• Title/Summary/Keyword: Shape Descriptor

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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.

A Survey of Shape Descriptors in Computer Vision (컴퓨터비전에서 사용되는 모양표시자의 현황)

  • 유헌우;장동식
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.2
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    • pp.131-139
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    • 2003
  • Shape descriptors play an important role in systems for object recognition, retrieval, registration, and analysis. Seven well-known descriptors including MPEG-7 visual descriptors arebriefly reviewed and a new robust pattern recognition descriptor is proposed. Performance comparison among descriptors are presented. Experiments show that the newly proposed descriptor yields better performance results than Fourier, invariant moment, and edge histogram descriptors.

Shape Recognition and Classification Based on Poisson Equation- Fourier-Mellin Moment Descriptor

  • Zou, Jian-Cheng;Ke, Nan-Nan;Lu, Yan
    • International Journal of CAD/CAM
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    • v.8 no.1
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    • pp.69-72
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    • 2009
  • In this paper, we present a new shape descriptor, which is named Poisson equation-Fourier-Mellin moment Descriptor. We solve the Poisson equation in the shape area, and use the solution to get feature function, which are then integrated using Fourier-Mellin moment to represent the shape. This method develops the Poisson equation-geometric moment Descriptor proposed by Lena Gorelick, and keeps both advantages of Poisson equation-geometric moment and Fourier-Mellin moment. It is proved better than Poisson equation-geometric moment Descriptor in shape recognition and classification experiments.

Efficient Representation and Matching of Object Movement using Shape Sequence Descriptor (모양 시퀀스 기술자를 이용한 효과적인 동작 표현 및 검색 방법)

  • Choi, Min-Seok
    • The KIPS Transactions:PartB
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    • v.15B no.5
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    • pp.391-396
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    • 2008
  • Motion of object in a video clip often plays an important role in characterizing the content of the clip. A number of methods have been developed to analyze and retrieve video contents using motion information. However, most of these methods focused more on the analysis of direction or trajectory of motion but less on the analysis of the movement of an object itself. In this paper, we propose the shape sequence descriptor to describe and compare the movement based on the shape deformation caused by object motion along the time. A movement information is first represented a sequence of 2D shape of object extracted from input image sequence, and then 2D shape information is converted 1D shape feature using the shape descriptor. The shape sequence descriptor is obtained from the shape descriptor sequence by frequency transform along the time. Our experiment results show that the proposed method can be very simple and effective to describe the object movement and can be applicable to semantic applications such as content-based video retrieval and human movement recognition.

Algorithms for Indexing and Integrating MPEG-7 Visual Descriptors (MPEG-7 시각 정보 기술자의 인덱싱 및 결합 알고리즘)

  • Song, Chi-Ill;Nang, Jong-Ho
    • Journal of KIISE:Software and Applications
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    • v.34 no.1
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    • pp.1-10
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    • 2007
  • This paper proposes a new indexing mechanism for MPEG-7 visual descriptors, especially Dominant Color and Contour Shape descriptors, that guarantees an efficient similarity search for the multimedia database whose visual meta-data are represented with MPEG-7. Since the similarity metric used in the Dominant Color descriptor is based on Gaussian mixture model, the descriptor itself could be transform into a color histogram in which the distribution of the color values follows the Gauss distribution. Then, the transformed Dominant Color descriptor (i.e., the color histogram) is indexed in the proposed indexing mechanism. For the indexing of Contour Shape descriptor, we have used a two-pass algorithm. That is, in the first pass, since the similarity of two shapes could be roughly measured with the global parameters such as eccentricity and circularity used in Contour shape descriptor, the dissimilar image objects could be excluded with these global parameters first. Then, the similarities between the query and remaining image objects are measured with the peak parameters of Contour Shape descriptor. This two-pass approach helps to reduce the computational resources to measure the similarity of image objects using Contour Shape descriptor. This paper also proposes two integration schemes of visual descriptors for an efficient retrieval of multimedia database. The one is to use the weight of descriptor as a yardstick to determine the number of selected similar image objects with respect to that descriptor, and the other is to use the weight as the degree of importance of the descriptor in the global similarity measurement. Experimental results show that the proposed indexing and integration schemes produce a remarkable speed-up comparing to the exact similarity search, although there are some losses in the accuracy because of the approximated computation in indexing. The proposed schemes could be used to build a multimedia database represented in MPEG-7 that guarantees an efficient retrieval.

Region-based Shape Descriptor with Moving a Vision Center for Image Representation (영상표현을 위한 비전 중심점 이동에 따른 영역기반 형태 기술자)

  • Kim Seon-Jong;Kim Young-In
    • Journal of Intelligence and Information Systems
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    • v.12 no.1
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    • pp.95-105
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    • 2006
  • This paper proposes a novel approach to represent the image by using shape descriptor having an information of area. The proposed descriptor is a set of vectors, consists of radius, area and direction parameters in the concentrated center point. Due to the area parameter, we know our descriptor can obtain the information of area. Also, we give an extended shape descriptor to get more detailed representation. To do this, we move the center point of our vision to that point for region of interest. By doing so about all of region of interest, we can get our descriptor for detailed information of the image. From more detailed descriptor, it's natural that it's more efficient fur representation, retrievals and so on. We make it the normalized pattern and expand to improve its quality. The proposed method is invariant to scale, position and rotation. The results show that it can be used efficiently for image representation as we can see in retrievals of silhouette images.

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Analysis on Particle Shape Characteristics of Jumunjin Sand using Fourier Descriptor (Fourier descriptor를 이용한 주문진표준사의 형상특성분석)

  • Min, Tuk-Ki;Kim, Seong-Gon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1182-1189
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    • 2010
  • The mechanical behavior of a granular material is governed by the applying effective stresses and its skeletal structure which is considered to be the packing of particles giving overall density and degree of anisotropic. Factors that affect soil packing are the particle size, size distribution and shape, and the arrangement of grain contact. Soil particle size and shape are the most important factor, but difficult to quantify. In this study, 2D Fourier analysis is applied to quantify the shape of granular particles. Jumunjin sand was used in the experiment and particle images are captured using an optical microscope. The results showed that three lower order Fourier descriptor are closely related with roundness, sphericity of the granular particle. Also statistical approach is used to determine roundness, form factor, elongation ratio, roughness of Jumunjin sand.

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Development of Web-based Bio-Image Retrieval System (웨이블릿 변환을 이용한 실시간 화재 감지 알고리즘)

  • Cheong, Kwang-Ho;Ko, Byoung-Chul;Nam, Jae-Yeal
    • Proceedings of the Korea Information Processing Society Conference
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    • 2006.11a
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    • pp.227-230
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    • 2006
  • A content-based image retrieval system using MPEG-7 is designed and implemented in this thesis. The implemented system uses existing MPEG-7 Visual Descriptors. In addition, a new descriptor for efficient retrieval of bio images is proposed and utilized in the developed content-based image retrieval system. Comparing proposed CBSD(Compact Binary Shape Descriptor) with Edge Histogram Descriptor(EHD) and Region Shape Descriptor(RSD), it shows good retrieval performance in NMRR. The proposed descriptor is robust to large modification of brightness and contrast and especially improved retrieval performance to search images with similar shapes. Also proposed system adopts distributed architecture to solve increased server overload and network delay. Updating module of client efficiently reduces downloading time for metadata. The developed system can efficiently retrieve images without causing server's overload.

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3D Models Retrieval Using Shape Index and Curvedness (형태 인덱스와 정규 곡률을 이용한 3차원 모델 검색)

  • Park, Ki-Tae;Hwang, Hae-Jung;Moon, Young-Shik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.3
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    • pp.33-41
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    • 2007
  • Owing to the development of multimedia and communication technologies, multimedia data become a common feature of the information systems and are on the increase. This has led to the need of 3D shape retrieval systems that, given a query object, retrieve similar 3D objects. Therefore, shape descriptor required to describe a 3D object effectively and efficiently. In this paper, a new descriptor for 3D model retrieval based on shape information is proposed. The proposed descriptor utilizes the curvedness together with the shape index that provides local geometry information. The existing 3D Shape Spectrum Descriptor (3D SSD), which is defined as the histogram of shape index values, represents the characteristics of local shapes of the 3D surface. However, it does not properly represent the local shape characteristics, because many points with different curvedness may have the same shape index value. Therefore, we add a new feature that represents the degree of curvedness, thereby improving the discriminating power of the shape descriptor. We evaluate the performance of the proposed method, compared with the previous method. The experimental results have shown that the performance of retrieval has been improved by 23.6%.

Shape Sequence Descriptor for Describing Shape Variation by Object Movement (움직임에 의한 모양 변화 기술을 위한 모양 시퀀스 기술자)

  • 공영민;최민석;김회율
    • Proceedings of the IEEK Conference
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    • 2001.09a
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    • pp.355-358
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    • 2001
  • 본 논문에서는 객체의 움직임에 의한 모양 변화를 표현하기 위하여 MPEG-7 에 제안된 모양 시퀀스 기술자(Shape Sequence Descriptor)에 대하여 설명하고, 모양 시퀀스 기술자 추출에 필요한 Shape Variation Map 생성을 위한 두 가지 방법을 비교하였다. 기존의 방법은 물체의 평균 적인 모양에 가중치를 두어 생성되며, 새로운 방법은 물체의 움직임에 의해 변화되는 부분에 더 가중치를 두는 방법으로 생성된다. 또한 최종적으로 사용되는 특징 값으로 Zernike moment를 이용하는 방법과 ART(Angular Radial Transform)을 이용하는 방법을 비교하여 모양 시퀀스 검색을 위한 가장 효율적인 방법을 제안하였다.

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