• Title/Summary/Keyword: distance transform

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Feature Extraction in 3-Dimensional Object with Closed-surface using Fourier Transform (Fourier Transform을 이용한 3차원 폐곡면 객체의 특징 벡터 추출)

  • 이준복;김문화;장동식
    • Journal of the Institute of Convergence Signal Processing
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    • v.4 no.3
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    • pp.21-26
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    • 2003
  • A new method to realize 3-dimensional object pattern recognition system using Fourier-based feature extractor has been proposed. The procedure to obtain the invariant feature vector is as follows ; A closed surface is generated by tracing the surface of object using the 3-dimensional polar coordinate. The centroidal distances between object's geometrical center and each closed surface points are calculated. The distance vector is translation invariant. The distance vector is normalized, so the result is scale invariant. The Fourier spectrum of each normalized distance vector is calculated, and the spectrum is rotation invariant. The Fourier-based feature generating from above procedure completely eliminates the effect of variations in translation, scale, and rotation of 3-dimensional object with closed-surface. The experimental results show that the proposed method has a high accuracy.

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Denoising of Speech Signal Using Wavelet Transform (웨이브렛 변환을 이용한 음성신호의 잡음제거)

  • 한미경;배건성
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.5
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    • pp.27-34
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    • 2000
  • This paper deals with speech enhancement methods using the wavelet transform. A cycle-spinning scheme and undecimated wavelet transform are used for denoising of speech signals, and then their results are compared with that of the conventional wavelet transform. We apply soft-thresholding technique for removing additive background noise from noisy speech. The symlets 8-tap wavelet and pyramid algorithm are used for the wavelet transform. Performance assessments based on average SNR, cepstral distance and informal subjective listening test are carried out. Experimental results demonstrate that both cycle-spinning denoising(CSD) method and undecimated wavelet denoising(CWD) method outperform conventional wavelet denoising(UWD) method in objective performance measure as welt as subjective listening test. The two methods also show less "clicks" that usually appears in the neighborhood of signal discontinuities.

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A Study On Positioning Of Mouse Cursor Using Kinect Depth Camera (Kinect Depth 카메라를이용한 마우스 커서의 위치 선정에 관한 연구)

  • Goo, Bong-Hoe;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.18 no.4
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    • pp.478-484
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    • 2014
  • In this paper, we propose new algorithm for positioning of mouse cursor using fingertip direction on kinect depth camera. The proposed algorithm uses center of parm points from distance transform when fingertip point toward screen. Otherwise, algorithm use fingertip points. After image preprocessing, the center of parm points is calculated from distance transform results. If the direction of the finger towards the camera becomes close to the distance between the fingertip point and center of parm point, it is possible to improve the accuracy of positioning by using the center of parm point. After remove arm on image, the fingertip points is obtained by using a pixel on the long distance from the center of the image. To calculate accuracy of mouse positioning, we selected any 5 points. Also, we calculated error rate between reference points and mouse points by performed 500 times. The error rate results could be confirmed the accuracy of our algorithm indicated an average error rate of less than 11%.

Pedestrian Detection using RGB-D Information and Distance Transform (RGB-D 정보 및 거리변환을 이용한 보행자 검출)

  • Lee, Ho-Hun;Lee, Dae-Jong;Chun, Myung-Geun
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.65 no.1
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    • pp.66-71
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    • 2016
  • According to the development of depth sensing devices and depth estimation technology, depth information becomes more important for object detection in computer vision. In terms of recognition rate, pedestrian detection methods have been improved more accurately. However, the methods makes slower detection time. So, many researches have overcome this problem by using GPU. Here, we propose a real-time pedestrian detection algorithm that does not rely on GPU. First, the depth-weighted distance map is used for detecting expected human regions. Next, human detection is performed on the regions. The performance for the proposed approach is evaluated and compared with the previous methods. We show that proposed method can detect human about 7 times faster than conventional ones.

Cell Counting Algorithm Using Radius Variation, Watershed and Distance Transform

  • Kim, Taehoon;Kim, Donggeun;Lee, Sangjoon
    • Journal of Information Processing Systems
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    • v.16 no.1
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    • pp.113-119
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    • 2020
  • This study proposed the structure of the cluster's cell counting algorithm for cell analysis. The image required for cell count is taken under a microscope. At present, the cell counting algorithm is reported to have a problem of low accuracy of results due to uneven shape and size clusters. To solve these problems, the proposed algorithm has a feature of calculating the number of cells in a cluster by applying a radius change analysis to the existing distance conversion and watershed algorithm. Later, cell counting algorithms are expected to yield reliable results if applied to the required field.

An Unsupervised Clustering Technique of XML Documents based on Function Transform and FFT (함수 변환과 FFT에 기반한 조정자가 없는 XML 문서 클러스터링 기법)

  • Lee, Ho-Suk
    • The KIPS Transactions:PartD
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    • v.14D no.2
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    • pp.169-180
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    • 2007
  • This paper discusses a new unsupervised XML document clustering technique based on the function transform and FFT(Fast Fourier Transform). An XML document is transformed into a discrete function based on the hierarchical nesting structure of the elements. The discrete function is, then, transformed into vectors using FFT. The vectors of two documents are compared using a weighted Euclidean distance metric. If the comparison is lower than the pre specified threshold, the two documents are considered similar in the structure and are grouped into the same cluster. XML clustering can be useful for the storage and searching of XML documents. The experiments were conducted with 800 synthetic documents and also with 520 real documents. The experiments showed that the function transform and FFT are effective for the incremental and unsupervised clustering of XML documents similar in structure.

Hartley Transform Based Fingerprint Matching

  • Bharkad, Sangita;Kokare, Manesh
    • Journal of Information Processing Systems
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    • v.8 no.1
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    • pp.85-100
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    • 2012
  • The Hartley transform based feature extraction method is proposed for fingerprint matching. Hartley transform is applied on a smaller region that has been cropped around the core point. The performance of this proposed method is evaluated based on the standard database of Bologna University and the database of the FVC2002. We used the city block distance to compute the similarity between the test fingerprint and database fingerprint image. The results obtained are compared with the discrete wavelet transform (DWT) based method. The experimental results show that, the proposed method reduces the false acceptance rate (FAR) from 21.48% to 16.74 % based on the database of Bologna University and from 31.29% to 28.69% based on the FVC2002 database.

An Isolated Word Recognition Using the Mellin Transform (Mellin 변환을 이용한 격리 단어 인식)

  • 김진만;이상욱;고세문
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.5
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    • pp.905-913
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    • 1987
  • This paper presents a speaker dependent isolated digit recognition algorithm using the Mellin transform. Since the Mellin transform converts a scale information into a phase information, attempts have been made to utilize this scale invariance property of the Mellin transform in order to alleviate a time-normalization procedure required for a speech recognition. It has been found that good results can be obtained by taking the Mellin transform to the features such as a ZCR, log energy, normalized autocorrelation coefficients, first predictor coefficient and normalized prediction error. We employed a difference function for evaluating a similarity between two patterns. When the proposed algorithm was tested on Korean digit words, a recognition rate of 83.3% was obtained. The recognition accuracy is not compatible with the other technique such as LPC distance however, it is believed that the Mellin transform can effectively perform the time-normalization processing for the speech recognition.

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Hierarchical hausdorff distance matching using pyramid structures (피라미드 구조를 이용한 계층적 hausdorff distance 정합)

  • 권오규;심동규;박래홍
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.12
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    • pp.70-80
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    • 1997
  • This paper proposes a hierarchical Hausdorff distance (HD) matching algorithm baased on coarse-to-fine approach. It reduces the computational complexity greatly by using the pyramidal structures consisting of distance transform (DT) and edge pyramids. Also, inthe proposed hierarchical HD matching, a thresholding method is presented to find an optimal matching position with small error, in which the threshold values are determined by using the property between adjacent level of a DT map pyramid. By computer simulation, the performance of the conventional and proposed hierarchical HD matching algorithms is compared in therms of the matching position for binary images containing uniform noise.

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Infrared Gait Recognition using Wavelet Transform and Linear Discriminant Analysis (웨이블릿 변환과 선형 판별 분석법을 이용한 적외선 걸음걸이 인식)

  • Kim, SaMun;Lee, DaeJong;Chun, MyungGeun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.6
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    • pp.622-627
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    • 2014
  • This paper proposes a new method which improves recognition rate on the gait recognition system using wavelet transform, linear discriminant analysis and genetic algorithm. We use wavelet transform to obtain the four sub-bands from the gait energy image. In order to extract feature data from sub-bands, we use linear discriminant analysis. Distance values between training data and four sub-band data are calculated and four weights which are calculated by genetic algorithm is assigned at each sub-band distance. Based on a new fusion distance value, we conducted recognition experiments using k-nearest neighbors algorithm. Experimental results show that the proposed weight fusion method has higher recognition rate than conventional method.