• Title/Summary/Keyword: Adaptive edge detection

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A Motion Adaptive Deinterlacing Algorithm Using Improved Motion Detection (향상된 움직임 탐색 기법을 적용한 움직임 적응적 디인터레이싱 알고리듬)

  • Yun, Janghyeok;Jeon, Gwanggil;Jeong, Jechang
    • Journal of Broadcast Engineering
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    • v.18 no.2
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    • pp.167-177
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    • 2013
  • In this paper, a motion adaptive deinterlacing algorithm is proposed. It consists of three parts: (1) modified edge-based line average, (2) pixel-based consequent five-field motion detection, and (3) block-based local characteristic for detecting true motion and calculating the motion intensity by using an improved method which is able to detect the inner part of moving objects precisely as well as to reduce the risk of false detection caused by intrinsic noises in the image. Depending on the detected motion activity level, it combines spatial and temporal methods with weighting factor. Simulations conducted on several video sequences indicate that the performance of the proposed method is superior to the conventional methods in terms of both subjective and objective video quality.

Adaptive Median Filter by Local Central Variance (로컬 중간값 분산을 이용한 적응형 메디안 필터)

  • Cho Woo-Yeon;Choi Doo-Il
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.2
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    • pp.104-115
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    • 2005
  • Median filters in the signal processing have been most widely used and have demonstrated the strongest effects. This paper proposes the adaptive median filters with noise detection. The proposed basic algorithm of the filters is to judge whether or not the noises exist on the ground of The Noise Judgment Standards. Just in case the existence of the noises is verified by the algorithm, it takes the median filter. In order to judge the existence of the noises by the algorithm, this paper introduced the noise detection method by local central variance. As a result of comparing and analyzing the features and performance of the proposed filters and the existing [5]-[10] filters on the same conditions, it was verified that the former proved to be better than the latter, Observed even by naked eyes, it was similar, too. Accordingly, it's proved that the adaptive median filters by local central variance are useful in removing the impulse noise of the median filter and reinforce the edge preservation ability.

Automated Vessels Detection on Infant Retinal Images

  • Sukkaew, Lassada;Uyyanonvara, Bunyarit;Barman, Sarah A;Jareanjit, Jaruwat
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.321-325
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    • 2004
  • Retinopathy of Prematurity (ROP) is a common retinal neovascular disorder of premature infants. It can be characterized by inappropriate and disorganized vessel. This paper present a method for blood vessel detection on infant retinal images. The algorithm is designed to detect the retinal vessels. The proposed method applies a Lapalacian of Gaussian as a step-edge detector based on the second-order directional derivative to identify locations of the edge of vessels with zero crossings. The procedure allows parameters computation in a fixed number of operations independent of kernel size. This method is composed of four steps : grayscale conversion, edge detection based on LOG, noise removal by adaptive Wiener filter & median filter, and Otsu's global thresholding. The algorithm has been tested on twenty infant retinal images. In cooperation with the Digital Imaging Research Centre, Kingston University, London and Department of Opthalmology, Imperial College London who supplied all the images used in this project. The algorithm has done well to detect small thin vessels, which are of interest in clinical practice.

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Locally Adaptive Bi-level Image Segmentation Technique (국부 적응 2 진 화상 영역화 기법)

  • Jung, Gyoo-Sung;Park, Rae-Hong
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1367-1370
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    • 1987
  • This paper describes a new automatic bi-level image segmentation algorithm which determines local thresholds by applying a locally adaptive edge detection technique to a variable threshold selection method. Computer simulations show that the performance of the proposed algorithm is more robust than those of automatic global thresholding methods.

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Edge Detection Using a Water Flow Model (Water Flow Model을 이용한 에지 검출)

  • Lee, Geon-Il;Kim, In-Gwon;Jeong, Dong-Uk;Song, Jeong-Hui;Gwak, Won-Gi;Park, Rae-Hong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.4
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    • pp.422-433
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    • 2001
  • In this paper, we propose a flew edge detection method based on water flow model, in which gradient image surface is considered as a 3-dimensional (3-D) geographical feature. The edges of the objects in the background can be detected by the large gradient magnitude areas and to make the edges immersed it is required to invert the gradient image. The proposed edge detector uses a water flow model based enhancement and locally adaptive thresholding technique applied to the inverted gradient image resulting in better noise performance. Computer simulations with a few synthetic and real images show that the Proposed method can extract edge contour effectively.

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Application of An Adaptive Self Organizing Feature Map to X-Ray Image Segmentation

  • Kim, Byung-Man;Cho, Hyung-Suck
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1315-1318
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    • 2003
  • In this paper, a neural network based approach using a self-organizing feature map is proposed for the segmentation of X ray images. A number of algorithms based on such approaches as histogram analysis, region growing, edge detection and pixel classification have been proposed for segmentation of general images. However, few approaches have been applied to X ray image segmentation because of blur of the X ray image and vagueness of its edge, which are inherent properties of X ray images. To this end, we develop a new model based on the neural network to detect objects in a given X ray image. The new model utilizes Mumford-Shah functional incorporating with a modified adaptive SOFM. Although Mumford-Shah model is an active contour model not based on the gradient of the image for finding edges in image, it has some limitation to accurately represent object images. To avoid this criticism, we utilize an adaptive self organizing feature map developed earlier by the authors.[1] It's learning rule is derived from Mumford-Shah energy function and the boundary of blurred and vague X ray image. The evolution of the neural network is shown to well segment and represent. To demonstrate the performance of the proposed method, segmentation of an industrial part is solved and the experimental results are discussed in detail.

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Content Adaptive Interpolation for Intra-field Deinterlacting (공간적 디인터레이싱을 위한 컨텐츠 기반 적응적 보간 기법)

  • Kim, Won-Ki;Jin, Soon-Jong;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.10C
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    • pp.1000-1009
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    • 2007
  • This paper presents a content adaptive interpolation (CAI) for intra deinterlacing. The CAI consists of three steps: pre-processing, content classification, and adaptive interpolation. There are also three main interpolation methods in our proposed CAI, i.e. modified edge-based line averaging (M-ELA), gradient directed interpolation (GDI), and window matching method (WMM). Each proposed method shows different performances according to spatial local features. Therefore, we analyze the local region feature using the gradient detection and classify each missing pixel into four categories. And then, based on the classification result, a different do-interlacing algorithm is activated in order to obtain the best performance. Experimental results demonstrate that the CAI method performs better than previous techniques.

Edge Detection System for Noisy Video Sequences Using Partial Reconfiguration (부분 재구성을 이용한 노이즈 영상의 경계선 검출 시스템)

  • Yoon, Il-Jung;Joung, Hee-Won;Kim, Seung-Jong;Min, Byong-Seok;Lee, Joo-Heung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.21-31
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    • 2017
  • In this paper, the Zynq system-on-chip (SoC) platform is used to design an adaptive noise reduction and edge-detection system using partial reconfiguration. Filters are implemented in a partially reconfigurable (PR) region to provide high computational complexity in real-time, 1080p video processing. In addition, partial reconfiguration enables better utilization of hardware resources in the embedded system from autonomous replacement of filters in the same PR region. The proposed edge-detection system performs adaptive noise reduction if the noise density level in the incoming video sequences exceeds a given threshold value. Results of implementation show that the proposed system improves the accuracy of edge-detection results (14~20 times in Pratt's Figure of Merit) through self-reconfiguration of filter bitstreams triggered by noise density level in the video sequences. In addition, the ZyCAP controller implemented in this paper enables about 2.1 times faster reconfiguration when compared to a PCAP controller.

Feature Point Extraction of Sea Urchin using Adaptive Edge Detection (적응적 경계 검출을 이용한 성게의 특징점 추출)

  • Jeon, Young-Cheol;Woo, Young-Bae;Choi, Chul-Jae
    • The Journal of the Korea institute of electronic communication sciences
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    • v.12 no.1
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    • pp.173-180
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    • 2017
  • The albinism phenomenon of the East Sea is now in progress, and the area of the intensified bedrock has reached up to 61.7% of the whole bedrock area of the East Sea. The methods to eradicate the sea urchin that is known as the main cause of albinism and that influences huge damage on the selfish farm have been continuously studied but they have focused on the food using the sea urchin and recycling and the research on the recognition of the sea urchin has not been performed yet. Therefore, this study suggested the adaptive boundary detection to extract the characteristics of the sea urchin in order to catch the sea urchin in quantity that is the pirate of the sea, and it is believed to help the sea urchin recognition program a lot in the future.

Nonlinear Anisotropic Diffusion Using Adaptive Weighted Median Filters (적응 가중 미디언 필터를 이용한 영상 확산 알고리즘)

  • Hwang, In-Ho;Lee, Kyung-Hoon;Kim, Woong-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.5C
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    • pp.542-549
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    • 2007
  • Recently, many research activities in the image processing area are concentrated on developing new algorithms by finding the solution of the 'diffusion equation'. The diffusion algorithms are expected to be utilized in numerous applications including noise removal and image restoration, edge detection, segmentation, etc. In this paper, at first, it will be shown that the anisotropic diffusion algorithms have the similar structure with the adaptive FIR filters with cross-shaped 5-tap kernel, and this relatively small-sized kernel causes many iterating procedure for satisfactory filtering effects. Moreover, it will also be shown that lots of modifications which are adopted to the conventional Gaussian diffusion method in order to weaken the edge blurring nature of the linear filtering process increases another computational burden. We propose a new Median diffusion scheme by replacing the adaptive linear filters in the diffusion process with the AWM (Adaptive Weighted Median) filters. A diffusion-equation-based adaptation scheme is also proposed. With the proposed scheme, the size of the diffusion kernel can be increased, and thus diffusion speed greatly increases. Simulation results shows that the proposed Median diffusion scheme outperforms in noise removal (especially impulsive noise), and edge preservation.