• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권5호
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• pp.1814-1828
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• 2021

Low-light image enhancement is a key technique to overcome the quality degradation of photos taken under scotopic vision illumination conditions. The degradation includes low brightness, low contrast, and outstanding noise, which would seriously affect the vision of the human eye recognition ability and subsequent image processing. In this paper, we propose an approach based on deep learning and Retinex theory to enhance the low-light image, which includes image decomposition, illumination prediction, image reconstruction, and image optimization. The first three parts can reconstruct the enhanced image that suffers from low-resolution. To reduce the noise of the enhanced image and improve the image quality, a super-resolution algorithm based on the Laplacian pyramid network is introduced to optimize the image. The Laplacian pyramid network can improve the resolution of the enhanced image through multiple feature extraction and deconvolution operations. Furthermore, a combination loss function is explored in the network training stage to improve the efficiency of the algorithm. Extensive experiments and comprehensive evaluations demonstrate the strength of the proposed method, the result is closer to the real-world scene in lightness, color, and details. Besides, experiments also demonstrate that the proposed method with the single low-light image can achieve the same effect as multi-exposure image fusion algorithm and no ghost is introduced.

• 시큐리티연구
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• 제61호
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• pp.163-179
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• 2019

본 연구의 목적은 경비안전시스템 이용자들의 서비스품질이 기업이미지와 고객만족도에 미치는 영향을 분석하는데 있다. 이를 실증분석을 통해 확인하고자 전국적으로 이용자 200여명을 대상으로 2019년 5월 2일부터 6월 12일까지 약 40일 동안 설문조사를 실시하였다. 설문내용은 "서비스품질, 기업이미지, 고객만족도"로 구성하였다. 실증분석은 타당성과 중요도, 신뢰도, 연관성 분석을 중심으로 실행하였다. 설문조사를 통하여 탐색적요인 및 구조방정식 등을 추출하고자 SPSS WIN 18.0을 사용하였다. 연구 결과 경비안전시스템 이용자들은 서비스품질이 좋을수록 기업이미지가 좋아지고, 기업이미지가 좋을수록 고객만족도가 높아지는 것으로 나타났다. 또한 서비스품질이 좋을수록 고객만족도가 높아질 것으로 제시하였다. 따라서 각 경비안전시스템 업체들은 고객만족도 향상을 위해 서비스품질을 꾸준히 향상시켜 나가야 할 것이다.

• 디지털융복합연구
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• 제17권2호
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• pp.145-153
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• 2019

본 연구의 목적은 대학교육 환경에 변화속에서 교육 서비스품질이 학생만족, 대학이미지, 몰입 그리고 충성도에 미치는 영향을 파악하여 양질에 대학교육을 위한 전략적 방안을 제시하고자 함을 목적으로 한다. 이를 위해 수도권 소재 대학 4학년에 재학중인 학생 229명을 표본으로 6개의 가설을 설정하고 실증분석을 하였다. 연구의 결과는 교육 서비스품질이 만족과 대학 이미지에 긍정적인 영향을 미치고, 만족은 몰입과 충성도에 영향을 미치는 것으로 나타나고 있다. 그러나 이미지는 몰입에는 영향을 미치지 않는 것으로 검증되었다. 몰입은 충성도에 영향을 미치는 것으로 나타났다. 가설검증 결과를 통해서 교육 서비스품질 향상을 위한 대학에 노력이 대학이미지와 충성도에 영향을 주고 장기적인 대학의 경쟁력 향상을 가져 온다고 할 수 있다. 교육 서비스품질 관리를 위한 궁극적인 노력이 급변하는 대학환경에서 생존하는 방법을 제시해 줄 것이다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅲ
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• pp.1701-1704
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• 2003

In this paper, we proposed an watermarking algorithm in which invariable sign of DWT coefficients should be used and by which the quality of digital image can be preserved for the protection of copyright. According to the algorithm, through the calculation of the sign DWT coefficients and the use of elements, position of watermark and size value should be decided. By so doing, the algorithm can improve image quality(PSNR) and obtain good efficiency with which strong watermark can be inserted into the digital image.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.597-600
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• 1999

TMN5 used to test the performance of H.263 is a DCT-based H.263 which DCT is used as transform coding, but DWT is used instead of DCT and adaptive quantizer of being appropriate to DWT is designed in this paper while the structure of TMN5 is maintained. DWT-based H.263, which is proposed in this paper, is excellent in transplantation of the existing system and can improve frame rate by transmitting more Frame. Also, the average PSNR, objective quality of image, has been lost at degree of average 0.35㏈ in luminance signals, but has been improved over a average of 2㏈ in chrominance signals. Subjective quality of image has been improved as blocking effect, which has seriously occurred in DCT based H.263, is diminished. DWT-based H.263 can. therefore. advance video quality of image comparing with the existing ways.

• 대한방사선기술학회지:방사선기술과학
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• 제42권2호
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• pp.119-130
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• 2019

Positron emission tomography (PET) is widely used imaging modality for effective and accurate functional testing and medical diagnosis using radioactive isotopes. However, PET has difficulties in acquiring images with high image quality due to constraints such as the amount of radioactive isotopes injected into the patient, the detection time, the characteristics of the detector, and the patient's motion. In order to overcome this problem, we have succeeded to improve the image quality by using the dynamic image reconstruction method based on singular value decomposition. However, there is still some question about the characteristics of the proposed technique. In this study, the characteristics of reconstruction method based on singular value decomposition was estimated over computational simulation. As a result, we confirmed that the singular value decomposition based reconstruction technique distinguishes the images well when the signal - to - noise ratio of the input image is more than 20 decibels and the feature vector angle is more than 60 degrees. In addition, the proposed methode to estimate the characteristics of reconstruction technique can be applied to other spatio-temporal feature based dynamic image reconstruction techniques. The deduced conclusion of this study can be useful guideline to apply medical image into SVD based dynamic image reconstruction technique to improve the accuracy of medical diagnosis.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.7-13
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• 2021

Machine vision is a technology that helps the computer as if a person recognizes and determines things. In recent years, as advanced technologies such as optical systems, artificial intelligence and big data advanced in conventional machine vision system became more accurate quality inspection and it increases the manufacturing efficiency. In machine vision systems using deep learning, the image quality of the input image is very important. However, most images obtained in the industrial field for quality inspection typically contain noise. This noise is a major factor in the performance of the machine vision system. Therefore, in order to improve the performance of the machine vision system, it is necessary to eliminate the noise of the image. There are lots of research being done to remove noise from the image. In this paper, we propose an autoencoder based machine vision system to eliminate noise in the image. Through experiment proposed model showed better performance compared to the basic autoencoder model in denoising and image reconstruction capability for MNIST and fashion MNIST data sets.

• 정보처리학회논문지B
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• 제17B권3호
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• pp.233-238
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• 2010

본 논문에서는 화질 저하 모델에 기반한 다중 인식기 결합을 이용하여 저화질 영상에 대한 인식 성능을 개선하기 위한 방법을 제안한다. 제안하는 방법은 화질 저하 모델을 이용해 특정 화질에 각각 특화된 복수의 인식기들을 생성한다. 인식 과정에서는 인식기들의 결과를 가중 평균에 의해 결합함으로써 최종 결과를 결정한다. 이 때, 각 인식기의 가중치는 입력 영상의 화질 추정 결과에 따라 동적으로 결정된다. 입력 영상의 화질에 특화된 인식기에는 큰 가중치를, 그렇지 않은 인식기에는 작은 가중치를 지정한다. 그 결과, 입력 영상의 화질 변이에 효과적으로 적응할 수 있다. 뿐만 아니라, 복수의 인식기를 사용하기 때문에 저화질 영상에 대하여 단일 인식 시스템보다 더욱 안정적인 성능을 나타낸다. 제안하는 다중 인식기 결합 방법은 화질을 고려하지 않은 다중 인식기 결합 방법이나, 화질을 고려한 단일 인식 방법과 비교하여 더 높은 인식률을 보였다.

• 대한전자공학회논문지
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• 제25권4호
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• pp.447-452
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• 1988

This paper proposes a hybrid image coding in order to improve the coding performance by combining the BTC with the DPCM. And utilizing the human perceptual characteristics, a new objective image quality evaluation method has been proposed to obtain an excellent result in good agreement with the subjective quality evaluation. A hyb-1 method consisting of the DPCM and the AMBTC has retained a good picture quality at the bit rate of 1.5 bits/pel. A hyb-3 method combining the EBTC-3 with the DPCM has scarcely degraded the picture quality compared with the original image at the bit rate of 2.1 bits/pel. A newly proposed mehtod of picture quality evaluation accumulating a blocky noise at the edge block and an impulsive noise at the flat block selectively has been coincident with the subjective evaluation of quality.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(4)
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• pp.13-16
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• 2001

In the Dedicated Short Range Communication (DSRC) system channel, a large number of bit errors occur because of Additive White Gaussian Noise (AWGN) and fading. When an image data is transmitted under the condition, reconstructed image quality is significantly degraded. In this paper, as an alternative to the error correcting code and/or automatic repeat request scheme, we propose an error recovery scheme for image data transmission. We first analyze how transmission errors in the DSRC system channel degrade image quality. Then, in order to improve image quality, we propose error resilient and concealment schemes for still image transmission using DCT-based fixed length coding, hamming code, cyclic redundancy check, and interleaver. Finally, we show its performance by an experiment.