• Title/Summary/Keyword: Adaptive matching

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An Improved Stereo Matching Algorithm with Robustness to Noise Based on Adaptive Support Weight

  • Lee, Ingyu;Moon, Byungin
    • Journal of Information Processing Systems
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    • v.13 no.2
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    • pp.256-267
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    • 2017
  • An active research area in computer vision, stereo matching is aimed at obtaining three-dimensional (3D) information from a stereo image pair captured by a stereo camera. To extract accurate 3D information, a number of studies have examined stereo matching algorithms that employ adaptive support weight. Among them, the adaptive census transform (ACT) algorithm has yielded a relatively strong matching capability. The drawbacks of the ACT, however, are that it produces low matching accuracy at the border of an object and is vulnerable to noise. To mitigate these drawbacks, this paper proposes and analyzes the features of an improved stereo matching algorithm that not only enhances matching accuracy but also is also robust to noise. The proposed algorithm, based on the ACT, adopts the truncated absolute difference and the multiple sparse windows method. The experimental results show that compared to the ACT, the proposed algorithm reduces the average error rate of depth maps on Middlebury dataset images by as much as 2% and that is has a strong robustness to noise.

A Study on Adaptive Stereo Matching for DEM Generation (DEM 제작을 위한 Adaptive Stereo Matching 에 관한 연구)

  • 김정기;김정호;엄기문;이쾌희
    • Korean Journal of Remote Sensing
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    • v.8 no.1
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    • pp.15-26
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    • 1992
  • This paper describes an implementation of adaptive stereo matching for DBM generation. The matching method of two stereo satellite images to find corresponding points used in this paper is area-based matching, which is usually used in the field of making DBM. Same window size and search area used as in the conventional matching methods and we propose adaptive stereo matching algorithm in this paper. We cluster three areas which are consist of mountainous areas, cultivated areas and cities, and rivers and lakes by using proposed linear feature extracting method. These classified areas are matched by adaptive window size and search area, but rivers and lakes is excluded in this experiment. The matching time is three times faster than conventional methods.

Effective Reconstruction of Stereoscopic Image Pair by using Regularized Adaptive Window Matching Algorithm

  • Ko, Jung-Hwan;Lee, Sang-Tae;Kim, Eun-Soo
    • Journal of Information Display
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    • v.5 no.4
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    • pp.31-37
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    • 2004
  • In this paper, an effective method for reconstruction of stereoscopic image pair through the regularized adaptive disparity estimation is proposed. Although the conventional adaptive disparity window matching can sharply improve the PSNR of a reconstructed stereo image, but there still exist some problems of overlapping between the matching windows and disallocation of the matching windows, because the size of the matching window tend to changes adaptively in accordance with the magnitude of the feature values. In the proposed method, the problems relating to the conventional adaptive disparity estimation scheme can be solved and the predicted stereo image can be more effectively reconstructed by regularizing the extimated disparity vector with the neighboring disparity vectors. From the experimental results, it is found that the proposed algorithm show improvements the PSNR of the reconstructed right image by about 2.36${\sim}$2.76 dB, on average, compared with that of conventional algorithms.

Efficient 1:N Fingerprint Matching Algorithm using Matching Score Distribution (매칭 점수 분포를 이용한 효율적인 1:N 지문 매칭 알고리듬)

  • Kim, Kyoung-Min;Park, Joong-Jo;Lee, Buhm;Go, Young-Jin;Jung, Soon-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.18 no.3
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    • pp.208-217
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    • 2012
  • This paper presents two adaptive fingerprint matching methods. First, we experiment an adaptive threshold selection of 1:N matching system in order to raise the reliability of the matching score. Second, we propose a adaptive threshold selection using fitting algorithm for high speed matching. The experiment was conducted on the NITZEN database, which has 5247 samples. Consequently, this paper shows that our suggested method can perform 1.88 times faster matching speed than the bidirectional matching speed. And, we prove that FRR of our suggested method decreases 1.43 % than that of the unidirectional matching.

Local stereo matching using combined matching cost and adaptive cost aggregation

  • Zhu, Shiping;Li, Zheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.1
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    • pp.224-241
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    • 2015
  • Multiview plus depth (MVD) videos are widely used in free-viewpoint TV systems. The best-known technique to determine depth information is based on stereo vision. In this paper, we propose a novel local stereo matching algorithm which is radiometric invariant. The key idea is to use a combined matching cost of intensity and gradient based similarity measure. In addition, we realize an adaptive cost aggregation scheme by constructing an adaptive support window for each pixel, which can solve the boundary and low texture problems. In the disparity refinement process, we propose a four-step post-processing technique to handle outliers and occlusions. Moreover, we conduct stereo reconstruction tests to verify the performance of the algorithm more intuitively. Experimental results show that the proposed method is effective and robust against local radiometric distortion. It has an average error of 5.93% on the Middlebury benchmark and is compatible to the state-of-art local methods.

An Adaptive Speed Control of a Diesel Engine by means of a Model Matching method and the Nominal Model Tracking Method (모델 매칭법과 규범모델 추종방식에 의한 디젤기관의 적응속도제어)

  • 유희한;소명옥;박재식
    • Journal of Advanced Marine Engineering and Technology
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    • v.27 no.5
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    • pp.609-616
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    • 2003
  • The purpose of this study is to design the adaptive speed control system of a marine diesel engine by combining the Model Matching Method and the Nominal Model Tracking Method. The authors proposed already a new method to determine efficiently the PID control Parameters by the Model Matching Method. typically taking a marine diesel engine as a non-oscillatory second-order system. But. actually it is very difficult to find out the exact model of a diesel engine. Therefore, when diesel engine model and actual diesel engine are unmatched as an another approach to promote the speed control characteristics of a marine diesel engine, this paper Proposes a Model Reference Adaptive Speed Control system of a diesel engine, in which PID control system for the model of a diesel engine is adopted as the nominal model and Fuzzy controller and derivative operator are adopted as the adaptive controller.

Temporal Error Concealment Using Boundary Region Feature and Adaptive Block Matching (경계 영역 특성과 적응적 블록 정합을 이용한 시간적 오류 은닉)

  • Bae, Tae-Wuk;Kim, Seung-Jin;Kim, Tae-Su;Lee, Kun-Il
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.12-14
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    • 2005
  • In this paper, we proposed an temporal error concealment (EC) using the proposed boundary matching method and the adaptive block matching method. The proposed boundary matching method improves the spatial correlation of the macroblocks (MBs) by reusing the pixels of the concealed MB to estimate a motion vector of a error MB. The adaptive block matching method inspects the horizontal edge and the vertical edge feature of a error MB surroundings, and it conceals the error MBs in reference to more stronger edge feature. This improves video quality by raising edge connection feature of the error MBs and the neighborhood MBs. In particular, we restore a lost MB as the unit of 8${\times}$16 block or 16${\times}$8 block by using edge feature from the surrounding macroblocks. Experimental results show that the proposed algorithm gives better results than the conventional algorithms from a subjective and an objective viewpoint.

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The Performance improvement of CMA Blind Adaptive equalizer using the Constellation Matching Method (Constellation Matching 기법을 이용한 CMA 블라인드 적응 등화기의 성능 개선)

  • Lim, Seung-Gag;Kang, Dae-Soo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.1
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    • pp.121-127
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    • 2010
  • This paper relates with the improved CMA blind adaptive equalization algorithm which uses the constellation matching method that improve the inverse modelling efficiency of a communication channel compared to the present CMA blind adaptive equalizer. The amplitude distortion can be compensated in the present CMA blind adaptive equalizer which is used for the reduction of intersymbol interference by distortion that generate such as a band limited wireless mobile channel, but in the improved adaptive alogorithm operates with the minimize the amplitude phase distortion in the output of equalizer by applying the cost function that is composition of additional signal constellation matching error terms. In order to evaluation of the inverse modeling efficiency of improved algorithm, the residual intersymbol interference and recovered signal constellation were compared by computer simulation. As a result of comparion of computer simulation, the improved algorithm has a good stability in the residual intersymbol interference in the steady state, but it has a slow convergence rate in the adaptation state in initial state.

Object Tracking using Adaptive Template Matching

  • Chantara, Wisarut;Mun, Ji-Hun;Shin, Dong-Won;Ho, Yo-Sung
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.1
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    • pp.1-9
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    • 2015
  • Template matching is used for many applications in image processing. One of the most researched topics is object tracking. Normalized Cross Correlation (NCC) is the basic statistical approach to match images. NCC is used for template matching or pattern recognition. A template can be considered from a reference image, and an image from a scene can be considered as a source image. The objective is to establish the correspondence between the reference and source images. The matching gives a measure of the degree of similarity between the image and the template. A problem with NCC is its high computational cost and occasional mismatching. To deal with this problem, this paper presents an algorithm based on the Sum of Squared Difference (SSD) and an adaptive template matching to enhance the quality of the template matching in object tracking. The SSD provides low computational cost, while the adaptive template matching increases the accuracy matching. The experimental results showed that the proposed algorithm is quite efficient for image matching. The effectiveness of this method is demonstrated by several situations in the results section.

An Efficient Approximation method of Adaptive Support-Weight Matching in Stereo Images (스테레오 영상에서의 적응적 영역 가중치 매칭의 효율적 근사화 방법)

  • Kim, Ho-Young;Lee, Seong-Won
    • Journal of Broadcast Engineering
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    • v.16 no.6
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    • pp.902-915
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    • 2011
  • Recently in the area-based stereo matching field, Adaptive Support-Weight (ASW) method that weights matching cost adaptively according to the luminance intensity and the geometric difference shows promising matching performance. However, ASW requires more computational cost than other matching algorithms do and its real-time implementation becomes impractical. By applying Integral Histogram technique after approximating to the Bilateral filter equation, the computational time of ASW can be restricted in constant time regardless of the support window size. However, Integral Histogram technique causes loss of the matching accuracy during approximation process of the original ASW equation. In this paper, we propose a novel algorithm that maintains the ASW algorithm's matching accuracy while reducing the computational costs. In the proposed algorithm, we propose Sub-Block method that groups the pixels within the support area. We also propose the method adjusting the disparity search range depending on edge information. The proposed technique reduces the calculation time efficiently while improving the matching accuracy.