• Title/Summary/Keyword: descriptors

Search Result 505, Processing Time 0.033 seconds

Performance Evaluation of Shape Descriptors for Gait Analysis Based on Silhouette Sequence (실루엣 영상기반 보행 분석을 위한 형태 기술자의 성능 평가)

  • Kim, Seon-Jong
    • Journal of Intelligence and Information Systems
    • /
    • v.15 no.4
    • /
    • pp.53-64
    • /
    • 2009
  • This paper presents a performance evaluation of shape descriptors for gait analysis in case of silhouette sequence images. We used moment descriptors(MD), Fourier descriptors(FD) and Zernike descriptors(ZD) as a shape descriptor. To evaluate their performance, we firstly defined the performance index, that is, AI(asymmetry index) and PI(periodic index) based on the periodic property of the gait images. This is why they are represented by periodic parameters due to periodic gait images. This index means that how the shape is represented periodically. According to these indexes, we evaluated the data sets with periodic images, downloaded from internet. The results showed that Zernike descriptors had better performance of AI = 1.09 and PI = 2.21 than others. And in case of FD and ZD, it's efficient to implement the gait analysis with 5~10 parameters.

  • PDF

A Study on Multi-Lingual Thesaurus Database Construction of Scientific and Technical Terms (과학기술용어(科學技術用語) 시소러스 대역(對譯) 데이터베이스 구축(構築))

  • Kim, Eun-Shik
    • Journal of Information Management
    • /
    • v.22 no.2
    • /
    • pp.1-28
    • /
    • 1991
  • The objective of this study is to prepare a source data in order to establish a standardization of scientific and technical terms in Korean language. This will contribute to accelerate the production of Korean databases in scientific and technical field and will be used as the most convenient search tool for accessing to the foreign database. This study includes the construction of the multi-lingual thesaurus comprising of Korean, English, and Japanese. First of all a theoretical background on thesaurus is reviewed, and terms are collected from JICST Thesaurus, English-Japanese List and JICST Thesaurus, Japanese-English List published by JICST in 1987. This multi-lingual thesaurus covers 38,318 terms of Korean descriptors, 2,870 terms of Korean non-descriptors, 38,318 terms of English descriptors, 11,910 terms of English non-descriptors, and 38,318 terms of Japanese descriptors, 9,789 terms of Japanese non-descriptors.

  • PDF

A Study on Dimensioning of Traffic Descriptors for VBR Video Sources on ATM Networks (ATM 기반의 VBR 비디오 서비스를 위한 트래픽 기술자 Dimensioning에 관한 연구)

  • 유상조;홍성훈;김성대
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.24 no.7B
    • /
    • pp.1268-1278
    • /
    • 1999
  • In this paper, we propose an analytic method for dimensioning of traffic descriptors at the leaky bucket-based UPC for VBR MPEG video traffic on ATM networks. We analytically derive cell violation probabilities at the UPC by using the proposed scene-based video traffic model, and then we show that it is possible to select sets of traffic descriptors that have the same required violation probability. For two example video traces, numerical results show that our proposed traffic descriptors dimensioning method can approximate well the simulation-based traffic control results of the real video traces. When the effective bandwidth allocation method of an ON/OFF model is used for the call admission control in the networks, we present an efficient traffic descriptor selection method by studying the allocated bandwidth to each possible traffic descriptor set.

  • PDF

Evaluation of Histograms Local Features and Dimensionality Reduction for 3D Face Verification

  • Ammar, Chouchane;Mebarka, Belahcene;Abdelmalik, Ouamane;Salah, Bourennane
    • Journal of Information Processing Systems
    • /
    • v.12 no.3
    • /
    • pp.468-488
    • /
    • 2016
  • The paper proposes a novel framework for 3D face verification using dimensionality reduction based on highly distinctive local features in the presence of illumination and expression variations. The histograms of efficient local descriptors are used to represent distinctively the facial images. For this purpose, different local descriptors are evaluated, Local Binary Patterns (LBP), Three-Patch Local Binary Patterns (TPLBP), Four-Patch Local Binary Patterns (FPLBP), Binarized Statistical Image Features (BSIF) and Local Phase Quantization (LPQ). Furthermore, experiments on the combinations of the four local descriptors at feature level using simply histograms concatenation are provided. The performance of the proposed approach is evaluated with different dimensionality reduction algorithms: Principal Component Analysis (PCA), Orthogonal Locality Preserving Projection (OLPP) and the combined PCA+EFM (Enhanced Fisher linear discriminate Model). Finally, multi-class Support Vector Machine (SVM) is used as a classifier to carry out the verification between imposters and customers. The proposed method has been tested on CASIA-3D face database and the experimental results show that our method achieves a high verification performance.

Three-Dimensional Shape Recognition and Classification Using Local Features of Model Views and Sparse Representation of Shape Descriptors

  • Kanaan, Hussein;Behrad, Alireza
    • Journal of Information Processing Systems
    • /
    • v.16 no.2
    • /
    • pp.343-359
    • /
    • 2020
  • In this paper, a new algorithm is proposed for three-dimensional (3D) shape recognition using local features of model views and its sparse representation. The algorithm starts with the normalization of 3D models and the extraction of 2D views from uniformly distributed viewpoints. Consequently, the 2D views are stacked over each other to from view cubes. The algorithm employs the descriptors of 3D local features in the view cubes after applying Gabor filters in various directions as the initial features for 3D shape recognition. In the training stage, we store some 3D local features to build the prototype dictionary of local features. To extract an intermediate feature vector, we measure the similarity between the local descriptors of a shape model and the local features of the prototype dictionary. We represent the intermediate feature vectors of 3D models in the sparse domain to obtain the final descriptors of the models. Finally, support vector machine classifiers are used to recognize the 3D models. Experimental results using the Princeton Shape Benchmark database showed the average recognition rate of 89.7% using 20 views. We compared the proposed approach with state-of-the-art approaches and the results showed the effectiveness of the proposed algorithm.

Digital Video Steganalysis Based on a Spatial Temporal Detector

  • Su, Yuting;Yu, Fan;Zhang, Chengqian
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.11 no.1
    • /
    • pp.360-373
    • /
    • 2017
  • This paper presents a novel digital video steganalysis scheme against the spatial domain video steganography technology based on a spatial temporal detector (ST_D) that considers both spatial and temporal redundancies of the video sequences simultaneously. Three descriptors are constructed on XY, XT and YT planes respectively to depict the spatial and temporal relationship between the current pixel and its adjacent pixels. Considering the impact of local motion intensity and texture complexity on the histogram distribution of three descriptors, each frame is segmented into non-overlapped blocks that are $8{\times}8$ in size for motion and texture analysis. Subsequently, texture and motion factors are introduced to provide reasonable weights for histograms of the three descriptors of each block. After further weighted modulation, the statistics of the histograms of the three descriptors are concatenated into a single value to build the global description of ST_D. The experimental results demonstrate the great advantage of our features relative to those of the rich model (RM), the subtractive pixel adjacency model (SPAM) and subtractive prediction error adjacency matrix (SPEAM), especially for compressed videos, which constitute most Internet videos.

LAG TIME RELATIONS TO CATCHMENT SHAPE DESCRIPTORS AND HYDROLOGICAL RESPONSE

  • Kim, Joo-Cheol;Kim, Jae-Han
    • Water Engineering Research
    • /
    • v.6 no.2
    • /
    • pp.91-99
    • /
    • 2005
  • One of the most important factors for estimating a flood runoff from streams is the lag time. It is well known that the lag time is affected by the morphometric properties of basin which can be expressed by catchment shape descriptors. In this paper, the notion of the geometric characteristics of an equivalent ellipse proposed by Moussa(2003) was applied for calculating the lag time of geomorphologic instantaneous unit hydrograph(GIUH) at a basin outlet. The lag time was obtained from the observed data of rainfall and runoff by using the method of moments and the procedure based on geomorphology was used for GIUH. The relationships between the basin morphometric properties and the hydrological response were discussed based on application to 3 catchments in Korea. Additionally, the shapes of equivalent ellipse were examined how they are transformed from upstream area to downstream one. As a result, the relationship between the lag time and descriptors was shown to be close, and the shape of ellipse was presented to approach a circle along the river downwards. These results may be expanded to the estimation of hydrological response of ungauged catchment.

  • PDF

Genetic Diversity of Soybean Pod Shape Based on Elliptic Fourier Descriptors

  • Truong Ngon T.;Gwag Jae-Gyun;Park Yong-Jin;Lee Suk-Ha
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.50 no.1
    • /
    • pp.60-66
    • /
    • 2005
  • Pod shape of twenty soybean (Glycine max L. Merrill) genotypes was evaluated quantitatively by image analysis using elliptic Fourier descriptors and their principal components. The closed contour of each pod projection was extracted, and 80 elliptic Fourier coefficients were calculated for each contour. The Fourier coefficients were standardized so that they were invariant of size, rotation, shift, and chain code starting point. Then, the principal components on the standardized Fourier coefficients were evaluated. The cumulative contribution at the fifth principal component was higher than $95\%$, indicating that the first, second, third, fourth, and fifth principal components represented the aspect ratio of the pod, the location of the pod centroid, the sharpness of the two pod tips and the roundness of the base in the pod contour, respectively. Analysis of variance revealed significant genotypic differences in these principal components and seed number per pod. As the principal components for pod shape varied continuously, pod shape might be controlled by polygenes. It was concluded that principal component scores based on elliptic Fourier descriptors yield seemed to be useful in quantitative parameters not only for evaluating soybean pod shape in a soybean breeding program but also for describing pod shape for evaluating soybean germplasm.

A Study on Evaluation Method of Stream Naturalness for Ecological Restoration of Stream Corridors (우리나라 중소하천 코리도의 자연성 평가기법 연구)

  • 조용현
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.25 no.2
    • /
    • pp.73-81
    • /
    • 1997
  • The main purpose of this study was to develop a new method for evaluation of stream naturalness in order to appraise and prescribe for streams effectively in the process of ecological restoration of stream corridors. The results are as follows : 1) For this purpose six factors were selected on considering the spatial axes of stream corridor variation and total 20 descriptors about the physical structure were selected. 2) The calculation of S.N.I. for each segment was consisted of three steps, such as calculation of S.N.I.s of the individual descriptors, averaging all the descriptors's for each factor, and finally averaging the factors's for the Total S.N.I. 3) The evaluation unit was decided to be 100m size. The score system ranging 1~5 was adopted. Weighting parameters of factors were unified with each other. 4) A GIS model was adopted for classification, calculation, querying, analysing, and presenting S.N.I. information. And the format of S.N.I. maps including statistical graphs and other spatial watershed information was designed for the GIS odel. The naturalness of stream corridor was was investigated by the naturalness of habitat, and assessed by the descriptors focused on physical structure, therefore the S.N.I. can manifest prescriptions for restoration of the stream corridor. On the other hand because some evaluation factors such as water quality, water volume, fauna, flora, functions of stream exosystem has been excluded, S.N.I. could have some limits on representing the full aspects of stream naturalness. This evaluation method is hypothetical one, so it would be investigated through iterative applicatons.

  • PDF