• 제목/요약/키워드: Image quality

검색결과 6,263건 처리시간 0.037초

CMOS 영상센서에 대한 영상 신호 전처리기의 구현

  • 정영식;장영조
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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    • pp.15-18
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    • 2001
  • Recently, CMOS image sensor is rapidly used as an image capture device such as mobile phone or notebook PC. Because of poor quality of image by CMOS image sensor, ISP is essential step to improve image quality. In this paper, we implemented and simulated ISP algorithm for real time moving picture of CMOS image sensor. Especial Iy, we concentrated on color interpolation, which extracts three color component from uncompleted color information. Several algorithms for color interpolation are implemented and analyzed to acquire a good quality of picture. Finally, we proposed an improved algorithm and confirmed the effectiveness by experimental simulation results.

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구조적 왜곡특성 측정을 이용한 블록기반 DCT 영상 부호화기의 객관적 화질평가 (Objective Image Quality Metric for Block-Based DCT Image Coder Using Structural Distortion Measurement)

  • 정태윤
    • 대한전기학회논문지:시스템및제어부문D
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    • 제52권7호
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    • pp.434-441
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    • 2003
  • This paper proposes a new quantitative and objective image quality metric which is essential to verify the performance of block-based DCT image coding. The proposed metric considers not only global distortion of coded image such as spatial frequency sensitivity and channel masking using HVS based multi-channel model, but also structural distortions caused block-based coding. The experimental results show a strong correlation between proposed metric and subjective metric.

구조적 왜곡특성 측정을 이용한 블록기반 DCT 영상 부호화기의 객관적 화질평가 (Objective Image Quality Metric for Block-Based DCT Image Coder-using Structural Distortion Measurement)

  • 정태윤
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권7호
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    • pp.434-434
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    • 2003
  • This paper proposes a new quantitative and objective image quality metric which is essential to verify the performance of block-based DCT image coding The proposed metric considers not only global distortion of coded image such as spatial frequency sensitivity and channel masking using HVS based multi-channel model, but also structural distortions caused block-based coding. The experimental results show a strong correlation between propose(B metric and subjective metric.

Blind Image Quality Assessment on Gaussian Blur Images

  • Wang, Liping;Wang, Chengyou;Zhou, Xiao
    • Journal of Information Processing Systems
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    • 제13권3호
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    • pp.448-463
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    • 2017
  • Multimedia is a ubiquitous and indispensable part of our daily life and learning such as audio, image, and video. Objective and subjective quality evaluations play an important role in various multimedia applications. Blind image quality assessment (BIQA) is used to indicate the perceptual quality of a distorted image, while its reference image is not considered and used. Blur is one of the common image distortions. In this paper, we propose a novel BIQA index for Gaussian blur distortion based on the fact that images with different blur degree will have different changes through the same blur. We describe this discrimination from three aspects: color, edge, and structure. For color, we adopt color histogram; for edge, we use edge intensity map, and saliency map is used as the weighting function to be consistent with human visual system (HVS); for structure, we use structure tensor and structural similarity (SSIM) index. Numerous experiments based on four benchmark databases show that our proposed index is highly consistent with the subjective quality assessment.

Analysis of Image Quality and Optimized Reconstruction Window through Heart Rate and Its Variation in Retrospectively ECG-gated Coronary Angiography Using Multi-Detector Row CT

  • Lee, Sang-Ho;Park, Byoung-Wook;Kim, Hee-Joung;Haijo Jung;Kang, Won-suk;Son, Hye-Kyung;Choe, Kyu-Ok
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.461-463
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    • 2002
  • Image quality and selection of optimized window for good quality reconstruction in coronary angiography using multi-detector row CT (MDCT) have not been studied by heart rate and its variation. Therefore, the effect of heart rate and its variation was systemically analyzed. Eighty-three patients were undergone contrast-enhanced coronary angiography using MDCT. In this study, sixty cases were enrolled. Two radiologists graded image quality as follows: 4, excellent; 3, good; 2, fair; l, bad. The starting points of the reconstruction window were chosen at seventy and forty percent of R wave interval. Optimized window was scored as 1 when 40% reconstruction was better quality than 70%, as 2 when 40% reconstruction is same as 70%, and as 3 when 70% reconstruction was better than 40%. Regression analysis was performed. The range of variation of beats per minute (BPM) was well correlated with image quality (r=-0.55, p=0.000), however correlation with optimized window percentage was not statistically significant (p=0.969). By contraries, median value of BPM was comparatively well correlated with optimized window grade (r=-0.24, p=0.086). Median value of BPM was not well correlated with image quality (r=0.l70, p=0.l97). Image quality is more affected by variation of heart rate (VHR) than by higher heart rate. Selection of optimized reconstruction window for good image quality is mainly affected by heart rate and there is a tendency that systolic phase reconstruction is better in image quality than diastolic reconstruction in higher heart rate.

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Wavelet 변환 방식을 이용한 인쇄물 평가에 관한 연구 (A study on print estimation using wavelet transformation method)

  • 김택준;조가람;구철희
    • 한국인쇄학회지
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    • 제20권1호
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    • pp.28-44
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    • 2002
  • Wavelet transformation in image compression is to offer higher image compressibility and high-quality by quantization and entropy encoding. More image quality is good that reconstructed image by wavelet calculation than acquire cosine transform. Therefore, wavelet itself is function if it is wavelet's feature, in this function, do processing applying difference scale and resolution. That is, this is not that fixed resolution has been decided like existent compression way, when it regulated scale, damage goes in pixel and picture looks like break without giving damage entirely in reflex even if magnify or curtail Decoding. Therefore, this paper is in Image that using new wavelet application compression way research that see applies comparing In each image noted this time compressing step by step with circle image compression efficiency recognize. Also, estimated quality pass through by printing of compressed image, investigated compression ratio of most suitable that get print of high quality and elevation of transmission speed.

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JPEG 재 압축이 컬러 이미지 품질에 미치는 영향에 관한 연구 (A Study on the effect of JPEG recompression with the color image quality)

  • 이성형;구철회
    • 한국인쇄학회:학술대회논문집
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    • 한국인쇄학회 2000년도 춘계 학술발표회 논문집
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    • pp.17-24
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    • 2000
  • The Joint Photographic Experts Group (JPEG) is a standara still-image compression technique, established by the International for Standardization (ISO) and International Telecommunication Standardization Sector (ITUT). The standard is intended to be utilized in the various kinds of color still imaging systems as a standard color image coding format. Because JPEG is a lossy compression, the decompressed image pixel values are nto the same as values before compression. Image of JPEG compression is often made to JPEG recompression at saving to apply JPEG compression of color image. In general, JPEG is a lossy compression and compression image is predicted to be varied image quality according to recompressed Q-factor. Various distortions of JPEG compression and JPEG recompression has been reported in previous paper. In this paper, we compress four difference color samples (photo image, gradient image, vector drawing image, text image) according to various Q-factor, and then compressed images are recompressed according to various Q-factor once again. As the results, we inspect variation of quality and file size of recompressed color image, and ensure the optimum recompression factor.

고해상도 위성 SAR 영상품질 성능 분석 툴 개발 (Development of SAR Image Quality Performance Analysis Tool for High Resolution Spaceborne Synthetic Aperture Radar)

  • 오태봉;정철호;송선호;신재민;곽영길
    • 한국항공우주학회지
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    • 제38권2호
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    • pp.188-194
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    • 2010
  • 본 연구에서는 영상레이다 (SAR)의 영상품질 분석 변수 및 확장 보간법, 배경레벨 제거 기법 등의 분석 기법을 정의하고 이를 바탕으로 SAR 영상품질 분석 툴을 개발하였다. 개발된 SAR 영상품질 분석 툴은 크게 점 표적 분석 (PTA) 모듈, 분산 표적 분석 (DTA) 모듈, 모호성 분석 (AMA) 모듈, NESZ 분석 (NESZA) 모듈, 총 4개의 주요 모듈로 구성된다. 개발 툴은 SAR 제품 파일 포맷에서 다양한 시스템 파라미터 추출하고, 이를 바탕으로 임펄스 응답 특성, 방사 성능, 모호성 등의 SAR 영상 품질 변수를 계산한다.

The Effects of Image, Brand and Quality on Customer Loyalty of Sharia Banking

  • RIYADI, Slamet
    • The Journal of Asian Finance, Economics and Business
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    • 제8권3호
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    • pp.1315-1325
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    • 2021
  • This study aimed to design a strategy in encouraging the loyalty level of priority customers of Sharia banks in Indonesia. The strategy was outlined in a series of alternative applicative programs priority. The use of ANP intended to simplify the existing problems so that the offered solution was easier to apply. Each item was scored on a 5-point Likert scale. The expected outcome was to give priority scales to the offered solutions. The findings of this study are service quality, brand image, bank image which could build customer loyalty in Sharia banks. Priority customer gathering could strengthen the bonds between customers and also between customers and their banks. The excellence of Sharia banks in terms of service quality, brand image, and bank image, when combined with priority customer gathering activities, would become a powerful formula in increasing priority customer loyalty to banks that lead to increased revenue from banks. Originality of this research was the formulation process of a new approach in search of ways to increase the customer loyalty, as well as giving concrete proposals for the banking world in designing customer loyalty improvement programs. This paper shows the updated strategy in Customer Loyalty, Bank image, Brand image, Banking service quality.

JPEG 재압축이 컬러 이미지 품질에 미치는 영향에 관한 연구 (A study on the effect of JPEG recompression with the color image quality)

  • 이성형;조가람;구철희
    • 한국인쇄학회지
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    • 제18권2호
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    • pp.55-68
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    • 2000
  • Joint photographic experts group (JPEG) is a standard still-image compression technique, established by the international organization for standardization (ISO) and international telecommunication standardization sector (ITUT). The standard is intended to be utilized in the various kinds of color still imaging systems as a standard color image coding format. Because JPEG is a lossy compression, the decompressed image pixel values are not the same as the value before compression. Various distortions of JPEG compression and JPEG recompression has been reported in various papers. The Image compressed by JPEG is often recompressed by same type compression method in JPEG. In general, JPEG is a lossy compression and the quality of compressed image is predicted that is varied in according to recompression Q-factor. In this paper, four difference color samples(photo image, gradient image, gradient image, vector drawing image, text image) were compressed in according to various Q-factor, and then the compressed images were recompressed according to various Q-factor once again. As the result, this paper evaluate the variation of image quality and file size in JPEG recompression and recommed the optimum recompression factor.

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