• Title/Summary/Keyword: Curvedness

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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%.

Geometric Multiple Watermarking Scheme for Mobile 3D Content Based on Anonymous Buyer-Seller Watermarking Protocol

  • Lee, Suk-Hwan;Kwon, Seong-Geun;Kwon, Ki-Ryong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.2
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    • pp.504-523
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    • 2014
  • This paper presents a multiple-watermarking scheme for copyright protection and the prevention of illegal copying of mobile 3D contents with low resolution. The proposed scheme embeds a unique watermark and a watermark certification authority (WCA) watermark into the spatial and encryption domains of a mobile 3D content based on the buyer-seller watermarking protocol. The seller generates a unique watermark and embeds it into the local maximum curvedness of a 3D object. After receiving the encrypted watermark from the WCA, the seller embeds it into the encrypted vertex data using an operator that satisfies the privacy homomorphic property. The proposed method was implemented using a mobile content tool, and the experimental results verify its capability in terms of copyright protection and the prevention of illegal copying.

Robust 3D Hashing Algorithm Using Key-dependent Block Surface Coefficient (키 기반 블록 표면 계수를 이용한 강인한 3D 모델 해싱)

  • Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.1
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    • pp.1-14
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    • 2010
  • With the rapid growth of 3D content industry fields, 3D content-based hashing (or hash function) has been required to apply to authentication, trust and retrieval of 3D content. A content hash can be a random variable for compact representation of content. But 3D content-based hashing has been not researched yet, compared with 2D content-based hashing such as image and video. This paper develops a robust 3D content-based hashing based on key-dependent 3D surface feature. The proposed hashing uses the block surface coefficient using shape coordinate of 3D SSD and curvedness for 3D surface feature and generates a binary hash by a permutation key and a random key. Experimental results verified that the proposed hashing has the robustness against geometry and topology attacks and has the uniqueness of hash in each model and key.

3D Medical Image Data Watermarking Applied to Healthcare Information Management System (헬스케어 정보 관리 시스템의 3D 의료영상 데이터 다중 워터마킹 기법)

  • Lee, Suk-Hwan;Kwon, Ki-Ryong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.11A
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    • pp.870-881
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    • 2009
  • The rapid development of healthcare information management for 3D medical digital library, 3D PACS and 3D medical diagnosis has addressed security issues with medical IT technology. This paper presents multiple 3D medical image data for protection, authentication, indexing and diagnosis information hiding applied to healthcare information management. The proposed scheme based on POCS watermarking embeds the robust watermark for doctor's digital signature and information retrieval indexing key to the distribution of vertex curvedness and embeds the fragile watermark for diagnosis information and authentication reference message to the distance difference of vertex. The multiple embedding process designs three convex sets for robustness, fragileness and invisibility and projects 3D medical image data onto three convex sets alternatively and iteratively. Experimental results confirmed that the proposed scheme has the robustness and fragileness to various 3D geometric and mesh modifiers at once.

A Study on the Aesthetic Consciousness in the late Modernism Fashion (모더니즘 후기 복식에 표현된 미의식 연구)

  • 김정은;정흥숙
    • Journal of the Korean Society of Costume
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    • v.51 no.6
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    • pp.67-83
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    • 2001
  • The purpose of this study is to define the aesthetic consciousness in the late Modernism fashion which generated a sudden style change and craze, and to identify the essential meaning of the style. In order to achieve this the aesthetic approach was applied. Visual commonalities were sought between fashion and contemporary architecture, furniture, ceramic and metalware, to lead to a deeper insight into the aesthetic consciousness. Common visual characteristics are curvedness of the line, obliqueness of the line, asymmetry of the form, exaggeration of the form and symbolic nature of the form. The content which can be analogized from the visual characteristics are the beauty of the nature, the beauty of the glamourous feminity, the beauty of the ideal and the beauty of the creative personality. In the creating process, the existential aspect of human being became a focus of attention, and human being's subjectivity operated as a principal force. In the late Modernism fashion, the appreciator's aesthetic experience became more important, and the appreciator's psychological satisfaction and pleasure were considered in the creative process. Fashion, architecture and crafts, which fulfill functional duties in everyday life, facilitated the appreciator's aesthetic experience through empathy. This study inquires into the relationship between aesthetic consciousness and visual form. This study offers meaning because to uncover the connoted aesthetic consciousness in the late Modernism fashion is to pursue the roots of current aesthetic consciousness and it is hoped that in doing so this study will provide a basis for interpreting and understanding today's fashion style.

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