• Title/Summary/Keyword: Scale-invariant Feature

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A SHAPE FEATURE EXTRACTION FOR COMPLEX TOPOGRAPHICAL IMAGES

  • Kwon Yong-Il;Park Ho-Hyun;Lee Seok-Lyong;Chung Chin-Wan
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.575-578
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    • 2005
  • Topographical images, in case of aerial or satellite images, are usually similar in colors and textures, and complex in shapes. Thus we have to use shape features of images for efficiently retrieving a query image from topographical image databases. In this paper, we propose a shape feature extraction method which is suitable for topographical images. This method, which improves the existing projection in the Cartesian coordinates, performs the projection operation in the polar coordinates. This method extracts three attributes, namely the number of region pixels, the boundary pixel length of the region from the centroid, the number of alternations between region and background, along each angular direction of the polar coordinates. It extracts the features of complex shape objects which may have holes and disconnected regions. An advantage of our method is that it is invariant to rotation/scale/translation of images. Finally we show the advantages of our method through experiments by comparing it with CSS which is one of the most successful methods in the area of shape feature extraction

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Natural Object Recognition for Augmented Reality Applications (증강현실 응용을 위한 자연 물체 인식)

  • Anjan, Kumar Paul;Mohammad, Khairul Islam;Min, Jae-Hong;Kim, Young-Bum;Baek, Joong-Hwan
    • Journal of the Institute of Convergence Signal Processing
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    • v.11 no.2
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    • pp.143-150
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    • 2010
  • Markerless augmented reality system must have the capability to recognize and match natural objects both in indoor and outdoor environment. In this paper, a novel approach is proposed for extracting features and recognizing natural objects using visual descriptors and codebooks. Since the augmented reality applications are sensitive to speed of operation and real time performance, our work mainly focused on recognition of multi-class natural objects and reduce the computing time for classification and feature extraction. SIFT(scale invariant feature transforms) and SURF(speeded up robust feature) are used to extract features from natural objects during training and testing, and their performance is compared. Then we form visual codebook from the high dimensional feature vectors using clustering algorithm and recognize the objects using naive Bayes classifier.

2-D Conditional Moment for Recognition of Deformed Letters

  • Yoon, Myoong-Young
    • Journal of Korea Society of Industrial Information Systems
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    • v.6 no.2
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    • pp.16-22
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    • 2001
  • In this paper we mose a new scheme for recognition of deformed letters by extracting feature vectors based on Gibbs distributions which are well suited for representing the spatial continuity. The extracted feature vectors are comprised of 2-D conditional moments which are invariant under translation, rotation, and scale of an image. The Algorithm for pattern recognition of deformed letters contains two parts: the extraction of feature vector and the recognition process. (i) We extract feature vector which consists of an improved 2-D conditional moments on the basis of estimated conditional Gibbs distribution for an image. (ii) In the recognition phase, the minimization of the discrimination cost function for a deformed letters determines the corresponding template pattern. In order to evaluate the performance of the proposed scheme, recognition experiments with a generated document was conducted. on Workstation. Experiment results reveal that the proposed scheme has high recognition rate over 96%.

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An Improved 2-D Moment Algorithm for Pattern Classification

  • Yoon, myoung-Young
    • Journal of Korea Society of Industrial Information Systems
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    • v.4 no.2
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    • pp.1-6
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    • 1999
  • We propose a new algorithm for pattern classification by extracting feature vectors based on Gibbs distributions which are well suited for representing the characteristic of an images. The extracted feature vectors are comprised of 2-D moments which are invariant under translation rotation, and scale of the image less sensitive to noise. This implementation contains two puts: feature extraction and pattern classification First of all, we extract feature vector which consists of an improved 2-D moments on the basis of estimated Gibbs distribution Next, in the classification phase the minimization of the discrimination cost function for a specific pattern determines the corresponding template pattern. In order to evaluate the performance of the proposed scheme, classification experiments with training document sets of characters have been carried out on SUN ULTRA 10 Workstation Experiment results reveal that the proposed scheme had high classification rate over 98%.

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Cascade Fusion-Based Multi-Scale Enhancement of Thermal Image (캐스케이드 융합 기반 다중 스케일 열화상 향상 기법)

  • Kyung-Jae Lee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.19 no.1
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    • pp.301-307
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    • 2024
  • This study introduces a novel cascade fusion architecture aimed at enhancing thermal images across various scale conditions. The processing of thermal images at multiple scales has been challenging due to the limitations of existing methods that are designed for specific scales. To overcome these limitations, this paper proposes a unified framework that utilizes cascade feature fusion to effectively learn multi-scale representations. Confidence maps from different image scales are fused in a cascaded manner, enabling scale-invariant learning. The architecture comprises end-to-end trained convolutional neural networks to enhance image quality by reinforcing mutual scale dependencies. Experimental results indicate that the proposed technique outperforms existing methods in multi-scale thermal image enhancement. Performance evaluation results are provided, demonstrating consistent improvements in image quality metrics. The cascade fusion design facilitates robust generalization across scales and efficient learning of cross-scale representations.

Human Activity Recognition with LSTM Using the Egocentric Coordinate System Key Points

  • Wesonga, Sheilla;Park, Jang-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.6_1
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    • pp.693-698
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    • 2021
  • As technology advances, there is increasing need for research in different fields where this technology is applied. On of the most researched topic in computer vision is Human activity recognition (HAR), which has widely been implemented in various fields which include healthcare, video surveillance and education. We therefore present in this paper a human activity recognition system based on scale and rotation while employing the Kinect depth sensors to obtain the human skeleton joints. In contrast to previous approaches that use joint angles, in this paper we propose that each limb has an angle with the X, Y, Z axes which we employ as feature vectors. The use of the joint angles makes our system scale invariant. We further calculate the body relative direction in the egocentric coordinates in order to provide the rotation invariance. For the system parameters, we employ 8 limbs with their corresponding angles each having the X, Y, Z axes from the coordinate system as feature vectors. The extracted features are finally trained and tested with the Long short term memory (LSTM) Network which gives us an average accuracy of 98.3%.

Translation, rotation and scale invariant pattern recognition using spectral analysis and a hybrid genetic-neural-fuzzy networks (스펙트럴분석 및 복합 유전자-뉴로-퍼지망을 이용한 이동, 회전 및 크기 변형에 무관한 패턴인식)

  • 이상경;장동식
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1995.04a
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    • pp.587-599
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    • 1995
  • This paper proposes a method for pattern recognition using spectral analysis and a hybrid genetic-neural-fuzzy networks. The feature vectors using spectral analysis on contour sequences of 2-D images are extracted, and the vectors are not effected by translation, rotation and scale variance. A combined model using the advantages of conventional method is proposed, those are supervised learning BP, global searching genetic algorithm, and unsupervised learning fuzzy c-method. The proposed method is applied to 10 aircraft recognition to confirm the performance of the method. The experimental results show that the proposed method is better accuracy than conventional method using BP or fuzzy c-method, and learning speed is enhanced.

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A Study on the Classification of Document Pattern Image (문서 패턴 영상 분별에 관한 연구)

  • 진용옥;허동근
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.10
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    • pp.1554-1560
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    • 1989
  • This paper suggests the algorihtm which extracts the classification parameter relative to the only feature of document patterns even though they are rotated or scaled, and also classifies them. With the complex logarithmic conformal mapping, the sample of the document pattern image makes the pattern image of the complex logarithmic plane. Because the power spectrum of this plane is invariant to the rotation, and scale of the pattern image, it is used as the characteristics parameter of the patten image. By using the coherence function, this method analyzes the standard and input power spectrum. additionally, it classifies the input pattern image. Even though input image is rotated, our algorithm can classify it without reference to the rotation, and this is possible when the scale is in the range of 0.5-1.5.

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Parallel implementation of a neural network-based realtime ATR system using a multicomputer (다중컴퓨터를 이용한 신경회로망 기반 실시간 자동 표적인식시스템의 병렬구현)

  • 전준형;김성완;김진호;최흥문
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.2
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    • pp.197-208
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    • 1996
  • A neural network-based PSRI(position, scale, and rotation invariant) feature extraction and ATR (automatic target recognition) system are proposed and an efficient parallel implementatio of the proposed system using multicomputer is also presented. In the proposed system, the scale and rotationinvariant features are extracted from the contour projection of the number of edge pixels on each of the concentric circles, which is input t the cooperative network. We proposed how to decide the optimum depth and the width of the parallel pipeline system for real time applications by modeling the proposed system into a parallel pipeline implementation method using transputers is also proposed. The implementation results show that we can extract PSRI features less sensitive to input variations, and the speedup of the proposed ATR system is about 7.55 for the various rotated and scaled targets using 8-node transputer system.

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WLSD: A Perceptual Stimulus Model Based Shape Descriptor

  • Li, Jiatong;Zhao, Baojun;Tang, Linbo;Deng, Chenwei;Han, Lu;Wu, Jinghui
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.12
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    • pp.4513-4532
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    • 2014
  • Motivated by the Weber's Law, this paper proposes an efficient and robust shape descriptor based on the perceptual stimulus model, called Weber's Law Shape Descriptor (WLSD). It is based on the theory that human perception of a pattern depends not only on the change of stimulus intensity, but also on the original stimulus intensity. Invariant to scale and rotation is the intrinsic properties of WLSD. As a global shape descriptor, WLSD has far lower computation complexity while is as discriminative as state-of-art shape descriptors. Experimental results demonstrate the strong capability of the proposed method in handling shape retrieval.