• Journal of the Korean Society of Clothing and Textiles
• /
• v.30 no.8
• /
• pp.1242-1252
• /
• 2006

Many applications in computer graphics require complex, highly detailed models. However, to control processing time, it is often desirable to use approximations in place of excessively detailed models. Therefore, we have developed the notion of an optimal matrix to simplify the model surface which can then rapidly obtain high quality 2D patterns by flattening the 3D surface. Firstly, the woman's 3D body was modeled based on Size Korea data. Secondly, the 3D model was divided by shell and block for the pattern draft. Thirdly, each block was flattened by the grid and bridge method. Finally, we select the optimal matrix and demonstrate it's efficiency and quality. The proposed approach accommodates surfaces with darts, which are commonly utilized in the clothing industry to reduce the deformation of surface forming and flattening. The resulting optimal matrix could be an initiation of standardization for pattern flattening. This can facilitate much better approximations, in both efficiency and exactness.

• Journal of Digital Contents Society
• /
• v.11 no.3
• /
• pp.299-306
• /
• 2010

According to development of Internet and computer graphics technology, Digital fashion technology makes virtual fitting service capable by reappearing of clothes in 3D. In this paper, We suggest that combined solution which you could use virtual fitting service with various device. For example, imaginary mirror(such as digital information display), pc, mobile in different situations such as store, internet shopping market, commercial. Users can experience imaginary mirror that is located in store or 3D virtual fitting service for digital fashion in internet shopping market, mobile application. In addition, We proposed the solution that user can send experienced virtual fitting service results to other person by image file form of MMS.

• Advances in robotics research
• /
• v.2 no.1
• /
• pp.33-44
• /
• 2018

This paper presents a novel feature detection algorithm called depth-hybrid speeded-up robust features (DH-SURF) augmented by depth information in the speeded-up robust features (SURF) algorithm. In the keypoint detection part of classical SURF, the standard deviation of the Gaussian kernel is varied for its scale-invariance property, resulting in increased computational complexity. We propose a keypoint detection method with less variation of the standard deviation by using depth data from a red-green-blue depth (RGB-D) sensor. Our approach maintains a scale-invariance property while reducing computation time. An RGB-D simultaneous localization and mapping (SLAM) system uses a feature extraction method and depth data concurrently; thus, the system is well-suited for showing the performance of the DH-SURF method. DH-SURF was implemented on a central processing unit (CPU) and a graphics processing unit (GPU), respectively, and was validated through the real-time RGB-D SLAM.

• Journal of the Korea Computer Graphics Society
• /
• v.19 no.2
• /
• pp.1-8
• /
• 2013

Captured human motion data has been widely utilized for understanding the mechanism of human motion and synthesizing the animation of virtual characters. Searching for desired motions from given motion data is an important prerequisite of analyzing and editing those selected motions. This paper presents a new method of content-based motion retrieval without the need of additional metadata such as keywords. While existing search methods have focused on skeletal configurations of body pose or planar trajectories of locomotion, our method receives a three-dimensional trajectory as its input query and retrieves a set of motion intervals in which the trajectories of body parts such as hands, foods, and pelvis are similar to the input trajectory. In order to allow the user to intuitively sketch spatial trajectories, we used the Leap Motion controller that can precisely trace finger movements as the input device for our experiments. We have evaluated the effectiveness of our approach by conducting a user study in which the users search for dozens of pre-selected motions from baseketball motion data including a variety of moves such as dribbling and shooting.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.30 no.4
• /
• pp.335-342
• /
• 2012

3D point cloud is widely used in Architecture, Civil Engineering, Medical, Computer Graphics, and many other fields. Due to the improvement of 3D laser scanner, a massive 3D point cloud whose gigantic file size is bigger than computer's memory requires efficient preprocessing and visualization. We suggest a data structure to solve the problem; a 3D point cloud is gradually subdivided by arbitrary-sized cube grids structure and corresponding point cloud subsets generated by the center of each grid cell are achieved while preprocessing. A massive 3D point cloud file is tested through two algorithms: QSplat and ours. Our algorithm, grid-based, showed slower speed in preprocessing but performed faster rendering speed comparing to QSplat. Also our algorithm is further designed to editing or segmentation using the original coordinates of 3D point cloud.

• Journal of Game and Entertainment
• /
• v.2 no.1
• /
• pp.64-70
• /
• 2006

CAD system is a very important technology in designing many products which we are using today. This CAD technology have enlarging its area into 3D CAD systems with the development of computer graphics technologies. In particular, such advances have also been realized in special area such as the CAD system for designing shoes. 3D CAD systems for shoes design must provide compatibility between 3D and 2D data because shoes are made using 2D parts of pieces of leather or cloth. Many designers get high performances using 2D shoe CAD systems because they have had long practices with the 2D systems. Therefore, to get the mapping between 2D modeling and 3D modeling is one of very important components in 3D CAD system. In this paper, we proposed a flattening method that convert 3D shoes data to 2D data.

• Journal of information and communication convergence engineering
• /
• v.3 no.1
• /
• pp.49-55
• /
• 2005

This study is to suggest a visualization technique to display the relations of associated data in an optimal way when trying to display the whole data on a limited space by dealing with a large amount of data with linked information. For example, if you track an IP address through several steps and display the data on a screen, or if you visualize the human gene information on a 3-dimensional space, then it becomes even easier to understand the data flow in such cases. In order to simulate the technique given in this study, the given algorithm was applied to a large number of nodes made in a random fashion to optimize the data and we visually observed the result. According to the result, the technique given in this study is more efficient than any previous method in terms of visualization and utilizing space and allows to more easily understand the whole structure of a node because it consists of sub-groups.

• Cartoon and Animation Studies
• /
• s.48
• /
• pp.45-67
• /
• 2017

Many of the modern animations have 3D technology, and as time goes by, their production technology becomes more diverse and sophisticated. When John Alan Lasseter insisted on studying CG animation technology, he might have taken our jobs to the computer in the near future, as many people were worried about. It may be premature to worry that an unstable future may become a reality at this point, but I do not think there will be any difference in the fact that many animations are being produced using 3D technology. Since the Toy Story was screened in 1995, the 3D animation production technology has started to develop rapidly and now it has been elaborately developed so that it can not distinguish the part where computer graphics technology is applied from the live film. On the other hand, Disney's 2D animation part falls into the decline path because the appearance of 3D animation was perceived as a new expression technique at that time, and the efficiency of the work process was superior to the 2D animation in addition to receiving the attention from the audience. Is it necessary to accept the retrogression of 2D animation technology, reflecting the environment of the animation industry that 3D animation production technology has become mainstream in the first 20 years since the first theatrical works appeared? Since 2D animation technology has a long history and is still attractive to the audience, it is not hard to find an attempt to combine 2D and 3D animation technology. In this paper, I want to study 2D hand - drawn character in 3D animation. Through this, it is hoped that animation convergence technology will be applied more actively in the future.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.12
• /
• pp.641-655
• /
• 2007

Parameterization has been one of very important research subjects in several application areas including computer graphics. In the parameterization research, the problem of mapping 3D polygonal model to 2D plane has been studied frequently, but the previous methods often fail to handle complicated shapes of polygonal surfaces effectively as well as entail distortion between the 3D and 2D spaces. Several attempts have been made especially to reduce such distortion, but they often suffer from the problem when an arbitrary rectangular surface region on 3D model is locally parameterized. In this paper, we propose a new local parameterization scheme based on the projection level set method. This technique generates a series of equi-distanced curves on the surface region of interest, which are then used to generate effective local parameterization information. In this paper, we explain the new technique in detail and show its effectiveness by demonstrating experimental results.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.12
• /
• pp.665-682
• /
• 2007

Line drawing is a widely used style in non-photorealistic rendering because it generates expressive descriptions of object shapes with a set of strokes. Although various techniques for line drawing of 3D objects have been developed, line drawing of 2D images has attracted little attention despite interesting applications, such as image stylization. This paper presents a robust and effective technique for generating line drawings from 2D images. The algorithm consists of three parts; filtering, linking, and stylization. In the filtering process, it constructs a likelihood function that estimates possible positions of lines in an image. In the linking process, line strokes are extracted from the likelihood function using clustering and graph search algorithms. In the stylization process, it generates various kinds of line drawings by applying curve fitting and texture mapping to the extracted line strokes. Experimental results demonstrate that the proposed technique can be applied to the various kinds of line drawings from 2D images with detail control.