• 제목/요약/키워드: Improve image quality

검색결과 961건 처리시간 0.024초

프레임 차와 톤 매핑을 이용한 저조도 영상 향상 (Low-light Image Enhancement Based on Frame Difference and Tone Mapping)

  • 정윤주;이영학;심재창;정순기
    • 한국멀티미디어학회논문지
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    • 제21권9호
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    • pp.1044-1051
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    • 2018
  • In this paper, we propose a new method to improve low light image. In order to improve the image quality of a night image with a moving object as much as the quality of a daytime image, the following tasks were performed. Firstly, we reduce the noisy of the input night image and improve the night image by the tone mapping method. Secondly, we segment the input night image into a foreground with motion and a background without motion. The motion is detected using both the difference between the current frame and the previous frame and the difference between the current frame and the night background image. The background region of the night image takes pixels from corresponding positions in the daytime image. The foreground regions of the night image take the pixels from the corresponding positions of the image which is improved by the tone mapping method. Experimental results show that the proposed method can improve the visual quality more clearly than the existing methods.

An Optimal Method to Improve the Visual Quality of Medical Images

  • Shin, Choong-ho;Jung, Chai-yeoung
    • 통합자연과학논문집
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    • 제8권2호
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    • pp.141-144
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    • 2015
  • As the visual quality of X-ray images is a critical reference for the accuracy of the clinical diagnosis, the methods to improve the quality of X-ray images have been investigated. Among many existing methods, using frequency domain filter is a very powerful method to improve the visual quality of images. In this paper, the inherent noises of the input images are suppressed by adding the Laplacian image to the subjected image. The medical X-ray images using the optimal high pass filter has shown improved edges. Further, the optimal high frequency emphasis filter has shown the improved contrast of flat areas by using the result image from the optimal high pass filter. Also the resulting images of the global contrast have improved by the histogram equalization. As a result, the proposed methods have shown enhanced contrast and edges of the images with noise canceling effect.

사용자 선호에 기반한 효율적 최대 휘소 가시화 알고리즘의 선택 방법 (Algorithm Selection Method for Efficient Maximum Intensity Projection Based on User Preference)

  • 한철희;계희원
    • 한국멀티미디어학회논문지
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    • 제21권2호
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    • pp.87-97
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    • 2018
  • Maximum intensity projection (MIP) is a common visualization technique in medical imaging system. A typical method to improve the performance of MIP is empty space leaping, which skips unnecessary area. This research proposes a new method to improve the existing empty space leaping. In order to skip more regions, we introduce a variety of acceleration strategies that use some tolerance given by the user to take part in image quality loss. Each proposed method shows various image quality and speed, and this study compares them to select the best one. Experimental results show that it is most efficient to add a constant tolerance function when the image quality required by the user is low. Conversely, when the user required image quality is high, a function with a low tolerance of volume center is most effective. Applying the proposed method to general MIP visualization can generate a relatively high quality image in a short time.

Evaluation of Image Quality of Inkjet Printing on the Spun Polyester Fabrics

  • Park, Heung-Sup
    • 한국염색가공학회지
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    • 제18권5호
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    • pp.61-71
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    • 2006
  • This paper addresses the factors hindering the image quality of lines in inkjet printed on polyester fabric as printing media. Lines were printed onto different types of polyester fabrics in warp and filling directions. Line image quality including line width, edge blurriness, and edge raggedness was assessed. The effect of capillary wicking on line image quality of printed spun polyester fabric is discussed. The factors on the image quality include printing position(top of the yam or between the yarn), printing direction(warp or filling), yarn structures(filament or spun), thread size(yam or fiber), finishing, and ink properties(evaporation rate). More than 30% differences in image quality results were observed by changing the printing location on the spun polyester fabric. The best results of the image quality were obtained with the printed plain and spun polyester fabrics. The fiber sizes may affect capillary size; therefore, the image quality can be dissimilar. Types of finishing materials and inks greatly improve the line image quality on spun polyester fabrics.

An Image Quality Requirement Quantified Control Method in Display Development Life Cycle

  • Xue, Liqin;Zou, Xuecheng
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.660-664
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    • 2006
  • A novel quantified method based on requirement analysis of image quality to improve display image quality was proposed. Nowadays, the image quality was limited by the poor understanding of the image quality requirement, which led to the critical factors of image quality could not be controlled during display development. Our method was set up to resolve this problem by clarifying the relationship between the image quality level and the effect factors in image processing. Moreover, the subjective factors were eliminated extremely by the image quality quantification. The method was applied in the RPTV development life cycle and its efficiency was demonstrated.

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Disparity Refinement near the Object Boundaries for Virtual-View Quality Enhancement

  • Lee, Gyu-cheol;Yoo, Jisang
    • Journal of Electrical Engineering and Technology
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    • 제10권5호
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    • pp.2189-2196
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    • 2015
  • Stereo matching algorithm is usually used to obtain a disparity map from a pair of images. However, the disparity map obtained by using stereo matching contains lots of noise and error regions. In this paper, we propose a virtual-view synthesis algorithm using disparity refinement in order to improve the quality of the synthesized image. First, the error region is detected by examining the consistency of the disparity maps. Then, motion information is acquired by applying optical flow to texture component of the image in order to improve the performance. Then, the occlusion region is found using optical flow on the texture component of the image in order to improve the performance of the optical flow. The refined disparity map is finally used for the synthesis of the virtual view image. The experimental results show that the proposed algorithm improves the quality of the generated virtual-view.

임상가를 위한 특집 2 - 파노라마방사선영상의 화질관리 (Image quality evaluation for panoramic radiography)

  • 이삼선
    • 대한치과의사협회지
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    • 제52권3호
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    • pp.139-146
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    • 2014
  • The quality assurance program of a panoramic radiography is been discussed in two ways: phantom image tests and clinical image quality assurance tests. Methods and standards of each of the test are presented, which efforts guarantee a proper quality of image, improve standard of dental care and decrease radiation exposure.

그림자효과 보정을 통한 영상융합 품질 향상 가능성 (Potential for Image Fusion Quality Improvement through Shadow Effects Correction)

  • 손홍규;윤공현
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2003년도 추계학술발표회 논문집
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    • pp.397-402
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    • 2003
  • This study is aimed to improve the quality of image fusion results through shadow effects correction. For this, shadow effects correction algorithm is proposed and visual comparisons have been made to estimate the quality of image fusion results. The following four steps have been performed to improve the image fusion qualify First, the shadow regions of satellite image are precisely located. Subsequently, segmentation of context regions is manually implemented for accurate correction. Next step, to calculate correction factor we compared the context region with the same non-shadow context region. Finally, image fusion is implemented using collected images. The result presented here helps to accurately extract and interpret geo-spatial information from satellite imagery.

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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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경계 기반의 깊이 영상 개선 (The Enhancement of the Boundary-Based Depth Image)

  • 안양근;홍지만
    • 한국컴퓨터정보학회논문지
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    • 제17권4호
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    • pp.51-58
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    • 2012
  • 최근 깊이영상을 기반으로 한 3D 기술이 3D 공간감지, 3D 영상획득, 3D 인터랙션, 3D 게임 등 다양한 분야에서 응용되고 있다. 깊이영상을 생성하기 위해서는 깊이 카메라를 이용하게 되는데, 이렇게 생성된 깊이영상의 화질을 개선하기 위한 다양한 시도들이 이루어지고 있다. 본 눈문에서는 이러한 깊이 카메라 기반의 3D 응용에 있어서 깊이 영상을 개선하기 위해 영역기반의 에지 검출기를 사용하는 방법을 제안한다. 제안된 방법은 제한된 환경에서의 깊이영상을 획득하는 과정에서 발생 할 수 있는 화질열화를 후처리 또는 전처리를 통해 개선함으로써 보다 향상된 깊이 영상을 제공한다. 다양한 실험결과를 통해서 개선된 깊이영상을 객관적 화질 평가를 위해 가상시점 참조 소프트웨어에 적용하여 비교함으로써 최대 0.42dB의 화질 향상을 확인하였다. 또한 영상의 실제 시청 환경과 가장 유사한 방법인 DSCQS(Double Stimulus Continuous Quality Scale)방법을 통해서 주관적 화질의 객관적 평가를 수행함으로써 개선된 깊이영상의 효용성을 다시 확인하였다.