• Title/Summary/Keyword: shape retrieval

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3D Model Retrieval Using Geometric Information (기하학 정보를 이용한 3차원 모델 검색)

  • Lee Kee-Ho;Kim Nac-Woo;Kim Tae-Yong;Choi Jong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.10C
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    • pp.1007-1016
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    • 2005
  • This paper presents a feature extraction method for shape based retrieval of 3D models. Since the feature descriptor of 3D model should be invariant to translation, rotation and scaling, it is necessary to preprocess the 3D models to represent them in a canonical coordinate system. We use the PCA(Principal Component Analysis) method to preprocess the 3D models. Also, we apply that to make a MBR(Minimum Boundary Rectangle) and a circumsphere. The proposed algorithm is as follows. We generate a circumsphere around 3D models, where radius equals 1(r=1) and locate each model in the center of the circumsphere. We produce the concentric spheres with a different radius($r_i=i/n,\;i=1,2,{\ldots},n$). After looking for meshes intersected with the concentric spheres, we compute the curvature of the meshes. We use these curvatures as the model descriptor. Experimental results numerically show the performance improvement of proposed algorithm from min. 0.1 to max. 0.6 in comparison with conventional methods by ANMRR, although our method uses .relatively small bins. This paper uses $R{^*}-tree$ as the indexing.

Edge-based spatial descriptor for content-based Image retrieval (내용 기반 영상 검색을 위한 에지 기반의 공간 기술자)

  • Kim, Nac-Woo;Kim, Tae-Yong;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.5 s.305
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    • pp.1-10
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    • 2005
  • Content-based image retrieval systems are being actively investigated owing to their ability to retrieve images based on the actual visual content rather than by manually associated textual descriptions. In this paper, we propose a novel approach for image retrieval based on edge structural features using edge correlogram and color coherence vector. After color vector angle is applied in the pre-processing stage, an image is divided into two image parts (high frequency image and low frequency image). In low frequency image, the global color distribution of smooth pixels is extracted by color coherence vector, thereby incorporating spatial information into the proposed color descriptor. Meanwhile, in high frequency image, the distribution of the gray pairs at an edge is extracted by edge correlogram. Since the proposed algorithm includes the spatial and edge information between colors, it can robustly reduce the effect of the significant change in appearance and shape in image analysis. The proposed method provides a simple and flexible description for the image with complex scene in terms of structural features of the image contents. Experimental evidence suggests that our algorithm outperforms the recently histogram refinement methods for image indexing and retrieval. To index the multidimensional feature vectors, we use R*-tree structure.

Story-based Information Retrieval (스토리 기반의 정보 검색 연구)

  • You, Eun-Soon;Park, Seung-Bo
    • Journal of Intelligence and Information Systems
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    • v.19 no.4
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    • pp.81-96
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    • 2013
  • Video information retrieval has become a very important issue because of the explosive increase in video data from Web content development. Meanwhile, content-based video analysis using visual features has been the main source for video information retrieval and browsing. Content in video can be represented with content-based analysis techniques, which can extract various features from audio-visual data such as frames, shots, colors, texture, or shape. Moreover, similarity between videos can be measured through content-based analysis. However, a movie that is one of typical types of video data is organized by story as well as audio-visual data. This causes a semantic gap between significant information recognized by people and information resulting from content-based analysis, when content-based video analysis using only audio-visual data of low level is applied to information retrieval of movie. The reason for this semantic gap is that the story line for a movie is high level information, with relationships in the content that changes as the movie progresses. Information retrieval related to the story line of a movie cannot be executed by only content-based analysis techniques. A formal model is needed, which can determine relationships among movie contents, or track meaning changes, in order to accurately retrieve the story information. Recently, story-based video analysis techniques have emerged using a social network concept for story information retrieval. These approaches represent a story by using the relationships between characters in a movie, but these approaches have problems. First, they do not express dynamic changes in relationships between characters according to story development. Second, they miss profound information, such as emotions indicating the identities and psychological states of the characters. Emotion is essential to understanding a character's motivation, conflict, and resolution. Third, they do not take account of events and background that contribute to the story. As a result, this paper reviews the importance and weaknesses of previous video analysis methods ranging from content-based approaches to story analysis based on social network. Also, we suggest necessary elements, such as character, background, and events, based on narrative structures introduced in the literature. We extract characters' emotional words from the script of the movie Pretty Woman by using the hierarchical attribute of WordNet, which is an extensive English thesaurus. WordNet offers relationships between words (e.g., synonyms, hypernyms, hyponyms, antonyms). We present a method to visualize the emotional pattern of a character over time. Second, a character's inner nature must be predetermined in order to model a character arc that can depict the character's growth and development. To this end, we analyze the amount of the character's dialogue in the script and track the character's inner nature using social network concepts, such as in-degree (incoming links) and out-degree (outgoing links). Additionally, we propose a method that can track a character's inner nature by tracing indices such as degree, in-degree, and out-degree of the character network in a movie through its progression. Finally, the spatial background where characters meet and where events take place is an important element in the story. We take advantage of the movie script to extracting significant spatial background and suggest a scene map describing spatial arrangements and distances in the movie. Important places where main characters first meet or where they stay during long periods of time can be extracted through this scene map. In view of the aforementioned three elements (character, event, background), we extract a variety of information related to the story and evaluate the performance of the proposed method. We can track story information extracted over time and detect a change in the character's emotion or inner nature, spatial movement, and conflicts and resolutions in the story.

RGB Channel Selection Technique for Efficient Image Segmentation (효율적인 이미지 분할을 위한 RGB 채널 선택 기법)

  • 김현종;박영배
    • Journal of KIISE:Software and Applications
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    • v.31 no.10
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    • pp.1332-1344
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    • 2004
  • Upon development of information super-highway and multimedia-related technoiogies in recent years, more efficient technologies to transmit, store and retrieve the multimedia data are required. Among such technologies, firstly, it is common that the semantic-based image retrieval is annotated separately in order to give certain meanings to the image data and the low-level property information that include information about color, texture, and shape Despite the fact that the semantic-based information retrieval has been made by utilizing such vocabulary dictionary as the key words that given, however it brings about a problem that has not yet freed from the limit of the existing keyword-based text information retrieval. The second problem is that it reveals a decreased retrieval performance in the content-based image retrieval system, and is difficult to separate the object from the image that has complex background, and also is difficult to extract an area due to excessive division of those regions. Further, it is difficult to separate the objects from the image that possesses multiple objects in complex scene. To solve the problems, in this paper, I established a content-based retrieval system that can be processed in 5 different steps. The most critical process of those 5 steps is that among RGB images, the one that has the largest and the smallest background are to be extracted. Particularly. I propose the method that extracts the subject as well as the background by using an Image, which has the largest background. Also, to solve the second problem, I propose the method in which multiple objects are separated using RGB channel selection techniques having optimized the excessive division of area by utilizing Watermerge's threshold value with the object separation using the method of RGB channels separation. The tests proved that the methods proposed by me were superior to the existing methods in terms of retrieval performances insomuch as to replace those methods that developed for the purpose of retrieving those complex objects that used to be difficult to retrieve up until now.

THE SPECTRAL SHAPE MATCHING METHOD FOR THE ATMOSPHERIC CORRECTION OF LANDSAT IMAGERY IN SAEMANGEUM COASTAL AREA

  • Min Jee-Eun;Ryu Joo-Hyung;Shanmugam P.;Ahn Yu-Hwan;Lee Kyu-Sung
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.671-674
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    • 2005
  • Atmospheric correction over the ocean part is more important than that over the land because the signal from the ocean is very small about one tenth of that reflected from land. In this study, the Spectral Shape Matching Method (SSMM) developed by Ahn and Shanmugam (2004) is evaluated using Landsat imagery acquired over the highly turbid Saemangeum Coastal Area. The result of SSMM is compared with COST model developed by Chavez (1991 and 1997). In principle, SSMM is simple and easy to implement on any satellite imagery, relying on both field and image properties. To assess the potential use of these methods, several field campaigns were conducted in the Saemangeum coastal area corresponding with Landsat-7 satellite's overpass on 29 May 2005. In-situ data collected from the coastal waters of Saemangeum using optical instruments (ASD field spectroradiometer) consists of ChI, Ap, SS, aooM, F(d). In order to perform SSMM, we use the in-situ water-leaving radiance spectra from clear oceanic waters to estimate the the path radiance from total signal recorded at the top of the atmosphere (TOA), due to the reason that the shape of clear water-leaving radiance spectra is nearly stable than turbid water-leaving radiance spectra. The retrieved water-leaving radiance after subtraction of path signal from TOA signal in this way is compared with that estimated by COST model. The result shows that SSMM enabled retrieval of water-leaving radiance spectra that are consistent with in-situ data obtained from Saemangeum coastal waters. The COST model yielded significantly high errors in these areas.

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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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A Design and Implementation of Arbitrary Retrieval System Using Multi-resolution Edge Mathcing (다중 해상도 에지 정합을 이용한 임의물체 검색 시스템의 설계 및 구현)

  • Lee Kang-ho;Ahn Yonghak
    • Journal of the Korea Society of Computer and Information
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    • v.9 no.3
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    • pp.95-102
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    • 2004
  • In this paper, we proposed multi-resolution search method based on edge information that can be search a partial input pattern and detect a difference of minute shape information in effectively. The proposed method utilizes the small shape differences among objects as much as possible to distinguish an object from similar shaped objects. It consists of the GHT based candidate generation and top-down candidate verfication. The test results show that it can retrieve the correct object even with a part of object in reasonable time.

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Classification of Man-Made and Natural Object Images in Color Images

  • Park, Chang-Min;Gu, Kyung-Mo;Kim, Sung-Young;Kim, Min-Hwan
    • Journal of Korea Multimedia Society
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    • v.7 no.12
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    • pp.1657-1664
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    • 2004
  • We propose a method that classifies images into two object types man-made and natural objects. A central object is extracted from each image by using central object extraction method[1] before classification. A central object in an images defined as a set of regions that lies around center of the image and has significant color distribution against its surrounding. We define three measures to classify the object images. The first measure is energy of edge direction histogram. The energy is calculated based on the direction of only non-circular edges. The second measure is an energy difference along directions in Gabor filter dictionary. Maximum and minimum energy along directions in Gabor filter dictionary are selected and the energy difference is computed as the ratio of the maximum to the minimum value. The last one is a shape of an object, which is also represented by Gabor filter dictionary. Gabor filter dictionary for the shape of an object differs from the one for the texture in an object in which the former is computed from a binarized object image. Each measure is combined by using majority rule tin which decisions are made by the majority. A test with 600 images shows a classification accuracy of 86%.

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SOSiM: Shape-based Object Similarity Matching using Shape Feature Descriptors (SOSiM: 형태 특징 기술자를 사용한 형태 기반 객체 유사성 매칭)

  • Noh, Chung-Ho;Lee, Seok-Lyong;Chung, Chin-Wan;Kim, Sang-Hee;Kim, Deok-Hwan
    • Journal of KIISE:Databases
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    • v.36 no.2
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    • pp.73-83
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    • 2009
  • In this paper we propose an object similarity matching method based on shape characteristics of an object in an image. The proposed method extracts edge points from edges of objects and generates a log polar histogram with respect to each edge point to represent the relative placement of extracted points. It performs the matching in such a way that it compares polar histograms of two edge points sequentially along with edges of objects, and uses a well-known k-NN(nearest neighbor) approach to retrieve similar objects from a database. To verify the proposed method, we've compared it to an existing Shape-Context method. Experimental results reveal that our method is more accurate in object matching than the existing method, showing that when k=5, the precision of our method is 0.75-0.90 while that of the existing one is 0.37, and when k=10, the precision of our method is 0.61-0.80 while that of the existing one is 0.31. In the experiment of rotational transformation, our method is also more robust compared to the existing one, showing that the precision of our method is 0.69 while that of the existing one is 0.30.

Shape-based Leaf Image Retrieval using Venation Feature (잎맥 특징을 이용한 모양기반의 식물 잎 이미지 검색)

  • Nam Yun-Young;Park Jin-Kyu;Hwang Een-Jun;Kim Dong-Yoon
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06d
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    • pp.346-348
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    • 2006
  • 본 논문은 잎맥 특징을 이용한 식물의 잎 이미지 검색 방법을 제안한다. 식물의 검색을 위해 모양 기반의 검색방법을 사용하였으며, 잎의 외곽선 분만 아니라 내부의 잎맥 정보를 이용하여 정확율을 향상시켰다. 외곽선은 MPP(Minimum Perimeter Polygons) 알고리즘을 개선하여 표현하고, 내부의 잎맥의 특징은 CSS(Curvature Scale Space)를 개선하여 주맥과 교차점, 끝점을 추출하여 표현하였다. 특징 점들간의 관계와 거리값을 통해 가중치가 있는 그래프로 표현하고 이 값을 통해 유사도를 계산하였다. 실험에서는 식물도감에서 1000여개의 식물 잎 이미지를 추출하여 기존의 알고리즘인 Fourier Descriptor, CSSD, CCD, Moment Invariants, MPP와 비교하였다.

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