Matched Filter Design for Visual Object Tracking

Suho Shin,Jinsang Kim,Seung Joo Lee 한국정보기술학회 2017 JOURNAL OF ADVANCED INFORMATION TECHNOLOGY AND CON Vol.7 No.1

Matched Filter Design for Visual Object Tracking

신수호,김진상,이승주 한국정보기술학회 2017 JOURNAL OF ADVANCED INFORMATION TECHNOLOGY AND CON Vol.7 No.1

This paper proposes a matched filter for object tracking by taking into account the appearance features and optical flows of the moving objects. The proposed filter can improve the performance in case of tracking with limited information. This method requires relatively simple information and is easy to realize. Appearance features are used to produce the matched filter. Experimental results show that the training image of the proposed matched filter can reflect the entire appearance of the tracked objects compared to the existing filters.

Post Processing to Reduce Wrong Matches in Stereo Matching

Park, Hee-Ju,Lee, Suk-Bae Korean Society of Surveying 2001 Korean journal of geomatics Vol.1 No.1

Although many kinds of stereo matching method have been developed in the field of computer vision and photogrammetry, wrong matches are not easy to avoid. This paper presents a new method to reduce wrong matches after matching, and experimental results are reported. The main idea is to analyze the histogram of the image attribute differences between each pair of image patches matched. Typical image attributes of image patch are the mean and the standard deviation of gray value for each image patch, but there could be other kinds of image attributes. Another idea is to check relative position among potential matches. This paper proposes to use Gaussian blunder filter to detect the suspicious pair of candidate match in relative position among neighboring candidate matches. If the suspicious candidate matches in image attribute difference or relative position are suppressed, then many wrong matches are removed, but minimizing the suppression of good matches. The proposed method is easy to implement, and also has potential to be applied as post processing after image matching for many kinds of matching methods such as area based matching, feature matching, relaxation matching, dynamic programming, and multi-channel image matching. Results show that the proposed method produces fewer wrong matches than before.

강인한 H$_2$필터를 이용한 속도정합 알고리즘

양철관,심덕선,박찬국,Yang, Cheol-Kwan,Shim, Duk-Sun,Park, Chan-Gook 제어로봇시스템학회 2001 제어·로봇·시스템학회 논문지 Vol.7 No.4

We study on the velocity matching algorithm for transfer alignment of inertial navigation system(INS) using a robust H$_2$ filter. We suggest an uncertainty model and a discrete robust H$_2$filter for INS and apply the suggested robust H$_2$ filter to the uncertainty model. The discrete robust H$_2$filter is shown by simulation to have better performance time and accuracy than Kalman filter.

Guided Filter를 이용한 GA-Net Stereo Matching 개선

신용빈,허원석,장하준,임유나,이동해,이정진 한국차세대컴퓨팅학회 2020 한국차세대컴퓨팅학회 논문지 Vol.16 No.1

두 대의 카메라의 양안 시차를 이용해 깊이를 판별하는 stereo matching 분야에서는 최근에 개발되어 가장 효율적 인 알고리즘인 GA-Net이 존재한다. 본 논문에서는 Guided filter라는 경계 처리 알고리즘을 이용해 GA-Net에서 얻어낸 결과를 개선하는 방법을 제안한다. GA-Net에서 얻어낸 결과와 원본 스테레오 이미지를 Guided filter로 합성해 세밀한 경계를 이전보다 정확하게 처리할 수 있는 방법을 제시한다. 실험 결과 GA-Net에서 얻어진 결과는 Guided filter를 사용하여 평균 오차가 16.3% 감소하였다. 또한, Guided filter에서 사용자가 설정해야 하는 파 라미터를 변화하면서 결과를 측정해 파라미터의 변화에 대한 결과 이미지의 경향성을 분석하였다. In the field of stereo matching, the depth is determined by the disparities between two cameras and GA-Net shows the most accurate performance. In this paper, we improve the depth results from GA-Net using guided filtering as an edge enhancement technique. Depth results from GA-Net and original stereo images are merged to produce more detailed depth images. Experimental results showed that the average error of the depth acquired by guided filter was decreased by 16.3%. We analyzed the depth results by controlling user-defined parameters in guided filtering.

A Novel Scalable and Storage-Efficient Architecture for High Speed Exact String Matching

Ali Peiravi,Mohammad Javad Rahimzadeh 한국전자통신연구원 2009 ETRI Journal Vol.31 No.5

String matching is a fundamental element of an important category of modern packet processing applications which involve scanning the content flowing through a network for thousands of strings at the line rate. To keep pace with high network speeds, specialized hardware-based solutions are needed which should be efficient enough to maintain scalability in terms of speed and the number of strings. In this paper, a novel architecture based upon a recently proposed data structure called the Bloomier filter is proposed which can successfully support scalability. The Bloomier filter is a compact data structure for encoding arbitrary functions, and it supports approximate evaluation queries. By eliminating the Bloomier filter’s false positives in a space efficient way, a simple yet powerful exact string matching architecture is proposed that can handle several thousand strings at high rates and is amenable to on-chip realization. The proposed scheme is implemented in reconfigurable hardware and we compare it with existing solutions. The results show that the proposed approach achieves better performance compared to other existing architectures measured in terms of throughput per logic cells per character as a metric.

Impedance Matching Based Control for the Resonance Damping of Microgrids with Multiple Grid Connected Converters

Tan, Shulong,Geng, Hua,Yang, Geng The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

This paper presents an impedance-matching-based control scheme for the harmonic resonance damping of multiple grid-connected-converters (GCCs) with LCL filters. As indicated in this paper, harmonic resonance occurs if a GCC possesses an output impedance that is not matched with the rest of the network in some specific frequency bands. It is also revealed that the resonance frequency is associated with the number of GCCs, the grid impedance and even the capacitive loads. By controlling the grid-side current instead of the converter-side current, the critical LCL filter is restricted as an internal component. Thus, the closed-loop output impedance of the GCC within the filter can be configured. The proposed scheme actively regulates the output impedance of the GCC to match the impedance of the external network, based on the detected resonance frequency. As a result, the resonance risk of multiple GCCs can be avoided, which is beneficial for the plug-and-play property of the GCCs in microgrids. Simulation and experimental results validate the effectiveness of the proposed method.

Impedance Matching Based Control for the Resonance Damping of Microgrids with Multiple Grid Connected Converters

Shulong Tan,Hua Geng,Geng Yang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

This paper presents an impedance-matching-based control scheme for the harmonic resonance damping of multiple grid-connected-converters (GCCs) with LCL filters. As indicated in this paper, harmonic resonance occurs if a GCC possesses an output impedance that is not matched with the rest of the network in some specific frequency bands. It is also revealed that the resonance frequency is associated with the number of GCCs, the grid impedance and even the capacitive loads. By controlling the grid-side current instead of the converter-side current, the critical LCL filter is restricted as an internal component. Thus, the closed-loop output impedance of the GCC within the filter can be configured. The proposed scheme actively regulates the output impedance of the GCC to match the impedance of the external network, based on the detected resonance frequency. As a result, the resonance risk of multiple GCCs can be avoided, which is beneficial for the plug-and-play property of the GCCs in microgrids. Simulation and experimental results validate the effectiveness of the proposed method.

Practical Design Issues in a Linear Feedback Control System with a Notch Filter

김려화(Lihua Jin),김영철(Young Chol Kim) 대한전기학회 2010 전기학회논문지 Vol.59 No.1

This paper presents some practical design issues that should be carefully considered when a notch filter is included in a linear feedback controller. A notch filter is generally used to compensate the effects of resonant modes that may result in poor performance. It is very common that the practical engineers prefer to add such a notch filter after having previously designed a feedback controller without the filter. It is known that the resulting performance by this approach is not seriously different from when a feedback controller is designed for a plant previously compensated by a notch filter. However, we will point out that there are some cases where both approaches have different performances. In order to show this, a low-order controller design using the partial model matching method has been applied to a linear time invariant (LTI) model. The results suggest that there is a tendency to achieve much better time responses in terms of reducing the overshoot and shortening the settling time, and in the frequency domain characteristics such as the sensitivity function and the stability margins when the design of a feedback controller after including a notch filter is carried out.

2D Sketch Based Query Interface with Coarse Filter for 3D Shape Matching

Lee, Jae-Ho,Park, Joon-Young Society for Computational Design and Engineering 2007 International Journal of CAD/CAM Vol.7 No.1

Sketch based query plays an important role in shape matching for 3D shape retrieval system. Some researchers suggest the sketch based query interfaces. It is more effective to capture the needs of users rather than query by example. In this paper, we propose a new 2D sketch based query interface with coarse filters for shape matching. Coarse filtering enables to eliminate unfavorable shapes from shapes in DB. For the purpose of coarse filtering, we use two filters with the topological and geometric patterns. For the validity of our method, we show the experimental results.