• 전기학회논문지P
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• 제51권1호
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• pp.39-44
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• 2002

In this paper, implementation mode image segmentation method for separate image is presented. The method of segmentation image in conventional method, the error are generated by the threshold values. To improve these problem for segmentation image, the calculation of weighting factor using brightness distribution by histogram of stored images are proposed. For safe image of object and laser image, the computed weighting factor is set to the threshold value. Therefore the image erosion and spread are improved, the correct and reliable informations can be measured. In this paper, the system of 3-D extracting information using the proposed algorithm can be applied to manufactory automation, building automation, security guard system, and detecting information system for all of the industry areas.

• 정보처리학회논문지B
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• 제16B권4호
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• pp.263-270
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• 2009

히스토그램 평활화는 주어진 입력 영상의 누적분포함수 CDF (Cumulative Distribution Function)를 이용하여 영상의 동적영역 (Dynamic Range)을 확장하고 히스토그램의 분포를 균등하게 함으로써 명암비를 개선한다. 그러나 히스토그램 평활화는 영상의 밝기를 과도하게 변하게 하는 단점이 있다. 본 논문에서는 과도한 명암비 향상을 억제하기위해 서브-히스토그램의 면적비 기반의 히스토그램 재분배를 이용한 적응형명암비 향상 알고리즘. 제안한 알고리즘은 영상의 동적영역을 입력영상의 휘도 평균값을 기반으로 분할하고, 분할된 영역의 면적비에 따라 밝기 분포를 재분배함으로써 과도한 밝기 변화를 효과적으로 억제 할 수 있다. 실험결과를 통하여 시각적으로 색의 왜곡이 없는 자연스러운 영상을 확인하였고, 평균값의 비교를 통해 과도한 밝기 변화를 억제한 것을 확인 할 수 있었다. 또한 히스토그램의 분포에 상관없이 대부분의 영상에서 우수한 결과를 나타내는 것을 실험결과에서 알 수 있었다.

• 대한전자공학회논문지SP
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• 제48권2호
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• pp.1-10
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• 2011

본 논문은 조명 밝기 변화에 강건한 증강현실 시스템을 구현하기 위한 알고리즘을 제안한다. 본 논문에서 제안하는 방법은 미리 객체를 검출한 프레임으로부터 최적의 표본 밝기를 구해 모델링 한 후, 이를 이용하여 히스토그램 명세화를 수행한다. 또한 카메라 변위에 따라 유실된 객체의 특징 정보는 선형 칼만 필터로 추적하였다. 제안된 방법을 사용하였을 때 기존의 방법보다 약 3배 이상 객체 검출률이 향상되었으며, 객체 검출에 실패한 프레임 또한 선형 칼만 필터를 통해 위치 정보를 매우 정확하게 예측할 수 있었다. 본 알고리즘의 효율성을 증명하기 위해 실제 증강 현실을 이용한 게임 시스템에 적용한 결과 기존의 다른 방법보다 성능이 향상됨을 확인 할 수 있었다. 본 알고리즘은 게임 환경이나, 조명 변화가 심한 환경에서도 강건한 증강 현실 시스템의 구현에 적용될 것이라 판단된다.

• 스마트미디어저널
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• 제8권3호
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• pp.62-69
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• 2019

심전도 신호는 위조가 불가능하며 양쪽 손목에서 신호를 간편히 취득할 수 있는 장점이 있다. 본 논문에서는 심전도 신호의 방향 정보를 이용해 커플링 이미지를 생성하고, 이를 이용한 개인 인식 방법을 제안한다. 제안하는 커플링 이미지는 정방향 심전도 신호와 R-peak를 기준으로 회전된 역방향 심전도 신호를 이용해 생성하며, 생성한 커플링 이미지는 개인별로 고유한 패턴과 명암을 나타낸다. 또한 같은 주기의 심전도 신호 연산을 통해 R-peak 영역 데이터가 증가하여 개인 인식 성능 향상이 가능하다. 생성한 커플링 이미지는 제안한 합성곱 신경망을 이용해 패턴 및 명암에 대한 특징을 추출하며, 네트워크 속도 향상을 위해 다수의 풀링층을 사용해 데이터 크기를 축소한다. 실험은 47명의 공개된 심전도 데이터를 이용하며, 공개된 네트워크 중 top-5 성능이 상위권인 5개 네트워크와 제안한 네트워크를 이용해 비교 실험을 진행한다. 실험 결과 제안한 네트워크의 개인인식 성능이 99.28%로 가장 높게 나타남에 따라, 제안한 커플링 이미지를 이용한 개인 인식 방법이 유효함을 확인하였다.

• IEIE Transactions on Smart Processing and Computing
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• 제6권3호
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• pp.168-174
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• 2017

Videos recorded on surveillance cameras or by car black boxes at night have distorted images due to illumination variation. Therefore, it is difficult to analyze morphological characteristics of objects, and it is limiting to use such distorted images as evidence in traffic accidents. Image restoration is performed by amplifying the brightness of nighttime images using linearized gamma correction to increase their contrast (which destroys visual information) and by minimizing degradation factors caused by irregular traveling.

• 한국정밀공학회지
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• 제22권8호
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• pp.182-191
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• 2005

It is very important to obtain a high quality of bone image for an accurate ultrasonic measurement of bone mineral density. In this study, we suggested a technique to acquire an optimal image by adapting an acoustic lens and a properly selected ultrasonic probe. Also, we have applied an image processing algorithm with which automatically makes a decision of brightness and contrast of image by generating threshold level, a composition of ultrasonic data, an elimination of noise using modified median filter, and a real time interpolation. We could confirm much improved resolution of bone image with acoustic lens attached to the ultrasonic probe and with the image processing algorithm suggested in this study. Therefore, it became possible to precisely diagnose the osteoprosis using ultrasonic imaging technique.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.311-314
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• 1995

This paper presents a method for measuring tool wear parameters based on two dimensional image information. The tool wear images were obtained from an ITV camera with magnifying and lighting devices, and were analyzed using image processing techniques such as thresholding, noise filtering and boundary tracing. Thresholding was used to transform the captured gray scale image into a binary image for rapid sequential image processing. The threshold level was determined using a novel technique in which the brightness histograms of two concentric windows containing the tool wear image were compared. The use of noise filtering and boundary tracing to reduce the measuring errors was explored. Performance tests of the measurement precision and processing speed revealed that the direct method was highly effective in intermittent tool wear monitoring.

• 반도체디스플레이기술학회지
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• 제14권4호
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• pp.50-55
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• 2015

This paper proposes a new histogram partition stretching and shrinking method for infrared image enhancement. The proposed method divides the histogram of an input image into three partitions according to its mean value and standard deviation. The method stretches both the dark partition and the bright partition of the histogram, while it shrinks the medium partition. As the result, both the dark part and the bright part of the image have more brightness levels. The proposed method is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiments were conducted by using various infrared images. The results show that the proposed algorithm is successful for the infrared image enhancement.

• 한국도로학회논문집
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• 제18권6호
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• pp.145-152
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• 2016

OBJECTIVES : Visibility at night can be improved by using retroreflection for short distances and phosphorescent line markings for long distances. In this study, we analyzed the characteristics of the phosphorescent line marking through a laboratory luminance test. Field performance analysis was performed through tests conducted on the road. We also examined the luminance measurement methods using the digital image obtained during the phosphorescent visibility evaluation. METHODS : In this study, the laboratory luminance test of the phosphorescent line marking was conducted using seven specimens to characterize the luminance changes according to the type of the glass beads, the thickness of the phosphorescent line marking, and the brightness and irradiation time of the light source. Phosphorescent and general line markings were made at 150 m to investigate the field luminance performance. A preliminary review of the luminance measurement methods was made using a digital image from a digital single-lens reflex (DSLR) camera. The measured luminance ratio of the general and the phosphorescent line markings was compared with the calculated luminance ratio using luminance analysis. RESULTS : Through the laboratory luminance test, it was seen that the change in luminance, which corresponds to the brightness of the light source, appears large but the influence of the thickness and irradiation time is low. The field performance test of the phosphorescent line marking conducted on the road involved measuring the luminance on the day the marking was made and 7 days after the marking was made. The luminance was found to be $190mcd/m^2$ at 30 min after sunset and approximately $10-12mcd/m^2$ 4h after sunset. The results of the luminance test were captured using a digital image for each time group. The luminance ratio of the phosphorescent line marking, when compared to that of the general line marking, showed a similar trend within a 13% maximum error. Additionally, when this luminance ratio is compared to the direct field measurement, it could be confirmed that the luminance ratio, as captured in the digital image, showed a similar tendency. CONCLUSIONS : 1) The change in luminance corresponding to the brightness of the light source is significant in comparison with that corresponding to the thickness and the irradiation time. In addition, the results of the field test for the phosphorescent line marking satisfied the phosphorescent fire protection standard. 2) We examined the validity of the luminance measurement method using a digital image and we concluded that the change in the luminance ratio shows a similar tendency in both the cases. The results can form the basis for luminance measurement methodology for the construction and maintenance of phosphorescent line markings.

• ETRI Journal
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• 제34권1호
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• pp.138-141
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• 2012

This letter proposes a real-time digital image stabilization system for cell phone cameras without the need for frame memory. The system post-processes an image captured with a safe shutter speed using an adaptive denoising filter and a global color correction algorithm. This system can transfer the normal brightness of an image previewed under long exposure to the captured image making it bright and crisp with low noise. It is even possible to take photos in low-light conditions. By not needing frame memory, the approach is feasible for integration into the size-constrained image sensors of cell phone cameras.