• Title/Summary/Keyword: invariant feature extraction

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Feature Extraction Based on GRFs for Facial Expression Recognition

  • Yoon, Myoong-Young
    • Journal of Korea Society of Industrial Information Systems
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    • v.7 no.3
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    • pp.23-31
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    • 2002
  • In this paper we propose a new feature vector for recognition of the facial expression based on Gibbs distributions which are well suited for representing the spatial continuity. The extracted feature vectors are invariant under translation rotation, and scale of an facial expression imege. The Algorithm for recognition of a facial expression contains two parts: the extraction of feature vector and the recognition process. The extraction of feature vector are comprised of modified 2-D conditional moments based on estimated Gibbs distribution for an facial image. In the facial expression recognition phase, we use discrete left-right HMM which is widely used in pattern recognition. In order to evaluate the performance of the proposed scheme, experiments for recognition of four universal expression (anger, fear, happiness, surprise) was conducted with facial image sequences on Workstation. Experiment results reveal that the proposed scheme has high recognition rate over 95%.

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Spectral Normalization for Speaker-Invariant Feature Extraction (화자 불변 특징추출을 위한 스펙트럼 정규화)

  • 오광철
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1993.06a
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    • pp.238-241
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    • 1993
  • We present a new method to normalize spectral variations of different speakers based on physiological studies of hearing. The proposed method uses the cochlear frequency map to warp the input speech spectra by interpolation or decimation. Using this normalization method, we can obtain much improved recognition results for speaker independent speech recognition.

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Rotation Invariant 3D Star Skeleton Feature Extraction (회전무관 3D Star Skeleton 특징 추출)

  • Chun, Sung-Kuk;Hong, Kwang-Jin;Jung, Kee-Chul
    • Journal of KIISE:Software and Applications
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    • v.36 no.10
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    • pp.836-850
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    • 2009
  • Human posture recognition has attracted tremendous attention in ubiquitous environment, performing arts and robot control so that, recently, many researchers in pattern recognition and computer vision are working to make efficient posture recognition system. However the most of existing studies is very sensitive to human variations such as the rotation or the translation of body. This is why the feature, which is extracted from the feature extraction part as the first step of general posture recognition system, is influenced by these variations. To alleviate these human variations and improve the posture recognition result, this paper presents 3D Star Skeleton and Principle Component Analysis (PCA) based feature extraction methods in the multi-view environment. The proposed system use the 8 projection maps, a kind of depth map, as an input data. And the projection maps are extracted from the visual hull generation process. Though these data, the system constructs 3D Star Skeleton and extracts the rotation invariant feature using PCA. In experimental result, we extract the feature from the 3D Star Skeleton and recognize the human posture using the feature. Finally we prove that the proposed method is robust to human variations.

Facial Feature Extraction by using a Genetic Algorithm (유전자 알고리즘을 이용한 얼굴의 특징점 추출)

  • Kim, Sang-Kyoon;Oh, Seung-Ha;Lee, Myoung-Eun;Park, Soon-Young
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.1053-1056
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    • 1999
  • In this paper we propose a facial feature extraction method by using a genetic algorithm. The method uses a facial feature template to model the location of eyes and a mouth, and genetic algorithm is employed to find the optimal solution from the fitness function consisting of invariant moments. The simulation results show that the proposed algorithm can effectively extract facial features from face images with variations in position, size, rotation and expression.

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Ridge Feature Extraction of Fingerprint Using Sequential Labeling (순차적 레이블링을 이용한 지문 융선 특징 검출)

  • 오재윤;엄재원;최태영
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.3
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    • pp.217-226
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    • 2003
  • A novel fingerprint ridge feature extraction using sequential labeling of thinned fingerprint image is proposed, which is invariant to position translation, scaling, and rotation. the proposed algorithm labels ridges of thinned fingerprint image sequentially using vertical line that goes through fingerprint core point. Then, we extract a feature from each labeled ridge and the extraction process is based on the type fo the ridge and a minutiae ridge angle in the ridge. The feature extracted through this process enables us to find out the kind of various minutiae and minutiae angle. As a result of the experiment using two thinned fingerprint images, we finally confirm that proposed algorithm is not related to position translation, scaling, and rotation.

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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On the Study of Rotation Invariant Object Recognition (회전불변 객체 인식에 관한 연구)

  • Alom, Md. Zahangir;Lee, Hyo Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2010.04a
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    • pp.405-408
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    • 2010
  • This paper presents a new feature extraction technique, correlation coefficient and Manhattan distance (MD) based method for recognition of rotated object in an image. This paper also represented a new concept of intensity invariant. We extracted global features of an image and converts a large size image into a one-dimensional vector called circular feature vector's (CFVs). An especial advantage of the proposed technique is that the extracted features are same even if original image is rotated with rotation angles 1 to 360 or rotated. The proposed technique is based on fuzzy sets and finally we have recognized the object by using histogram matching, correlation coefficient and manhattan distance of the objects. The proposed approach is very easy in implementation and it has implemented in Matlab7 on Windows XP. The experimental results have demonstrated that the proposed approach performs successfully on a variety of small as well as large scale rotated images.

Comparative Study of Corner and Feature Extractors for Real-Time Object Recognition in Image Processing

  • Mohapatra, Arpita;Sarangi, Sunita;Patnaik, Srikanta;Sabut, Sukant
    • Journal of information and communication convergence engineering
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    • v.12 no.4
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    • pp.263-270
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    • 2014
  • Corner detection and feature extraction are essential aspects of computer vision problems such as object recognition and tracking. Feature detectors such as Scale Invariant Feature Transform (SIFT) yields high quality features but computationally intensive for use in real-time applications. The Features from Accelerated Segment Test (FAST) detector provides faster feature computation by extracting only corner information in recognising an object. In this paper we have analyzed the efficient object detection algorithms with respect to efficiency, quality and robustness by comparing characteristics of image detectors for corner detector and feature extractors. The simulated result shows that compared to conventional SIFT algorithm, the object recognition system based on the FAST corner detector yields increased speed and low performance degradation. The average time to find keypoints in SIFT method is about 0.116 seconds for extracting 2169 keypoints. Similarly the average time to find corner points was 0.651 seconds for detecting 1714 keypoints in FAST methods at threshold 30. Thus the FAST method detects corner points faster with better quality images for object recognition.

Organ Recognition in Ultrasound images Using Log Power Spectrum (로그 전력 스펙트럼을 이용한 초음파 영상에서의 장기인식)

  • 박수진;손재곤;김남철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.9C
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    • pp.876-883
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    • 2003
  • In this paper, we propose an algorithm for organ recognition in ultrasound images using log power spectrum. The main procedure of the algorithm consists of feature extraction and feature classification. In the feature extraction, as a translation invariant feature, log power spectrum is used for extracting the information on echo of the organs tissue from a preprocessed input image. In the feature classification, Mahalanobis distance is used as a measure of the similarity between the feature of an input image and the representative feature of each class. Experimental results for real ultrasound images show that the proposed algorithm yields the improvement of maximum 30% recognition rate than the recognition algorithm using power spectrum and Euclidean distance, and results in better recognition rate of 10-40% than the recognition algorithm using weighted quefrency complex cepstrum.

A Novel Approach for Object Detection in Illuminated and Occluded Video Sequences Using Visual Information with Object Feature Estimation

  • Sharma, Kajal
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.2
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    • pp.110-114
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    • 2015
  • This paper reports a novel object-detection technique in video sequences. The proposed algorithm consists of detection of objects in illuminated and occluded videos by using object features and a neural network technique. It consists of two functional modules: region-based object feature extraction and continuous detection of objects in video sequences with region features. This scheme is proposed as an enhancement of the Lowe's scale-invariant feature transform (SIFT) object detection method. This technique solved the high computation time problem of feature generation in the SIFT method. The improvement is achieved by region-based feature classification in the objects to be detected; optimal neural network-based feature reduction is presented in order to reduce the object region feature dataset with winner pixel estimation between the video frames of the video sequence. Simulation results show that the proposed scheme achieves better overall performance than other object detection techniques, and region-based feature detection is faster in comparison to other recent techniques.