의 색상 분포에 의한 영상 검색"을 제안한다. 영상의 변화가 큰 곳은 해상도를 높게, 낮은 곳은 해상도를 낮게 데이터를 샘플링하여 비교할 데이터의 양을 줄이고, 외각선 영역의 색상을 검출하는데 사용한다. 이때 에지 트리(Edge Tree)를 이용하여 에지(Edge)의 위치 정보와 색상 정보를 유지하며, 검색을 가능하게 하였다. 이와 같은 방법을 사용해서 원하는 영상을 찾을 수 있음을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.5
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• pp.42-51
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• 2001

Vehicle detection is the basic of traffic monitoring. Video based systems have several apparent advantages compared with other kinds of systems. However, In video based systems, shadows make troubles for vehicle detection, especially active shadows resulted from moving vehicles. In this paper, a new method that combines background subtraction and edge detection is proposed for vehicle detection and shadow rejection. The method is effective and the correct rate of vehicle detection is higher than 98% in experiments, during which the passive shadows resulted from roadside buildings grew considerably. Based on the proposed vehicle detection method, vehicle tracking, counting, classification and speed estimation are achieved so that traffic parameters concerning traffic flow is obtained to describe the load of each lane.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.239-245
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• 2004

A hue-based noise-tolerant corner detector is proposed for the exact detection of the real corners in spite of the shadows and random noise. Based on the fact that the hue gradient at the border of the opaque objects' shadow is smaller than the intensity gradient in HSI (hue-saturation-intensity) color space, the effects of shadow are eliminated by introducing the hue-weighted combination of vector gradient to the proposed corner detector. Furthermore, the proposed corner detector is robust to random noise by offsetting the contribution to the corner candidate when the polarities of the color gradients of the pixel pairs are out of phase each other. Results of the experiment show that the proposed corner detector can effectively detect the real corners.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05a
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• pp.675-678
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• 2003

현대 사회에서 가스 산업은 기반 기순 산업으로 영향력이 매우 커지고 있으며, 동시에 위험요소를 내포하고 있다. 본 논문은 가스밸브의 연결부분에서 폭발성 발화물질인 오일성분에 의한 안전사고를 방지하고자 유지분 검출시스템을 개발하였다. 용기 밸브의 영상을 $200{\times}200$ 크기의 흑백 이미지로 획득하고, 제안한 유지분 검출 알고리즘을 적용한다. 먼저, 영상에 소벨(Sobel) 연산자를 이용하여 에지(Edge)를 검출하고 오일이 존재하는 영상과 오일이 존재하지 않는 영상을 영상프로파일(image profile) 분석과 영상 감법 둥의 검출방법으로 비교 분석하였다. 첫 번째 방법은 영상프로파일기법으로 3가지 영역인 부분영역, 하위영역, 전체영역으로 오일을 삽입한 후 다항식 근사로 오일의 존재여부를 판별하였고, 두 번째는 영상감법으로 밸브의 특정한 위치에 위치조정표시를 한 후 두 영상의 차를 구하였다. 실험에서는 제안한 검출방법의 실용화 가능성을 확인하였다.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.9-16
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• 2012

The research of vehicle license plate recognition has been widely studied for the smart city project. The license plate recognition can be hard due to the geometric distortion and the image quality degradation in case of capturing the driving car image at CCTV without trigger signal on the road. In this paper, the high performance vehicle license plate recognition system using edge-based segment image is introduced which is robust in the geometric distortion and the image quality degradation according to non-trigger signal. The experimental results of the proposed real time license plate recognition algorithm which is implemented at the CCTV on the road show that the plate detection rate was 97.5% and the overall character recognition rate of the detected plates was 99.3% in a day average 1,535 vehicles for a week operation.

• 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.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.162-170
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• 2013

In recent years, the interests and needs of the Pedestrian Protection System (PPS), which is mounted on the vehicle for the purpose of traffic safety improvement is increasing. In this paper, we propose a pedestrian candidate window extraction and unit cell histogram based HOG descriptor calculation methods. At pedestrian detection candidate windows extraction stage, the bright ratio of pedestrian and its circumference region, vertical edge projection, edge factor, and PCA reconstruction image are used. Dalal's HOG requires pixel based histogram calculation by Gaussian weights and trilinear interpolation on overlapping blocks, But our method performs Gaussian down-weight and computes histogram on a per-cell basis, and then the histogram is combined with the adjacent cell, so our method can be calculated faster than Dalal's method. Our PCA reconstruction error based pedestrian detection candidate window extraction method efficiently classifies background based on the difference between pedestrian's head and shoulder area. The proposed method improves detection speed compared to the conventional HOG just using image without any prior information from camera calibration or depth map obtained from stereo cameras.

• Journal of KIISE:Software and Applications
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• v.34 no.10
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• pp.929-936
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• 2007

The novel vision-based scheme for real-time extracting traffic parameters is proposed in this paper. Detecting and tracking of vehicle is processed at local region installed by operator. Local region is divided to segmented regions by edge and frame difference, and the segmented regions are classified into vehicle, road, shadow and headlight by statistical and geometrical features. Vehicle is detected by the result of the classification. Traffic parameters such as velocity, length, occupancy and distance are estimated by tracking using template matching at local region. Because background image are not used, it is possible to utilize under various conditions such as weather, time slots and locations. It is performed well with 90.16% detection rate in various databases. If direction, angle and iris are fitted to operating conditions, we are looking forward to using as the core of traffic monitoring systems.

• 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.