• Journal of Korea Multimedia Society
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• v.11 no.6
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• pp.755-763
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• 2008

Silhouette is useful in computer graphics for a number of techniques such as non-photorealistic rendering, silhouette clipping, and blueprint generating. Methods for generating silhouette are classified into three categories: image-based, object-based, and hybrid-based. Hybrid-based method is effective in terms of time complexity but spatial coherence problem still remains. In this paper, we proposed a new hybrid-based method which produces 3D data for silhouette and also guarantees no spatial coherence problem. To verify the efficiency of the proposed algorithm, several experiments are conducted for various 3D models from simple to quite complex. Results show that our algorithm generates no gap between any two consecutive silhouette lines when the silhouette model is magnified significantly.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.645-646
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• 2008

Silhouette extraction is widely used in many computer graphics applications. In this paper, we proposed a method for extracting 3D silhouette and internal pattern from 3D vector data. To do this, we first make an edge-list, secondly define the silhouette, and finally remove hidden lines. After getting the silhouette, we extract internal pattern using adjacent edge's dihedral. The proposed method not only effectively improves the performance of extracting 3D silhouette and internal pattern from 3D vector data but also reduces the computational complexity.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.10-19
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• 2008

In this paper, we propose an automated silhouette extraction method that can effectively extract inner-patterns and silhouettes from 3D scan data of cultural asset. First of all, after creating the edge list of 3D vector data, we decide contour edge and crease edge according to viewpoint. In the next step, after extracting surface silhouette by investigating the vector variation of adjacent faces in crease edge, we finally extract the contour silhouette and surface silhouette for generating the blueprint of cultural asset. To evaluate the performance of the proposed silhouette extraction method, we performed experiments of silhouette extraction using a traditional tile model, a car model and a stone monument model. Comparing with the conventional threshold-based silhouette extraction method, the proposed method extracted more distinct and clear surface silhouettes and inner-patterns by effectively removing meaningless edges, such as noise.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.16 no.2
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• pp.87-94
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• 2016

In this paper, we discuss a gait representation based on the width of silhouette in terms of discriminative power and robustness against the noise in silhouette image for gait recognition. Its sensitivity to the noise in silhouette image are rigorously analyzed using probabilistic noisy silhouette model. In addition, we develop a gait recognition system using width representation and identify subjects using the decision level fusion based on majority voting. Experiments on CASIA gait dataset A and the SOTON gait database demonstrate the recognition performance with respect to the noise level added to the silhouette image.

• Korean Journal of Computational Design and Engineering
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• v.6 no.2
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• pp.89-100
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• 2001

Swept volume is the sweeping region of moving objects. It is used in various applications such as interference detection in assembly design, visualization of manipulator motions in robotics, simulation of the volume removal by a cutter in NC machining. The shape of swept volume is defined by the envelope, which is determined by the boundary of moving objects and its direction of motion. In order to implement the generation of swept volume, researchers have taken much effort to develop the techniques how to generate the envelope. However, their results are confined to envelope generated only in simple shape objects, such as polyhedra or quadric surfaces. This study provided the envelope generation algorithm of NURBS objects. Characteristic points were obtained by applying the geometric conditions of envelope to NURBS equations, and then characteristic curves were created by means of interpolating those points. Silhouette edges were determined in the following procedures. First, two adjacent surfaces which have the same edge were found from B-Rep data. Then, by taking the scalar product of velocity vector of a point on that edge with each normal vector on two surfaces, silhouette edges were discriminated. Finally, envelope was generated along moving direction in the form of ruled surfaces by using both the partial information between initial and final position of objects affecting envelope along with characteristic curves and silhouette edge. Since this developed algorithm can be applied not only to NURBS objects but also to their Boolean objects, it can be used effectively in various applications.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.495-502
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• 2017

Modern ceramics is exploring the expansion of the area with various expression techniques. The silhouette technique among various expressive decoration techniques is a representative expression technique of object form expression. This emphasizes the outline of the form and expresses it and omits the inner form. It gives simplicity and intensity, and awakens aesthetic sensibility and imagination. Therefore, the researcher designed the material related to the core image of the story by designing it as a silhouette technique by using the "Acorn Story" as a subject and then making the transfer paper by using the vector graphic. The transferred paper was expressed on a ceramic plate by transferring technique. Therefore, I hope that this research, beyond the merely decorative function of ceramic expression, will become a ceramic design that will awaken imagination and aesthetic sensibility in digital information age.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.177-180
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• 2005

Three dimensional shaded images are standard visualization method for CAD models on the computer screen. Therefore, much of the effort in the visualization of CAD models has been focused on how conveniently and realistically CAD models can be displayed on the screen. However, shaded 3D CAD data images captured from the screen may not be suitable for some application areas. Technical document, either in the paper or electronic form, can more clearly describe the shape and annotate parts of the model by using projected 2D line drawing format viewed from a user defined view direction. This paper describes an efficient method for generating such a 2D line drawing data in the vector format. The algorithm is composed of silhouette line detection, hidden line removal and cleaning processes.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.192-195
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• 2008

본 논문에서는 발전하는 3D 그래픽스 기술을 이용하여 문화재의 도면 실루엣을 생성하는 방법을 제안하고자 한다. 3D 스캐너로 정밀 실측된 3D 데이터를 이용하여 문화재의 도면을 생성하기 위한 벡터 실루엣(Silhouette) 추출 과정은 다음과 같다. 먼저 실측된 3D 데이터를 정규화 된 3D공간으로 이동하고, 이동 후에는 데이터에 존재하는 모든 에지(edge)를 검출하여 에지리스트(edge list)를 생성한다. 생성된 에지리스트는 다시 윤곽에지(Contour edge)와 주름에지(Crease edge)로 분류하는데, 윤곽에지는 문화재의 윤곽 실루엣을 형성하는데 이용하고, 윤곽에지를 제외한 주름에지는 문화재의 표면 특징을 나타내는 내부문양 실루엣을 형성하는데 이용한다. 내부문양 실루엣은 사용자가 입력하는 임계값과 주름에지를 구성하는 두면의 방향 벡터의 내적을 비교하여 추출한다. 추출한 벡터 실루엣은 윤곽 실루엣과 내부문양 실루엣으로 구분되며, 두 벡터 실루엣을 이용함으로써 문화재의 구조적 해석과 표면의 특징을 해석할 수 있는 도면 실루엣 생성이 가능했다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.47-56
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• 2003

Geometric cutting-simulation and verification play an important role in detecting NC machining errors in mold & die manufacturing and thereby reducing correcting time & cost on the shop floor. Current researches in the area may be categorized into view-based, solid-based, and discrete vector-based methods mainly depending on workpiece models. Each methodology has its own strengths and weaknesses in terms of computing speed, representation accuracy, and its ability of numerical inspection. The paper proposes a hybrid modeling scheme for workpiece representation with z-map model and discrete vector model, which performs 3-axis and 5-axis cutting-simulation via tool swept surface construction by connecting a sequence of silhouette curves.

• Journal of Platform Technology
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• v.11 no.3
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• pp.12-23
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• 2023

In the 2020s, the K-Pop market has been dominated by girl groups over boy groups and the fourth generation over the third generation. This paper presents methods and results on lyric clustering to investigate whether the generation of girl groups has started to change. We collected meta-information data for 1469 songs of 47 groups released from 2013 to 2022 and classified them into lyric information and non-lyric meta-information and quantified them respectively. The lyrics information was preprocessed by applying word-translation frequency vectorization based on previous studies and then selecting only the top vector values. Non-lyric meta-information was preprocessed and applied with One-Hot Encoding to reduce the bias of using only lyric information and show better clustering results. The clustering performance on the preprocessed data is 129%, 45% higher for Spherical K-Means' Silhouette Score and Calinski-Harabasz Score, respectively, compared to Hierarchical Clustering. This paper is expected to contribute to the study of Korean popular song development and girl group lyrics analysis and clustering.