• Title/Summary/Keyword: Image Gradient

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An Intelligent Video Image Segmentation System using Watershed Algorithm (워터쉐드 알고리즘을 이용한 지능형 비디오 영상 분할 시스템)

  • Yang, Hwang-Kyu
    • The Journal of the Korea institute of electronic communication sciences
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    • v.5 no.3
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    • pp.309-314
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    • 2010
  • In this paper, an intelligent security camera over internet is proposed. Among ISC methods, watersheds based methods produce a good performance in segmentation accuracy. But traditional watershed transform has been suffered from over-segmentation due to small local minima included in gradient image that is input to the watershed transform. And a zone face candidates of detection using skin-color model. last step, face to check at face of candidate location using SVM method. It is extract of wavelet transform coefficient to the zone face candidated. Therefore, it is likely that it is applicable to read world problem, such as object tracking, surveillance, and human computer interface application etc.

Spatial Analysis of Turbulent Flow in Combustion Chamber using High Resolution Dual Color PIV (고분해능 이색 PIV를 이용한 가솔린 엔진 연소실내 난류의 공간적 해석)

  • Lee, K.H.;Lee, C.S.;Lee, H.G.;Chon, M.S.;Joo, Y.C.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.132-141
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    • 1998
  • Particle image velocimetry(PIV), a planar measuring technique, is an efficient tool for studying the complicated flow field such as in-cylinder flow, and intake port flow. PIV can be also used for analyzing the integral length scale of turbulence, which is a measure of the size of the large eddies that contain most of the turbulence kinetic energy. In this study, dual color scanning PIV was designed and demonstrated by using a rotating mirror and a beam splitter. This PIV system allowed enlargement of flexibility in the intensity of vectors to be calculated by spatial filtering technique, even in combustion chamber with high velocity gradient and high vorticity$({\sim}1000s^{-1})$. A new color image processing algorithm was developed, which was used to find the direction of particle movement directly from the digital image. These measuring techniques were successfully applied to obtaining the turbulence intensity (~0.1m/s) and the turbulent integral length scale of vorticity(~1mm).

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Architecture design of the straight - line Hough Transform processor for image analysis (영상해석용 직선 Hough Transform 연산기의 아키텍쳐 설계)

  • Park, Young-June;Song, Nag-Un
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.10
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    • pp.2553-2561
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    • 1997
  • In this paper, a hardware architecture to calculate straight-line Hough transform algorithm for image recognition is suggested. This processor consists of the filtering module for gradient calculation and the HT calculation module, and the angle information are stored in memory table. For the suggested architecture, firstly, algorithm simulation is executed using C language to confirm the operation and to decide the precision of calculation, and secondly, architecture simulation is executed using VHDL language for the total blocks. According to C & VHDL simulation results, it is confirmed that the calculated data value is similarly obtained and the calculation defference is decreased as image clarity and bits increase.

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Genetic Algorithm Based Feature Reduction For Depth Estimation Of Image (이미지의 깊이 추정을 위한 유전 알고리즘 기반의 특징 축소)

  • Shin, Sung-Sik;Gwun, Ou-Bong
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.2
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    • pp.47-54
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    • 2011
  • This paper describes the method to reduce the time-cost for depth estimation of an image by learning, on the basis of the Genetic Algorithm, the image's features. The depth information is estimated from the relationship among features such as the energy value of an image and the gradient of the texture etc. The estimation-time increases due to the large dimension of an image's features used in the estimating process. And the use of the features without consideration of their importance can have an adverse effect on the performance. So, it is necessary to reduce the dimension of an image's features based on the significance of each feature. Evaluation of the method proposed in this paper using benchmark data provided by Stanford University found that the time-cost for feature extraction and depth estimation improved by 60% and the accuracy was increased by 0.4% on average and up to 2.5%.

Stop Object Method within Intersection with Using Adaptive Background Image (적응적 배경영상을 이용한 교차로 내 정지 객체 검출 방법)

  • Kang, Sung-Jun;Sur, Am-Seog;Jeong, Sung-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.5
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    • pp.2430-2436
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    • 2013
  • This study suggests a method of detecting the still object, which becomes a cause of danger within the crossroad. The Inverse Perspective Transform was performed in order to make the object size consistent by being inputted the real-time image from CCTV that is installed within the crossroad. It established the detection area in the image with the perspective transform and generated the adaptative background image with the use of the moving information on object. The detection of the stop object was detected the candidate region of the stop object by using the background-image differential method. To grasp the appearance of truth on the detected candidate region, a method is proposed that uses the gradient information on image and EHD(Edge Histogram Descriptor). To examine performance of the suggested algorithm, it experimented by storing the images in the commuting time and the daytime through DVR, which is installed on the cross street. As a result of experiment, it could efficiently detect the stop vehicle within the detection region inside the crossroad. The processing speed is shown in 13~18 frame per second according to the area of the detection region, thereby being judged to likely have no problem about the real-time processing.

Automatic Registration Between KOMPSAT-2 and TerraSAR-X Images (KOMPSAT-2 영상과 TerraSAR-X 영상 간 자동기하보정)

  • Han, You-Kyung;Byun, Young-Gi;Chae, Tae-Byeong;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.29 no.6
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    • pp.667-675
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    • 2011
  • In this paper, we propose an automatic image-to-image registration between high resolution multi-sensor images. To do this, TerraSAR-X image was shifted according to the initial translation differences of the x and y directions between images estimated using Mutual Information method. After that, the Canny edge operator was applied to both images to extract linear features. These features were used to design a cost function that finds matching points based on the similarities of their locations and gradient orientations. For extracting large number of evenly distributed matching points, only one point within each regular grid constructed throughout the image was extracted to the final matching point pair. The model, which combined the piecewise linear function with the global affine transformation, was applied to increase the accuracy of the geometric correction, and the proposed method showed RMSE lower than 5m in all study sites.

Real-time Detection Technique of the Target in a Berth for Automatic Ship Berthing (선박 자동접안을 위한 정박지 목표물의 실시간 검출법)

  • Choi, Yong-Woon;;Kim, Young-Bok;Lee, Kwon-Soon
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.5
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    • pp.431-437
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    • 2006
  • In this paper vector code correlation(VCC) method and an algorithm to promote the image-processing performance in building an effective measurement system using cameras are described far automatically berthing and controlling the ship equipped with side-thrusters. In order to realize automatic ship berthing, it is indispensable that the berthing assistant system on the ship should continuously trace a target in the berth to measure the distance to the target and the ship attitude, such that we can make the ship move to the specified location. The considered system is made up of 4 apparatuses compounded from a CCD camera, a camera direction controller, a popular PC with a built-in image processing board and a signal conversion unit connected to parallel port of the PC. The object of this paper is to reduce the image-processing time so that the berthing system is able to ensure the safety schedule against risks during approaching to the berth. It could be achieved by composing the vector code image to utilize the gradient of an approximated plane found with the brightness of pixels forming a certain region in an image and verifying the effectiveness on a commonly used PC. From experimental results, it is clear that the proposed method can be applied to the measurement system for automatic ship berthing and has the image-processing time of fourfold as compared with the typical template matching method.

Reduced-Reference Quality Assessment for Compressed Videos Based on the Similarity Measure of Edge Projections (에지 투영의 유사도를 이용한 압축된 영상에 대한 Reduced-Reference 화질 평가)

  • Kim, Dong-O;Park, Rae-Hong;Sim, Dong-Gyu
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.3
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    • pp.37-45
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    • 2008
  • Quality assessment ai s to evaluate if a distorted image or video has a good quality by measuring the difference between the original and distorted images or videos. In this paper, to assess the visual qualify of a distorted image or video, visual features of the distorted image are compared with those of the original image instead of the direct comparison of the distorted image with the original image. We use edge projections from two images as features, where the edge projection can be easily obtained by projecting edge pixels in an edge map along vertical/horizontal direction. In this paper, edge projections are obtained by using vertical/horizontal directions of gradients as well as the magnitude of each gradient. Experimental results show the effectiveness of the proposed quality assessment through the comparison with conventional quality assessment algorithms such as structural similarity(SSIM), edge peak signal-to-noise ratio(EPSNR), and edge histogram descriptor(EHD) methods.

Speed Optimization Design of 3D Medical Image Reconstruction System Based on PC (PC 기반의 3차원 의료영상 재구성 시스템의 고속화 설계)

  • Bae, Su-Hyeon;Kim, Seon-Ho;Yu, Seon-Guk
    • Journal of Biomedical Engineering Research
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    • v.19 no.2
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    • pp.189-198
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    • 1998
  • 3D medical image reconstruction techniques are useful to figure out complex 3D structures from the set of 2D sections. In the paper, 3D medical image reconstruction system is constructed under PC environment and programmed based on modular programming by using Visual C++ 4.2. The whole procedures are composed of data preparation, gradient estimation, classification, shading, transformation and ray-casting & compositing. Three speed optimization techniques are used for accelerating 3D medical image reconstruction technique. One is to reduce the rays when cast rays to reconstruct 3D medical image, another is to reduce the voxels to be calculated and the other is to apply early ray termination. To implement 3D medical image reconstruction system based on PC, speed optimization techniques are experimented and applied.

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PIV measurement on flow characteristics behind a Tetrapod in uniform flow (균일 흐름에 놓인 테트라포드 후류 유동특성에 대한 PIV 계측)

  • Gim, Ok-Sok;Lee, Kyeong-Woo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.3
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    • pp.207-217
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    • 2008
  • Costal regions in Korea often suffer severe damages due to wave-induced disasters, storm surge disasters and so on. therefore, many engineers and researchers have devoted their energy to prevent these costal disasters. The development of artificial reefs including sunken vessels is one of their remarkable achievements and various kind of these artificial upwelling structures have been designed and applied. However, the flow characteristics around a Tetrapod under the water has not been investigated experimentally. So in this article, in uniform flow of circulating water channel and some different velocities, PIV measurement has been conducted on the flow characteristics behind a Tetrapod. The results were analyzed on the flow characteristics of both cases of a Tetrapod. Therefore, it can be concluded that the both cases have its own distinctive flow characteristics behind the bluff body; Case A has an steep upstream flow pattern. On the contrary, Case B has an developed downstream flow pattern in the near wake of the Tetrapod. The velocity gradient at position x=150mm of Case-A appears gently up and down But, the velocity gradient at the same position of Case-B appears better highly up and down.