• Title/Summary/Keyword: False contour

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Equalizing pulse with error diffusion technique using Look-up-Table and subfield pattern for reducing dynamic false contour

  • Seo, Ki-Ho;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.321-324
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    • 2003
  • We reported the method for the relatively simple equalizing pulse to reduce dynamic false contour. Equalizing pulse is determined by look-up-table and moving direction and velocity of the image. Used lookup-table is a few. If image moves to right or left, necessary LUT is only one for the velocity of 1 pixel/tvfield to right or left. This technique makes the process simple after obtaining motion information.

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An Improved Subfield Method for PDP Employing a Constant Slope Code (기울기가 일정한 코드를 사용한 개선된 PDP용 subfield 기법)

  • Lee, Young-Sam;Kim, Rin-Chul;Lee, Byung-Uk
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.5
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    • pp.504-512
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    • 2002
  • This paper presents a new subfield method that can alleviate the visual artifact called the dynamic false contour (DFC), which occurs on plasma display panels. Nothing that the DFC is caused by the difference of time intervals between the adjacent subfields, we propose a constant slope code, in which the differences are maintained to be constant. Also, we propose a subfield code that can minimize the mean absolute error, considering the trade-off between the peak magnitude of the error and its duration. We will show that the proposed subfield method maintains an adequate performance in the view point of the human visual system, since the bound of the errors increases with the gray scale.

A Quantitative Measure in Uniform Color Space for Dynamic False Contours on PDP

  • Park, Seung-Ho;Kim, Choon-Woo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.617-620
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    • 2002
  • Quantitative analysis of dynamic false contours on PDP is essential to evaluate the performance of algorithms for false contour reduction. It also serves as an optimization criterion for selecting the subfield pattern. In this paper, a color difference in uniform color space is defined as a new measure for dynamic false contours. Unlike the measures in previous works, it accounts for the channel dependencies among the RGB color channels.

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A Look-Up Table Based Error Diffusion Algorithm for Dynamic False Contour Reduction of Plasma Display Panels

  • Lee, Ho-Seop;Kim, Choon-Woo
    • Journal of Information Display
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    • v.2 no.2
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    • pp.32-38
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    • 2001
  • PDP(plasma display panel) represents the gray levels by the pulse number modulation technique that results in undesirable dynamic false contours on moving images. This paper proposes a LUT(Look-up table) based error diffusion algorithm for reduction of the dynamic false contours. A quantitative measure of the dynamic false contours is defined first. The measure of the dynamic false contours is calculated through simulation of every gray level combination of two consecutive frames. Based on the calculated measures, a modified gray level for a pair of gray levels of two consecutive frames is chosen to reduce the dynamic false contours. The chosen gray levels serve as contents of a gray level conversion LUT. Given a pair of gray levels of two consecutive frames, the gray level of current frame is modified based on the gray level conversion LUT. The new gray level is displayed on PDP. An error diffusion algorithm is, then, applied to compensate for the differences in the gray levels.

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Genetic Algorithm based B-spline Fitting for Contour Extraction from a Sequence of Images (연속 영상에서의 경계추출을 위한 유전자 알고리즘 기반의 B-spline 적합)

  • Heo Hoon;Lee JeongHeon;Chae OkSam
    • Journal of KIISE:Software and Applications
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    • v.32 no.5
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    • pp.357-365
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    • 2005
  • We present a B-spline fitting method based on genetic algorithm for the extraction of object contours from the complex image sequence, where objects with similar shape and intensity are adjacent each other. The proposed algorithm solves common malfitting problem of the existing B-spline fitting methods including snakes. Classical snake algorithms have not been successful in such an image sequence due to the difficulty in initialization and existence of multiple extrema. We propose a B-spline fitting method using a genetic algorithm with a new initial population generation and fitting function, that are designed to take advantage of the contour of the previous slice. The test results show that the proposed method extracts contour of individual object successfully from the complex image sequence. We validate the algorithm by false-positive/negative errors and relative amounts of agreements.

Reduction of Dynamic False Contours based on Gray Level Selection method in PDP (계조 수 감소를 이용한 PDP내에서 의사 윤곽 제거 기법)

  • Ahn Sang-Jun;Eo Yoon-Phil;Lee Sang-Uk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.7C
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    • pp.716-725
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    • 2005
  • In this paper, we propose a new approach for the reduction of the dynamic false contours, which detects and compensates false contour artifacts adaptively. First, we develop a simple but effective method to select the pixels that are likely to cause the motion artifacts, based on the distribution of pixel values. Then, we merge the selected pixels into several regions using tree structure. Next, we reduce number of gray levels within the regions slightly to reduce the false contours. Note that reducing number of gray levels yield the distortion, thus it is applied only to the selected regions, instead of the whole picture. Intensive simulations on real moving image show that the proposed algorithm alleviates the dynamic false contours effectively with tolerable computational complexity.

Reduction of Dynamic False Contour Using Motion Estimation Method in PDP (움직임 예측을 통한 PDP 내에서의 의사 윤곽 제거 기법 연구)

  • 안상준;김창수;이상욱
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.23-26
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    • 2003
  • In this work. we propose an algorithm for detecting and compensating dynamic false contours in plasma display panels (PDPs). First, we detect the candidate pixels, which are likely to be corrupted by false contours, and merge those pixels into several regions. Second, we estimate the motion vectors of the selected regions. Finally, based on the motion information. we modify the luminance values of the pixels in the regions to alleviate the effects of false contours. Simulation results demonstrate that the proposed algorithm efficiently reduces dynamic false contours at low computational complexity.

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A Novel Driving Algorithm for Reducing Dynamic False Contour in PDPs

  • Yoon, Seok-Jeong;Choi, Sang-Yoon;Lee, Seung-Yong;Choi, Byong-Deok;Kwon, Oh-Kyong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1269-1272
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    • 2005
  • We propose a simple and efficient driving algorithm to reduce Dynamic False Contour(DFC) in Plasma Display Panels(PDPs) by using both accumulation and combination of light emission periods. Although the accumulative way of light emission in sustain period is regarded as more effective than combinational way to reduce DFC, it takes much addressing time to express high gray-scale. Therefore, we combine accumulative and combinational light emission methods to reduce DFC. In the proposed method, one TV field (16.7ms) is composed of four combinational subfields for expressing small gray scales and fifteen accumulative subfields for large gray scales. In addition, we use some Graphic Signal Processing(GSP) algorithm to get more natural images by reducing DFC.

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The Study for Improvement of False Contour in the Plasma Display Panel (플라즈마 디스플레이 패널의 의사윤곽 개선에 관한 연구)

  • Shin, Jae-Hwa;Ha, Sung-Chul;Lee, Seok-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.52 no.3
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    • pp.113-120
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    • 2003
  • Plasma display panels normally utilize the binary coded light emission scheme for gray scale expression. Subsequently, this expression method makes dynamic false contours. We propose the "E3DSM(enhanced 3-dimension scattering method)" that improved existing 3-d scattering method and the "HAM(histogram analysis method)" that is decided the driving schemes and subfield selections with histograms of images. Simulation results show the improving image quality.

Method of Human Detection using Edge Symmetry and Feature Vector (에지 대칭과 특징 벡터를 이용한 사람 검출 방법)

  • Byun, Oh-Sung
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.8
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    • pp.57-66
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    • 2011
  • In this paper, it is proposed for algorithm to detect human efficiently using a edge symmetry and gradient directional characteristics in realtime by the feature extraction in a single input image. Proposed algorithm is composed of three stages, preprocessing, region partition of human candidates, verification of candidate regions. Here, preprocessing stage is strong the image regardless of the intensity and brightness of surrounding environment, also detects a contour with characteristics of human as considering the shape features size and the condition of human for characteristic of human. And stage for region partition of human candidates has separated the region with edge symmetry for human and size in the detected contour, also divided 1st candidates region with applying the adaboost algorithm. Finally, the candidate region verification stage makes excellent the performance for the false detection by verifying the candidate region using feature vector of a gradient for divided local area and classifier. The results of the simulations, which is applying the proposed algorithm, the processing speed of the proposed algorithms is improved approximately 1.7 times, also, the FNR(False Negative Rate) is confirmed to be better 3% than the conventional algorithm which is a single structure algorithm.